In our survey of the processes and organs of digestion, we saw that after food has traversed the stomach and small intestine it passes into the colon, where it must remain for some considerable time, while the absorption of its digested elements is completed. And this brings us to the most important of the discoveries of the new hygiene. It has been found that some of the foods which human beings eat are loaded with injurious bacteria, and with the poisons which these bacteria produce. And others of them are indigestible, and when they reach the colon, become a source of incubation for countless billions of other bacteria. It was demonstrated by Metchnikoff that these poisons are absorbed into the system, and are the cause of manifold evils. This is the process which is called “autointoxication.”
It would not be regarded as an exaggeration by the leading physiologists of the world to-day to speak of autointoxication as the primary source of nine-tenths of the afflictions from which humanity suffers. Any one would be prepared to admit that the banquet he had attended on the previous night was responsible for the headache which he has on the present morning; but the investigations of bacteriologists have revealed that the food habits of which banquets are typical are responsible for a chronic ailment, of which such diseases as gout, rheumatism, Bright’s disease, consumption, and pneumonia are merely symptoms.
Elie Metchnikoff, sub-director of the Pasteur Institute of Paris, is a philosopher, as well as a physiologist; a philosopher who brings to the support of his speculations the exact methods of the laboratory. He, with the other great leaders of the new art of health, is at last removing from science the reproach leveled at it by Metchnikoff’s great fellow-country-man and friend, Tolstoi, who said that science was useless to man, since it did not direct its attention to the problems which mean most to humanity, such as the great questions of life and death, but confined its efforts to investigating useless birds and butterflies.
The books in which Metchnikoff has recorded the results of the investigations which for many years he has been making into the problems of old age and death, have caused a profound sensation in the scientific world. In these books, the great Russian emphatically and definitely ranks himself with the optimists. He states that scientific study of the constitution of man, and of the workings of man’s nature, and of his environment in the world, do not support the view that man is born unto sorrow as the sparks fly upward—to quote the words of the Psalmist—but can really be fitted to live a useful and happy life, ending in a calm and peaceful old age—if man will but turn his attention to the knowledge by which he can really live in harmony with his environment. Metchnikoff has arrived at the conclusions that man and woman would live to be at least one hundred years old, if they could enable their bodies to eliminate those deadly toxins which are the product of the activities of the bacteria which inhabit the human body, as well as of the body’s own organic processes.
Age is not always to be computed in years. As a common saying puts the case, “A man is as old as he feels, a woman as old as she looks.” A famous French physiologist has altered this to read, “A man is as old as his arteries.” The primary change produced by the coming of old age is the hardening and withering of the arteries. As the result of this withering process, a large number of the smaller arteries disappear, so that the blood supply of the muscles, brain, heart, and other important organs, is cut off. This is the change that is technically known as “arterio-sclerosis.” It is quite often found in persons of less than fifty years of age. On the other hand, Harvey, the famous discoverer of the circulation of the blood, declared that in the post-mortem examination made of Old Parr, the celebrated Englishman who died at the age of one hundred and fifty-two years and nine months, he found not a trace of this degenerative change.
In the United States the average length of life is about forty-two years; but a large and growing school of modern scientists (comparative anatomists) declare that the natural age of the human family cannot be much less than from one hundred, to one hundred and twenty-five years. Any death that comes at least before one hundred years, is not a natural death but accidental or violent. From the point of view of science, death through disease is just as accidental and violent as the extinguishment of life in a railway wreck or by drowning in the sea; and the fact that the average life of man is to-day only about one-third of that which nature designed for him is due to the operation of autointoxication more than to any other cause.
Natural death in man is therefore more a possibility than an actual occurrence. Nevertheless, instances have been recorded of the actual appearance of the instinct in aged people, where the wished-for death came not because life was burdensome, not because of poverty, disease, or loneliness, but seemed to arrive as naturally as sleep to a younger person, or the wish for more extended life which all of us possess. Metchnikoff states that instances of veritable cases showing an instinct of death are extremely rare, yet this instinct really does seem to lie deep in the constitution of man. And if the cycle of human life followed an ideal course, he concluded men and women after living a healthy and useful life extending over at least a century, with their usefulness and satisfaction in life at maximum during the latter portion of that period, would then give themselves up calmly and gracefully to the arms of death, as to the arms of a friend laying them down to earned and wished-for rest. Old age would have no terrors, and death no victory.
It has been, perhaps, Metchnikoff’s crowning discovery, that the immediate cause of old age is not merely the accumulation of poisonous wastes, but is due to a destruction of the tiny cells which make up the tissues by certain cells of the body, which he describes as macrophages. These are of an especial kind, which wander through the body and devote their energies to the destruction of waste particles and organic débris—particles of material which are not used in the building up of tissue, just as particles of brick and wood might be left on the ground after the erection of a house. These macrophages enact the part of scavengers, very much like the turkey buzzards, which in southern cities eat up the refuse from the back alleys. Just so long as these wandering cells confine themselves to this useful and necessary work, all goes well; but when the vigor of the body cells has been lowered by the accumulation of tissue poisons, these scavenger cells turn traitor to the cause of the body and attack the very cells which they formerly guarded. They have been photographed in the very act of devouring nerve cells in the brains of old people.
It can readily be seen that if the pernicious activity of these macrophages can be prevented, the coming on of degenerative changes in the body tissue will be much delayed. The practical question, which Metchnikoff therefore asked himself was, How may this revolt of the macrophages, this rebellion of the body’s army, be prevented?
It is not possible to attack the macrophages themselves without at the same time doing damage to the body. For these wandering cells are more hardy and vigorous than the higher cells by which the bodily functions are performed, and which they attack, so whatever might be done to weaken the attack of the wandering cells would to a greater degree damage the higher cells of the body. The conclusion that Metchnikoff reached was that the only direction in which we can hope for success in the attempt to prolong human life, lies in giving attention to the predisposing causes which weaken the vitality of the higher body cells and thus expose them to the successful attacks of the scavenger cells. In other words, if we are to prolong human life, we must make the conditions of life such that the premature accumulation of body wastes or poisons shall be prevented.
One of the first steps to take to affect that end is, obviously, the avoidance of the introduction of poisons, and poison-forming foods, into the body. Out of all proportion to all other causes which lead to the formation of body poisons, is the production of toxins in the colon or large intestine. Metchnikoff’s studies show beyond a doubt that there is a close connection between the size of the colon and the duration of life in various birds and animals. Where the colon is used, and has attained large proportions, as in man, in the horse, and many other animals, life is comparatively short, and death is premature. Where the colon is rudimentary, or where only such foods are eaten as do not decay or ferment in the colon, then life is long.
Thus the most important problem, according to Metchnikoff, is how to prevent the development of poisons in the colon. He believes that the colon, indeed, is quite superfluous, and that man would be better off without it. He quotes several curious cases in which the colon has been removed from the body, and the subjects of the operations have recovered impaired health and lived for long periods afterwards. Since the colon cannot be generally removed from the body, however, the practical problem comes down to this: How may we avoid the evils which result from the fermentative and putrefactive processes which go on in this organ?
If the large intestine is kept clean, if only those foods which are antitoxic are eaten, then there will be very few poisons generated in the colon, and the health of the body will be maintained in a higher degree and for a much longer period than can be possible when toxic foods are freely partaken of. It is here that the great argument for vegetarianism on its scientific side arises. All meats and fish are not only “toxic” foods in themselves, but they are quite likely to contain parasites of various kinds.
Ordinary bread has been shown to contain a sufficient amount of proteid to supply all the body needs, as do also rice and other cereals and potatoes. Nuts and dried peas and beans are exceedingly rich in proteid, like meat, and therefore should be eaten sparingly. The best foods in the order of excellence are given by Dr. Kellogg, as follows—the antitoxic foods being in italics: fresh ripe fruits, cooked fresh fruits, cooked dried fruits, nuts, cooked cereals, rice, zweibach, toasted corn flakes, potato, cauliflower, and other fresh vegetables, honey, malted nuts, yogurt, or buttermilk, sterilized milk, and cream, peas, beans, lentils, raised bread, and sterilized butter.
Since the poisons which are produced in the colon are due to the growth and cultivation of germs, the remedy which naturally suggested itself to a bacteriological specialist like Metchnikoff was to find some harmless or comparatively harmless germ with which the poison-forming germs might be fought—or, in other words, to introduce into the body an extra battalion of soldiers to assist the warrior cells in the battle of the blood.
After years of study and research, Metchnikoff found this beneficient germ in various lactic acid forming microbes, particularly an especial microbe known by the name of Bulgarian bacillus, or Yogurt. This bacillus grows in milk, and in growing it produces large quantities of pure lactic acid. It does not decompose fats, nor does it produce alcohol, as do other lactic forming germs, such as those found in kumyss, matzoon, and kephir.
Milk is first sterilized by boiling for a few minutes, then allowed to cool and a quantity of the ferment is added. In a few hours a sour taste which is pleasant to all whose palates relish mild buttermilk, is developed. Metchnikoff advises that a pint or a pint and a half of this sour milk be taken daily. By this means large quantities of the acid forming and beneficient germs are taken into the intestine, and by degrees the poison producing germs are killed or driven out. Thus the work required of the kidneys, the liver, the skin, and other excretory organs is lessened, and the vigor of the living cells is maintained so that the macrophages do not attack and destroy them.
In Bulgaria where Yogurt is a staple article of food, there are more centenarians, and more vigorous old people to be found than anywhere else on earth. Not only are the Bulgarians and the Hungarians the longest lived races in Europe, but they show a remarkable freedom from appendicitis, colitis, and other diseases due to intestinal infections, circumstances which called the attention of European physicians to a study of the milk ferment which produced Yogurt, and led to the scientific investigations, first by Masson of Geneva and later and more completely by Metchnikoff and Kellogg, which have placed its use both as a curative and a preventive agent upon a thoroughly scientific basis.
Its use is bound to supersede that of kumyss, kephir, matzoon, and other lactic acid ferments on account of the fact that these ferments are able to live only in the small intestine, while Yogurt bacillus thrives in the colon, where it may be found weeks after the administration of Yogurt has ceased. The importance of this fact will be seen at once when it is recalled that the colon is the chief seat of the anaerobic infection and poison production which are the causes of intestinal autointoxication. Thus the last word of modern science on this subject would seem after all to be but the confirmation of a means for reaching natural old age which has been known for hundreds of years. But to-day we are learning to use means for the prolongation of life by the light of knowledge; no longer blunderingly, handicapped by evil habits which nullify the value of the small fraction of hygienic truth which we possess. To-day, Hygeia, while it holds out to our lips an elixir of life, insists that if it is to have its maximum power, we must also breathe rightly, sleep rightly, and eat and drink rightly.