THE DIGESTIVE SYSTEM: GENERAL PRINCIPLES IN HUMAN NUTRITION AND
DIETETICS
The Digestive Tract; Care of the Mouth and Teeth; Controlling
Factors of Digestion; Psychic Aspect of Digestion; Importance
of Mechanical Factors; Chemical Changes of Food in the Stomach;
Intestinal Digestion; Metabolism; Constipation and its Treatment.
The Amount of Food Required; the Classification of Foods; Standard
Dietaries; Maintenance Diet; Relations of Diet to Various
Conditions of Life; Practical Facts for Guidance; Dietary in the
Tropics; Food Economics; Table of Food Values.
The Physiologic Action of Moderate Doses of Alcohol; the Effect
of Alcohol on the Muscular System; the Effect of Alcohol on the
Nervous System.
“If there is anything new of importance in the practice of medicine
it is this modern work in nutrition.”—_Mendel_, 1914.
The activities of animals are carried on by a certain expenditure of
energy which is set free as the result of a chemical breaking down of
the living tissues of the body. In order to maintain the equilibrium
of the body this waste must be replaced by new material which is
taken in the shape of food, drink, and oxygen.
_Digestion_ is the term applied to those changes in the food-stuffs
which precede absorption; it is a refining process which separates
the useless from the useful, and further prepares the latter to be
used as building-stones for the repair of organs and tissues and to
furnish fuel to supply the motor energy of the body.
In the human body the digestive processes are brought about by
mechanical disintegration; by the action on the food-stuffs of acid
and alkaline fluids; by changes produced by active substances called
enzymes; and, lastly, decomposition is produced by the growth of
microörganisms.
The =digestive tract=, or alimentary canal, begins at the mouth and
ends at the anus. It consists of the mouth, the esophagus or gullet,
the stomach, the small and large intestines. Two large glands, the
liver and pancreas, pour their secretions into the small intestine
to aid in the digestion of foods. The alimentary canal, liver, and
pancreas together constitute the digestive system.
[Illustration: Fig. 4.—General scheme of the digestive tract, with
the chief glands opening into it (Stockton).
Nose
Salivary (parotid) gland
Salivary glands
Pharynx
Vein
Trachea
Thoracic or chyle duct
Esophagus
Liver
Gall-bladder
Stomach
Spleen
Pancreas
Duodenum
Lacteals
Large intestine
Small intestine
Vermiform appendix
Rectum
]
The contraction of the muscular walls of the digestive tract is the
propelling power that carries the food downward and brings it into
contact with the digestive fluids. These movements will be referred
to later, under the Mechanics of Digestion.
The digestive tract is lined throughout its entire course by mucous
membrane; that lining the mouth gives some idea of its character. It
is from the mucous membrane lining the stomach and intestines, as
well as from the liver and pancreas, that the digestive fluids are
poured forth into its cavity.
In passing downward the food meets with five different digestive
fluids: the saliva in the mouth; the gastric juice in the stomach;
and the bile, pancreatic, and intestinal juices in the small
intestine. Each digestive fluid acts only on some particular kinds
of food. This action of the digestive fluids on food is called the
chemical part of digestion.
=The Care of the Mouth and Teeth.=—It is of the first importance that
the mouth should be kept clean and as nearly aseptic as possible,
for as the food is rolled about in the mouth by the process of
mastication it is obvious that it will carry all the germs and mucus
with it into the stomach. A nasal spray containing some solution of
an alkaline or antiseptic nature should form an essential part of the
toilet of the mouth.
_The Teeth._—From simply an esthetic point of view well-kept teeth
are beautiful and greatly enhance the charm of the face. But the
proper care of the teeth is also essential to good digestion and good
health.
In perhaps the majority of people the teeth are sufficiently far
apart for small particles of food to become lodged between them. If
not promptly removed, the heat and moisture of the mouth, acting on
these small particles, cause their decomposition and set up acid
fermentation in the mouth; and it is this acid which causes the decay
of the enamel and finally of the teeth. The decayed tooth gives still
further lodgment to particles of food, and these, left to decompose,
give rise to the most offensive gases, giving fetor to the breath,
poisons the blood, and so injures the digestive and nervous systems.
Where possible a tooth-pick and dental floss should be used
immediately after each meal; the waxed dental floss between the
teeth, and the flat end of the tooth-pick to remove any particles
that may have worked in about the roots of the teeth and gums.
A tooth-brush with good tooth-powder should be used twice a day. The
brush should not be too broad, and is better if slightly curved. The
bristles should not be too hard. The use of tooth-powder, which must
be very fine, or tooth-paste is needed to produce sufficient friction
to clean the teeth well. Warm water is a better solvent than cold,
and, therefore, it is well to use it for cleansing the teeth.
While it is generally known that decay if neglected will destroy a
tooth, it is not so well known that many teeth are lost as the result
of the accumulation of tartar at the gum margin. There is a great
tendency to this, especially about the necks of the lower incisors
and upon the teeth that are not used in chewing. The deposit of
tartar encroaches upon the neck of the tooth and presses upon the
gum; the latter becomes irritated or inflamed, and recedes from the
tooth; malnutrition and loosening of the tooth follows.
With very imperfect or decayed teeth proper mastication is impossible.
The teeth should be examined by a good dentist twice a year, so that
small cavities shall be discovered at an early stage, the tartar
removed, and the teeth kept in their best condition. This will
prevent the early loss of the teeth. Lost teeth must be replaced, so
that the teeth shall be opposite each other, for a very important
factor in mastication is that the teeth shall strike properly.
=Digestion.=—The factors controlling digestion are psychic,
mechanical, and chemical.
Briefly stated, the process of digestion consists first in the
liquefaction of the solid portions of food and the conversion of
the insoluble into soluble and diffusible, for no nutriment can be
assimilated until reduced to a state in which it can pass through a
cell membrane. These chemical changes are carried on by a series of
enzymes.
[Illustration:
Fig. 5.—Location of the viscera of the body and their relation to
each other: D, D, Lungs with air expelled; E, E, diaphragm cut away
to show, F, liver cut to show stomach; 2, gall-bladder; H, H, large
intestine; K, small intestine; L, vermiform appendix (after Heath).
]
_Enzymes_ are unorganized ferments which possess the power of
producing chemical changes in certain substances with which they come
in contact under particular conditions without themselves suffering
permanent alteration. The digestion of food is largely accomplished
by the specific action of these enzyme bodies, of which every
digestive fluid contains one or more.
But neither solubility nor diffusibility is adequate. Freely soluble
substances like cane-sugar need to undergo digestive changes just
as definite as those carried out in the case of fats or coagulated
proteins. The changes which they undergo before absorption serve a
more fundamental purpose than the mere hastening of their passage
through the lining membrane of the intestine.
In the light of modern chemical knowledge we can be somewhat specific
in regard to the molecular aspects of the digestive processes. They
are probably always cleavages, large molecules giving rise to smaller
ones. When the original molecule is of extraordinary size, as with
proteins and starches, these cleavages have a serial character, and a
number of intermediary products must accordingly be formed; that is
to say, the earlier products are in turn subjected to digestion. Such
cleavages are generally, if not always, hydrolytic; that is, water
enters into the reaction and its elements are found combined in the
products.
=The Psychic Aspect or the Effect of the Emotions on Digestion.=—The
relation of the emotions to the activities of the alimentary canal
are of very practical importance, because recent investigations have
shown that not only are the first stages of the digestive processes
normally started by the pleasurable smell, sight, and taste of food,
but also the pouring out of the gastric juice.
The importance of the initial psychic secretion of the saliva for
further digestion is indicated when we realize that materials can be
tasted only when dissolved in the mouth, and thereby brought into
relation with the taste organs. The saliva which waters the mouth
assures the dissolving of the dry but soluble food even when it is
taken in large amounts.
The importance of the initial psychic secretion of gastric juice is
made clear by the fact that the continued flow of this juice during
digestion not only stimulates the glands of the stomach to pour out
the chemical gastric juice, but by its action on the mucous membrane
of the duodenum it also starts the flow of bile and pancreatic juice.
These facts are of fundamental importance in the cooking and serving
of food, especially when the appetite is fickle. A bright and cheery
dining-room, the daintiness of the table service, the center-piece
of ferns or flowers, all are factors in exciting the pleasurable
emotions, and so stimulate the appetite.
On the other hand, the digestive processes may be wholly abolished
by vexation, worry, and anxiety, or when such strong emotions as
anger or fear are allowed to prevail. This fact has long been known
in regard to the salivary secretion, and it has now been established
in regard to the secretion of the gastric juice. It is necessary to
avoid all circumstances likely to provoke emotional reactions.
The inhibitory influence of excitement on the flow of the gastric
juice has been studied by Professor Cannon, of Harvard University, in
an interesting series of experiments on dogs. And a most important
point is that the cat, which was allowed to infuriate the dog being
experimented on, was only in the room for five minutes, and in spite
of the fact that the animal was hungry and ate eagerly; there was
almost a complete suppression of the flow of gastric juice for a
period of twenty minutes.
A similar experiment was tried on a boy with a gastric fistula. Food
was shown to the boy and then withheld. He was so vexed because he
could not eat at once that he began to cry and flew into a towering
passion, with the result that no secretion appeared even after the
child was calmed. In both the case of the dog and boy there was not
only a temporary inhibition of the flow of gastric juice, but it is a
noteworthy fact that the effects of the emotional excitement remained
long after its cause had been removed.
The practical point is, that if the digestive processes have been
inhibited by emotional disturbances any food taken will lie stagnant
in the stomach; and not only will there be a suppression of the
gastric but of the pancreatic secretion as well, with the consequence
that there is likely to be an accumulation of unabsorbed organic
material in the colon and perhaps higher up as well. Bacterial
decomposition will be fostered and actual harm may be done the
organism.
And just as a single occasion may lead to a passing digestive
disturbance, so continual mental depression, worry, or grief may
permanently impair the working of the tract and so undermine the
vigor and capacity of the sufferer.
It is believed that many acute attacks of indigestion in children are
due to sharp rebukes administered at the table.
_The Psychic Tone._—Just as there is a psychic secretion, so
likewise there is a “psychic tone,” or psychic contraction of the
gastro-intestinal muscles, as a result of taking food. And just as
the secretory activities of the stomach are inhibited by strong
emotions, so also are the movements of the stomach. And, indeed, the
movements of nearly the entire alimentary canal are almost completely
stopped during moments of great excitement.
The condition of mental discord may thus give rise to a sense of
gastric inertia, so that anxiety may be accompanied by a feeling of
weight as if the food remained in the stomach, and every addition of
food causes an increase of the distress.
=The Importance of the Mechanical Factor in Digestion.=—The
mechanical reduction of food in the alimentary canal is preliminary
to its actual digestion. The first stage of digestion takes place
in the mouth, and this is the only portion of the digestive canal
which is under the control of the will. It is here that the food is
ground into fine particles by the act of mastication, and the more
thoroughly the food is pulverized in the mouth, the more rapidly and
easily can it be acted on by the gastric juice, and the very act of
chewing increases the flow of saliva as well as shortens the time
that the food will remain in the stomach.
[Illustration:
Fig. 6.—The ribs removed, showing relation of thoracic to abdominal
viscera: A, Trachea; B, heart; C, C, lungs; D, liver; E, stomach;
F, small intestine; G, large intestine; H, bladder (after Masse).
]
The _saliva_ not only protects the mucous membrane of the mouth,
but it keeps it free from small food particles, which if allowed
to remain would decompose, and thus injure the teeth by the action
upon them by the acids produced. It also moistens the dry food, aids
in the process of swallowing, and has some action on the starchy
substances of the food. By the process of mastication, then, the food
is divided into small particles and thoroughly admixed with the
saliva until the whole is converted into a fine pulp.
Besides favoring the mechanical part of digestion and its slight
chemical action on starchy foods, saliva, being an alkaline fluid,
is a distinct stimulation to the secretion of gastric juice. After
the food has been reduced into a pulp in the mouth, and the change of
starches into sugar has begun, it is swallowed and passes into the
next compartment of the digestive apparatus, namely, the stomach.
The _stomach_ may be felt at the lower extremity of the breast bone,
in the triangular space formed by the divergence of the ribs. It is
a large hollow, compound gland, the walls of which contain muscular
fibers in addition to the tubules which elaborate the special
secretions. Its cavity is lined with a thick mucous membrane, packed
with tubular glands, into which is poured out a complex secretion
called the gastric juice.
=The Chemical Changes which Food Undergoes in the Stomach.=—There are
two chief phases or periods of gastric secretion: (_a_) The psychic
or appetite juice, and (_b_) the chemical juice. Gastric juice is
not constantly poured into the stomach to accumulate there, but is
secreted only as it is needed under the influence of certain stimuli.
These stimuli may be classified as psychic and chemical.
In the second phase, or period of gastric digestion, the exciting
agent is the presence of food in the stomach. It has been shown that
a correlation of the different organs of the body is brought about by
_hormones_ or chemical messengers. The hormones of gastric digestion
are produced from proteins in the early stage of gastric digestion,
and this shows the importance of the psychic or appetite juice. A
similar effect is produced by meat extracts or infusions, which are
well-known provocatives of gastric secretion.
_Gastric Juice._—The principal active agents of the gastric juice are
hydrochloric acid and the enzymes; pepsin, the proteolytic enzyme;
rennin, the milk-curdling ferment; and lipase, the fat-splitting
ferment. The uses of the gastric juice are digestive, activating, and
disinfecting.
Gastric juice does not dissolve and chemically change all food that
enters the stomach, but acts only on that class of foods called
proteins, converting them into peptones.
The changes which food undergoes in the stomach are as follows:
food is disintegrated; meat is broken up, gelatin dissolved; the
muscle-fibers fall apart, and are split into disks and sarcous
elements; the framework of fatty tissue undergoes similar dissolution
of cellular membranes; milk is curdled; the caseinogen is transformed
into casein, and the latter broken down by pepsin. Bread and other
starchy foods are disintegrated, some of the starch being formed into
sugar by ptyalin. The other vegetable foods are but little digested
by this viscus. The whole is broken into irregular fragments by the
disintegrating power of the stomach and gradually converted into
_chyme_, the creamy emulsion which passes through the pylorus into
the intestines. The passage from the stomach into the duodenum is
aided by the motor activity of this organ.
_The Mechanics of Digestion in the Stomach._—Recent investigations,
especially those of Cannon, have thrown much light on this subject.
The food introduced into the stomach from the esophagus is lodged
first in the fundus or cardiac end of the stomach; from here it
is moved by slow degrees toward the pylorus, from which it enters
the small intestine. Formerly it was taught that this movement was
brought about by a churning motion of the stomach throughout its
entire length. Cannon has shown the error of this conclusion. From
his observations it appears that the stomach is quiet at first. The
waves of peristaltic constriction begin at the duodenal and middle
portions and move the food toward the pylorus. In this way the
constrictions that begin near the pyloric end gradually extend to the
cardiac end. The latter part of the stomach is distended after a full
meal, but gradually diminishes in size during digestion.
Moreover, there is a difference in the character of the gastric juice
coming from the different areas of the stomach; that from the middle
portion being acid, and that from the cardiac and pyloric being
neutral or nearly so. These facts show that the food remains for some
time in the fundus and meets there a neutral liquid; consequently,
the alkalinity of the mass is retained for a time, and the saliva
acts upon the starch for a much longer period than has been supposed.
It is believed that the length of time which food remains in the
stomach varies with its kind. The digesting mass is not forced into
the intestine until it becomes well saturated with the free acid of
the stomach, a result that will be reached later with a meat than
with a vegetable diet; for it is plain that much more acid will be
required to combine with the proteins of meat than with the smaller
amounts in the carbohydrate foods, and so free acid is longer in
accumulating.
Digestion is aided by the movements of the food mass through the
contractions of the walls of the stomach, so that anything which
lowers the tone of the stomach or impairs the integrity of its lining
membrane seriously interferes with the digestive processes.
The nature of the food influences the rate of its passage through
the pylorus. It has been shown by means of the _x_-rays that when
the meal consisted of lean meat, suet, and rice, properly cooked and
prepared in such a manner that the constituents were properly mixed
together, the carbohydrates (rice) began to leave the stomach in
fifteen minutes, but the protein (lean meat) and fat did not begin to
leave it under one-half hour, and were much longer in passing through.
It was further found that in a normal stomach a meal of rice and
potatoes gets out of the stomach rapidly, no trace being left in
three hours, while a meal of protein and fat meat was much slower,
some being present six hours after the meal. Indigestible substances
are rejected by the sphincter and returned to the digestive cavity
over and over again, but in the course of time the sphincter relaxes
and the peristaltic contractions increase, until the force is
sufficient to drive through the opening hard substances like peas,
plum-stones, and coins.
_The Absorption of Food from the Stomach._—A very wide-spread
misconception prevails in regard to the amount of absorption that
takes place through the gastric walls. This is very limited indeed;
some sugar, alcohol and other fluids, and a small proportion of
nitrogenous matter are taken up, but that is all. The legitimate
rôle of the stomach is a peptonizer and grinder only. Absorption of
nutrients is the special work of the intestines, and occupies but a
subordinate place in the duties of the stomach.
Proteins undergo peptonization, but that does not change them
sufficiently. The mere splitting into peptones, formerly thought
sufficient, is now known to be quite inadequate. Recent researches
have shown that the complex protein molecule has to be quite crushed
into a heterogeneous assemblage of fragments, from which those
suitable for building up into the body protein are selected for that
purpose, the remainder being used as fuel; that is, as a source of
energy. In the case of the other food principles, fats and starches,
the chemical processes are much simpler.
=Intestinal Digestion.=—The chemical changes which food undergoes in
the small and large intestines are exceedingly complex. Digestion in
the intestine is due to the combined action of the bile, pancreatic
juice, and succus entericus. The material which enters the duodenum
from the stomach is known as the chyme. The acid chyme provokes a
flow of bile and pancreatic juice. It acts upon the _prosecretin_
in the duodenal mucous membrane in such a manner that _secretin_,
a hormone, is formed and carried by the blood to the cells of the
pancreas which it stimulates.
_Bile_ is a secretion of the cells of the liver and from the inner
wall of the gall-bladder; after elaboration, bile is stored up in
part at least in the gall-bladder. The secretion of bile is irregular
in quantity, as is the case with the gastric juice, and appears
to be induced by chemical excitants, of which acids, especially
hydrochloric, seems to be especially effective. Of the nutrients,
the proteins exert the most influence. Less secretion follows the
ingestion of carbohydrates than of proteins.
Formerly it was supposed that fatty foods checked the secretion of
bile, but later experiments have proved that, to the contrary, they
increase its secretion; and olive oil is a powerful cholagogue.
Bile precipitates the proteins of the chyme, neutralizes the acidity
of the gastric juice, dissolving the fatty acids, and activates
the lipase or steapsin of the pancreatic juice and assists in the
absorption of fats. When for any reason the discharge of bile is
retarded and the organism attempts to eliminate it through the
kidneys, the tissues become charged with its compounds and take on a
yellowish coloration.
_Pancreatic Juice._—The second action upon the food in the intestine
is that of the bicarbonate of soda contained in the pancreatic and
intestinal juices, which neutralizes its acidity; and pancreatic
digestion can only take place in an alkaline medium.
The pancreatic juice has the most comprehensive action of all of
the digestive fluids; it contains a great variety of enzymes and
acts upon all classes of nutrients. Its flow is intermittent, being
induced by the action of the acids in the partially digested food
from the stomach.
The pancreatic secretion attains its maximum pressure about three
hours after a meal, but this varies according to the character of the
meal. The enzymes of the pancreatic fluid are _trypsin_, _amylopsin_,
_lipase_ or _steapsin_, and _pancreatic rennin_.
_Trypsin._—Pancreatic juice alone has but little influence on
proteins, but when mixed with succus entericus its influence is
great. Trypsin differs from pepsin by acting in an alkaline or
neutral solution, and a free mineral acid, like hydrochloric, stops
its operations; it acts much more powerfully and rapidly than pepsin.
In conjunction with other enzymes it splits protein foods into
simpler compounds, which may be regarded as the building stones of
the original proteins.
_Amylopsin._—The digestion of starch in the intestine is mainly
effected by means of a diastatic ferment or enzyme in the pancreatic
juice, called “amylopsin.” This enzyme has the power of hydrolyzing
the starch mostly into maltose.
_Steapsin or Lipase._—The pancreatic secretion acts vigorously on
fats, not only splitting them into fatty acids and glycerin, but, in
conjunction with the bile, also effects their emulsification. This
latter result is doubtless aided by the soaps which form a union of
the fatty acids and alkaline bases (mostly sodium) in the bile. The
cleavage of the fats is due to the enzyme steapsin.
The _succus entericus_ is the secretion of the glands of Lieberkühn.
It contains quite a number of enzymes, including four which act
on carbohydrates, namely, _amylase_, _maltose_, _lactase_, and
_invertase_; the proteolytic enzyme is _erepsin_, which seems to
supplement the action of trypsin. It has no action on native proteins
except casein, but it breaks down proteoses and peptones into
_amino-acids_.
In other words, the discovery of erepsin in the succus entericus and
its effects has led to the now almost generally accepted view that
the digestion of the proteins is carried further than the stage of
proteoses and peptones; in fact, that this enzyme hydrolyzes them
into amino-acids, in which form they are taken up by the cells of the
intestinal mucous membrane.
_The Absorption of Food from the Intestines._—It was formerly
believed that the main stream of the nutrient passed out of
the intestines through the lacteals and thoracic duct into the
circulation. But it is now known that only the fats take this course,
and that the dissolved proteins, carbohydrates, some fats and salts
find their way into the circulation through the portal system and the
liver.
The blood contains a constant proportion of serum-albumin and
serum-globulin, which are constructed out of the amino-acids
resulting from the digestion of protein foods. The reconstruction
of proteins takes place chiefly in the cells. Fuchs believes that
the amino-acids from the food are carried to all the tissues; and
that the cells of the muscles and glands pick out from the blood the
“building stones” necessary for the construction of their special
proteins.
Fat is absorbed for the most part in the form of an emulsion and as a
solution of soap. Only about 60 per cent. of the fat in the food is
absorbed by the lacteals; the remaining 40 per cent. gets directly
into the blood. The fat is carried directly by the blood-stream
to the tissues all over the body; it is oxidized in the tissues
to produce heat and energy; what is not immediately used for this
purpose is stored up in the cells for future use.
_Carbohydrates._—Practically all of the carbohydrates digested are
absorbed in the form of sugar. The absorption takes place more
rapidly in the upper than in the lower bowel. A portion of the
ingested carbohydrates is destroyed in the alimentary canal by
bacteria, whose enzymes transform them into various acids and gases.
_The Absorption of Sugar._—The sugars pass into the blood through
the portal circulation, and not through the lymphatic vessels. The
question is, Where does sugar go after it gets into the blood? The
proportion of sugar in the general circulation is not greater after
a meal than before it. It is necessary that there should be some
means of storing it, for it cannot all be immediately used for the
production of energy. Is it stored as glycogen? Bunge believes that
a considerable amount of carbohydrate is stored as fat, since the
total amount of glycogen in the liver never exceeds 150 grams, and
there is a similar store in the whole mass of muscles. It is evident,
therefore, that only a small proportion of carbohydrates is laid
down as glycogen, and we must assume that the greater part of it is
converted into fat. That fat accumulates in the body on a purely
carbohydrate diet is proved beyond a doubt, and the formation of fat
from sugar is considered proved by experimental evidence.
Sugar is an important source of energy for the muscles, and
provision is made for a sufficiency of it always to be in the blood
circulating through them, and the storehouse from which it is derived
is the liver. When the liver and muscles contain enough glycogen to
keep the blood supplied with it, the excess of sugar is converted
into fat, and is reconverted into sugar when there is a demand for it.
_Mechanics of Digestion in the Intestines._—The intestinal movements,
like those of the stomach, have recently been studied by means of the
_x_-rays. There are three kinds: A pendulum-like motion, consisting
of a gentle, swaying, rhythmic movement occurring in all parts of the
intestines. These movements do not affect the whole of the gut at one
time, but occur in successive segments of it, and are more obvious
in those parts which are distended with food, at a period of three
or four hours after a meal. They are most energetic in the upper
and least so in the lower part of the gut, and proceed from above
downward with the course of the food.
The movement consists in lengthening and narrowing, followed by
shortening and widening, of the canal; the contraction involves both
the longitudinal and circular muscular coats, and in the course of
its progress divides the bowel into many segments. This movement
breaks up the food, sways it backward and forward, diffuses the
digestive fluids through it, and drives chyle into the lacteals.
The second kind of movement consists of peristalsis, or wave-like
propulsive movements; also localized dilatation, followed by
contraction of the canal, progressing from above downward at the
rate of 1 or 2 inches per second, and is from three to four hours
traveling the entire length of the intestines.
Under pathologic conditions a third movement is observed, consisting
of a swift venicular movement, starting at the pylorus and traveling
the entire length of the gut in about one minute. It is produced by
toxins, gases, and other irritants.
Digestion is practically completed in the small intestine.
The _colon_ consists of a proximal portion, consisting of the cecum,
ascending colon, and one-half of the transverse colon; a mesial part,
formed by the other half of the transverse colon and part of the
descending colon and a distal portion, formed by the remainder of
the descending colon and of the rectum. The contents of the proximal
portion are fluid; food accumulates in this portion; it is gradually
concentrated by the absorption of water. It has been shown by the
_x_-rays that a meal reaches the cecum in four or five hours; the
hepatic flexure in six or seven hours; the splenic flexure in nine
hours; and the rectum in about eighteen hours.
The feces consist of the residue of the food, digestive secretions,
etc. The contents of the alimentary canal become altered in character
as they descend its course. The mass attains a greater density as it
descends, more and more nutrient being absorbed from it, and even
in the colon it becomes more solid; its color is brownish and its
odor characteristic. The amount of feces from an average mixed diet
represents from one-seventh to one-eighth of the food consumed.
_Defecation._—The waste matter which collects in the lower bowel
must be evacuated every day. Allowed to remain longer than this, the
digestive system is clogged by the non-removal of worn-out material,
and the blood is constantly absorbing matter which is poisonous
to the body. Decomposition goes on without being suspected by the
sufferer.
_Intestinal bacteria_ or _organized ferments_ are present throughout
the entire intestinal canal and play a part in the food changes.
They are most abundant in the lower part of the small intestine and
the upper part of the large. They act upon the proteins, causing
putrefaction, dissolve cellulose, and cause a decomposition of the
carbohydrates. The products of these fermentations include indol
and skatol, which have the characteristic fecal odor; volatile
fatty acids and gases, some of which are carbon dioxid, hydrogen,
marsh-gas, and hydrogen sulphid.
Fermentations of this character up to a certain extent are normal
and may be beneficial, but they may proceed so far as to be
deleterious to health. Anything which retards digestion, such as
imperfect mastication, excessive eating, abnormal amounts of meat in
the diet, and failure of the organs secreting the digestive fluids to
supply these secretions in sufficient quantity, gives these bacteria
a better opportunity to act on the food residues and so increases
their bad effects.
Some foods, especially vegetables of the leguminous class, appear
to be provocative of excessive intestinal fermentation. Flatulence
and even toxic poisoning may be the result of great bacterial
activity in the digestive tract. It is hardly possible to check this
by administering septics, but purging is of value by removing the
fermentative material. Particular foods, especially soured milk and
kephir, have been shown to have a preventive action on putrefaction.
_Influence of Food on Secretion._—The more recent investigations
reveal the fact that the kind of food has an influence not only on
the abundance, but also on the kind of digestive secretions; this
is most important because an abundant supply of digestive juices
is necessary for good digestion. Broths, meat extracts, and milk
stimulate the secretion of the gastric juice, which makes rational
the taking of soup or bouillon as the first course at dinner, or the
eating of toast or zwieback by persons with weak digestions. Fats,
on the other hand, tend to inhibit gastric secretion, so that an
excessive proportion of fat in the meat might hinder digestion in the
stomach.
Food may exert an indirect influence on the pancreatic secretion.
The acid in the chyme stimulates the flow of pancreatic juice. One
is almost inclined to speak of the physiologic education of the
digestive glands, and to conceive them as being trained for fat,
protein, or carbohydrate digestion.
=Metabolism.=—Life consists, so far as material phenomena are
concerned, in the transformation of matter into energy. To these
transformations the term _metabolism_ is applied. In the metabolism
of matter the changes are chemical; in energy the changes are
physical. It is commonly assumed that the laws of conservation of
matter and energy are conformed to or obeyed in animal bodies.
The body converts potential into kinetic energy by metabolism in
the body. The potential energy of food is transformed into the
actual energy of heat and mechanical labor. In this respect the only
difference between man and other vertebrates is the nervous and
intellectual processes, which are not yet understood.
Metabolism is anabolic and katabolic. _Anabolism_ is constructive;
it includes growth and the act of the tissues in selecting,
appropriating, and making substances absorbed from the alimentary
canal a part of themselves. The body is never stable; while growth
and nutrition progress, destruction or demolition takes place,
and this is called _katabolism_. To ascertain the exact amount of
matter and energy used daily by the body a balance sheet of the
exchange of material is necessary. The _income_ consists of (_a_)
matter—food, drink, and the oxygen of the air; (_b_) _energy_, the
potential energy of the food and drink. The _outgo_ consists of
(_a_) matter in the feces, urine, perspiration, and breath; (_b_)
energy—the potential energy of feces, urine, products of respiration,
and perspiration. A complete account would show the amount of C, N,
H, O, P, S, Cl, Na, Ca, K, Mg, and Fe in the income and outgo, it
would also show the compounds in the excreta, including proteins,
carbohydrates, water, and carbonic acid.
Experiments show that the body requires a given quantity of given
energy producing substances for sustenance, and something more to
meet the demands for muscular work.
The metabolism of nitrogen is usually measured by the amount of urea
in the urine, taking into account the small proportion of uric acid
and other nitrogenous bodies. In fasting the organism lives on its
own flesh and fat.
_The Effects of a Nitrogenous Diet on Metabolism._—The most striking
effect of a purely nitrogenous diet is a large increase in the
nitrogenous metabolism, but it also increases the metabolism of the
non-nitrogenous elements of the body. With an ordinary mixed diet the
normal excretion of urea varies from 33 to 37 grams a day, while with
a meat diet the urea may rise to 50 or even 80 grams daily.
_Carbohydrates as a Protein Protector._—It has long been observed
that when there was a deficiency of protein in the food the
metabolism of nitrogen will be spared and the tissues protected if
the food contains plenty of carbohydrates and fat. The subject was
fully investigated by Lusk. When the diet contains an abundance
of protein, carbohydrates, and fat the organism gains a little
nitrogen; when the diet contains the same amount of protein but no
carbohydrates, the body loses considerable nitrogen. Again, when
the food was the ordinary mixed kind, and contained a sufficiency
of energy, but was of a low protein character, the excretion of
nitrogen was normal. These results led to the conclusion that the
carbohydrates were a protein protector.
_Fat as a Protector of Proteins._—The metabolism of nitrogenous
tissue and elimination of nitrogen is not prevented by the
consumption of fat, but the consumption of fat reduces the metabolism
of protein so much that one-quarter or one-third as much meat will
suffice to maintain the nitrogen equilibrium as would have to be
consumed if only lean meat was used.
The nutritive value of meat extracts is comparatively small; their
chief value is in promoting digestion and metabolism of other foods.
_Water and Metabolism._—The body consists of 530 parts of water per
1000. It is of greatest importance as a component of the tissues to
assist in the exchange of nutritive substances, the discharge of the
products of metabolism, the regulation of temperature, and other
vital functions. If the supply of water is stopped the body will
die, and it may die sooner from the deprivation of water than from
starvation.
A reduction in the amount of water consumed accelerates the
decomposition of protein and fat to replace the water essential for
the bodily functions. As the result of experiments it has been found
that the average income of water is 4 pints, and the excretion is 4½
pints; so that at the lowest estimate ½ pint of water is formed in
the tissues by the oxidation of hydrogen in the food and tissues;
and during ordinary work it was found that 17 ounces of water was
excreted daily in excess of that consumed in food and drink.
The intense suffering entailed by prolonged thirst is to be accounted
for by the absolute necessity for preserving the normal aqueous
dilution throughout the body.
Water is also essential for removing the effete materials arising
from metabolism, cell growth, and other disintegration.
_Chlorids._—About 15 to 18 grams of sodium chlorid (common salt) are
excreted daily in the urine, and smaller quantities in the feces and
perspiration. It is, therefore, a most important food. The tissues
retain common salt most tenaciously, and when there is none in the
food it gradually disappears from the urine. It facilitates the
absorption of the protein foods and increases tissue metabolism. And,
further, an insufficiency of common salt is followed by a diminution
of hydrochloric acid from the gastric juice, and consequently a
failure of nutrition. There can be no doubt that the hydrochloric
acid of the gastric juice originates from the chlorids of the blood.
On the other hand, a very large number of people consume more salt
than they require. Salt is not only a food, it is a condiment, and
as such it is liable to abuse. It has been estimated that from 2 to
4 grams of salt a day is sufficient, whereas most people take from
20 to 30 grams daily in one way or another. The kidneys have to
excrete the excess of salt, which they seem to do in health without
any difficulty; but in nephritis the kidneys do not excrete it so
readily, and this may lead to a retention of salt in the body.
_Iron_ is essential to the human body. It is taken into the body
in the form of food, and is excreted from the body in the bile and
feces. It has been estimated that typical food contains 10 mgm. of
iron daily. The hemoglobin of the blood contains 0.04 per cent. of
iron.
=Constipation.=—It must be remembered that the intestine is a
permanent source of poisons, which, under certain conditions, cause
grave alterations in the principal organs, notably in the liver,
kidneys, and skin, and serious functional disturbances of the nervous
system.
Normally, the organism manages to protect itself against the
microörganisms which are found in the intestines; given, however,
certain conditions, the toxic products can be generated in excess
of the powers of the organism to dispose of them, such as errors
of diet, quantitative or qualitative, atony of the muscular walls
of the intestine, and, above all, constipation. The higher up in
the intestine the stasis occurs, the more serious is the result.
Constipation is considered by many surgeons as the most important
factor in the production of appendicitis.
There is frequently a condition present which is known as
semiconstipation, and which is most deceptive to the patient. There
may be a bowel movement every day, but the bowel is never emptied;
only the lower portion of the hardened fecal matter is broken off.
This is repeatedly found to be the case in examining women for some
form of pelvic trouble, and in a woman who says that she has a daily
evacuation of the bowels, and has had one that very morning, the
sigmoid flexure will be found to be packed with hardened feces.
Besides the clogging up of the digestive system by the non-removal
of the waste-products of digestion, the formation of hemorrhoids,
which is caused by the mechanical pressure on the veins, and so
interferes with their emptying out in the normal way, and the general
autointoxication of the entire system, there are also caused in
women serious displacements of the pelvic organs together with their
congestion and inflammation.
The general symptoms of autointoxication are: headache, vertigo,
palpitation of the heart, a feeble and irregular pulse, irritability
of temper, melancholia, numbness and tingling in the hands and feet,
and the emaciation and loss of weight are sometimes so marked as to
lead to the suspicion of malignant disease.
=Treatment of Constipation.=—This should always be preventive, and
the diet is a most important factor. The food should be of a coarse
quality, that is, such as directly stimulates the walls of the
intestine to contraction by their constitutents, or by the large
amount of the indigestible bulk. Corn and Graham bread should be
substituted for white bread. Toast is always constipating. Plenty of
fresh fruit and vegetables should be eaten. For those who can digest
them, raw apples, eaten just before retiring, are a great aid. The
drinking of a sufficient quantity of water daily is also essential,
and this quantity must be 3 pints. A glassful of cold water, taken
the first thing in the morning on rising, is often very effective. If
this is insufficient, the phosphate of soda, one teaspoonful to one
tablespoonful, may be added.
_Habit._—Nowhere is the effect of habit more conspicuous than in the
matter of a daily evacuation of the bowels. There should be a fixed
time every day for this, and the very best time is in the morning,
directly after breakfast. Such a habit, once established, will
enforce itself upon the attention and make regularity a necessity.
It not infrequently happens that constipation is the result of
irregularity in going to the toilet. The school-girl or woman gets up
a little late, and, although she may feel the inclination to empty
the bowels, she is able to defer it.
If the movement is sufficiently large, one stool daily is sufficient,
but where the stool is slight in quantity, there may be two or three
during the day, entirely consistent with health, and in a run down
state of the system there are apt to be several small movements
rather than one full stool. So long as the stools are not watery, the
individual may rest assured that there is no looseness of the bowels.
Constipation should never be allowed to become chronic. It is, as has
already been shown, the progenitor of myriads of the most serious
diseases; and, after the bad habits of years have been established,
it is one of the most obstinate of diseases to cure. In every case a
good physician should be consulted at once, and the treatment should
be persevered in until the cure is complete. It is a well-known fact
that all medicines for this trouble lose their effect, the dose has
to be increased, and a frequent change made from one laxative to
another. When everything else fails, electricity may be resorted to.
It is one of our most valuable remedies, since it brings about a cure
through the toning up of the muscular walls of the intestine.
The constant use of hot clysters to empty the rectum is one of
the most pernicious habits; in this manner the bowel becomes
overdistended and loses its tone, and the fecal mass is not
sufficiently large to cause the distention of the rectum, which is
the normal stimulus leading to the desire to defecate.
=The Amount of Food Required.=—Food is required for growth and for
repair; that is, to build up the organism and make good the loses
sustained by physiologic processes, to maintain the heat of the
organism, and to supply it with mechanical energy.
It has become an established custom to compare the human body to a
machine. Both derive their power from fuel; in both instances the
potential energy of the fuel is transformed into kinetic energy or
mechanical power which works the machine; in both cases the energy
which is not used in work escapes in the form of heat.
The human body uses the mechanical power chiefly in muscular work;
the heat is used in warming the body and causing the evaporation of
moisture from its surface. The animal organism is much superior to
the mechanical engine. It is more economic in the use of fuel; it
has a nervous organization rendering it sensible to impressions and
capable of directing its energies. The human machine is capable of
adapting itself to many circumstances and changes in the demands upon
it.
But to enable the body to continue to perform these functions
indefinitely it must be properly fed, and a proper feeding of the
body requires a knowledge of its composition and the exchanges which
are constantly going on. This knowledge is to be derived from a study
of its metabolism, the analysis of foods, and a determination of
their heat values.
=The Classification of Foods.=—Foods are divided into proteins,
carbohydrates, fats, mineral salts, and water. The body is composed
of materials belonging to the same groups. Proteins form the
principal part of muscles, bones, and many other tissues of animal
bodies; they also constitute some of the most important vegetable
structures.
_Proteins_ are probably the most complex compounds in nature; all
contain carbon, hydrogen, oxygen, and nitrogen, generally sulphur,
and sometimes phosphorus also. They are, with rare exceptions,
colloids, that is, glue-like, non-crystalline bodies, which even in
solution cannot pass through animal membranes.
The building stones of the body are the amino-acids. All proteins
contain them, but the kinds and proportions are not always the same.
It has been shown by biologic experiments that life and growth cannot
be maintained when certain amino-acids are deficient.
Proteins are of use to the human body as tissue formers, and,
secondly, as producers of energy, but they also have a food value
as flavoring agents, rendering the food appetizing, and so are to a
certain extent stimulants. The palatability of meats and soups are
due to their presence. The amino-acids have decided heat value.
The necessity for proteins in the diet has been abundantly
demonstrated. Many investigations have shown that when the food
contains no protein the waste of nitrogen continues, no matter how
abundant the supply of carbohydrates and fats. In other words, a
continuous protein cleavage is demanded by the animal organism, and
no other nutriments can serve as a substitute for protein to meet
this demand. If the food contains no protein, the body tissues will
be depleted. It cannot be said that carbohydrates or fats are an
essential part of the diet in the sense that protein is, because it
is possible to substitute one for the other to produce energy, or to
substitute proteins for both.
In spite of these facts, it is safe to assert that the welfare of
the human organism is best promoted by a mixed diet, including all
three classes of food. The larger part of man’s food is used for the
production of energy, and it is physiologically economic that this
energy be supplied by the non-nitrogenous nutrients, particularly the
carbohydrates, and to allocate to protein, so far as practicable, its
special rôle of building material.
_Nitrogenous Waste Products._—The end-product of proteins is urea,
which is formed from protein decomposition products in relatively
large amounts in the liver cells, and, being readily soluble and
diffusible, is easily eliminated by the kidneys. Besides urea there
are other smaller quantities of nitrogen compounds, the one most
deserving of notice being uric acid.
When the proteins are broken down to supply energy, there is always
a definite proportion of urea and uric acid residue that must be
eliminated through the kidneys. An excessive protein diet would
burden these organs beyond their accustomed habit, and flooding
the system with these nitrogenous wastes increases the tendency to
rheumatism and gout.
Uric acid is of general interest, and when present in the system
in abnormally large amounts, as in gouty persons, has a pathologic
significance. It is more complex in its composition, and, what is of
particular importance, is that it does not readily dissolve. It forms
very insoluble salts which have unpleasant tendencies to settle in
the joints, causing great pain. Did its metabolism proceed properly,
it should be resolved into urea and carbon dioxid. The quantity of
uric acid that appears in the urine is the residue that has escaped
this oxidation.
Uric acid is built up from purin bodies in the food, so that it would
be well for those with a gouty diathesis to abstain, at least when
an attack of gout threatens, from all aliment in which purin is at
all abundant. The most valuable of the purin-free foods are eggs and
milk, and to these the uric-acid sufferer has to turn in times of
trouble.
_Carbohydrates Physiologically Economic._—This group of compounds
comprises starches, sugars, and gums; the elements of which they are
composed—namely, carbon, hydrogen, and oxygen—are so balanced that if
all of the carbon were removed the residual hydrogen and oxygen would
be in the proportions to form water.
Carbohydrates are usually characterized as the fuel portions of the
food, or, in other words, that part which is burned to produce the
various forms of energy. They are also essential for the well-being
of the organism; reduction of the intake below the essential point
frequently leads to acetonuria.
When the metabolism is perfect, any carbohydrates consumed in excess
of the ordinary requirements are converted into glycogen and fat and
stored for providing fuel at a future date. When stored as fats they
are completely oxidized in the simplest compounds, carbon dioxid and
water, and are eliminated through the lungs and skin, possibly part
of the water so formed acting as a solvent for the urinary compounds.
Investigations seem to prove that the body has a preference for the
carbohydrates over fats or other nutrients as a source of energy.
There is every justification for the abundance of starches in man’s
diet.
_Fat_ is essential in the food of mankind; it is absorbed ready
formed from the food, or manufactured in the body from the proteins
and carbohydrates. Neutral fats and fatty acids are valuable foods;
their primary function is to supply the body with fuel for heat and
energy.
The _mineral substances_ form 5 or 6 per cent. by weight of the
human body, and are constantly leaving it by different channels;
they are indispensable elements of food. They give solidity and
stability to the organism, constituting a considerable proportion
of the bones. They keep various proteins in solution and confer
upon them the property of electric conductivity. They are necessary
for all of the secretions and assist in the general metabolism. The
carbonates of soda, potash, iron, and other minerals render the blood
and secretions alkaline. The removal of carbon dioxid is performed
mainly by the alkaline carbonates, which take it from the blood and
surrender it to the lungs. We have already considered the need of
sodium chlorid. The total daily requirements of salts is estimated at
about 360 grains.
_Vitamins a New Factor in Nutrition._—But recent investigation has
proved that something more is essential for the maintenance of growth
and well-being than protein, carbohydrates, fats, and salts; that
food contains a minute portion of accessory bodies, and that when
they are deficient or absent from the diet the immature body does
not grow, the mature body does not maintain its condition, and there
are manifestations of more or less serious disease. These accessory
bodies have been called “vitamins,” and they are essential to
maintain the normal metabolism of the body.
It is recognized that although vitamins are undoubtedly widely
distributed in food products, they occur for the most part in very
minute amounts, and the various foods differ in the proportion which
they contain. If the diet is made up of substances which are poor
in vitamins, or rendered so by their mode of preparation, abnormal
metabolic processes have been found to follow.
The study by many scientists during the past few years of the enzymes
and their striking specificity; of the salts; of the insufficiency
of many proteins, and of the vitamins is epoch making, and has
caused a corresponding advance in dietetics. These discoveries are
so important as to raise the question whether nutritive failure or
success does not depend as much on the accessory bodies—the vitamins,
the enzymes, and lipoids—as on the primary element of the diet.
In addition to these food principles, there exists in our food a
number of compounds which, while not indispensable, act beneficially
as flavorings, stimulants to digestion, etc.; these are termed food
adjuncts, and comprise such bases as caffein, essential oils, organic
acids, etc.
=Standard Dietaries: The Maintenance Diet.=—There is great need of
_standardization_ and of knowledge regarding the maintenance diet,
first among physicians and then among the people in general, or
scientific dietaries based on the nutritive value of foods. These
are given in terms of proteins, carbohydrates, and fats, together
with the aggregate energy of the nutritive value in each. This is the
corner-stone of dietetics.
_Dietetics_ is the science of feeding. It has to do with the
necessities of the body and the ability of the food to meet these
necessities in the various circumstances and conditions of life. The
ultimate scientific knowledge concerning human nutrition should be to
promote the healthful and economic use of food.
The problems to be dealt with are quite complex. These are: (1)
changes in the economic conditions of the population; (2) changes
in food production and food supply; (3) changes in the methods of
preparing food.
In regard to the influence of the economic conditions of the people
on the composition of their diet, it might be expected that a
considerable decrease in the earning capacity of the poorer people,
or an increase in the cost of foods, would be followed by a change in
their diet. Everyday experience teaches that under such conditions
the more expensive foods—meat, eggs, and milk—are reduced in the
diet. These same foods are also rich in vitamins, so that a reduction
here would, therefore, reduce the vitamin content of the dietary
unless other dietary complements rich in vitamins, such as legumes,
were introduced.
The value of any food as a source of heat and energy is measured by
a bomb-calorimeter. The heat given off during the combustion is a
measure of the latent or potential energy of the food. The kinetic
energy of the food is the amount of heat developed by the proportion
which is digested. The unit commonly used is the calorie, or the
amount of heat which would be required to raise the temperature of
1 kilogram of water 1° C., which is about equal to that required to
raise the temperature of 1 pound of water 4° F.
_Heat Value and Digestibility of Foods._—One of the chief functions
of food is to supply the body with heat and energy; the food must
be capable of digestion and absorption. Herein lies the exact value
of any food to the consumer. In science the figures that are given
for the digestibility of the various foods refer to the completeness
or extent to which the food is dissolved and transferred to the
circulation, and an indigestible one is that of which a considerable
portion passes out of the system into the feces without being
disintegrated and absorbed.
_Animal food_ is more completely digested than vegetable food, as
shown by the difference of nitrogen in the feces. In meats 97 per
cent. of the protein and 98 per cent. of the fat are absorbed. Lean
meat is more rapidly digested than fat, and the flesh of young
animals than that of older ones.
The breast of chicken, fresh beef, and mutton are among the most
digestible of the solid foods. Raw and rare meats are more easily
digested than well-done meats; in other words, cooking lessens the
digestibility of meats. Steak should be broiled and never fried; all
fried foods are difficult to digest. Veal and pork are both difficult
to digest.
_Eggs_ are almost as nutritious as meat; their digestibility is
unsurpassed and only equalled by a few foods, such as milk and
oysters. They are most easily digested when soft boiled or poached.
Dry toast finely broken up and mixed with a soft-boiled egg aids in
its digestion. Soft-boiled eggs are more easily digested than raw
eggs, but the latter are less irritating to the stomach, probably
because they are digested in the intestines. It has been found that
two poached or soft-boiled eggs leave the stomach in from two to
three hours; that is, in the same time as milk, oysters, white bread,
and light fish.
_Milk._—Although one of the most completely digested of foods in a
mixed diet, milk is not quite so completely digested as meat and
eggs. When milk is the sole food (milk diet) the proportion digested
depends partly on the amount consumed. With the consumption of 3½
pints of milk daily the loss of milk solids varies from 10 to 11.16
per cent. Young children digest milk more completely than adults.
The addition of aërated waters or crackers broken up in the milk
prevent the formation of tough clots, and hence render it more
digestible. Hot (not boiled) milk is more digestible than cold.
Boiling increases the toughness of the curd, but it destroys the
bacteria. Buttermilk and koumiss are more easily digested than cows’
milk.
_Wheat flour_ enters largely into the diet of every family. In
producing it the outer coating of the wheat kernel is removed, thus
throwing into the milling offals that part of the kernel which is
most heavily charged with mineral ingredients and vitamins. The
proportion of digestible proteins in white flour is not less than in
whole wheat flour, as is so often claimed, but because the latter is
richer in mineral ingredients its use is recommended.
Bread is readily digestible; white bread digests more rapidly than
brown or black; and crackers more rapidly than either.
_Rice_ is another cereal of great economic importance. As a food for
invalids it possesses a high value on account of its digestibility,
especially in intestinal diseases. Ordinarily polished rice contains
only 0.5 per cent. of cellulose, and almost all of the substance of
the grain is absorbed.
There is a perfect analogy between the well-known relation of the
polishing of rice to its nutritive value, and the milling of wheat
and corn to the nutritive value of wheat, flour, and cornmeal; that
is, it loses the mineral ingredients and vitamins.
_Potatoes._—In European countries potatoes rank next to bread; this
arises from the ease of their digestion. From 92 to 95 per cent. of
the starch is absorbed, but there is a loss of 23 per cent. of the
protein.
The manner of preparation of vegetable foods determines the
proportion of loss. When potatoes are baked or boiled in the skins
the loss is negligible. The greatest amount of loss occurs when the
skins are removed, the potatoes then allowed to soak in cold water,
and placed in cold water to boil. The potatoes should be pared just
before cooking, and the water should be boiling hard before they are
put in. Mealy potatoes digest more rapidly than waxy ones, and mashed
quicker than unmashed.
Oatmeal, barley meal, and other cereals which are not ground very
fine do not digest so easily as wheat flour, but much depends on the
mode of cooking. When oatmeal-gruel is consumed with a sufficient
amount of milk it forms a complete diet.
Nuts are valuable as a source of protein and fat, but they are rather
difficult of digestion.
_Fats._—As a rule, children do not thrive whose diet is deficient in
fats, and even adults are prone to tuberculosis and nervous diseases
when fat in the body is deficient.
Cheese is one of the most indigestible of foods. All fried foods are
highly indigestible because the fat envelope of the foods has to be
melted off before the gastric juice can act on the food substance
itself. Pastry is also very indigestible. Of the vegetables, beans,
while highly nutritious, are exceedingly difficult of digestion; also
boiled cabbage, cauliflower, hot breads, iced drinks, ice-cream, and
water-ices.
=The Relation of Diet to Various Conditions of Life.=—The chief
factors influencing bodily needs are age, height, weight, occupation,
idiosyncrasies, and atmospheric conditions.
All activity of the human body, whether in the maintenance of its
functions or in the performance of labor, is work. These two forms
of work may be classified as physiologic and mechanical. Nothing in
nutrition is more important than the relation of food to work.
_Children_ are practically in constant motion during their waking
hours, and their demand for food energy is from two to three times as
much per unit of weight as that for adults.
_Sex._—Men and women of the same age and weight, doing the same kind
and amount of work, require the same amount of food. The fact that
men usually require more food than women is because, as a rule, they
weigh more, are more active physically, and perform more external
work.
_Temperament._—Persons of a nervous type, being more active, use more
energy than the phlegmatic, and, therefore, require more food.
_Brain Workers._—A man whose work is sedentary and chiefly mental
does not need so much food as a man doing muscular work. The amount
of carbohydrates required is less, and the amount of fat rather more
than for the man doing light muscular work.
Ranke’s diet for the brain worker is: Protein, 100 grams; fats, 100
grams; carbohydrates, 240 grams; giving an energy value of 2310
calories.
The diet should not be bulky, but light and easily digestible. Excess
of food and heavy foods are especially bad for brain workers because
they produce heaviness, dulness, and drowsiness. Spiced and rich
foods upset the alimentary functions, whereby the circulation is
flooded with the products of imperfect metabolism to the detriment of
the brain.
Trained workmen will do a given amount of labor on less food than
untrained, because when persons take up mechanical operations with
which they are unfamiliar, or undertake work which exercises a new
set of muscles, a unit of work accomplished costs more in food energy
than when the muscles have been trained to do a particular thing.
Very strenuous exercise, like athletic contests and unnaturally slow
movements, are both wasteful of food energy.
Again, a continuance of the same labor for hours, and a state of
fatigue, whether it comes after a longer or shorter time, causes an
increase in the energy expenditure per unit of work performed.
Economy in the use of energy that food supplies to the body is most
fully secured when the movements of the body are at the natural rate;
when periods of intense effort do not occur, and when the labor is
not too long continued and is not carried to the point of fatigue.
_Standard for Daily Dietaries (American)—Atwater._
Fuel
Protein. value. Nutritive
Grams. Calories. ratio.
Woman with light muscular exercise 90 2400 5.5
Woman with moderate muscular work } 100 2700 5.6
Man without muscular work }
Man with light muscular work 112 3000 5.5
Man with moderate muscular work 125 3500 5.8
Man with hard muscular work. 150 4500 6.3
=The Relation of Food Economics to Social Welfare.=—A virile nation
is one whose citizens are of a good physical type, which means that
they are well nourished. A well-fed people, other conditions being
favorable, is a strong people. Food is the physical basis not only
of the individual activity, but also of social energy. Any causes,
therefore, which limit the food supply or increase the burden of
securing adequate nourishment strike a blow at the nation’s vital
power.
We must constantly keep in mind that the energy output is practically
the energy requirement, under given conditions, of course; and
the expenditure caused by the muscular activity of a particular
individual cannot be reduced without affecting the work done or
causing the loss of body substance.
Investigation has shown that there is a necessary daily protein
minimum use. When insufficient protein is taken in the food, the
necessary balance will be supplied by drawing on the tissues of
the body. The food standards which are based on the observation
of practice call for not less than 100 grams of protein daily for
professional men and 175 grams for men at severe labor.
It is held to be significant that communities holding leading
positions in the world consume a liberal amount of protein, or,
conversely, that communities with an inferior physical and mental
status use a low proportion of proteins in the diet. Again, if we
argue from the analogies in feeding farm animals, generous protein
feeding is desirable for the growth and maintenance of vigorous
organisms and a satisfactory rate of production.
On the other hand, the well-known experience of the ages has shown
that the poor who live on a low protein diet are the most liable
to disease. It cannot be gainsaid that the meat eater has greater
stamina and energy than the one whose diet is poor in protein.
The conclusion is, that while a minimum of protein is essential to
the organism, a greater proportion is advantageous by acting as a
stimulant to the metabolism and as a ready source of energy; that
people are better for the consumption of proteins in quantities
greater than in Chittenden’s standard, and possess greater resistance
to disease, probably because the body is stimulated to manufacture
antibodies.
=Practical Facts for Guidance.=—The housewife who keeps the following
facts in mind may combine foods in an approximate way that will fully
meet the demands of the human organism.
The proper ratio is 1 part of protein to 5 parts of non-protein; and
the fat should equal one-half of the weight of the protein. This
gives the following normal dietary:
Energy
Weight. supplied.
Grams. Ounces. Calories.
Protein 100 3½ 410
Carbohydrates 400 14½ 1640
Fats 50 1¾ 465
————
2515
=Proportion of Proteins in Foods.=—_Foods Rich in Proteins._—Lean
meat, dried peas, beans, and lentils, 18 to 25 per cent.; fat meat,
12 to 18 per cent.; eggs, 12 per cent.; oatmeal, 10 to 15 per cent.;
cheese, 25 to 35 per cent.
_Foods with Moderate Amounts of Proteins._—Milk averages 3½ per
cent.; fresh peas, beans, and lentils, 3 to 8 per cent.; white bread,
6 to 7 per cent.; fine wheat flour and barley, 8 to 10 or 12 per cent.
_Food with Usually Less than 3 Per Cent. of Proteins._—Green
vegetables, potatoes, and roots, such as carrots, turnips, and
onions, etc.
Legumes and certain nuts supply relatively more protein than other
vegetable foods, so that when the cost of meat, fowl, fish, eggs, or
milk is prohibitive, the freer use of beans, peas, lentils, and nuts
is strongly recommended.
The unmodified foods, such as grain, vegetables, fruit, meat, eggs,
and milk, may be depended upon to amply supply all the necessary
elements to sustain growth, functions, and waste of the human
body. On the other hand, foods which it is proper to designate as
“artificial” are not only not essential to an adequate diet, but when
they are used freely may render a diet very one-sided or deficient.
Foods may be so selected as to furnish an abundant supply of mineral
ingredients. For instance, the dry substance of certain vegetables
like asparagus, lettuce, spinach, and such animal foods as eggs, and
beef extracts are relatively rich in iron compounds, and the dried
substance of leguminous seeds, carrots and other vegetables, milk,
and cheese are relatively rich in calcium compounds.
_Variety of foods_ is necessary, for monotony of even the best kinds
leads to satiety, loss of appetite, loathing of food, and subsequent
ill-health. Vegetables and fruits are absolutely essential, but
raw fruits are not so easily digested as cooked. Salads, lettuce,
water-cress, green onions, celery, tomatoes, etc., are so valuable
for the juices contained in them that they cannot be too strongly
recommended to those who can digest them. Similar juices are
contained in cabbage, cauliflower, spinach, etc., but these are lost
to a very great measure in the cooking.
Oranges, lemons, grapes, strawberries, and bananas contain equally
valuable juices, and may be eaten raw with advantage to the consumer;
but apples, pears, plums, gooseberries, and many other fruits are
better cooked before being eaten.
The simpler the meals, the less work will be expended in their
preparation, and there is no advantage in an elaborate meal. The main
thing is that the table should furnish a sufficient variety from day
to day.
The following specimen dietary has been found to be most satisfactory
for women with sedentary occupations. On it women have maintained
good health and other women have regained their health:
_Breakfast._—Fruit, bacon and eggs, breakfast hominy, rolls or toast
and butter, a glass of milk, and one cup of coffee.
The fruit may be any raw fruit in season except apples or bananas;
apples should always be cooked for breakfast because they are more
easily digested; bananas are too heavy and indigestible to be served
for breakfast. Stewed prunes are good and especially laxative.
Bacon is not a necessity, though it is an appetizer. Eggs may be
served in any way, though they are most digestible when soft boiled
or poached.
The hominy is boiled in water and served as a vegetable, with a
little salt and butter, but _no_ sugar.
For women with good digestion and taking more active exercise,
oatmeal and cream may be substituted for the eggs, hominy, and glass
of milk.
_Luncheon_ may be served in a very appetizing way from the cold meat
and vegetables which have been left from the previous day’s dinner
in the form of stews, baked hash, etc. Stewed fruit should always be
served, and oysters always make a nice dish for lunch.
The criticism of the ordinary lunch for women is that it is too
light. The food served for lunch should furnish about 1000 calories;
90 per cent. of these should be in the form of starches and fats.
_Dinner._—The following is a balanced ration given in the Educational
Lunch Room of the New York Department of Health:
Proteins.
Price. Quantity. Calories. Grams.
Vegetable soup 5 cents. ½ pint. 150 5
Roast beef 20 cents. 4 oz. lean. 140 30 or
Roast beef with 4 oz. fat. 460 27
Mashed potatoes, creamed Av. helping. 110 4.0
String beans 5 cents. 2 h. tbsp. 10 .5
Salad a la Sauté 8 cents. Av. helping. 370 2.0
Whole wheat bread 2 slices. 140 5.5
Butter ½ ounce. 120
Apple pie 5 cents. ⅙ pie. 300 4.0
Black coffee 3 cents. 1 cup.
Sugar 2 squares. 60
—————————— ———— —————
46 cents. 1760 or 50 or
1440 53
One glass of water is served with each meal; it should be taken when
the meal is finished.
The mineral waters promote digestion by promoting an earlier and more
abundant secretion of the gastric juice.
Lemon juice should be substituted for vinegar in all salad dressings.
For a French dressing the correct proportions are 1 tablespoonful of
lemon juice and water each to 2 of olive oil. Mix well, and pour over
the salad just before serving.
Three meals a day has been found to be the best arrangement, and
there should be an interval of five hours between the meals. If
possible dinner, which is the principal meal, should be taken at the
end of the day, after its work is over, so that comparative repose
may be enjoyed after it. It is of extreme importance that the meals
be served at the same hour every day. The perfectly healthy woman
should never take anything to eat between meals.
A hearty meal should never be eaten when one is exhausted or
greatly fatigued. Half an hour’s rest before dinner is a great
aid to digestion. Sleep directly after a hearty meal is injurious
and sometimes proves fatal because there is a depression of the
circulation, and the digestive processes may stop absolutely during
sleep.
_Preparation of Food._—Fresh meats are highly nutritious, but in
order that the nutritive properties may not be lost in the cooking,
they must be eaten “rare,” that is, beef and mutton should be at
least pink.
A roast should be done in a quick oven, so that the albumin shall
rapidly coagulate on the surface and prevent the escape of the
nutritive juices. Or if the meat is boiled, it should for the same
reason be plunged into boiling water.
On the other hand, in treating meats in order to obtain “stock” for
soup, the meat after having been cut up into small pieces should be
allowed to stand in cold water for twenty minutes and then be put on
to simmer for six hours or more.
Plenty of bones with gristle should be gotten with the soup meat;
these do not add to the cost, and add materially to the value of the
stock; for, while the gelatinoids are not flesh formers, they are
admirable protein sparers. The same thing holds true of gelatin and
its preparations.
_Indigestible Combination of Foods._—The acid of vinegar being a
fermentation acid renders the digestion of many foods with which
it is taken more difficult, while vegetable acids, such as citric
and tartaric, do not cause that objectionable effect. Vinegar also
retards salivary and gastric digestion.
_Strong tea_ taken with any meat meal converts the albumin of the
meat into a dense precipitate that is absolutely indigestible. The
tannin of tea inhibits the salivary and gastric secretions and so
retards digestion. Indigestion, atony, or catarrh of the stomach
is frequently due to excessive tea drinking, and the artificial
stimulation of the nervous system may be carried so far as to produce
insomnia, palpitation, muscular tremors, and other signs of nervous
irritability.
Claret and coffee both delay digestion.
Water is the best beverage to be taken with meals; but the
moderate use of tea and coffee is commendable because they have an
invigorating effect arising from the caffein and the essential oils,
but their use should not be abused.
_The Proper Way of Making Tea._—The water should be freshly boiled;
the tea-pot heated so that the water will be maintained at the
boiling-point; one teaspoonful of tea is allowed to the cup. The
tea is measured out, put into the tea-pot, and the requisite amount
of boiling water poured over it. It is then allowed to stand on the
kitchen table, _not_ the range, for from two to three minutes; it
should then be strained into the tea-pot for the table.
Unless the tea is strained off the leaves the infusion continues
for some time; this extracts the tannic acid and bitter principles.
In addition, the prolonged infusion dissipates the volatile oil, to
which much of the fragrance of a good cup of tea is due.
As it is almost impossible to have the requisite amount of care
exercised in the making of tea in the kitchen, it is much better that
it should be made on the table. Sugar detracts from the healthfulness
of the beverage.
_Coffee._—Most that has been said about tea is true of coffee. It is
aromatic and refreshing, stimulates the mental activity, invigorates
the muscular system, and removes the sense of fatigue. The excessive
use of coffee often leads to insomnia. Its use retards gastric
digestion, but less so than tea; but strong coffee or café noir has
a still greater inhibitory effect. It has a slightly aperient effect
on the intestines by increasing the peristaltic action. It is also
slightly diuretic.
The aromatic oils are dissipated by boiling, and the best temperature
of the water is 210° F., or just below the boiling-point.
_Defective Methods in the Preparation of Breads which Reduces
the Vitamin Contents, Especially of Corn Bread._—By resorting to
artificial methods for procuring the lightness of breads, baking
soda (sodium bicarbonate) is used. In order to prepare bread in this
way the cornmeal is mixed with milk or water to which baking soda
has been added, and put in the oven to bake. The high temperature of
the oven liberates the carbon dioxid (CO_{2}) from the baking soda,
causing the bread to rise, and the sodium bicarbonate is transformed
into sodium carbonate, a strong alkali. Recent experiments have
clearly demonstrated the destructive action of the alkalies on the
vitamins, this being especially true at high temperatures.
It should be strongly emphasized that the old-fashioned way of
combining baking soda with sour milk in the preparation of bread is
an entirely harmless procedure, provided that sufficient sour milk
is added to perfectly neutralize the alkalinity of the soda. The
label on some brands of baking soda clearly states that sour milk, or
tartaric acid, should be added in order to obtain the best results.
=Dietary in the Tropics.=—Sir R. Havelock Charles says, “It is
impossible to form exact rules for dietary in the tropics because
there are differences in climate which require modifications.” He
says nothing about limiting the amount of meat, but he does say, “no
_cold_ meat whatever should come on the table.” It is important that
everything should come straight from the fire to the table. It cannot
then cause bacillary mischief, and there should be no fear of cholera
or dysentery.
Boiled water only should be drunk. No salads of any kind should be
used except in the greatest moderation.
_Fruit._—Every fruit which possesses a rind that can be removed
may be eaten raw with impunity by a healthy man at any time of the
year. Fruits which do not possess a rind are incapable of being
thoroughly cleansed; such fruit may be contaminated and dangerous
to the consumer, and, at any rate, ought only to be eaten after it
is cooked. Therefore oranges, grape-fruit, pears, apples, bananas,
mangoes, pineapples, custard-apples, mangosteen, tomatoes, etc.,
may be eaten raw after peeling them. But it would be unsafe to eat
grapes, currants, strawberries, and other fruits which cannot be
peeled until they are cooked.
As regards proteins, some fish, fowl, or meat may be taken for
breakfast; animal food ought not to be taken in the middle of the
day. It is better to take dinner in the evening. Beef, mutton, pork,
kid (goat-flesh), venison (deer and antelope), poultry, many kinds
of birds, eggs, and fish are obtainable in one place or another.
Tinned meats and fish should be avoided; indeed, the importance of
fresh meat is so great that hunting, shooting, and fishing should be
strongly recommended as exercise.
Fat is obtained in the form of meat, dripping, butter, ghee, nuts,
and various oils used in cooking. The pure oil from peanuts,
palm-nuts, and cocoanuts is salutary; but many samples are
adulterated with sesamé oil, poppy-seed oil, and colza oil, which are
deleterious by causing dyspepsia or other gastro-intestinal troubles.
These in turn render the subject susceptible to dysentery, sprue, and
other tropical disorders.
=Food Economics: Regulation of Diet with Reference to Minimum
Expenditure.=—The cost of a meal for an individual or a family is
made up of two factors—the money cost of the raw materials, and the
time, cost of labor, and other expenses required for the preparation
and serving of the food.
_The Cost of Raw Food Materials._—Meats of all kinds, poultry, and
fish are the most expensive articles of diet. Then, too, the waste
has to be considered—the bones and legs of a dressed fowl and the
bones and skin of fish.
At the present time the dairy products supply the cheapest nutriment
among animal foods, but the price of butter and eggs are apt to soar
enormously during the winter months.
_Leguminous Food._—The dried pea, bean, or lentil are especially rich
in protein, and are thus fit to take the place of a part of meat
in the dietary. Their price is low in comparison to their value,
and must be considered next to bread in importance. They are less
completely digested than cereals if eaten in any quantity; and,
highly nutritious as these are, it cannot be denied that in large
quantities they are very indigestible for any but persons with strong
constitutions and leading an active outdoor life.
Great care is needed in their preparation. Dried legumes should be
soaked in cold water for eight hours, and then boiled for one hour
and a half. They are then sufficiently soft to be pressed through
a sieve. The skin of peas and beans that have been dried should be
removed, for they pass through the intestines unchanged. Soft water
should be used in preference to hard, as insoluble lime compounds are
formed by the latter with the protein “legumin.”
_Outside Preparation Expensive._—From the standpoint of food value,
white bread is more than twice as costly as the wheat flour from
which it is made. A barrel of flour of 196 pounds will make on the
average 315 5-cent loaves of bread. The bread costs the consumer
$15.75, whereas the flour can be bought at the time of writing for
$6.50.
Breakfast foods ready for the table, instead of the cheaper cornmeal,
oatmeal, and hominy cooked at home, and bread, cake, and other pastry
cost double the amount of the raw materials.
There are, however, other factors which complicate and increase the
cost of living. At present the exorbitant cost of labor, cost of
fuel, etc., and the amount of the housewife’s time consumed are all
important factors to be taken into consideration.
The size of the family, the number of small children demanding the
mother’s attention, the kind of labor in which they are engaged,
whether hired help has to be depended on for all the work, etc., are
all factors which must be taken into consideration as to whether
the outside preparation is more expensive than when the labor is
performed in the home. This is a matter for every housewife to work
out in making her monthly and yearly budgets.
TABLE OF FOOD VALUES[4]
——————————————————————————————+————————————————————————————
| Percentage composition.
|
Kind of food, edible +————————+———————————+———————
portion only. | Water. | Protein. | Fat.
| | |
——————————————————————————————+————————+———————————+———————
_Meats._ | | |
Beef: | | |
Roast, average | 48.25 | 22.25 | 28.55
Roast ribs, fat | 45.20 | 19.14 | 39.04
Boiled, average | 39.10 | 26.30 | 35.00
Broiled steak | 44.25 | 23.45 | 26.50
Corned | 51.19 | 26.32 | 18.65
Veal: Cooked, average | 51.88 | 32.20 | 11.40
Mutton: | | |
Roast, average | 51.00 | 26.00 | 22.60
Boiled leg | 57.67 | 27.60 | 14.38
Lamb: | | |
Roast leg | 67.10 | 19.70 | 12.70
Various parts | 47.25 | 23.80 | 28.50
Pork: Roast, various parts | 45.00 | 32.00 | 20.00
Organs: | | |
Heart, cooked, average | 62.60 | 16.60 | 20.00
Kidney, ox, cooked, average | 76.15 | 16.50 | 4.90
Liver, ox, cooked, average | 71.00 | 20.60 | 4.60
Sweetbread, ox, cooked, | | |
average | 71.00 | 16.80 | 12.00
Tongue, ox, cooked, average | 71.00 | 19.00 | 9.00
| | |
_Soup, etc._ | | |
Beef-tea | 93.00 | 4.30 | .50
Bouillon | 96.50 | 2.30 | .10
Chicken broth | 94.00 | 3.80 | .10
Consomme | 95.50 | 2.40 | .10
Meat hash | 80.00 | 6.50 | 2.00
Meat stew | 84.50 | 4.60 | 4.30
Oxtail soup | 89.00 | 4.00 | 1.50
Pea soup | 87.00 | 4.00 | .80
Soup stock, beef | 89.10 | 5.80 | 1.50
Tomato soup | 89.00 | 2.00 | 1.50
Meat juice (natural), average | 90.00 | 5.37 | .19
| | |
_Fowl._ | | |
Domestic, average | 64.00 | 19.00 | 16.00
Chicken | 67.00 | 22.70 | 10.00
Capon | 56.00 | 21.80 | 21.00
Duck | 55.75 | 17.50 | 25.00
Goose | 52.00 | 16.50 | 35.10
Turkey | 55.50 | 21.10 | 23.00
Roast | 52.00 | 27.80 | 18.50
Roast capon | 59.00 | 27.00 | 11.50
Chicken | 66.90 | 22.00 | 8.10
Boiled fowl | 57.60 | 27.00 | 12.80
| | |
_Eggs._ | | |
Chicken eggs: | | |
Raw | 73.70 | 13.40 | 11.50
Boiled, white. | 86.30 | 12.80 | .20
Yolk | 50.00 | 14.80 | 33.70
| | |
_Fish and Shell-fish._ | | |
Bluefish | 78.50 | 19.10 | 1.20
Haddock, fresh | 81.40 | 17.20 | .30
| | |
Halibut steak | 74.80 | 18.50 | 5.30
Mackerel | 74.80 | 18.50 | 6.50
Oysters | 80.00 | 10.60 | 2.60
Perch | 75.70 | 19.00 | 4.00
Salmon, Atlantic | 63.60 | 21.60 | 13.90
Sardines | 56.30 | 24.80 | 12.70
Shad | 70.60 | 18.50 | 9.50
Roe | 71.20 | 21.00 | 3.80
Trout: | | |
Brook | 77.70 | 19.30 | 2.10
Lake | 69.30 | 18.30 | 10.60
Salmon | 70.80 | 17.80 | 10.20
Calf’s foot jelly | 77.50 | 4.50 | ....
| | |
_Milk Products._ | | |
Cows’ milk, average | 87.30 | 3.50 | 3.70
Skimmed | 90.30 | 4.00 | .20
Condensed milk, full cream, | | |
unsweetened | 62.40 | 10.60 | 10.80
Full cream, sweetened | 20.00 | 10.50 | 9.90
Skimmed and sweetened | 26.40 | 10.40 | .90
Cream, hand skimmed | 74.00 | 2.50 | 18.50
Buttermilk | 90.00 | 3.20 | 1.20
Cheese from skimmed milk. | 45.30 | 32.00 | 16.50
Butter: | | |
Best quality | 13.00 | 1.00 | 82.50
Second quality | 16.00 | 2.00 | 73.00
Margarine | 16.00 | 1.10 | 76.70
| | |
_Cereal Foods._ | | |
Wheat flour, superfine, white.| 10.50 | 11.90 | 1.60
Entire wheat | 10.80 | 12.20 | 2.20
Graham | 8.60 | 12.60 | 2.40
Maize | 10.90 | 10.20 | 4.80
Meal | 12.50 | 7.10 | 1.30
Rice | 12.40 | 6.90 | .40
Boiled | 72.50 | 2.80 | .10
Oatmeal, boiled | 84.50 | 2.80 | .50
Macaroni, cooked | 78.40 | 3.00 | 1.50
| | |
_Bread._ | | |
White, best | 44.10 | 7.70 | .90
Entire wheat | 49.10 | 7.40 | 1.10
Brown (Graham) | 47.20 | 7.70 | 1.20
Gluten bread | 38.20 | 9.30 | 1.40
Toasted bread | 24.00 | 11.50 | 1.60
Zwiebach | 5.80 | 9.80 | 9.90
| | |
_Pies and Puddings._ | | |
Apple pie | 42.50 | 3.10 | 9.80
Cornflour blanc mange | 66.00 | 2.60 | 3.10
Custard with crust | 62.40 | 4.20 | 6.30
Maize pudding (Indian meal) | 60.00 | 5.50 | 5.00
Rice pudding | 60.00 | 4.00 | 4.70
Tapioca pudding | 64.50 | 3.30 | 3.20
With apples | 70.10 | .30 | .10
| | |
_Roots and Tubers._ | | |
Carrots, boiled | 92.50 | .50 | .20
| | |
Beets, boiled | 91.70 | 1.40 | .10
Parsnips, boiled | 92.10 | 1.30 | .30
Potatoes, boiled | 75.50 | 2.50 | .10
Mashed, with cream | 75.10 | 2.60 | 3.00
Fried in fat | 2.20 | 6.80 | 39.80
| | |
_Vegetables._ | | |
Asparagus, cooked and buttered| 91.60 | 2.10 | 3.30
Brussels sprouts, boiled | 93.70 | 1.50 | .10
Cabbage | 85.50 | 2.30 | .70
Boiled | 97.00 | .60 | .10
Cauliflower, boiled | 97.30 | .60 | .10
Celery, boiled | 97.00 | .40 | .07
Green peas, boiled | 73.80 | 6.70 | 2.50
Beans, string, boiled | 89.20 | 2.30 | .30
| | |
_Salads._ | | |
Celery | 94.50 | 1.10 | .10
Cucumber | 94.90 | .70 | .20
Endive | 93.00 | 1.00 | .10
Lettuce | 93.80 | 1.80 | .60
Onions | 87.60 | 1.60 | .30
Radishes | 91.80 | 1.20 | .10
Tomatoes | 91.80 | 1.20 | .10
Watercress | 92.80 | .70 | .40
| | |
_Dried Legumes._ | | |
Peas | 9.50 | 23.80 | 1.80
Haricot beans | 12.60 | 22.50 | 1.90
Butter beans | 10.50 | 20.60 | 2.00
| | |
_Nuts._ | | |
Almonds, dried | 4.80 | 21.00 | 54.90
Brasil nuts | 5.40 | 18.00 | 66.00
Butter nuts | 4.50 | 28.00 | 61.00
Chestnuts | 4.80 | 11.60 | 15.30
Cocoanut, fresh | 19.20 | 5.40 | 51.00
Hazel and filbert nuts | 48.00 | 8.00 | 28.50
Peanuts | 9.20 | 26.00 | 38.60
Walnuts, dried | 4.90 | 15.50 | 62.70
| | |
_Fruits._ | | |
Apples: | | |
Raw | 85.20 | .40 | .50
Cooked and sweetened | 66.10 | .20 | .80
Dried | 28.10 | 1.60 | 2.20
Apricots | 85.00 | 1.10 | ....
Canned | 81.40 | .90 | ....
Bananas | 75.70 | 1.30 | .50
Blackberries | 86.30 | 1.30 | 1.00
Cherries | 82.00 | .90 | .80
Cranberries | 88.90 | .50 | .60
Dates, dried | 20.00 | 3.50 | 2.30
Figs, dried | 22.70 | 4.30 | .70
Grapes, fresh | 80.50 | .90 | .80
Dried, raisins | 18.60 | 3.00 | 2.80
Jam, or preserve, average | 30.50 | 1.50 | ....
| | |
Melon | 89.50 | .60 | .30
Oranges | 82.80 | .90 | .20
Peaches | 88.80 | .50 | .20
Canned | 88.10 | .70 | .10
Pears | 80.90 | .90 | .50
Canned | 81.10 | .30 | .30
Pineapples | 89.30 | .40 | .30
Plums | 74.50 | .90 | .20
Prunes: | | |
Dried | 22.30 | 2.10 | .20
Stewed | 76.60 | .50 | .10
Raspberries | 86.20 | .50 | ....
Strawberries | 94.00 | 1.00 | .60
——————————————————————————————+————————+———————————+———————
——————————————————————————————+—————————————————+——————————+——————————
| Percentage | Heat | Food
| composition. | value | values
Kind of food, edible +——————————+——————+ calories |comparison
portion only. | Carbo- | Ash. | per | of 1000
| hydrate. | | ounce. | grams.
——————————————————————————————+——————————+——————+——————————+——————————
_Meats._ | | | |
Beef: | | | |
Roast, average | ... | 1.25 | 160 | 1868
Roast ribs, fat | ... | .82 | 122 | 2057
Boiled, average | ... | 1.00 | 175 | 2268
Broiled steak | ... | 1.43 | 100 | 1942
Corned | ... | 4.10 | 80 | 1810
Veal: Cooked, average | ... | 1.50 | 68 | 1896
Mutton: | | | |
Roast, average | ... | 1.19 | 90 | 1805
Boiled leg | ... | 1.05 | 67 | 1738
Lamb: | | | |
Roast leg | ... | .80 | 66 | 1318
Various parts | ... | 1.25 | 100 | 1966
Pork: Roast, various parts | ... | 1.76 | 90 | 2122
Organs: | | | |
Heart, cooked, average | ... | 1.00 | 70 | 1370
Kidney, ox, cooked, average | .40 | 1.20 | 32 | 940
Liver, ox, cooked, average | 1.80 | 1.50 | 38 | 1150
Sweetbread, ox, cooked, | | | |
average | ... | 1.60 | 51 | 1157
Tongue, ox, cooked, average | ... | 1.00 | 46 | 1188
| | | |
_Soup, etc._ | | | |
Beef-tea | 1.10 | 1.10 | 8 | 234
Bouillon | .20 | .90 | 3 | 116
Chicken broth | 1.80 | 1.00 | 6 | 200
Consomme | .30 | 1.10 | 3 | 120
Meat hash | 9.00 | 2.40 | 24 | 560
Meat stew | 5.50 | 1.10 | 23 | 420
Oxtail soup | 4.30 | 1.50 | 13 | 278
Pea soup | 8.50 | 1.30 | 15 | 291
Soup stock, beef | ... | 3.60 | 11 | 324
Tomato soup | 5.50 | 1.30 | 12 | 158
Meat juice (natural), average | ... | 1.36 | 7 | 269
| | | |
_Fowl._ | | | |
Domestic, average | ... | 1.00 | 65 | 1130
Chicken | ... | 1.00 | 62 | 1395
Capon | ... | 1.30 | 91 | 1656
Duck | ... | 1.00 | 95 | 1554
Goose | ... | 1.20 | 110 | 1800
Turkey | ... | 1.00 | 85 | 1679
Roast | ... | 1.30 | 82 | 1872
Roast capon | ... | 1.30 | 60 | 1677
Chicken | ... | 1.70 | 58 | 1298
Boiled fowl | ... | 1.90 | 80 | 1708
| | | |
_Eggs._ | | | |
Chicken eggs: | | | |
Raw | ... | 1.00 | 45 | 983
Boiled, white. | ... | .70 | 16 | 633
Yolk | ... | 1.20 | 106 | 1883
| | | |
_Fish and Shell-fish._ | | | |
Bluefish | ... | 1.20 | 27 | 935
Haddock, fresh | ... | 1.10 | 21 | 922
| | | |
Halibut steak | .... | 1.40 | 35 | 850
Mackerel | .... | 1.10 | 40 | 1086
Oysters | 6.50 | 1.30 | 25 | 655
Perch | .... | 1.20 | 33 | 1049
Salmon, Atlantic | .... | 1.40 | 64 | 1445
Sardines | .... | 5.00 | 79 | 1560
Shad | .... | 1.30 | 47 | 1170
Roe | 2.50 | 1.50 | 38 | 1252
Trout: | | | |
Brook | .... | 1.20 | 28 | 995
Lake | .... | 1.20 | 48 | 1190
Salmon | .... | 1.20 | 48 | 1156
Calf’s foot jelly | 17.40 | .70 | 26 | 210
| | | |
_Milk Products._ | | | |
Cows’ milk, average | 4.60 | .73 | 20 | 320
Skimmed | 4.60 | .83 | 11 | 245
Condensed milk, full cream, | | | |
unsweetened | 14.10 | 2.00 | 52 | 973
Full cream, sweetened | 57.50 | 2.10 | 100 | 1368
Skimmed and sweetened | 60.20 | 2.10 | 40 | 1232
Cream, hand skimmed | 4.50 | .50 | 56 | 210
Buttermilk | 5.00 | .60 | 10 | 238
Cheese from skimmed milk. | 2.00 | 4.20 | 85 | 2140
Butter: | | | |
Best quality | 1.50 | 2.00 | 225 | 2371
Second quality | 4.00 | 5.00 | 203 | 2235
Margarine | .... | 6.30 | 220 | 2210
| | | |
_Cereal Foods._ | | | |
Wheat flour, superfine, white.| 75.40 | .50 | 114 | 1283
Entire wheat | 73.60 | 1.00 | 114 | 1300
Graham | 74.50 | 1.70 | 116 | 1330
Maize | 71.00 | 1.30 | .... | 1242
Meal | 78.30 | .60 | 108 | 1106
Rice | 79.40 | .50 | 102 | 1084
Boiled | 24.50 | .20 | 45 | 258
Oatmeal, boiled | 11.50 | .70 | 18 | 244
Macaroni, cooked | 15.80 | 1.30 | 26 | 558
| | | |
_Bread._ | | | |
White, best | 46.90 | .30 | 71 | 793
Entire wheat | 41.70 | .50 | 65 | 770
Brown (Graham) | 42.80 | .90 | 67 | 780
Gluten bread | 49.80 | 1.30 | 72 | 910
Toasted bread | 61.20 | 1.70 | 90 | 1126
Zwiebach | 73.50 | 1.00 | 125 | 1399
| | | |
_Pies and Puddings._ | | | |
Apple pie | 43.00 | 1.80 | 80 | 866
Cornflour blanc mange | 27.00 | 1.00 | 36 | 456
Custard with crust | 26.10 | 1.00 | 52 | 604
Maize pudding (Indian meal) | 28.00 | 1.40 | 51 | 628
Rice pudding | 32.00 | .60 | 52 | 608
Tapioca pudding | 28.50 | .80 | 45 | 505
With apples | 30.00 | .20 | 36 | 289
| | | |
_Roots and Tubers._| | | |
Carrots, boiled | 4.50 | .80 | 8 | 70
| | | |
Beets, boiled | 5.13 | 1.00 | 11 | 102
Parsnips, boiled | 6.50 | .70 | 11 | 126
Potatoes, boiled | 21.00 | 1.00 | 26 | 312
Mashed, with cream | 17.80 | 1.50 | 31 | 364
Fried in fat | 46.70 | 4.50 | 166 | 1807
| | | |
_Vegetables._ | | | |
Asparagus, cooked and buttered| 2.20 | .80 | 30 | 200
Brussels sprouts, boiled | 3.40 | .20 | 6 | 98
Cabbage | 5.10 | 1.70 | 9 | 89
Boiled | 1.40 | .20 | 3 | 41
Cauliflower, boiled | 1.40 | .50 | .... | 41
Celery, boiled | 1.00 | .50 | | 26
Green peas, boiled | 14.60 | 1.50 | 34 | 588
Beans, string, boiled | 7.40 | .80 | 12 | 176
| | | |
_Salads._ | | | |
Celery | 9.70 | 1.00 | 13 | 144
Cucumber | 3.10 | .50 | 4 | 64
Endive | 3.00 | .60 | 8 | 73
Lettuce | 4.80 | 1.20 | 9 | 138
Onions | 9.50 | 1.10 | 13 | 167
Radishes | 5.60 | .70 | 5 | 107
Tomatoes | 5.60 | .70 | 5 | 107
Watercress | 4.00 | 1.20 | 6 | 79
| | | |
_Dried Legumes._ | | | |
Peas | 60.30 | 2.60 | 104 | 1544
Haricot beans | 59.60 | 3.50 | 100 | 1654
Butter beans | 62.60 | 4.20 | 102 | 1519
| | | |
_Nuts._ | | | |
Almonds, dried | 17.30 | 2.50 | 189 | 2645
Brasil nuts | 8.00 | 2.70 | 204 | 2606
Butter nuts | 3.50 | 2.90 | 192 | 2956
Chestnuts | 65.70 | 2.60 | 117 | 1537
Cocoanut, fresh | 10.00 | 1.20 | 108 | ....
Hazel and filbert nuts | 11.50 | 1.50 | 160 | ....
Peanuts | 24.20 | 2.00 | 160 | 2071
Walnuts, dried | 7.50 | 1.90 | 190 | 2364
| | | |
_Fruits._ | | | |
Apples: | | | |
Raw | 12.60 | .30 | 18 | 149
Cooked and sweetened | 37.20 | .70 | 46 | 395
Dried | 66.10 | 2.00 | 84 | 753
Apricots | 13.40 | .50 | 18 | 176
Canned | 17.30 | .40 | 21 | 208
Bananas | 21.70 | .70 | 29 | 276
Blackberries | 8.40 | .50 | 17 | 120
Cherries | 14.30 | .60 | 23 | 197
Cranberries | 4.00 | .20 | 14 | 76
Dates, dried | 69.00 | 1.30 | 101 | 885
Figs, dried | 62.50 | 1.30 | 80 | 805
Grapes, fresh | 14.70 | .50 | 28 | 201
Dried, raisins | 70.50 | 2.70 | 100 | 870
Jam, or preserve, average | 60.00 | .50 | 70 | 744
| | | |
Melon | 7.20 | .60 | 11 | 103
Oranges | 10.60 | .70 | 15 | 146
Peaches | 9.20 | .60 | 12 | 117
Canned | 10.80 | .30 | 14 | 128
Pears | 15.70 | .40 | 18 | 203
Canned | 18.00 | .30 | 22 | 195
Pineapples | 10.00 | .90 | 13 | 112
Plums | 19.10 | .50 | 24 | 200
Prunes: | | | |
Dried | 73.30 | 2.30 | 86 | 724
Stewed | 22.30 | .50 | 27 | 243
Raspberries | 5.60 | .50 | 16 | 76
Strawberries | 8.80 | .60 | 12 | 144
——————————————————————————————+——————————+——————+——————————+——————————
=The Physiologic Action of Moderate Doses of Alcohol.=—The result of
a series of experiments by Dr. Parke were as follows: “By quickening
the action of the heart, it shortens the interval of rest, and,
therefore, interferes with the nutrition of the heart. It also
produces palpitation and breathlessness. Even small doses of alcohol,
by increasing unnecessarily the action of the heart, are injurious.
It acts on the nervous system by lessening the rapidity and the
delicacy of the impressions, as well as by lessening the power of
control of a train of thought. Further, by this same blunting of the
nervous system, voluntary muscular power is impaired, and the finer
combined movements are less perfectly made. It causes a lowering of
the temperature of the body, and, although it is taken to overcome
the effects of exposure to cold, it has been learned that persons who
take it are less able to resist the exposure to cold.”
As the result of modern scientific investigation and experimentation,
alcohol with its compounds has been taken out of the list of
beverages, where it has heretofore been classified with tea and
coffee, and out of the list of foods, to which class it had been
admitted because of the known oxidation of alcohol in the body, and
has been placed in that list of drugs known as narcotics, alongside
of ether, chloroform, opium, and cocain—all of them, the most deadly
drugs in the Pharmacopeia, yet, when used by skilled hands, the most
beneficent.
The first effect of this class of drugs is a short temporary stage of
exhilaration, more or less rapidly followed, according to the amount
taken, by a stage of sleepiness or actual insensibility, which lasts
longer than the stage of excitement, and this in turn is followed by
a long period of depression.
Like other members of its class, alcohol has a cumulative action, the
residual quantities habitually taken accumulate and gradually affect
the efficiency and well-being of the individual.
A point that must always be borne in mind in giving any medicine is
that not a few drugs have a curious tendency to induce a craving for
their repetition.
The amount of alcohol contained in some of the most commonly used of
the alcoholic beverages is as follows: beer, 4 to 5 per cent.; hard
cider, from 5 to 10 per cent.; claret, 8 to 11 per cent.; port, 9 to
22 per cent.; champagne, 10 to 15 per cent.; rum, gin, and strong
liquors, 40 to 50 per cent.; whisky, 44 to 50 per cent.; brandy, 48
to 56 per cent.
These alcoholic beverages are often made still more harmful by
adulterations by ingredients in themselves harmful.
A large percentage of alcohol is also found in bitters and patent
medicines.
We will consider the subject of alcohol under the following aspects:
First, the question of alcohol as a food; second, the effects of
alcohol on the digestive system and the metabolism; third, the
effects of alcohol on the heart and the muscular system; and fourth,
the effects of alcohol on the nervous system.
_First, Is Alcohol a Food?_—The substances used as foods act in
providing energy for muscular work, in maintaining the heat of the
body, in building up of the tissues, and in saving the waste of
the tissues. Moreover, a food which does harm to any organ, or to
the system as a whole, when taken in moderate repeated quantities,
becomes a poison for that individual.
A food may be defined as any substance which, when absorbed into
the blood, will nourish, repair waste, and furnish force and heat
to the body, without causing injury to any of its parts or loss of
functional activity. From any one of these four standpoints alcohol
cannot be regarded as a food.
The physiologic effects of alcohol and real food-stuffs are totally
different. Fats, carbohydrates, and nitrogenous foods after
mastication at once begin to be digested and assimilated, and
to fulfil the true functions of a food by maintaining a natural
temperature, pulse-rate, and tissue repair of the body, without any
disturbance of its mental and physical functions and activities.
Alcohol, on the contrary, is absorbed from the stomach unaltered by
the digestive processes; circulated in the blood in its original
form, it at once interferes with the ordinary activity of the
brain and other organs, and, by its anesthetic action, hampers the
mental and physical activities and interferes with the processes of
metabolism.
_The Effects of Alcohol on the Digestive System and Metabolism._—The
local action of alcoholic liquids is particularly destructive on an
empty stomach; and when taken in strong solution, but it is also
known that smaller doses, taken continuously, are liable to effect
the digestive organs in a slower though similar way.
The injurious effects of alcohol are that it acts as a local
irritant, producing dilatation of the blood-vessels of the stomach
and subsequent gastritis; it leads to hyperacidity, by stimulating
the secretion of hydrochloric acid; the tartrates and malates
contained in wine are decomposed in the stomach, setting free organic
acids, and thus producing acidity; the acetic acid and yeast in beer
set up an acetic acid fermentation in the stomach-contents.
Whether taken alone or with food, the tendency of alcohol throughout
is to lessen the churning movements of the stomach, and leads to
atony of that organ, which in turn leads to dilatation of the stomach.
Alcohol appears to have a particularly deleterious effect on the
digestion of women. This is explained by the fact that men lead a
more active outdoor life, and consequently retain their appetite
for food longer than women. For the same reason, they are able to
work off the effects of drinking more easily and start afresh the
assimilation of food. The indoor life led by women, their clothing,
worn tight around the stomach, are added causes for lack of appetite.
Catarrh of the stomach results; this is followed by insufficient food
and an increased amount of stimulants. There follow nausea, irregular
and insufficient nutrition, indigestion, and a faulty elaboration of
the food.
By its action on the liver alcohol interferes with the amount
and quantity of bile, and so inevitably leads to indigestion and
constipation, and a similar interference with the action of the
liver-cells and their chemical changes set up in many cases gouty
conditions, accompanied by mental depression and irritability.
Diseases of the liver occur more frequently as the result of taking
frequent small doses of alcohol, though never reaching the stage of
intoxication, than as the result of indulging more freely, but at
longer intervals.
_The Effect of Alcohol on the Blood._—The blood is a mixture of
corpuscles and a fluid known as the blood plasma. The corpuscles are
of two kinds—red and white. The red blood-corpuscles are the oxygen
carriers; they carry the oxygen to the tissues, where they readily
give it up. They are constantly being destroyed by the liver and
spleen, and are replaced by new ones, which come from the red marrow
of bones. The white corpuscles are much fewer in number, but they
play a most important part in protecting the body against disease. It
is now about twenty years since Professor Metchnikoff, of the Pasteur
Institute of Paris, announced to the world his discovery that the
white corpuscles have the power of destroying the microbes to which
so many diseases are due. These white blood-cells form the standing
army or policemen of the body, and their duty is to attack, and, if
possible, to destroy, any foreign matter, such as dust or disease
germs.
The plasma of the blood contains various kinds of salts, and include
sodium chlorid or common salt, the phosphates, and chlorids of
calcium and potassium.
The way which the body fights disease is partly by means of the
white blood-corpuscles, which totally destroy the germs, and partly
by the increase in the blood of those chemical substances which are
antidotes for the poisons given out by the germs.
Alcohol taken into the stomach is quickly absorbed and reaches the
blood in two minutes. The maximum of alcohol is found in the blood in
fifteen minutes after it is swallowed.
The blood is the medium by which food and oxygen are conveyed to the
tissues, and by which the refuse material from the tissues is carried
away; alcohol interferes with both these processes.
The red cells are liable to become damaged and anemia results. It has
now been proved that even tiny doses of alcohol paralyze more or less
the white cells, and thus interfere with their power of destroying
microbes. Chemical substances tend to exert a delaying or inhibitory
influence over the chemical processes of the body. These chemical
processes are oxidation, the storing up of nutriment, the manufacture
of secretion, the production of energy and muscular movement, and the
excretion of waste materials.
The greatest possible difference exists as to the rate at which
oxidation goes on. When there is nothing to hinder its occurrence,
the poisonous toxins and waste matters are rapidly burned up and
eliminated and health prevails. Alcohol, by its affinity for
oxygen, robs the tissues of oxygen which they would otherwise use
for combustion. Hence the tissues are kept starving for oxygen,
metabolism is interfered with, and they cannot get rid of their waste
material.
This delayed oxidation tends to increase the body weight. The cells
in an intermediate stage of fatty degeneration clog the body, and, of
course, add to its weight. The natural effect of taking alcohol is
to make the body obese. On abstaining from alcohol, the superfluous
tissue is often burned away, and the weight of the body reduced, and
a look and feeling of youth is recovered.
_The Effect of Alcohol on the Heart and Circulation._—By the
circulation we understand the driving of the fluid blood around the
body, through the blood-vessels, such driving being maintained by the
pumping power of the heart, which is practically a hollow muscle.
In consequence of this pumping power of the heart, the blood in the
vessels is under considerable pressure, which is naturally increased
if the blood-vessels are narrowed or contracted, and diminished if
the blood-vessels are expanded or dilated.
Gradual deterioration in the heart power is a cause of premature
death. One of the early indications that the foregoing changes may
be occurring in a heart is a sense of fatigue and breathlessness on
slight exertion, or a feeling of disinclination for normal effort.
The result of such depression of the efficiency of the heart is often
seen when the individual is attacked by some disease; she succumbs
to heart failure, instead of being able to resist the disease. This
probably accounts for a great many deaths between forty and sixty
years of age.
Further, it must be remembered that all the nutritive action of the
blood depends on its power of rapidly filtering through the walls
of the blood-vessels to the tissues, and, conversely, its power of
drawing off the waste-products of the tissues depends on the facility
with which such products can penetrate its walls.
As soon as degeneracy sets in, the walls of all vessels tend to
become thickened, and the active transference through them, more and
more prevented; the nutrition of the body is thus gravely hampered,
and, with the advance of this thickening of the walls, the vessels
are less able to adjust themselves to the variations in pressure from
within; and, finally, when unable to withstand the pressure, they
rupture, causing hemorrhage and apoplexy, which, when occurring in
the brain, cause paralysis and mental decay.
A similar degeneration takes place in old age, but the point is,
that many persons, instead of waiting until old age comes to them,
deliberately precipitate these senile changes.
_The Effect of Alcohol on the Kidneys._—The elaborate mechanism of
the kidneys consist of a filtering system of thousands of tubules,
arranged closely side by side, whose function it is to carry away
from the body the waste material, which otherwise would interfere
with the vitality of the different organs.
The part played by the kidneys in rapidly eliminating effete material
cannot be too carefully safeguarded. Anything which interferes with
its work will sooner or later cause a retention of waste-products
in the system, and will also permit of the escape of valuable
albuminous materials of the substance of the blood through the
filtering apparatus. The effect of alcohol upon the kidneys can only
be described as disastrous. In proportion as the kidney shrinks,
there is a diminution of the excretion of urine, and, finally, the
condition known as Bright’s disease is established.
_The Effect of Alcohol on the Muscular System._—The muscular tissue
forms 43 per cent. of the body weight. It has been proved that under
the moderate use of alcohol the muscles become flabby and less
vigorous and effective; that troops cannot work or march on alcohol;
that in training for athletics, for races, or for other sports, total
abstinence is always practised; the true sportsman depends quite as
much on his brain as on his muscles for success. In England it is
recognized that total abstinence is a necessity where great exertions
are concerned, and it is now beyond all question that alcohol, in
even so-called dietetic quantities, diminishes the output of muscular
work, both in quantity and quality, and that the best physical
results are obtained under total abstinence from its use.
Alcohol actually lowers the temperature of the body from
three-fourths of one degree to three degrees. This depression of
temperature is not transient, but lasts for several days, so that
its use, when the person is exposed to intense cold, is extremely
hazardous to life.
_The Effects of Alcohol on the Nervous System._—Kraepelin has
carried out a series of experiments to prove the effects of small
doses of alcohol on the output of work. In all mental work there are
two elements to be considered, namely, quality and speed. Now, all
observers are agreed that the quality of mental work is affected even
before speed, more mistakes being made. Tests were made in reading
aloud; in adding figures in various combinations; in type-setting;
and in memorizing; in all these instances it was found that, after
taking moderate doses of alcohol for a number of consecutive days,
the work done was less, was less accurate, and that there was a
decrease in the power of memorizing.
Another series of investigations, made by Rudin to determine how long
the intellectual abilities continue to be depressed after the effects
of alcohol pass off, showed that the effects of a single dose of
alcohol persisted until noon or evening of the next day.
Von Helmholtz, one of the greatest observers and thinkers of the
nineteenth century, noted on himself the effect of alcohol in
interfering with the highest powers of thought and conception.
Describing the conditions under which his highest scientific
thoughts had matured and come to fruition, he said: “As far as my
experience is concerned, they never come to a wearied brain or at the
writing-desk; they were especially inclined to appear to me while
indulging in a quiet walk in the sunshine or over the forest-clad
mountains, _but the smallest quantity of alcohol seemed to drive them
away_.”
Professor Sikovsky’s testimony is that “alcohol diminishes the
rapidity of thought, makes the imagination and the power of
reflection commonplace and deprived of originality, acts upon
fine and complex sensations by transforming them into coarse
and elementary ones, provokes outbursts of evil passions and
dispositions, and in this predisposes men to strife and crime, and
upsets habits of work and perseverance.”
Self-control is one of the highest functions of the brain, and the
racial power which results to a people as a consequence of the
individual practice of self-control cannot be too highly estimated.
Therefore, children are trained as far as possible to control their
emotions and actions. Alcohol diminishes and breaks down this
power of acquired self-control, undoing the work of parents and
educationalists. Quite small doses are often responsible for reckless
and self-pleasing actions, which are far reaching in their results
in loss of moral tone and self-respect. The ideals of duty are lost
sight of, and, at best, leave the individual in a laissez-faire
attitude. Among the depressant effects of alcohol are intellectual
lethargy and a sense of fatigue, which, combined with the other
factors, lessen the capacity for genuine enjoyment and pleasure.
FOOTNOTES:
[4] Compiled from Tibbles’ “Dietetics, or Food in Health and Disease.”