expectation of life has improved in this country during the period that
increasing attention has been paid to sanitation. This is shown by the
tables of the Registrar-General. For most of the following information
I am indebted to Dr. T. H. C. Stevenson of the General Register
Office, Somerset House. In 1838–54 the expectation of males at birth
in England and Wales was 39·91 years, in 1901–10 the male and female
expectations at birth were 48·53 and 52·38 years respectively, and the
latest available expectations at birth (English Life, Table No. 8,
Supplement to the Seventy-fifth Annual Report of the Registrar-General,
Cd. 7512) are 51·6 for males and 55·35 years for females. But the
expectation is probably considerably more now, as the death rates
have fallen appreciably since 1910–12. The Prussian male expectation
of life at birth has increased from 35·38 years in 1867–77 to 46·43
in 1906–10;[60] and the Swedish[61] expectation of life at birth from
39·5 years in males and 43·6 years in females in 1816–40 to 54·5 and
57 years respectively in 1901–10. In North America[62] there has been
a fall in the death rate in every age group in 1920 as compared with
1910.
The increased expectation of life has been especially prominent in
early and adult life. Examination of the Registrar-General’s census
returns from 1851 to 1911 show that although there were more persons
per million living between the ages of 55 and 75 there were less above
the age of 75 at the end than at the beginning of this 60-years’
period. It has been suggested that the increased survival in the
earlier period of old age is due to the saving of life in infancy and
that, as these lives are not prolonged above the age of 75 or so, the
diminished proportion of persons living to become octogenarians is
explained (H. Weber).
_The influence of past diseases_ is perhaps most conveniently
considered in connexion with environment. As infection must necessarily
impair the vitality of the cells of the body, either temporarily or
permanently, it would be natural to expect that those who live to a
great age would show a remarkably clean bill of health. This is often
true. But it is at first sight rather disconcerting to find that nearly
half of the 824 persons between 80 and 100 years of age analysed by
Sir George Humphry had had severe illnesses at one time or another;
many of these, however, were acute infections. It is noticeable that
85 per cent were free from rheumatism in the hands (selected as a
convenient test in his collective investigation), which in the light
of present opinion that arthritis is the result of a focal infection
would appear to show that these old people are remarkably free from
chronic disease. Long-continued infection or intoxication would be a
far more potent factor than a transient illness in producing permanent
change in the cells. A short acute infection would cause changes in the
cells which might, like those of fatigue, be temporary and recoverable.
Saundby’s[63] dictum may be accepted as fairly accurate, exception
being made for peripheral mutilations, namely, that those only can
expect to live to extreme old age who at the age of 60 possess bodies
free from disease. But critical examination would no doubt show that
focal infections become increasingly frequent as the years go on;
this is particularly true as regards oral sepsis; after two years’
experience of 500 pensioners at the Royal Hospital, Chelsea, Thompson
and Todd have never seen a tooth in a healthy condition there. It is
noteworthy that dental disease seems to have become common with the
advent of civilization, as judged by examination of ancient skulls,
though the loss of teeth is an accompaniment of the bony changes in old
age, and very old people seldom have more than a few teeth left. On
the other hand, an acute illness is often the apparent starting-point
of old age; there may be a long and imperfect convalescence due to
persistence of infection, or deterioration may be due to auto- or
hetero-suggestion (_vide_ p. 48).
The influence of syphilis, whether congenital or acquired, is one of
the most important in the prevention of healthy longevity; it not
only directly disables and kills, especially in infancy and in the
fifth decade, but it damages the vitality of the cells thus producing
degeneration and premature senility, and favours secondary infections.
It is clear that for the preservation of health detection of disease
in the earliest stage is all-important, and that this can be attained
by periodic examination by a medical man; but obvious though this may
be, the average man waits to call in a doctor until he knows that he is
ill. Timely advice as to methods of life, food and drink, occupation,
or environment would often prevent disease and premature death. In 1913
the Life Extension Institute was founded in New York for such periodic
examination and report, and the Life Assurance Companies, finding that
persons so examined showed, at any rate for some years, a death rate
lower than that anticipated, gave it financial support.
FUNCTIONAL ACTIVITY
As is well known, disuse leads to atrophy, and biologically conditions
rendering an animal’s supply of food extremely easy and safe are
followed by atrophy of the parts no longer necessary in a state which
may thus come to border on parasitism; in an extreme degree this
result is shown in barnacles (degenerated crustaceans) and ascidians
(degenerated vertebrates). In man the cessation of an active life on
retirement to the country, described by Samuel Johnson as “a kind
of mental imprisonment,” or the sudden acquisition of wealth, often
exerts a most evil influence; for if the whole body is no longer kept
in a condition of functional activity, those parts allowed to remain
relatively idle begin to degenerate and atrophy; loss of function means
a diminished blood supply and nutrition, and so degenerative atrophy.
According to Laurentius “nothing hastens old age more than idleness.”
James Easton,[64] who collected 1712 records of centenarians, many of
them open to criticism, endorses Hufeland’s dictum that no idler has
ever attained to a remarkably great age; and Sir Thomas Browne’s[65]
quaint injunction “Dull not away thy days in sloathful supinity and the
tediousness of doing nothing” is old but true wisdom.
The axiom that disuse leads to atrophy applies perhaps even more to
mental activity, for resting and rusting of the brain slow the pace
of the whole body, whereas an alert mind can exist in an infirm body.
There is no doubt that occupation with a strong desire to live for
the accomplishment of a definite purpose exerts a most beneficial
influence, and there have not been wanting some, such as Karl Marx, who
have preached that old age is in great part a matter of will. Speaking
of the circle in which Madame du Deffand moved Lytton Strachey[66]
says “They refused to grow old; they almost refused to die. Time
himself seems to have joined their circle, to have been infected with
their politeness, and to have absolved them, to the furthest possible
point from the operation of his laws. Voltaire, d’Argental, Moncrif,
Hénault, Madame d’Egmont, Madame du Deffand herself all lived to be
well over eighty, with the full zest of their activities unimpaired.”
Want of this joy in life necessarily engenders carelessness and
neglect of personal hygiene, and loss of the power to react to the
environment. As the years advance and the younger generation come up,
the suggestion that “his day is done,” that he has had his innings,
and that it is time for him to step aside, is made to the senior not
only by his family and his juniors--hetero-suggestion--but by himself,
and he may then, after the modern fashion, get into the habit of
repeating mentally “I am getting older and older every day.” A slight
illness or incapacity may be magnified into a conviction that the
end is near, and as a result of the loss of self-reliance a state of
increasing invalidism is established and becomes progressive without
any other cause. Just as a fall, an exacerbation of rheumatic pain,
a slight operation or indisposition, necessitating rest in bed for a
short time, may be followed by a functional loss of power in the lower
extremities, so a more general suggestion of failing powers may lead
to mental deterioration. Thus too often a man’s last occupation is
to shorten his existence and make it miserable. Finot,[67] who rather
optimistically believes that man should be able to live 150 years,
regards this poisonous auto-suggestion as one of the factors that
prevent such an achievement. Observation of contemporaries suffering
from premature senile changes, due to pathological factors, may no
doubt stimulate this destructive form of auto-suggestion. There is
therefore a basis for the idea[68] attributed to the late Lord Rhondda
that old age was a transferable disease, and for his avoidance, as
far as possible, of the society of the aged on account of the risk of
contagion. Association with the young keeps one more or less of the
same age, very probably by suggestion to the unconscious, or in Oliver
Wendell Holmes’s words “While we’ve youth in our hearts we can never
grow old.” From experience at the Royal Hospital, Chelsea, where there
are 500 pensioners, Thompson and Todd[69] are convinced of the powerful
factor of lowered mentality due to loss of self-reliance, self-respect,
and the instinct of self-preservation in inducing premature senility,
and have been most successful in counteracting this by antidotal
suggestion conveyed by cheerful chaff and by the avoidance of
sympathetic condolence.
In addition to the _joie de vivre_ a happy disposition that thinketh no
evil, has no jealous suspicions, and is free from the tendency to worry
has an important influence in keeping the mind and body young. The
power of detachment from work and anxieties, as if the mind were fitted
with thought-tight compartments, is a valuable asset in maintaining
vitality unimpaired; this was a trait in Gladstone and Kitchener.
Professional men who retain their offices as in the Church, the Civil
Government, the Bar, tend to live longer than business men who retire
to leisured ease after a strenuous struggle. B. Yeo’s[70] analysis of
42 Bishops and Deans, 49 Judges, and 188 Peers, showed that in all
three classes the average duration of life was practically the same,
namely, 72 years. Among churchmen mention may be made of Cardinal de
Salis (110), Gregory IX. (100), Abbé Maignon (100), Martin Routh (100),
for 63 years President of Magdalen College, Oxford, thus surpassing
the more modern instance of Edward Atkinson, aged 96 years, for 59
of which he was Master of Clare, but not that of Laurence Chaderton
(1536–1640) who, after being Master of Christ’s College, Cambridge,
with great success for 38 years, survived for 18 years and became a
centenarian. There are some remarkable examples of artists retaining an
active life to a very advanced age, such as Titian, Giovanni Bellini,
Michael Angelo, Sidney Cooper. Politics often keep men busy and active
to an advanced age, and the names of Palmerston, Brougham, Lyndhurst,
the octogenarian premiers Gladstone and Clemenceau, Strathcona, Sir
Charles Tupper naturally come to one’s mind. In the legal profession
Chief Justices and Judges can retain their seats and so keep up their
vigour long past what is regarded in some walks of life as the retiring
age. Sir Edward Coke (82), Lord Mansfield (89), Lord Brampton (90),
Lord St. Leonards (93), and Lord Halsbury (97), are examples in point.
Within recent years there have been two octogenarian Lord Mayors of
London, Sir Thomas Crosby (in 1911), and Sir John James Baddeley
(1921); the first created a record by being the first medical man
to hold this office, and Sir John Baddeley celebrated his year of
Mayoralty by bringing out a beautiful historical account of Cripplegate.
[Illustration:
FIG. 9.--Sir Henry Alfred Pitman (1808–1908), M.D., Camb.,
F.R.C.P., Registrar of the Royal College of Physicians of
London, 1858–1889.
From portrait in the Royal College of Physicians of London, painted in
1886 by W. W. Ouless, R.A.]
From the inevitable exposure to infection and worry the medical
fraternity is generally considered to rank low in the professions as
regards longevity, but it is easy to point to exceptions especially
among those whose mental vigour made them prominent in their own and
in one instance for all time. Hippocrates is variously stated to have
died at the ages of 85, 90, 104, or 106 years with the words “I leave
behind me two great physicians, temperance and frugality.”[71] I have
references to 43 medical centenarians for 18 of which, including the
record of W. G. Meade, physician at Tunbridge Wells and buried at Ware,
Herts, in November 1652, aged 148¾ years, I am indebted to my friend
Mr. R. R. James. The only one that I knew personally was Sir Henry
Pitman, for 31 years (1858–89) and until his 82nd year Registrar of the
Royal College of Physicians of London. Among the others Dr. de Bossy
of Paris may be mentioned as the son of a centenarian. From analysis
of 2113 eminent medical men Drinkwater[72] found that the average
age was 67 years, or considerably above the average age of the male
population over 21 years, which was estimated at 59 years, and that 627
or nearly a third of them all were between 71 and 80 years of age.
But the examples given of mental activity late in life, and they could
easily be multiplied,[73] are exceptions to the rule that the majority
of men begin to fail in their work between 60 and 70. This no doubt
is because most septuagenarians suffer in greater or less degree from
pathological old age. In the case of the healthy vigorous man enforced
retirement at the age of 65 or 70 is not to the advantage of either the
retiring victim or the community, for it restricts his opportunities
for production and useful activities guided by ripe experience. To
quote examples of epoch-making work done by men long past the age when
the majority have lost originality, initiative, and elasticity of mind:
Galileo, Newton, Charles Darwin, Sophocles, Voltaire, Molière, Goethe,
Michael Angelo, and Titian, made original and lasting contributions
to science, literature, and art long after fifty. Morgagni’s famous
_De Sedibus et Causis Morborum_, brought out when he was 80, and
the Commentaries of W. Heberden (aged 91), published posthumously,
represent the accumulation of many years and so cannot be fairly quoted
as examples of ability persisting into late life. Rules and regulations
must, however, be based on what is best for the majority and hence,
though the exceptions are prominent and regrettable, the age limit
of 65 to 70 must at present be accepted as generally advisable for
otherwise permanent appointments.
Although functional activity maintains the tissues in a state of
health, it is not an infallible panacea for the prolongation of life;
in the first place the danger of overwork and excessive fatigue must
be borne in mind. While the attractive suggestion that excessive
functional activity leading to extreme hypertrophy may exhaust the
vitality of the tissues and lead to atrophy, may not be borne out by
the examples quoted in its favour, such as the occupational neuroses
and atrophy of the upper arm muscles in hammermen and file-cutters,
there is some reason to retain a belief that this sequence of events
may occur, for example in dilatation of the extremely hypertrophied
hearts seen in long-continued high blood pressure, renal disease,
and valvular lesions;[74] but even here the possibility of other
degenerative changes, due to toxaemia, must be borne in mind. Further,
functional activity while keeping the cells of the body in a healthy
state depends on their structural integrity, and this in its turn is
the outcome of the modifications due to environment, and possibly of
the inborn lease of vitality. So that although an active life may
within limits prolong life, there are many instances in which, from
extrinsic pathological influences or inherent inadequacy, it fails to
do so, and a man becomes unequal to the demands of his position.
PERSONAL HABITS
All experience, medical and lay, such as is embodied in Cornaro’s
oft-quoted memoirs, Leonardus Lessius’s _Hygiasticon or the right
course of preserving life and health until extreme old age_ (1613),
George Cheyne’s _Essay of Health and Long Life_ (1724), Metchnikoff’s
orthobiosis, and the Arabian proverb of the ninth century, quoted by
Lacassagne,[75] that “the greatest dangers for an old man are a good
cook and a young wife,” is in agreement as to the immense importance of
strict moderation in indulging the appetites for the prolongation of
life. The life histories of centenarians show that they have usually
been small eaters, especially of meat. This is generally explained in
terms of minimizing toxaemia, and it has been said that “man does not
die, he kills himself” (Montaigne) and more graphically, if coarsely,
that “he digs his grave with his teeth.” In some lower forms of life,
such as the planarians (Child), partial starvation and the resulting
reduction lead to rejuvenescence and so to the inhibition of the onset
of senescence; hibernation has somewhat the same effect, though perhaps
this might be partly explained as merely starvation during prolonged
sleep. The question has often been raised whether partial starvation
in man has any such positive influence, and unprofessional “cures” on
these economical lines have not been unfashionable. It might indeed
be argued that the Allen treatment of diabetes, in which starvation
is followed by increased carbohydrate tolerance, depends on a certain
degree of rejuvenescence. Cures consisting in purgation may act by
partial starvation as well as by obviating toxaemia. After a period
of starvation a normal person may become heavier than before, and his
general health be improved. But in the present state of our knowledge
and in the light of the dangers of starvation the further investigation
in man of this problem is one that demands serious hesitation.
As to the bad influence of alcohol on longevity there can be no
reasonable doubt. Alcohol is a protoplasmic poison causing degenerative
changes in the cells and reducing the resistance to infection. A
collective investigation undertaken by Sir Isambard Owen[76] showed
that there were very few hard drinkers among the long-lived, and
Sir George Humphry concluded that the characteristics of the aged
included temperance; among 46 centenarians one, and among 73 men over
90 one confessed to taking too much occasionally, and out of 298 men
between 80 and 90 years of age 45, or 15 per cent, were classified
as taking much alcohol. That such exceptions occur is explicable by
great inherent vitality. It has been said that “wine is the milk of
old people,” but from his experience of the hygiene of the elderly Sir
Hermann Weber was not in sympathy with this view, and he pointed out
the weakness of the popular idea that the moderate enjoyment of alcohol
was harmless; for so-called moderate drinking is in reality often
immoderate indulgence for the individual, and most of us must have
recognized from observation that long-continued though moderate use
of alcohol is followed by premature deterioration. The proverb _vinum
lac veneris_ and the tendency that alcohol has to lead to incontinence
and so to venereal infection may be borne in mind in considering its
influence on longevity. As a medicine alcohol has its occasional use,
and though it may be a food it is an expensive one.
Smoking among centenarians was specially investigated by Sir George
Humphry, who found that among 19 male centenarians 8 smoked much,
one a little, and 10 not at all; while out of 30 female centenarians
4 smoked much, 2 moderately or little, and 24 not at all. There is
no doubt that with advancing years there is commonly a relative loss
of tolerance for tobacco, so that unpleasant symptoms ranging from
cardiac extra-systoles, through abdominal pain, to tobacco angina,
may dictate discontinuance of the habit. But a large number of old
people have smoked in earlier life though subsequently non-smokers.
Personal tolerance to tobacco shows great variations, and there is no
doubt that well-marked symptoms may be caused by tobacco. But that
moderate smoking diminishes the chance of longevity has certainly not
been proved. Much discussion has taken place as to the relation between
smoking and arteriosclerosis; it is true that in animals nicotine in
considerably larger doses than can be absorbed by smokers, damages
the arteries, and Huchard and Lazarus were convinced that it caused
arteriosclerosis. Sir Clifford Allbutt,[77] after quoting the various
opinions, points out that if tobacco be a cause of arterial disease,
it acts very slowly, for at 45 years of age, after a quarter of a
century’s exposure, the smoker’s arteries are not distinguishable from
those of the abstainer’s; and he mentions the arteriosclerosis of
the ancient Egyptians and of women as incidents detracting from any
argument that tobacco is an important cause of arterial disease.
A large proportion of the centenarians and persons over 80 years of
age collected by Sir George Humphry obeyed the adage early to rise and
early to bed, and I well remember that he used to lay stress on the
factor of getting up directly one woke and so denying the flesh the
luxury of further sleep. Whether going to bed early and getting up
early is more than an index of a life otherwise spent in accordance
with the late Sir Andrew Clark’s “laws of physiological righteousness”
may be questioned.
_Bodily Conformation._--Long-lived people are usually spare, obesity
being rare, and, allowing for some shortening due to age, of a good
average height (Humphry). It is interesting in this connexion to quote
the conclusions arrived at by Robertson and Ray[78] from comparison of
groups of long-lived and short-lived white mice in similar conditions.
The long-lived were relatively stable, highly resistant to external
disturbing factors, displaying subnormal variability and a more or
less well-marked, but not invariable, tendency to early overgrowth
and relative paucity of tissue accretion in late life; while the
short-lived animals showed exactly the opposite features with a
tendency to rapid increase of tissue in late life.
The importance of a healthy life with plenty of fresh air, sunshine,
exercise, proper diet, and absence of worry hardly needs insistence.
Leonard Williams[79] has epigrammatically summed up the hygiene of old
age as “Fresh air, meagre fare, freedom from care.”
V
THE CAUSES OF SENESCENCE AND GENERAL ATROPHY: LIMITED VITALITY
OF CELLS--INFLUENCE OF THE ENDOCRINE GLANDS--METCHNIKOFF’S
PATHOLOGICAL EXPLANATION
SENESCENCE AND CARCINOMA
The causation of old age is so complex that it is not possible to
argue with any conviction that any one of the following explanations
exclusively solves the problem satisfactorily.
LIMITED VITALITY OF THE CELLS