ANTISCORBUTIC FOODS
=Historical Review.=[39]--It is impossible to state when and how the
knowledge of the value of antiscorbutic foodstuffs came to be
appreciated. It is probable that the potency of herbs and fruits in
scurvy was known empirically to individuals and groups of people long
before the fact gained general recognition. A most interesting history
of antiscorbutics is given in the excellent work of Hirsch and in our
great classic on scurvy by Lind. The first realization of the value of
lemons and oranges seems to have been the result of a chance discovery.
Budd tells us that in the sixteenth century sailors of a Dutch sailing
vessel laden with these fruits were attacked with scurvy, and that, when
they partook of the lemons and oranges in the cargo, a miraculous cure
resulted. He narrates also the following striking incident, which is
mentioned likewise by Lind:
[39] It is of interest that John Hall, the son-in-law of Shakespeare,
and a prominent physician of Warwickshire, was one of the first to urge
the use of antiscorbutics. In a quaint work entitled, "Select
Observations on English Bodies, or Cures both Empericall and Historical"
(1657 London), he describes how he cured scurvy by means of brewing a
beer or ale from "Scorbutick hearbs, _viz._: scurvy grass, water-cresses
and brook lime." This book, which ran through at least two editions, has
not achieved the popularity of the works of the father-in-law.
In the year 1600 four sailing vessels left England for the East Indies.
The sailors on three of these ships did not receive lime juice, whereas
those on the fourth received their daily quota. The men of the first
three ships suffered severely from scurvy, but those on the fourth
escaped.
In an excellent work on "Scorvey," published in 1685, Harvey wrote:
"Wherefore most acids, especially spirit of salt marine, juice of
sorrel, limons, citrons, etc., are so deservedly extolled in some
scorbutic distempers and seconded with good success." Thus we see that
even at this early date it was taken for granted that citrous fruits
possessed virtue in curing scurvy. Bachstrom (Observationes circa
Scorbutum, 1734) evidently was well-acquainted with the antiscorbutic
value of scurvy grass, and relates the story of a sailor severely
disabled from scurvy who was put ashore to perish on Greenland, and
crawled on the ground, grazed on scurvy grass like a beast of the field,
and was able to return home perfectly recovered. (Cited from Lind.)
The credit for forcing a general acceptance of the antiscorbutic value
of fresh food belongs to Lind. He did not, however, have an easy task,
and in 1747, in order to convince those who still were skeptical, he
resorted to an experiment on human beings. Twelve patients in his
hospital were given the same diet, except that some received sea-water
in addition to their dietary, others vinegar, or elixir of sulphuric
acid, or a daily portion of cider, or oranges and one lemon daily. The
last two groups, as we should expect, recovered quickly; one man who
received cider improved, but in no other case was any alleviation noted.
Lind extols the value of lemons and oranges, of berries, of sour
cabbage, of cider, and of all fresh fruits and vegetables. In spite of
the fact, however, that Lind's teaching was based on an experience with
thousands of patients suffering from scurvy in the naval hospital, his
ideas did not take root. It required an event which came directly under
the official eye to bring about radical changes in the diet of the
sailors. In 1795 the English Fleet suffered from a severe epidemic of
scurvy, which was finally controlled by giving the sailors fresh
vegetables and fruit. This therapeutic result was so convincing that
thenceforth a daily ration of lime juice was ordered for the sailors and
a regular issue provided for the navy. This marks the cessation of
scurvy as a scourge of the British navy. From this time the disease
appeared only sporadically. The sharp decrease in the incidence can be
appreciated by Budd's statement that 1457 cases of scurvy were admitted
to the Royal Naval Hospital in 1780, whereas in 1810 an English
physician reported that in the seven preceding years he had not treated
a single patient in this hospital suffering from scurvy. In another
marine hospital, between the years 1806 and 1810, only two cases of
scurvy were admitted.
Nothing was done for the British merchant service until over half a
century later, although scurvy continued to make its appearance among
the sailors with varying severity. Smith states in the article on this
subject in Allbutt's System of Medicine: "In 1864 it was pointed out by
Doctor Barnes that during the twelve years following 1851, 1058 cases of
scurvy had been admitted into the hospital ship _Dreadnought_." In 1854
a law was passed requiring every vessel to carry an adequate supply of
lime juice. This law, however, failed in effect, due to the fact that a
large part of the lime juice was adulterated. A new shipping-act was
passed, therefore, in 1867, with the object of preventing adulterations,
at the same time increasing the daily quota for each seaman from half an
ounce to one ounce.
It may be of interest to add a few words concerning certain
antiscorbutics which have been under discussion or recognized for so
many years that they have acquired an historical aspect. One of these
foodstuffs is sauerkraut, which was recognized by Lind in 1772 as having
particular potency in this disease. It is interesting to note, in this
connection, that this writer appreciated the close relationship of
acidity to antiscorbutic virtue. "One quality," he writes, "entering the
most perfect antiscorbutic composition is a vegetable accescency." He
prized sauerkraut for its inherent value, and particularly, because he
found that "sour cabbage will keep for an East-India voyage."
The famous navigator Cook, whose voyages were remarkable for the freedom
from illness which his sailors enjoyed and the absence of scurvy, always
kept a large supply of sauerkraut on hand. It was believed by many that
the immunity of the Dutch seamen to scurvy was due to their large
consumption of this vegetable. As the result of this empirical
knowledge, the English navy in 1780 introduced the use of sauerkraut
into its ration. As just noted, however, this antiscorbutic was
supplanted some few years later by an issue of lime juice.
It is common knowledge that outbreaks of scurvy follow closely upon a
failure of the potato crop. This has been particularly the case in
Ireland, where it was especially evident in relation to the great
epidemic of scurvy in 1847. Holst and Froelich inform us that "all
scurvy epidemics in Norway in the nineteenth and beginning of this
century followed failure of the potato crop." Nor is this danger past.
In an article entitled "The Rôle of Antiscorbutics in Our Dietary," the
author recently reported that the partial failure of the potato crop in
the eastern part of the United States led to the development of scurvy
in numerous institutions, in one of which over 200 cases of definite
scurvy developed in the spring (1916).
The occurrence of scurvy in the navy and on sailing vessels has been
associated in the minds of many with the large amounts of salted meat
which necessarily was included in the dietary. It was evident that meat
that was salted had no antiscorbutic value, but the query has been
raised whether eating a considerable amount of salted meat did not
induce scurvy. Lind mentions "flesh long salted" as leading to the
development of scurvy. The question of the value of meat as an
antiscorbutic is of importance at the present time, chiefly in
connection with Polar expeditions and army rations. As the result of an
outbreak of scurvy in the Polar expedition of 1875-6, a British Arctic
Survey Committee was appointed to make an investigation. In 1877 it
reported that "although the scurvy was due to the absence of lime juice
from the sledge dietaries, meat in large amounts is able to prevent the
disease." Stefánsson also emphasized the value of meat in preventing
scurvy in the Polar regions. In his expeditions he has found that raw
meat, if taken in sufficient quantity, is able to afford complete
protection. Jackson, who lived for some years among the Samoyeds, tells
us that this tribe, owing to the fact that they consumed considerable
reindeer meat, never suffered from scurvy in spite of the fact that they
ate no vegetables or fresh fruit during the winter.
The following account, a personal communication from Dr. Harrison J.
Hunt, who spent four years in the Arctic regions, is of interest in this
connection:
"For some four years I was with the Smith Sound Eskimos, on the
northwest coast of Greenland. These people get nothing but animal food
normally, and have lived that way for many generations, yet are healthy,
of good physique, and are normal in other ways. Scurvy was unknown to
them as far as I could ascertain; certainly there was none while I was
among them. Much of their meat is eaten raw, and the rest only partly
cooked; that is, 'rare done.'
"Whalers who were accustomed to winter in Hudson Bay practically always
had scurvy in the crew. It was common knowledge among the captains that
fresh meat was curative of scurvy, and it was their practice to obtain
meat from the Eskimos whenever possible for that purpose. The last
English expeditions to the South Polar regions were afflicted with
scurvy which was entirely and quickly eradicated by the use of fresh
seal meat in the place of salt meats and canned foods. They do not state
that this meat was eaten raw or even rare cooked. On the Danish coast of
Greenland, during seasons poor in game, scurvy is quite common, but the
natives there live largely on breadstuffs (very coarse rye bread).
Personally, during my four years in the Arctic, I took no fresh
vegetables whatever, or other commonly-called antiscorbutics, relying
solely on rare or raw meat. I never was stronger or more healthy in my
life. I did have dried fruits and vegetables, and usually plenty of
fresh bread. Usually the Eskimos eat their raw meat in a frozen
condition, and I can attest that it is extremely palatable in that
condition."
We do not wish to discuss, in this place, the value of meat as an
antiscorbutic; in passing, however, it may be said that, as in the case
of the other antiscorbutics, its efficacy will depend largely upon the
amount consumed. The British Mesopotamia Commission Report of 1917 shows
that scurvy can develop on a ration which includes 28 ounces of meat a
week. We must remember, however, that this refers to cooked meat,
whereas in the Polar expeditions meat generally was eaten in a raw
state.
Recently an historical inquiry has appeared in an article by Chick, Hume
and Skelton as to the antiscorbutic virtue of limes and lemons. This
sketch is of exceptional interest because it treats of the oldest and
most cherished antiscorbutics, and particularly because it has unearthed
a peculiar fallacy in their connection. As they state, there would
appear to be every reason for believing "that the use of so-called lime
juice was responsible for the disappearance of scurvy from the British
navy in the first decade of the nineteenth century." It would seem,
however, that the lime juice which gained this great reputation in the
navy some 125 years ago was in reality lemon juice, and that it was not
until about 50 years ago that lime juice was really used. These authors
show--by one of those striking human experiments which, occasionally, is
available--that in a Polar exploration which was organized in 1850 lemon
juice was issued to each man, and that no case of scurvy developed,
whereas in a similar expedition which went out in 1875 lime juice was
issued and scurvy developed the following spring with great severity
among the sledge crews. This investigation, therefore, seems to prove
that lime juice, the prototype of antiscorbutics, has been accorded a
false position; that in reality the sailors of the past have been
protected by lemon juice.
=Antiscorbutic Foods.=--As far as has been ascertained, the
antiscorbutic food factor exists in all fresh vegetable and animal
tissues, being present to a far greater degree in the former than in the
latter. It is distinguished by being associated in nature with cells
which are the seat of active metabolism, just as the water-soluble
vitamine is associated mainly with cells which are in an inactive or
dormant state. Vegetables or fruits may be mildly or highly
antiscorbutic; there is indeed a remarkable difference in their content
of antiscorbutic factor or vitamine. They vary widely also in the degree
to which their potency is affected by physical or chemical conditions.
In this chapter the most common animal and vegetable antiscorbutic
foodstuffs will be considered and the effect which processes such as
drying, canning, change of reaction, etc., exert on their specific
value. Their therapeutic application in the prevention and cure of
scurvy will be considered in a subsequent chapter. Until recently our
knowledge of this subject was empirical and inaccurate; as the result of
scientific work, however, carried out during the past few years in
different parts of the world, quantitative and comparative figures of
antiscorbutic food values have been evolved.
=Milk.=--It is important to have as accurate an idea as possible of the
value of milk as an antiscorbutic, as the infant depends on it during
the first months of its life for a supply of this essential factor.
Considerable attention has been paid to this question in the last few
years, and recent reports tend to confirm the former estimations which
had been overlooked and forgotten. In 1847 Curran wrote that in the
Irish epidemic of this year they had admitted to the Dublin Union
Hospital 80 cases of scurvy which had been on a diet which included one
pint of milk daily, but was deficient in vegetables. From this
experience he realized that milk was not rich in the principles which
protect against scurvy. In the following year Parkes came to the same
conclusion, stating that 500 to 750 c.c. of raw milk did not always
suffice to prevent scurvy. In addition to these opinions concerning
adults, similar conclusions have been drawn from clinical experience
with infants. Barlow (1894) realized that a small amount of milk was
insufficient to protect against scurvy. Still writes: "The antiscorbutic
power of fresh, unboiled milk is evidently slight." In 1914 Hess and
Fish pointed out that "milk must not be considered as having potent
antiscorbutic properties." Nevertheless, when this question was raised
recently by the experimental work of Jackson and Moore, and that of
McCollum and Pitz, it was not appreciated that, like other
antiscorbutics, milk must be regarded from a quantitative standpoint,
and that, as it is a weak antiscorbutic, its effect must depend largely
on the quantity consumed.
The first laboratory work on this subject was that of Froelich in 1912,
who showed that guinea-pigs could be protected by an exclusive diet of
fresh milk, and that raw milk is more effective than heated milk. In his
work, the amount of milk taken by the animals was not measured, so that
it is impossible to glean from it more than these general conclusions.
In the following year, as a result of some quantitative experiments,
Funk stated that he was able to protect guinea-pigs with 50 c.c. of
fresh milk in addition to an oat diet. This estimate, as subsequent
workers showed, is too low. Chick, Hume and Skelton were the first,
however, to investigate the antiscorbutic potency of milk in a
systematic and convincing manner. They demonstrated that if the daily
consumption of fresh milk was less than 50 c.c., a guinea-pig died
almost as quickly as if it received no milk; if the daily quota varied
from 50 to 100 c.c., a greater or less protection from scurvy was
observed, varying proportionately with the amount consumed; if 100 to
150 c.c. were taken daily, which practically amounts to a complete milk
diet, satisfactory growth and development occurred, and no symptoms of
scurvy were observed. This represents in a general way the present
conception of the antiscorbutic power of milk. In passing, it may be
remarked that it is not altogether clear why 50 c.c. of milk do not
afford partial protection, and prolong the life of the animal for a
definite length of time. The authors conclude that "milk is evidently a
food poor in the antiscurvy accessory factor, and a ration large in
comparison with that of other antiscorbutic materials is necessary to
afford satisfactory protection from scurvy." The error must be avoided,
however, of regarding milk as a standard article of diet containing a
definite and specific amount of vitamine per cubic centimetre. It will
be shown later that this point of view cannot be taken in regard to
vegetables, and it is probable that it cannot be assumed for milk.
A general conception of the antiscorbutic potency of cow's milk may be
gleaned from the fact that it requires a minimum of about sixteen ounces
(500 c.c.) daily to protect an infant from scurvy or to cure it. Twelve
ounces have failed to effect a cure in several instances, although the
milk was raw and of the best grade. If it is pasteurized, a larger
quantity is required, depending upon various conditions connected with
the heating process and upon the age of the milk, circumstances fully
discussed in relation to etiology. Thus it becomes evident that
pasteurized milk assumes a two-fold rôle, acting as an antiscorbutic if
little of its vitamine content has been destroyed and if a large
quantity is consumed, or leading to the development of scurvy when one
or both of these conditions is unfavorable. The same holds true for milk
which has been boiled for a short period. If the milk has been heated
twice, it tends to produce scurvy; if it is condensed, the greater part
of its antiscorbutic value is destroyed.
It seems necessary to emphasize again the important fact that _dried
milk_ may possess marked antiscorbutic potency, depending on the method
of preparation (Fig. 11). As stated, sixteen ounces of milk dried by the
Just-Hatmaker process cured scurvy promptly, in spite of the fact that
the milk had been dried six months previously. Here, therefore, is a
food of high caloric value, compact, antiscorbutic, and stable. The fact
that milk, in spite of drying, retains this labile vitamine for so long
a period, demonstrates that it is available in the most remote parts of
the world, and that the possibilities of its transportation are
unlimited.
Little is known regarding the antiscorbutic content of the milk of the
various domestic animals. Some claim that goat's milk is notably rich in
this particular, but experiments with it are too few to warrant
conclusions. Lind writes: "Goats, of all animals, afford the richest
whey, possessed of the greatest antiscorbutic virtue ... which in a
singular manner restores the constitution when weakened and impaired by
scurvy." Human milk possesses about the same potency as cow's milk, as
mentioned in the discussion of the occurrence of infantile scurvy in
countries where the adult form is endemic. Twelve ounces of human milk,
from a woman on a liberal and varied diet, barely sufficed to alleviate
the symptoms of a case of moderate intensity.
FRUIT JUICES
=Orange and Lemon Juice.=--The most thoroughly studied antiscorbutic
foods are orange and lemon juice, which have been singled out because
they contain the antiscorbutic factor in the highest concentration. It
has been ascertained through the work of various investigators that
guinea-pigs require about 3 c.c. daily of either of these juices to
protect them from scurvy, but that about half this amount is sufficient
to prevent the manifestation of clinical signs.
Both of these juices withstand heat remarkably well. Orange juice can be
boiled for 10 minutes without noting any diminution of its antiscorbutic
value, and lemon juice heated to 110° C. without appreciably losing its
efficacy. However, orange juice undergoes some change as the result of
being heated in an autoclave for 45 minutes at a temperature of 110°
under 10 to 15 pounds pressure. Although 6 c.c. of this heated
preparation were able to prevent the development of scurvy, the
guinea-pigs did not gain nearly as well as those which received 3 c.c.
of the unheated juice. It seemed as if there was a destruction of some
factor apart from the antiscorbutic principle.
In spite of the fact that these juices withstand heat well, they are
sensitive to some other conditions. Orange juice which had been stored
in the cold for three months was unable to protect guinea-pigs in the
dosage of 3 c.c. per animal, resembling in its action the autoclaved
juice. When this orange juice was six months old, double this quantity
failed to protect; throughout this period it was kept in the ice-box
and covered with a layer of oleum petrolatum to avoid the access of air
or possible contamination. Harden and Zilva met with a similar
experience, and state that "after storing treated (concentrated) lemon
juice for about a fortnight in a cold room, a marked loss can be
observed in its potency."
These authors reported also that when orange juice is _rendered slightly
alkaline_ it loses its antiscorbutic potency. This question was
investigated in relation to canned tomato juice, as well as to orange
juice, and it was found that shortly after having been rendered 0.05 N
alkaline to phenolphthalein, neither of these foods had lost an
appreciable amount of its antiscorbutic factor. Five cubic centimetres
per capita daily of freshly-alkalized orange juice were able to cure a
group of pigs which had developed scurvy on another diet. If, however,
24 hours were allowed to elapse instead of only one-half to one hour,
between the alkalization and the feeding, then a considerable amount of
the antiscorbutic factor was lost. The same general rule seems to hold
for alkalization as for heating, _i.e._, the length of time the
antiscorbutic food is subjected to the deleterious influence is fully as
important as the intensity of the process. Advantage has been taken of
the fact that freshly-alkalized orange juice retains its potency, in
using it intravenously in the treatment of infantile scurvy.
_Subcutaneous injections_ of neutralized orange juice failed to cure
scurvy in guinea-pigs; Harden and Zilva were equally unsuccessful with
large doses of their concentrated lemon juice. This is of interest in
view of the marked therapeutic result which Shiga obtained with
subcutaneous injections of the water-soluble vitamine in pigeons
suffering from polyneuritis. It should be added that Holst and Froelich
(1912) failed to cure scurvy in guinea-pigs by intraperitoneal
inoculations of orange juice.
_Lemon juice or orange juice may be dried_ and lose little of its
antiscorbutic power. In their paper of 1912 Holst and Froelich reported
the efficacy of lemon juice evaporated in a vacuum, and recently Harden
and Zilva published experiments which proved that "by evaporating the
treated lemon juice to dryness in an acid medium an active dry residue
is obtained." Still more recently Givens has shown that orange juice
reduced to a powdered form by means of a spraying process has lost
little of the antiscorbutic factor. These results prove that under
certain conditions the antiscorbutic factor withstands drying; one of
these favorable influences is an acid reaction, and another, rapidity of
desiccation.[40]
[40] Preserved mulberries which had been sugared and cooked for
one-quarter to one-half an hour were found by Holst and Froelich (1912)
to possess good antiscorbutic power three months later.
=Lime Juice.=--Recently an investigation of lime juice has been carried
out by Chick, Hume and Skelton. They were "unable to detect any
significant protection in a daily ration of from 5 to 10 c.c. of
preserved lime juice which was several months or a year or more old."
Crude lime juice of various ages had slight antiscorbutic value,
affording only partial protection in a daily ration of 5 c.c. Even fresh
juice was found not to be very efficacious compared with lemon juice.
The authors conclude that "the relative value of these two fruit juices
deduced from the trials with monkeys is therefore in accord with that
obtained in the experiments with guinea-pigs, _i.e._, the value of fresh
lemon juice is approximately four times that of fresh lime juice." Holst
and Froelich in 1907 carried out a similar but less extensive
investigation. They also found that lime juice was unable to protect
guinea-pigs from scurvy. Fuerst, a co-worker of Holst, continued this
work, and in his article of 1912 stated that guinea-pigs should not be
protected by a daily addition to their ration of 25 g. of lime juice;
these guinea-pigs received a mixed diet consisting of dry vegetables,
butter, almonds and malt extract. These two reports of the Norwegian
investigators on this interesting subject should have attracted
attention.
=Other Fruits.=--A word may be said in regard to some other fruits. The
antiscorbutic potency of _raspberries_ was tested by Holst and Froelich
(1912) and found comparable to oranges and to lemons. The juice was also
highly resistant to heat, so that 10 c.c. of freshly-pressed juice were
of protective value, even after it had been subjected to 100 or 110° C.
for one hour. Guinea-pigs which were thus treated showed no microscopic
signs of scurvy in any of the ribs, in the tibiæ or the femora.
TABLE 3
TABLE SHOWING THE RELATIVE DISTRIBUTION OF THE ANTISCORBUTIC FACTOR
IN THE COMMONER FOODSTUFFS[*]
=====================================================================
Classes | Anti- | Classes | Anti-
of |scorbutic| of |scorbutic
Foodstuffs | Factor | Foodstuffs | Factor
------------------------+---------+------------------------+---------
_Meat, Fish, Etc.:_ | |_Vegetables and Fruits:_|
Lean meat (beef, | | Cabbage, fresh | +++
mutton, etc.) | + | Cabbage, cooked | +
Liver | + | Cabbage, dried | Very
Tinned meats | 0 | | slight
Beef juice | + | Swede, raw expressed |
| | juice | ++
_Milk, Cheese, Etc.:_ | | Lettuce | ++
Milk, cow's, whole raw| + | Carrots, fresh raw | +
Milk, cow's, skim raw | + | Carrots, dried | 0
Milk, cow's, dried | + | Beetroot, raw, | Less
Milk, cow's, | Less | expressed juice | than +
boiled | than + | Potatoes, raw | ...
Milk, cow's, | Less | Potatoes, cooked | +
pasteurized | than + | Potatoes, dried | 0
Milk, cow's, condensed| Less | Beans, fresh, raw | ++
(sweetened) | than + | Onions | ++
| | Lemon juice, fresh | +++
_Eggs:_ | | Lemon juice, preserved| ++
Fresh | ?0 | Lime juice, fresh | ++
Dried | ?0 | Lime juice, preserved | Very
| | | slight
_Cereals, Pulses, Etc.:_| | Orange juice | +++
Wheat, maize, rice, | | Raspberries | ++
whole grain | 0 | Grapes | +
Wheat germ | 0 | Apples | +
Wheat, maize, bran | 0 | Bananas | Very
White wheaten flour, | | | slight
pure corn flour, | | Tomatoes (canned) | ++
polished rice, etc. | 0 |
Linseed, millet | 0 |_Miscellaneous:_ |
Dried peas, lentils, | | Yeast, autolyzed | 0
etc. | 0 | Meat extract | 0
Soy beans, haricot | | Beer | 0
beans | 0 | Cod liver oil | 0
Germinated pulses or | | Olive oil | 0
cereals | ++ | Human blood | +
---------------------------------------------------------------------
[*] This table is a modification of one prepared by the Medical
Research Committee
These authors also reported that they found _banana_ and _apple_ poor in
antiscorbutic power, 30 g. daily being insufficient to protect a
guinea-pig (Table 3). This was our experience with banana in the
treatment of infants suffering from mild scurvy. The banana has been
shown by Sugiura and Benedict to be poor also in the water-soluble
vitamine. It would be of interest to determine the difference in
vitamine content between the fully ripe and the unripe fruit.
In view of the fact that _grapes_ are used considerably in the treatment
of infantile scurvy, it is of importance to realize that they are poor
in the antiscorbutic principle. Chick and Rhodes found that three of
four guinea-pigs receiving 20 g. daily developed scurvy; they rated the
potency as ten times less than that of orange juice.
VEGETABLES
It is everyday knowledge that fresh vegetables are of great value in the
protection from, and cure of, scurvy. The first experimental
investigation of this subject was that of Holst and Froelich, published
in 1907, and continued in a series of papers extending to 1916. These
investigators tested the potency of a large number of vegetables by
feeding them in varying quantities to guinea-pigs. They found that all
vegetables have antiscorbutic value but to a markedly varying degree.
Cabbage, sorrel leaves, endive, head salad, and dandelion leaves, were
found to be of most avail in protecting against scurvy, whereas carrots,
cooked potatoes and cooked turnips, and cauliflower proved to be of less
value. In general, it may be stated that the leafy vegetables have more
antiscorbutic power than the roots or the tubers. This generalization,
we shall see, is not without exception, _e.g._, the swede. Similar
experimental work has been recently carried on by a group of
investigators at the Lister Institute, who have added considerably to
our knowledge in this field. In all this experimental work cabbage has
been found to be the most potent of the vegetables, and therefore
experiments have centered about it just as in considering fruits the
work has centered about orange juice or lemon juice. We shall,
therefore, discuss in detail its reaction to heat and dehydration.
=Cabbage.=--Holst and Froelich found that 1 g. daily of fresh cabbage
afforded nearly complete protection to guinea-pigs, and Delf has
corroborated this work. This amount is sufficient to prevent the
development of manifest scurvy, although it does not induce satisfactory
growth. In this respect it is comparable to giving 1.5 c.c. of orange
juice daily. If guinea-pigs take only 0.5 g. of raw cabbage, scurvy will
develop; whereas 2 g. or more will promote satisfactory growth and no
scorbutic changes will be found on microscopic examination.
=Effect of Heating.=--Vegetables are of decidedly less antiscorbutic
value when cooked than raw; cabbage, for instance, on being boiled is
weakened about one-half. Heating to 110° C. for an hour destroys almost
all of its antiscorbutic factor. Delf's tests did not show so great a
loss. She came to the conclusion, of theoretical and practical value,
that slow cooking at a low temperature is much more deleterious than
rapid cooking at a higher temperature. Hess and Unger found that carrots
lost much of their antiscorbutic power after boiling, and that this was
the result of a true destruction, the vitamine not having been merely
dissolved in the water of boiling; for if guinea-pigs consumed 40 c.c.
per capita of this water, they were not protected against scurvy (Fig.
11). Acidulating the water with 10 per cent. vinegar did not reduce the
loss, an experience similar to that of others using citric acid or lemon
juice.
_Vegetables cannot be considered from an antiscorbutic standpoint as a
standard and uniform foodstuff, as they vary in their content of this
factor according to their freshness and age._ This was demonstrated by
means of feeding experiments with carrots. For example, 35 g. of old
carrots, such as were used for feeding the laboratory animals, afforded
but little protection after having been cooked in an open vessel for
about 45 minutes, whereas the same amount of young carrots cooked this
way protected the guinea-pigs. It is obvious that this distinction is of
importance in evaluating the antiscorbutic content of the various foods,
and in considering whether individuals and groups of individuals are
receiving an adequate quota of antiscorbutic vitamine. It will be noted
later that it is also of importance in connection with the potency of
dehydrated vegetables. Recent experiments indicate that not only age,
but the _degree of ripeness_ must be considered in appraising the food
value of vegetables. Feeding experiments showed that tomatoes which were
fully ripe were more potent than those which were slightly green.
Probably many other factors play a rôle in determining the richness of
vegetables in vitamine. It may not be immaterial whether they are
allowed to ripen on the vine or shrub, or mature subsequently. The
nature of the soil may also affect the antiscorbutic quality of the
vegetables or fruit. So that it is evident that we must not be schematic
in considering this question, and must realize that a table of
antiscorbutic values, such as accompanies this text (Table 3), does not
furnish definite and inflexible values.
There is a marked difference between _vegetables and vegetable juices_
in keeping quality, and in their reaction to heat and to acid. In
general, it may be stated that the juices are much more sensitive. Holst
and Froelich brought out this point in 1912 and enlarged upon it in
their publication of 1916. The different juices vary greatly in this
respect; for example, dandelion juice is acutely sensitive to heat,
whereas sorrel leaves withstand high temperatures very well. In regard
to these differences an analogy may be drawn to the fruit juices. Lemon,
orange and raspberry juices are markedly thermostable, but lime juice is
weakened markedly by heat. Many of these juices are protected by the
addition of acid--5 per cent. of lemon juice increasing the
thermostability of cabbage juice--whereas, as we have stated, little is
gained by cooking vegetables in an acid medium.
=Potato.=--The civilized world is dependent for its quota of
antiscorbutic foodstuff largely upon the potato. It might be thought,
therefore, that this would signify that the potato is endowed with great
antiscorbutic power. Such is not the case, however, as demonstrated both
by laboratory tests and clinical experience. Considering its importance,
there have been surprisingly few feeding experiments carried out with
potato. Holst and Froelich (1912) found that 17 g. of potatoes, steamed
at 100° C. for 30 minutes, afforded but slight protection, and that it
required 20 g. to fully protect a guinea-pig. Givens and Cohen failed to
ward off scurvy by means of cooked potatoes fed to the equivalent of 5
g. of the raw vegetable (guinea-pigs will not eat raw potatoes). There
are no accurate figures as to the quantity of potatoes needed to protect
a human being from scurvy. The statement of Doctor Guy, however, who
after careful study of convicts' diets, concluded that 14 ounces daily
would protect them from scurvy (if the ration included one ounce of
other fresh vegetable and 4 ounces of meat), is probably close to the
mark.[41] With the experience that potatoes play such a significant rôle
in the prevention of scurvy, how are we to interpret the fact that they
are only mildly antiscorbutic? Potatoes are consumed in very large
amounts; in the Temperate Zone probably twice as many pounds of potatoes
are consumed during the winter as of all other vegetables combined (Fig.
1). It is evident, therefore, that in a practical evaluation of
antiscorbutic foodstuffs, not only the intrinsic antiscorbutic potency
must be considered, but also the quantity of the vegetable or fruit
consumed.
[41] Dr. Guy's evidence, Report of the Lords Commissioners of the
Admiralty on the Outbreak of Scurvy in the Recent Arctic
Expedition--1877 (cited from Chick and Hume).
=Swede.=--We cannot leave the consideration of vegetable antiscorbutics
without adding a few words as to the value of swede juice,[42] which has
been recently highly recommended by Chick and Rhodes, who found it
comparable to the cabbage and the onion, and even to orange juice. For
example, 25 c.c. of raw swede juice were equivalent to 1.5 g. of raw
cabbage. It is, therefore, more potent than the juice of raw carrot, and
far more efficacious than the juice of the beetroot (Table 3). Tests
carried out with this antiscorbutic in infant feeding seemed to show
that it is of value in this field. The authors believe that the potency
of vegetables is closely associated with certain botanical species, and
that in this way the marked virtue of the swede can be explained, as it
belongs to the natural order of Cruciferæ, which includes also the
cabbage, the scurvy grass and the cresses. If, however, this is a rule
of nature, it is difficult to explain the marked difference between the
lime and the lemon, which are both varieties of Citrus Medica.
[42] The swede is a root vegetable of the natural order Cruciferæ. It is
grown to a large extent in England, but is practically unknown in the
United States.
=Dehydrated Vegetables.=--For hundreds of years fresh vegetables have
been dried to serve as food during the winter months and have fulfilled
a useful purpose on account of their small bulk and great food value.
The question for us to consider, however, is whether dehydrated
vegetables still retain their antiscorbutic quality and can be counted
on to supply this factor in the dietary. At present this subject is
engaging the attention of laboratory workers as well as of practical
dietitians and food hygienists. The experience of the past is not happy
in this regard. In the Medical and Surgical History of the War of the
Rebellion we read as follows: "A scorbutic tendency was developed at
most of our military posts during the winter season, after the troops
had been confined to the use of the ordinary ration with desiccated
vegetables. The latter in quantities failed to repress the disease." In
spite of this and similar military experiences[43] the employment of
dehydrated vegetables was urged recently for rationing our soldiers, the
claim being made that "by simply soaking in water and boiling in the
same water these vegetables are brought back to the condition of fresh
vegetables." Both in this country and in England there was strong
propaganda during the war to dehydrate vegetables on an enormous scale
and to substitute them for the fresh food.
[43] "We find the College of Physicians at Vienna sent to Hungary great
quantities of the most approved antiscorbutic herbs dried in this
manner; which were found to be of no benefit. Many of these would have
their virtues as little impaired by drying as spinage, _e.g._, marsh
trefoil. Kramer tried almost every species of dried herbs to no
purpose." (Treatise on The Scurvy. James Lind, London, 1772, p. 143.)
[Illustration: FIG. 12.--Hay, oats, water _ad libitum_, and 7 g. of
dehydrated carrots dried at a room temperature of about 130° F. about 1
month previously. All animals developed scurvy. The marked gain in
weight when an equivalent amount of fresh carrots was substituted for
the dehydrated vegetable corresponded to the disappearance of scorbutic
signs. Guinea-Pig B 951 did not receive fresh carrots, as it was
evidently ailing at the time the second period began.]
Experimental investigation on this subject may be summarized as showing
that vegetables dried according to present methods lose their
antiscorbutic value as the result of dehydrating (Fig. 12), and that
they become still more impoverished as the result of aging. We should
not sweepingly condemn the principle of dehydration, as very possibly
some slight modifications in the process may be devised which will
counteract the deteriorating influence. In their paper of 1912, to which
reference has been made so often, Holst and Froelich reported that
potatoes, carrots, peas, lentils and almonds have practically no
protective value after they are thoroughly dried. In two reports--one
giving the results of feeding various brands of dehydrated carrots to
guinea-pigs, and the other of an attempt to cure scurvy in babies by
means of these carrots--we also came to the conclusion that the
antiscorbutic factor had been almost completely destroyed. Givens and
Cohen (1918) found that even cabbage dried at a low temperature retained
only a small amount of its potency after a month, and Delf and Skelton
came to practically the same conclusion, also noting that the cabbage on
being kept, steadily lost what little of the antiscorbutic factor had
survived the drying process. The same was true of the fat-soluble
factor. These authors made an observation which may prove of value in
helping to solve this problem, namely, that "the residual amount is
distinctly greater if the cabbage is plunged into boiling water before
drying." This protective action of heat they suggest may indicate that:
"Some at least of the destruction may be due to the activity of an
enzyme or other body originally present in the living tissue."
Another observation which may prove of practical value in rendering
dehydrated vegetables the nutritional equivalent of the fresh vegetable
is that when the carrots selected for dehydration are young and fresh a
product is obtained which possesses decided antiscorbutic power. In this
connection the following statement by Falk and his co-workers in a study
of the enzyme action of vegetables and the effect of dehydration is
significant: "In considering these enzyme results, it may be pointed out
that the state of ripeness and the age of the vegetable undoubtedly
influence the activities."
The most promising dehydration experiment has been conducted by Holst
and Froelich and was published in 1916 in a paper which has passed
unnoticed. They dried white cabbage so that it retained its
antiscorbutic properties, and, to a large extent, its color and taste,
for a period of two years. This result was accomplished by keeping out
all moisture and preventing hydrolysis,[44] a method which is employed
in preserving antitoxins, toxins and agglutinins. It is by far the most
encouraging test reported, and should be made the basis of further work
by those actively interested in perfecting dehydration.
[44] The cabbage was subjected to a preliminary drying for 8 days at 37°
C. It was then put in an air-tight desiccator which contained a dish of
phosphorus pentoxid. (The pentoxid was replaced for several weeks until
it ceased to liquefy.) It was then placed in cylinders which had been
rendered air free by means of a suction pump and which contained
phosphorus pentoxid. This was kept at 37° C. and examined after 10, 18
and 26 months. A similar result was not obtained when calcium chlorid
was employed, the temperature held at 37° C. and the cabbage was kept in
an air-tight cylinder rather than in a vacuum. However, under these
conditions if the cabbage was placed in the ice-box at a temperature of
4°, 10° or 12° C. the antiscorbutic property was conserved after
boiling.
[Illustration: FIG. 13.--Cure of scurvy by the addition of canned
tomato. In this case, as frequently, the alleviation of symptoms
preceded the gain in weight.]
=Canned Food (Tomatoes).=--In the course of canning, as in dehydrating,
most vegetables and fruits lose their antiscorbutic properties. A
general denunciation, however, of all canned foods is incorrect, as
there are exceptions to this rule. It has been shown by Hess and Unger
that canned tomatoes possess a high degree of antiscorbutic power (Fig.
13), and it is probable that most of the acid fruits and vegetables are
able to withstand the canning process. It was found, in an experiment
embracing many series of guinea-pigs, that 4 c.c. daily of strained,
canned tomato are sufficient to afford protection, even when a lot was
used which had been prepared a year previously. This is indeed
remarkable, considering that the food undergoes a two-fold heating in
the course of canning, during one of which ("processing") the
temperature is raised to fully 230° F. Tomatoes have another advantage
over most other vegetables in that they are richly endowed with the
water-soluble vitamine, as shown by our tests on pigeons suffering from
polyneuritis, and by the experiments on rats of Osborne and Mendel, who
found tomatoes far superior in this respect to turnips, onions,
beetroots or beans. They are also rich in the fat-soluble vitamine. In
view of the availability of canned tomatoes and their excellent keeping
quality they are well suited to an extended use as an antiscorbutic. In
the subsequent chapter we shall discuss their employment in infant
feeding and in the army ration.
=Germinated Cereals and Pulses.=--In 1912 Fuerst reported that although
the resting seed--the cereal grain, the pea, bean and lentil--are poor
in antiscorbutic vitamine, they develop this principle as soon as they
germinate. They possess, in other words, latent antiscorbutic
properties, and are potentially antiscorbutic. This observation is not
only of scientific interest but of practical value, as these pulses are
well suited for transport and do not readily deteriorate. For this
reason, Chick and her co-workers at the Lister Institute, who were
searching for an antiscorbutic foodstuff for the army, directed their
attention to the utilization of the pulses. In the course of a thorough
investigation (1919) they found that although it required 30 to 40 g.
daily of dry green peas to prevent scurvy in the guinea-pig, a
consumption of 10 g. of the germinated peas afforded satisfactory
protection.[45] The soaked seeds have an antiscorbutic value comparable
to many of the fresh vegetables; by no means as great as cabbage, but
somewhat greater than that of carrots. As the result of cooking, their
potency was found to be reduced about 75 per cent. We shall have
occasion to refer to this antiscorbutic food in the chapter on treatment
in connection with the rationing of armies.
[45] The pulses, after having been soaked in water for 24 hours, were
kept moist, with access of air, for about 48 hours at room temperature,
and during this time germinated, developing a radicle usually about 1
cm. in length.
=Meat and Eggs.=--As has been stated, animal tissues are distinctly
inferior to fruits and vegetables in the antiscorbutic principle. As
there has been no accurate evaluation of these foods--the only test
being one by Chick, Hume and Skelton, where 10 c.c. of raw beef juice
failed to protect guinea-pigs--we have to depend upon clinical
experience for our knowledge. Beef juice is highly rated by physicians
in the prevention of infantile scurvy, but it is probably far less
potent than vegetables or fruit juices. The Arctic explorers, and many
who have lived in the Arctic regions, agree that the inhabitants are
protected from scurvy during the winter months by their diet of fresh
meat and fish. The Admiralty Enquiry on the outbreak of scurvy in the
Arctic Expedition of 1875 reported that a large ration of meat is
necessary to afford protection. Curran (1847) described three cases
admitted to the hospital in the great Irish epidemic of that year, where
the diet previously had included three-quarters of a pound of meat on
five days of the week. From these and similar experiences the conclusion
is manifest that the divergence of opinion regarding the value of meat
is based upon quantitative differences in the rations. Evidently, if
sufficient meat is provided, the development of scurvy will be obviated.
Another factor which must be borne in mind is that those who refer to
meat in the Arctic regions refer to fresh raw meat, which is a far more
valuable antiscorbutic than the ordinary cooked meat.
There is almost no experimental data on the antiscorbutic value of
_eggs_. Hard-boiled eggs were fed to guinea-pigs and it was found that 9
g. per capita daily was insufficient to protect them. An attempt was
also made to cure infantile scurvy with a daily addition of one raw egg
to the dietary, but without avail. It is possible that fresh raw eggs
have an antiscorbutic value comparable to meat, but the large quantity
required makes dependence upon them impracticable.
=Beer and Alcoholic Beverages.=--For generations beer has been highly
regarded as an antiscorbutic. Captain Cook prized it greatly and always
supplied his men with a freshly-made infusion of malt called
"sweetwort." Lind writes: "Beer and fermented liquors of any sort will
be found the best antiscorbutic remedies" (p. 76). He refers at
different times to the value of spruce beer, ale, wine and other vinous
liquors. In his excellent book on "Military Hygiene," Munson writes:
"Good beer and wine have decided value, also vinegar." On the other
hand, recent scientific experiment has shown that beer has practically
no antiscorbutic value. There is but one study on this subject, that of
Harden and Zilva, which is quite convincing. They found that guinea-pigs
and monkeys developed scurvy in spite of the fact that they received,
respectively, 50 c.c. and 180 c.c. of beer daily. They conclude, as a
result of their experiments, that "bottled ale and stout and fined beer
as brought on to the market, are lacking both in antineuritic and
antiscorbutic accessory factors, and that kilned material is also
wanting in these two principles." The apparent contradiction between
practical experience and laboratory investigation in regard to beer is
due to a difference in the process of brewing. Cook and Lind and the
older authors refer to freshly-made beer, whereas the modern beer which
was tested in the laboratory was made from "high-dried" material. The
antiscorbutic potency of beer as formerly used was due to its
preparation from freshly-germinated grain and its consumption shortly
after brewing. Dyke tells us of an interesting incident illustrating the
importance of this distinction. In the recent war an outbreak of scurvy
occurred among the Kaffir labor battalion in France. At home these
natives consume a large amount, as much as three gallons a day, of
Kaffir beer, which is made from freshly-germinated corn, and is consumed
shortly after it is made. The French prepared a similar fermented
beverage for their South African laborers, the sole difference in
preparation being that the process of germination had been omitted for
reasons of convenience. Scurvy resulted, a disorder which is practically
unknown among the natives at home.
=Miscellaneous Foodstuffs.=--During the past few years a great many
different kinds of foods have been tested in the laboratory for their
antiscorbutic value. It will be well for completeness' sake to say a
word about them, although they have been found to possess little or no
antiscorbutic properties. The studies of Holst and Froelich showed
definitely that all the cereals--oat, barley, rye, maize, and
preparations made from the bran or from the endosperm--are devoid of
antiscorbutic vitamine. Cohen and Mendel added 3 per cent. of calcium
lactate or sodium chloride, or 5 per cent. of butter, without enhancing
the value of oats in this respect.
[Illustration: FIG. 14.--Failure of yeast as a prophylactic; latent
scurvy promptly yielding to orange juice.]
As is well known, yeast possesses the water-soluble vitamine in marked
concentration. It is natural, therefore, that its antiscorbutic power
was put to the test, especially as it has been accorded therapeutic
value. Hess and Unger showed that autolyzed yeast was of no value in
the cure of infantile scurvy (Fig. 14); Chick and Hume (1917) and Cohen
and Mendel (1918) came to the same conclusion in regard to guinea-pig
scurvy, making use of autolyzed yeast, yeast extract and dried brewers'
yeast.
In view of the fact that cod liver oil is practically a specific for
human rickets, Hess and Unger tried the effect of this oil both in
infantile scurvy and in that of guinea-pigs. It proved to have no
protective or curative value. The animal experiments were confirmed by
Cohen and Mendel. The use of olive oil also proved futile.
Pitz in 1918 reported that in animal experiments he had found that
lactose was able to protect against scurvy, and attributed this result
to its power to alter the intestinal flora. We shall not enter into a
detailed discussion of this question, as the study was carried out on a
ration embodying unlimited and uncontrolled amounts of milk, and it has
since been shown that the apparent cure was due to an increased
consumption of milk by the animals in the progress of the experiment.
Cohen and Mendel, Harden and Zilva, Hart, Steenbock and Smith (1919) all
failed to protect or to cure their animals with lactose when they were
placed on a ration which was definitely measured and limited. Hess and
Unger failed to cure infantile scurvy by means of lactose.
It has been suggested that scurvy is due to a lack of secretion of the
endocrine glands, a question which will be referred to again in
considering the relation of scurvy to other "deficiency diseases." With
this idea Ingier added thyroid, hypophysis, thymus and parathyroid to
the food of guinea-pigs, or gave it parenterally. She was unable to
observe any beneficial results. Jackson and Moore met with the same
result on feeding desiccated thyroid gland. We may add that we gave
dried thyroid and also parathyroid glands in the treatment of infantile
scurvy without effect.
CONCLUSIONS
Any consideration of the question of antiscorbutic foodstuffs brings
into sharp relief the difference between empiricism and scientific
investigation. For well over a hundred years it was generally known that
scurvy could be cured by fruits or vegetables, and yet no further
progress was made toward a more complete understanding of the value of
these foodstuffs. As far back as 1847 Budd ascribed the action of
antiscorbutic foods "to an essential element, which, it is hardly too
sanguine to state, will be discovered by organic chemistry or the
experiments of physiologists in a not far distant future." Busk, in
giving his testimony in 1877 before the British Scurvy Commission, said
that it was his belief "that scurvy was due to the fact that the diet
was lacking in a peculiar and as yet little-understood factor." The
question remained in this hypothetical and inactive state until it was
attacked recently by experimental methods. Decided advance has been made
only in the past few years, since these foodstuffs have been studied
from a quantitative viewpoint.
The antiscorbutic factor is abundant in fresh foods, especially in
vegetables and fruits, and to a considerably less extent in animal
foods, such as milk, meat and fish. Among the vegetables there is a
marked distinction in potency. A beginning has been made in
standardizing these various foodstuffs, in grading them approximately
according to their antiscorbutic efficacy (Table 3). It should be
remembered, however, that the importance of an antiscorbutic food
depends not only on its intrinsic content of the antiscorbutic factor,
but quite as much on the amount of the food which is eaten. For example,
although potatoes possess only moderate virtue compared with orange
juice, they are of greater practical value in view of the large
quantities which are consumed and their availability when green
vegetables are lacking. Furthermore, the fact recently brought out that
the various vegetables, and perhaps the fruits as well, have
considerably more value when they are fresh and young than when they are
old, warns us not to carry our quantitative standardization too far.
Fruits and vegetables which are dehydrated have been found to have lost
their antiscorbutic properties. This generalization is not without its
exception, for it has been found that cabbage and tomato withstand
drying well, and that if milk is dried under favorable conditions it
retains a very large part of its antiscorbutic value. It may be stated
that the outlook is bright in regard to dehydration, as the problem has
not yet been thoroughly studied, and the process may be so improved that
there will be little difference in the nutritional value between the
fresh and the dehydrated food.
The study of antiscorbutic values points a lesson in regard to the
methods of cooking vegetables. It has demonstrated that short cooking,
associated with a high degree of temperature, is less deleterious than
longer cooking at a low degree. In other words, that less damage is
brought about by boiling or by steaming vegetables than by stewing them.
Here age and freshness again play a rôle; in fact, a double rôle, as the
older and tougher vegetables contain not only less antiscorbutic, but
require more prolonged cooking.
In general, the belief is correct that canning destroys the
antiscorbutic value of foods, but once more an exception must be made,
for it has been found that acid foods, such as the tomato, withstand the
canning process with but little loss of potency.
The field of antiscorbutic foodstuffs is one which is fertile for future
investigation. The antiscorbutic status of milk heated to various
heights of temperature and subjected to various degrees of aging
furnishes problems of great practical importance. A lack of growth has
been noted when antiscorbutics are given which have been subjected to a
high degree of heat (_e.g._, autoclaved orange juice). Whether this is
due to the destruction of some other growth factor is a question which
has been raised by several experimental studies and requires an answer.
It is quite possible that we shall find useful antiscorbutic foods which
at present are unknown or unappreciated. The recent introduction of the
swede, of the canned tomato and of germinated pulses suggests and even
renders this probable. On the other hand, the recognition of the
comparative poverty of the antiscorbutic factor in lime juice shows the
importance of putting each foodstuff to the experimental test.