The Secret of Longevity

I

IT is safe to say that primitive man was little concerned about the length of time he had to live. The struggle for existence occupied most of his time and there was little opportunity for reflection, introspection, or speculation about anything but the present or the immediate future. However, as man ascended a little higher in the evolutionary scale he became curious about his span of life. The prayer of the Psalmist, ‘Lord, make me to know mine end, and the measure of my days, what it is; that I may know how frail I am,’ is one of the early indications of this developing trait.

While he was curious as to the length of his days, there was little evidence that he took any active steps to prolong them. The science of medicine developed slowly, and illness and death were ascribed to the influence of evil spirits rather than to evil germs or to the natural process of senescence.

However, as man became further civilized he finally arrived at the point where it was not necessary to devote his entire time to the struggle for the necessaries of life, and he had leisure to reflect and formulate ideas regarding life and also regarding death and its causes. Medical science began to delve into the abnormal activities of the various organs of the body, and the science of pathology began to show that death was the result of changes in certain of the organs resulting from disease processes. It is rather remarkable that little attempt was made by scientific men in the early days of medicine to investigate changes which occurred in the body by means of postmortem examination. There was a strong prejudice against allowing this sort of examination to be carried out, and the early anatomists were frequently subjected to considerable personal danger by insisting on postmortem examinations and anatomical dissection.

Up to the time of Vesalius, medical men learned anatomy by a study of Galen instead of by performing anatomical dissections. Practical demonstrations were usually made on lower animals, and the pig was frequently chosen for this purpose. Furthermore, the professor was inclined to occupy an elevated seat and discourse learnedly from the writings of Galen and Avicenna while the demonstrator pointed with a long staff to the various organs and the dissection itself was performed by a barber. Vesalius complained bitterly of this arrangement and remarked that his teacher, Guinterius, never used his knife for any other purpose than to cut his steak.

The populace was decidedly against this means of investigation, and, while this feeling has disappeared to a great extent, it has by no means been eradicated even at the present time. The percentage of autopsies in our modern hospitals has been greatly increased in recent years and medical men are losing no opportunity to perfect themselves and to acquire additional skill and knowledge regarding disease processes by this measure. Our hospitals are now graded partly on the percentage of autopsies obtained. An institution showing a decidedly low percentage of autopsies can hardly be expected to be in good standing in the eyes of the medical profession. The inspectors of such a hospital are inclined to believe that the staff of the institution was probably not particularly concerned about what caused the patient’s death.

There is probably no one procedure which will tend to enhance medical knowledge and to further the development of the physician’s skill to a greater degree than careful and thorough post-mortem examinations.

As the knowledge of the causes of death was increased, it was but a step for medical men to inquire as to what means might be employed to combat these various causes. It was found that in many instances death was due to an illness which could have been prevented if the weapons known to medical science had been employed at the proper time. From this point the science of preventive medicine began to assume tremendous proportions.

It has only been in comparatively recent years that the germ theory of disease has been definitely established. The magnificent work of Pasteur served to establish beyond any reasonable doubt that many diseases, the origin of which had been obscure up to that time, were due to microörganisms which gained entrance to the body, with dire results to the patient. From this important discovery rapid strides were made, and preventive medicine has now succeeded in controlling in large measure many of the infectious and contagious diseases which only a short time ago caused tremendous havoc. These preventive measures also resulted in a tremendous drop in infant mortality and a consequent increase in the average span of life.

II

As we ascend in the scale of life and as the organism becomes more complicated and specialized, the power of rejuvenation manifested in some of the lower forms of life becomes lost. Restoration of certain parts which may become lost through violence or disease becomes completely impossible when we reach man. Disability and death are necessary if evolution is to proceed. As the higher organism develops specialized functions of the various organs, death becomes inevitable and really serves to advance life further in the evolutionary scale.

The unicellular organism at the bottom of the scale is immortal in the sense that natural death does not occur. With a favorable environment, the Paramecium, a genus of infusorians, has been observed to pass through 8500 generations without a single natural death. However, there was no advancement in these succeeding generations, and to pay for immortality at such a price would be a decidedly poor investment. As life becomes more worth-while and as specialized functions of the various organs become the rule, the capacity for rejuvenescence becomes increasingly less. It is estimated that, in certain species of worms, 1/250 of the original worm will regenerate and grow into a complete animal. Furthermore, these reconstituted animals appear younger than the parent from which the piece was taken.

In spite of the fact that death is inevitable, man has arrived at the stage where he is devoting considerable time and energy to postponing this change as long as possible. Death still remains a mystery from which the individual instinctively shrinks.

The transition from life to death does not take place in the twinkling of an eye, and it is often difficult to state at just what moment the actual change occurred. In many instances the heart continues to beat for as much as fifteen minutes after respiration ceases. We know that many of the cells of various organs continue to live after what we term death has occurred. If these cells are placed under proper environmental surroundings, they may continue to live for an indefinite period. Nevertheless the individual, as a whole, has ceased to exist.

Self-preservation, the desire to live, may be considered a universal attribute of the human race, in spite of the fact that there are occasionally isolated examples where this desire to live has ceased. The occasional individual who takes it upon himself to end his existence, or the individual who, through disease or suffering, looks forward eagerly toward death, represents but a small percentage of the human race. However, to well-regulated minds death loses much of its sinister quality and comes to be regarded, in due course, as a fitting climax to human destiny, so that it can be approached with a feeling of resignation much as one, after a hard day, looks forward to evening sleep.

The desire to live long is accompanied by the desire to live efficiently, and any programme which has for its object the prolongation of human life must also have, accompanying this increased span of life, the ability of the individual to engage actively and with some degree of effectiveness in the affairs of life. Merely to live offers little to the individual if he has lost the ability to think, to grieve, or to hope. There is perhaps no more depressing picture than that of the person who remains on the stage after his act is over. To prolong physical life beyond the period of mental activity could hardly be regarded as a worth-while procedure. In other words, in addition to promoting longevity, it becomes essential that a certain degree of health, both mental and physical, be maintained. The term ‘health’ is a most elastic quality, difficult to define. I can find no more illuminating definition than that given by Culverwell in a treatise published in 1848: —

He who can see well, hear rightly, can feel his firm purchase on the earth, can fill and empty his lungs, knows the pleasing pain of hunger, and possesses the satisfaction of appeasing it; can sleep soundly — can run or jump — whose memory is obedient to what he stores it with — whose heart is light, and whose body carries with it no pain; — is not such a state of existence delightful? for such is health.

Probably at no other time in the history of the human race has so much attention been paid to the problem of prolonging the span of life. This problem is being attacked from many different angles and by workers in widely separated fields. National and international organizations are directing their energies along these lines, and the governments of practically every civilized country are taking steps to promote longevity among their citizens.

Public-health officials are constantly striving to curtail and eventually eliminate the communicable diseases. Quarantine measures to prevent the spread of this type of disease are being rigidly enforced.

Communities have taken it upon themselves to protect the individual health of their citizens, and no political régime could long remain in power which did not have among its primary objectives that of ensuring an adequate supply of good water, an efficient sewage disposal system, a careful sanitary inspection of foods and drinks, and the protection of its citizens against contagious disease which might arise in their midst. These measures, when intelligently employed, have a remarkable effect in lowering the morbidity and mortality rate of the community. The citizens so protected are on a better economic basis, and the community as a whole is decidedly more prosperous.

The result of this work has greatly justified the efforts made, and the expectation of life in practically every civilized country has become greatly lengthened as a result.

III

From time to time questions are raised about this increase in the span of life, and the Biblical ages are frequently brought forward to disprove the point that man’s average length of life is greater at the present time. It is certainly questionable whether the term ‘years’ used in the Bible had the same significance that we attach to it at present. No doubt there were some individuals, as Moses and Jacob, who lived considerably beyond the average span of life of their times. The old records found in the Egyptian tombs indicate that the expectancy of life about two thousand years ago was only a little over thirty years. The mortality among children and young adults was decidedly higher than now. Among the Romans, the expectancy of life was little better. Rome was notorious for her hatred of doctors. Gradually Greek physicians settled in Rome, but were received with little enthusiasm on the part of the Roman citizenry. Pliny comments on this attitude of the Roman as follows: ‘The dignity of the Roman does not permit him to make a profession of medicine, and the few Romans who begin to study it are venal renegades to the Greeks.’

One of the first tables showing the expectancy of life was prepared by the astronomer, Halley, more familiar to us because of the comet bearing his name than as a statistician. Halley showed that the expectancy of life at birth in the city of Breslau in 1691 was approximately thirty-three years. In the middle of the eighteenth century the expectancy of life at birth in England was thirty-nine years. Following the great sanitary awakening which occurred in practically all civilized countries, the span of life has greatly increased, due to the magic wand of preventive medicine.

At the present time the expectancy of life at birth in the United States has risen to fifty-eight years. These figures represent the trend except for certain countries such as India, where overcrowding and poor sanitation leave the expectancy of life at birth still not more than thirty years.

The desire to prolong life further has resulted in much interesting study, and there is hardly an avenue at present that has not been opened up as a field for investigation to promote longevity still further. In his desire to escape the inevitable as long as possible, man has not always confined himself to strictly scientific measures. Many bizarre, amusing, and even ridiculous measures have been advocated from time to time to ensure longer life.

The secret of life, or the so-called ‘elixir of life,’has been sought by many gallant and adventurous spirits in many climes, but always without success. Ponce de Leon’s search for the Fountain of Youth is but an instance of man’s desire through the ages to escape senescence, decay, and death.

In our own day and age equally startling formulas for escaping senility have been advanced and recommended to an unsuspecting public. Perhaps no one method of ensuring longevity has been oftener advocated by extremists than some sort of dietary régime. The disciples of a strictly vegetarian diet often become very insistent on the virtues of this procedure. One is able to call up a long array of enthusiasts who have recommended first one and then another article of diet as having particular value in promoting longevity. We have advocates of the milk diet, a ration confined to peanuts, a dietary which contains a reasonable amount of alcoholic spirits, and on the other hand a dietary which excludes all alcoholic liquors. No claim is too startling to receive attention and, as a rule, the more unusual the diet which is recommended, the greater hold it has on popular fancy for the moment.

There can be little doubt that food has a material and decided bearing on health and length of life. Many scientific data have been accumulated by experts in this field to show the important bearing which food intake has on health. We know that the absence of certain foods may result in disease and we have also learned that overindulgence in certain foods has a decided tendency to produce disease. The discovery of principles in foods to which the name ‘vitamins’ has been applied has shown that it is not sufficient to consider merely the caloric value of food, but that this content of vitamins must be considered as practically of equal importance with the calorie intake. There are well-established vitamin-deficiency diseases, such as scurvy, rickets, and beriberi, and the list of diseases due to such food deficiencies will no doubt lengthen as additional knowledge is accumulated.

There are dietary régimes handed down from the earliest recorded time, as panaceas for almost all bodily ills. It is a rather significant fact that the diet of races in different parts of the world differs widely and has become adapted to the varying needs of these particular races.

Among the rules of health laid down by Plutarch, the most important, perhaps, were those dealing with diet. He emphasized particularly the merits of a simple ration, and the observations of this sage can still be applied to the modern dietary with great advantage.

Perhaps next in the frequency with which their value has been stressed come the various forms of exercise which have been recommended for their particular health-giving qualities. The public is besieged with importunities to adopt this or that particular system of physical culture, and no claim is too extravagant for some of the advocates of this means of prolonging life.

It is generally recognized that exercise of the various muscles of the body is quite necessary if their tone is to be maintained and if a correct posture is to be ensured. Daily moderate exercise in the open air can be put down as a distinct asset and a health-giving procedure. This need for exercise, however, is a distinct development of civilization. Prehistoric man was compelled to take his exercise if he would procure an adequate supply of food and if he would insure himself against attack by wild animals and molestation by marauding tribes. He had no means of transportation and made his way across country without hope of a lift, with little in the way of trails, with practically no bridges, and often at great personal risk from the elements and from unfriendly neighbors. The unfit physically as well as mentally were unable to keep up with this strenuous pace, and eventually fell by the wayside or were abandoned. A stout heart, good wind, and strong limbs were an absolute necessity if the individual hoped to survive. No hospitals, charitable institutions, or asylums served to keep the unfit alive, and life was little prolonged beyond the useful productive period.

It is difficult to imagine ‘Chief Running Bear’ assembling his tribe and delivering an address to them on the advantage of regular daily exercise in the open air. These things were as necessary to the survival of the tribe as food or drink, and the natives would no doubt have considered the Chief to be in his dotage if he had delivered such a dissertation — just as much so, perhaps, as if he had advised them to partake daily of food and drink. Modern civilization, however, has made it possible for the individual to survive with less and less in the way of physical exertion. Modern means of transportation, labor-saving devices, the push button, the telephone and telegraph, and finally the radio have made it possible for the individual of even moderate circumstances to procure the necessaries of life and even a certain amount of relaxation and amusement without the necessity of indulging in much physical exertion.

Can you conceive of Governor Winthrop issuing an edict to the early colonists, advising them to assemble each morning for regular setting-up drill? No doubt the colonists, receiving such an order after a hard day in the fields, would have held a meeting and immediately put the Governor down as being stark mad.

Nevertheless, at the present day the necessity for encouraging regular daily exercise is generally recognized. One great life-insurance company, at considerable expense, broadcasts each morning a set of exercises designed to improve bodily health and prolong life. Now life-insurance companies are not exactly philanthropic institutions, but they recognize the fact that regular daily exercise tends to promote health and increase longevity, and as a consequence results in increased savings and greater dividends to the stockholders.

Physiologists have shown the profound influence which many of the glands of the body have on growth and health, and indeed it is not surprising that the glands of reproduction have come in for particularly close investigation. Numerous researches have been made and much experimental work undertaken in an attempt to show that the glands of reproduction have a bearing on longevity.

It can be said without hesitation that at the present time there is little or no evidence to show that the so-called ‘ gland transplantation ’ has any bearing whatever in promoting the span of productive life. Nevertheless, the claims for this particular procedure are extravagant and spectacular, and the public is reluctant to abandon such a simple method of escaping senescence. It would be nearer the truth to say that normal functional activity of these glands was the result of robust health in the individual rather than the cause of it.

While it is possible at present to prevent, in many instances, death due to contagious or infectious disease, not nearly so much headway has been made in curtailing deaths due to the degenerative diseases, particularly those affecting the heart, blood vessels, and kidneys. A careful study has been instituted in recent years on the hereditary factors in disease; and, while these studies are still in their infancy, it has become increasingly apparent that there is no one factor which has a greater bearing on the span of life than heredity. Long-lived families tend to produce long-lived offspring, and the children of short-lived families show a decided tendency to be short-lived themselves.

It is recognized that every individual comes into the world endowed with a certain quality as well as quantity of cells. In some instances this quality is inferior; in others, the standard is high. Diseases of the heart and blood vessels now lead all other causes of death, and it is a common observation that the children of apoplectic parents are frequently endowed themselves with arterial tubing of an inferior quality. No doubt future studies will show an even greater relationship between heredity and disease tendencies than we are able to establish at present.

IV

It is interesting to survey the recorded instances where the span of life has been prolonged greatly beyond the average. A careful survey of biographical examples indicates that there is considerable capriciousness with which the gods of longevity select individuals to join their ranks. When the records of many of the so-called ‘centenarians’ are critically examined, it is found that data regarding their birth often are obscure or impossible to obtain and that the individual himself, although admittedly old, has a tendency to confuse events which he heard about in his childhood and gradually assume that they took place during his early life. Nevertheless, when these instances are eliminated, there still remains a considerable group who have attained an expectancy of life decidedly greater than the average.

It is possible to find to-day many individuals who have passed the age of ninety, and even some who have passed the age of one hundred and whose records leave no doubt as to these facts. However, when we come to examine these individuals closely, we find that they do not conform to any particular type, race, color, or creed. Further, if we question them regarding the secret of their longevity, the answers are often vague, misleading, or absolutely contradictory. One centenarian may attribute his long life to the fact that he never used tobacco or alcoholic liquor, while the very next one interviewed may ascribe his long life to the moderate indulgence in tobacco and alcoholic spirits. We find in some instances that the individual has eaten meat regularly throughout his life and in other instances that he curtailed or entirely abstained from this article of diet. One man may give a history of regular daily exercise, whereas in another instance there is little to indicate that he ever took any more exercise than that necessary to go down to the corner store for another cigar.

The mental traits of these centenarians are sometimes advanced as having a distinct bearing on their increased span of life. There can be little doubt that, other things being equal, a calm, placid, and optimistic outlook on life is a health asset. On the other hand, some of our longest livers have been men of impetuous natures, quick to anger, and given to violent emotions. The greatest longevity attained by any of our Presidents was that of John Adams, who was particularly noted for his quarrelsome disposition, hot temper, and violent outbreaks of rage. Yet he lived well into his ninety-first year.

The influence of the mind over the state of bodily well-being is frequently stressed, and there are those who ascribe tremendous weight to this influence. That there is such a relationship no careful investigator questions, but that the mental faculties can of themselves protect the individual against disease, or against the natural processes of senescence, still lacks adequate proof, to say the least.

No statistics are available to indicate that this group of individuals are more free from disease or attain any greater longevity than that of the average of their community.

We must admit that the fountain of eternal youth has not been located and that all signs point to the fact that it does not exist. Furthermore, it is undoubtedly to the best interest of the human race that the elixir of life has not and probably never will be compounded. Goethe speaks of death as nature’s device for securing an abundance of life.

Nevertheless, efforts to increase longevity and to defer as long as possible the processes of senescence and death will continue to be made, and it is reasonable to assume that man’s span of useful life will be still further lengthened as a result of these efforts.

V

From this brief survey, then, what factors can we stress that may have a favorable influence on longevity? In the first place, if you would attain long life, select your ancestors with great care from long-lived stock and ensure that you are endowed with a good quality of cells whose functional activity will continue through the stress and strain of many years. Having started out in life with this superior equipment, husband your resources carefully. You have at the outset a considerable surplus of functional activity of practically all organs. You have probably at least twice as much kidney substance as is necessary to carry on efficiently the work of these structures. Likewise, the lungs, heart, and other vital organs have a considerable amount of reserve. You may expend this reserve freely and even riotously, or you may conserve it rigidly and even add to the store by careful personal hygiene. To attempt to lay down rules of life regarding work, sleep, play, and rest which all might follow would be particularly futile. Each individual is equipped with an heredity and is surrounded with environmental influences which serve to distinguish him from every other individual. ‘One man’s meat is another man’s poison’ contains an element of truth which would serve to discredit a common routine of hygiene for all individuals.

Moderation, temperance, sobriety, are terms somewhat synonymous, but are attributes worthy to acquire if one would extend his span of life.

Medical science offers to the individual the opportunity to protect himself against many of the communicable diseases, and there is little excuse for the well-informed person to succumb or to allow his children to succumb to the ravages of such diseases as diphtheria, typhoid fever, smallpox, and scarlet fever.

The science of dietetics has now been placed on a much firmer foundation than at any time in past history, and it behooves the individual to inform himself on these matters.

To hope that medical science will some day bring forth a simple recipe which will ensure health and promote longevity without effort on the part of the individual or the community is distinctly fallacious and misleading.

Public health has passed far beyond the idea of simply preventing contagious disease. The problem of the future will probably be intimately connected with that of heredity. In his early stages of development man was subjected to the process of natural selection, but upon reaching the civilized state he has gotten further and further from this path. The unfit physically as well as mentally are now surrounded by a multitude of protective laws; and tremendous sums are available from charitable organizations and from the public treasury further to perpetuate this group of individuals who, in a primitive state, would quickly be eliminated.

Herbert Spencer, years ago, expressed his fear of these measures as follows: —

Any arrangements which, in any considerable degree, prevent superiority from profiting by the rewards of superiority, or shield inferiority from the evils it entails — any arrangements which tend to make it as well to be inferior as to be superior, are arrangements diametrically opposed to the progress of organization and the reaching of a higher life.

While no one would advise that these unfortunate individuals be cast out, it might certainly be worth while to inquire as to whether it is not possible to curtail the production of such individuals, or at least to see that such derelicts and incompetents do not perpetuate their stock.

Hardly a week passes without the announcement that some new movement is under way which has as its object the saving of human life. Modern medicine is now being taught throughout the world, and the saving or prolongation of human life will continue to go forward and our humanitarian instincts will continue to dominate our activity.

While the desire to live long is making itself manifest with increasing force, at the same time death has lost much of its terror for the well-trained mind. It can be said that, as a rule, the nearer the individual approaches a natural death, the less repugnant it becomes, and that, having fulfilled his destiny on earth, man, buoyed up by faith and hope, steps off into the Unknown courageously and with firm tread.