The Influence of Fasting on
Growth and Regeneration


   In a previous chapter I have discussed the chemistry changes in the body during a fast and have there shown how the body distributes its reserves as need arises. At this point I desire to approach this subject from a slightly different angle. A brief study of Growth and Regeneration during the fast will help us to see the remarkable power of the body to refine and use the materials it has on hand, when deprived of food from without.

   Growth is determined by two groups of causes--namely; the internal factor, of Growth Impulse, and the external factor, of Growth Control. The nature of the growth force or impulse, which is the real cause of growth, is wholly unknown. It is deeply rooted in the constitution of the organism and we say it is a predetermined, hereditary impulse to grow to a certain maximum under the most favorable conditions. This growth impulse is latent in the germ plasm and may be considered identical with life. The factors that control growth are pretty well known. These are food, water, air, warmth, sun light, or the absence of these. Internally we find, in the ductless glands, a remarkable chemical mechanism for regulating growth.

   As before stated the growth capacity, which varies greatly with various species, is determined by heredity. Experiment seems to show that this impulse cannot be increased or completely repressed, although it is subject to considerable limitation. The interruption of nutrition by food deficiency or insufficiency or by inanition interferes with growth, but neither of these wholly suspend it. Judged by the gross weight of the body, growth may seem to be at a standstill, or even seem to be sliding backward. But this is very deceptive. A fasting organism that is losing weight and is consuming its reserves quite rapidly, may still be growing.

   Prof. Morgulis says the body "is a mosaic of interrelated parts, each, however, having its own growth history. The growth curve of one portion of the organism may be ascending while that of another has already reached the peak of its growth or indeed is on the downward course. Furthermore, the growth impulse of one may be great and that of another feeble. At times of plenty when there is enough nutriment to furnish building material for every part of the organism, the gross increase in weight is a good measure of the resultant growth; but it obscures the essential fact of the composite nature of the growth phenomenon. Walter's experiments with growing calves and Aaron's work on dogs illustrate this idea. These investigators discovered independently of each other that through chronic under-feeding they could keep their animals at a constant body weight but could not bring about complete standstill of the growing process. The part of the organism which at that phase of the development possesses the strongest growth impulse is potent to attract to itself whatever building material is available, and this not sufficing, will even encroach upon the reserves of other tissues. We witness, therefore, cataplasia or reduction of certain parts of an organism along with a progressive building up, or euplasia, of others. Such a condition has already been shown to exist in the salmon during the spawning season when these animals take no food sometimes for several months, and while all organs are used up, especially the muscles, in furnishing energy to the starving salmon, their gonads grow and develop luxuriantly. The young calves and dogs whose diet was thoroughly adequate in quality but not enough in amount, continued to grow though retaining a constant weight, but the growth was limited only to the skeleton. This increased both in size and mass, and as a result the animal actually grew in stature. Even the muscles were depleted of their stored material to satisfy the growth impulse of the skeleton."

   The process of "robbing Peter to pay Paul" seen in these phenomena shows to a remarkable extent the power possessed by the body to distribute its supplies according to need, and thus preserve the integrity of the whole. If the robbing of Peter is not carried too far, no harm comes from it, for the consumed stores are readily and quickly replenished as soon as food is added. Growth seems to be independent of food in the sense that food is not the cause but only the material of growth. Dr. Morgulis finds in the phenomenon of regeneration a most remarkable exemplification of the fact "that the growth impulse of a particular organ may be sufficiently puissant to draw to itself nutriment and to infringe upon the reserves of the less active tissues and cause them to undergo cataplasia."

   Properly conducted, fasting actually promotes growth. Thompson and Mendel found that a period of suppressed growth, due to under-feeding is followed by increased growth when better food is given, and that the acceleration of growth following this suppression, is ordinarily accomplished on less food than is consumed during a period of equal growth at normal rate from the same initial weight. Morgulis says: "It has been repeatedly emphasized that just as soon as an animal, which through acute or any other form of inanition lost weight, is given proper nourishment, it commences to grow at a spectacular rate and in a comparatively brief period regains all it had lost or even increases beyond the original level. The rapid gain in weight is a manifestation of a vigorous process of growth. There is not merely an accumulation of reserve substance, but a true growth in the sense defined previously. There is prolific cell multiplication, great expansion of the cells and a reaccumulation of reserves in the form of intracellular and intercellular deposits of products of their metabolism. Nitrogen is retained with an avidity characteristic of the young growing organism. Frequently, in a short span of time an increase of the body mass is accomplished, which required years of normal growth to bring about. The inanition has produced a rejuvenation of the organism. In the study of histological phenomena accompanying inanition, it has already been learned that except in the advanced stages (in the starvation period) there is scarcely any evidence of tissue degeneration. On the contrary, the cells remain intact though they lose a large portion of their substance. In the keen competition which reigns in the organism subjected to inanition the weaker and less essential parts of the cellular organism are sacrificed first, just as we have seen this to happen to the less essential parts of the entire organism. The more vital parts remain and the vitality of the cells and their vigor is thereby improved. This seems to be the rationale of the invigorating and rejuvenating effects of inanition. Biologically speaking, though the organism acquires no new assets it becomes stronger by ridding itself of liabilities. In the foregoing it has been pointed out that the cell-nucleus ratio changes in such a manner as to increase the preponderance of the nucleus. Morphologically, therefore, the cells composing the entire organism assume a youthful condition. They resemble more the embryonic cell in this respect, and this may account for the expansive growth which they display under the proper nutritive regimen."

   Again, he says: "Further experiments performed with the salamander, demonstrated that the growth impulse and not the quantity of food consumed plays the leading role. These experiments substantiated the idea that growth which ensues after a preliminary inanition is not unlike embryonic growth in its intensity. It is well to bear in mind that the reduced size of the cell, or rather the altered cell-nucleus ratio is probably in some way responsible for the vigorous growth process, and that the rejuvenescence of the organism is dependent upon this condition. Many years ago, Kagan observed that following 17 days of complete inanition rabbits gained 56 per cent in weight on a diet which could just barely maintain a state of equilibrium in the normal condition."

   Regeneration is common to a greater or lesser degree to all plants and animals. If man loses a fingernail, he quickly grows another, but even more remarkable examples of regeneration are seen in many animals, some of them being able to grow a new head, a complete new limb or an eye. In some worms a mere fragment of the body is capable of becoming a complete new worm, Many examples of this have been presented in a prior volume.

   Prof. Morgulis says: "It is a remarkable fact that the starvating organism does not lose its regenerative power. An organism already much emaciated through prolonged inanition will draw upon its scanty reserves in the effort to renew a severed part of its body. The little flat worms, planaria, commonly found in stagnant waters, possess an extraordinary regenerative capacity. Morgan has shown that even in advanced stages of inanition, when the planarian has been reduced to a small fraction of its original size, the regenerative impulse is still sufficiently strong to reduce still further the much depleted tissues in rebuilding parts of the body which have been cut off. Of course, during inanition the missing organ does not regenerate as rapidly or as fully as in a well-fed animal. The important thing, however, is that inanition does not deprive the organism of its inherent regenerative impulse."

   Discussing the fact that fasting does not interfere with the regeneration and growth of a new tail in the salamander, whose tail has been cut off, Morgulis tells us that, although the tail grows slower while the animal is fasting than the tails of animals not fasting, "when, after several weeks of starvation (fasting), the salamanders having in the meantime lost one-fourth their original weight, they were fed once more, the regeneration of the tail was immediately improved and in the course of time attained or even exceeded in length the tails which were cut off."

   The Rhine salmon take no food from the time they enter the fresh water until their spawning season is over; a period varying from eight to fifteen months. The King Salmon of the Pacific coast, the largest and finest of the salmons, present an even more remarkable case of growth while fasting. They make a long and extremely exhausting journey upstream without food. There is evidence to show that they cease to feed before they begin their migrations upstream.

   Salmon waste quite rapidly during their migrations, due not only to their vigorous activities, but to the rapid growth of their gonads. It has been estimated by Paton that 5 per cent of the fat and 14 per cent of the proteins of the wasting muscles of male salmon go to build up their rapidly growing testicles; while 12 per cent of the fat and 23 per cent of the protein of the muscles of the female go to build up the rapidly growing ovaries. The rest of the fat and protein that disappear from the muscles are used up in maintenance and work. Despite the rapid wasting of muscles in fasting salmon, Miescher maintains that not a fiber undergoes actual disintegration.

   Our interest in the phenomena at this place, is to point out the remarkable manner in which the body regulates its internal economy and distributes its stored supplies to various parts of the body as need arises. This ability to analyze and redistribute and re-synthesize the supplies on hand, is our supreme guarantee that none of the vital tissues shall ever be damaged for lack of food, so long as the body's reserves hold out.

The continuance of growth while fasting and the rapid acceleration of growth after the fast, indicate very strongly that the body holds onto and uses to greater advantages those substances or qualities in food which are called vitamins and which are claimed to play such important roles in growth and regeneration of tissue. It may even be true that the body does not lose any of its stored supply of vitamins during the most prolonged fast. The complete lack of evidence to show that it does lose vitamins is as suggestive as is the positive evidence that fasting does not only not stop growth, but actually, accelerates it.