ch_pic3VITAMINESandCALORIES
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byD. D. COMSTOCK, M.D.for years Medical Superintendent of GlendaleSanitarium, Glendale, California
The body is a machine, intricate, complicated, "fearfully and wonderfully" constructed. In one way, it is simple in its operations; but in another, so ultrascientific in the detail of its automatic control, and so deep in the mysteries of its chemical processes, that the investigation of ages has not been able to fathom its greater scientific depths, and bring to the surface a knowledge of its ultimate structure and its wonderful workings. The Master Designer of the living machine so adjusted its mechanism that in its original environment and relationship, its care would be easy, and the laws of its preservation few and exceedingly simple.
Like most machines, the human machine requires the impartation of energy. Similarly, also, this is supplied by the combustion of certain carbonaceous substances. It needs constant repair. These and its other needs are all furnished in the daily food supply.
The life of this machine can be greatly lengthened by intelligent care, or shortened by neglect and abuse. Its efficiency may be similarly affected. While one cannot hear the pounding of the engine or the rattling of the machinery, yet the machine is damaged if run under too high a pressure and at too great speed.
There are seven classes of the essential elemental food substances,—proteins, fats, carbohydrates, vitamines, salts, cellulose, and water. The ideal diet is one in which these seven elements are regularly supplied to the body in the amounts required to meet its daily needs. A person living close to nature, receiving his food first-handed, direct from nature's health food factory, and eating it with only the cooking and seasoning necessary, and with a reasonable variety, would probably find his diet sufficient, and the elements in about the proper proportions; and with an honest appetite, steadied by a little temperate-in-all-things ballast, he probably would not go far astray as to the proper amounts. But unfortunately, the average individual is not living close to nature. Much that is artificial has come in. Our appetites are capricious, deceitful, and unreasonable. Our foods come to us processed, cartonned, and tinned, often embalmed, devitalized, or adulterated. They are often served to us so disguised that we cannot tell whether their nutritive substance has been concentrated or diluted, or indeed whether or not the body will recognize it as having any nutritive value at all, despite its pleasing flavor. Therefore, in order that the ideal may be approximated to a reasonable and practical degree, we must have some knowledge not only of the needs of the body, but also of these food elements, and how their values may be estimated in the various food substances.
The foods that enter into the make-up of the body and supply its heat and energy are three,—protein, fat, andcarbohydrate. While the salts to a certain extent enter into the body structure, they have but little to do with heat and energy production. The remaining food classes are adjuncts, their use being simply to make possible the utilization, by the body, of the tissue and fuel foods. The cellulose assists mechanically in digestion; the water furnishes the necessary fluid; and the vitamines provide the battery, as it were, which sets the whole apparatus in motion.
The Heat Unit
Of the many persons who, for economical or hygienic reasons, have tried to adjust their diet better, some have undertaken the task without a fundamental knowledge of the physiological and caloric value of foods, their composition, or the nutritional needs of the body, and have done themselves more harm than good. It is possible for us to measure the value of our foods, and to express it in terms of heat units; and with a knowledge of the bodily needs, we may supply ourselves with foods in approximately the amounts needed, and in the best combinations. Food oxidized in the body produces the same amount of heat as that burned outside the body, and the instrument by which the heat value of any substance is determined is called a calorimeter. The unit of measure of heat is called the calorie or heat unit.
The calorimeter consists of a double chamber, the outer one containing a given quantity of water. The inner chamber is thus surrounded by a water jacket. In it is placed a definite amount of pure, water-free food to be tested; for example, an ounce of sugar. By means of an electric connection, the sugar is ignited and burned, and the heat produced thereby is imparted to the water in the outer chamber. When the process is complete, the difference in the temperature of the water is noted, and theamount of heat generated is computed. The calorie is the amount of heat necessary to raise the temperature of one pound of water four degrees F., or one kilogram one degree C. In this way, the heat values of pure protein, fat, starch, and sugar have been determined. In the laboratories of the United States government, the composition and caloric value of practically every food substance known has been worked out. Any person can have access to these tables of food values by applying to the government, or by purchasing from almost any bookstore any one of the several books on food values, that are on the market. (See pages 23-27 of this book.)
The heat value of a gram of pure, water-free protein—for example, the casein of milk, egg albumen, or fiber of meat—is a trifle more than four calories. That of pure starch or sugar is also four calories. Fat is more than double this value, one gram yielding nine and three tenths calories. Since an ounce equals about thirty grams, the number of calories to an ounce is determined by multiplying the above figures by thirty. Different kinds of food vary greatly in the proportion of the food elements and also of the water and cellulose they contain. (Cellulose has no fuel value in the human body.) We therefore find a great variation as to their caloric values also. For example, one heaping tablespoonful of home-baked beans will weigh about fifty grams, thirty of which is water and cellulose. Its total caloric value is one hundred, divided among protein fifteen, fat forty (the fat has largely been added), and carbohydrate forty-five. Contrast with this the same quantity of mashed turnips. One heaping tablespoonful will weigh about seventy grams, of which sixty-five is water and cellulose. Its total fuel value is three calories.
By a little study, one may very readily become familiar with the approximate values of the more common foods,and be able to arrive at some conclusion in regard to the correctness of one's daily food ration as to amount and proportions. Many would be surprised to see how far short their diet comes of the ideal.
It is easy to remember that an ordinary slice of bread—about three and one half inches square—contains approximately one hundred calories; an average egg, sixty-five; a glass of milk, one hundred fifty; an average potato, one hundred twenty-five; a tablespoonful of gravity cream, fifty; the usual serving of cooked cereal, seventy-five to one hundred; vegetables, except potatoes, an ordinary serving, twenty-five to fifty, depending on the amount of fat or milk added as seasoning; legumes, average serving, one hundred to one hundred fifty. Desserts are usually high in value, ranging from one hundred twenty-five calories in the usual serving of simple custard or junket to three hundred fifty or more in the usual one sixth of some pies, or the ordinary piece of cake.
Housewives who wish to go into the question of foods thoroughly, and combine the science with the art of cookery, may arrange a table of the staples and raw food that ordinarily enter into their various recipes, somewhat after the following, the items of which have been taken at random from such a list or table already prepared and in use:
If the housewife desires to know the food value of a cake, for instance, that she is about to bake, whose recipe calls for two cups flour, one and one half cups sugar, one half cup butter, four eggs, she can very easily find out by consulting her table; as:
If the cake is cut into twelve servings, the value of each may be determined by dividing each of these sums by twelve. Thus each piece will represent in value, protein, twenty-one calories; fat, ninety calories; carbohydrate, one hundred seventy-five calories; total, two hundred eighty-six calories.
The number of calories needed by the individual varies with height, age, sex, climate, and state of muscular activity; but for the average person, two thousand calories daily may be taken as a working basis. If one is engaged in active muscular labor, the requirement may be three thousand or more. Many persons of sedentary habits do better on less than two thousand. Other things being equal, men need about ten per cent more than women. Children need about ten per cent more than adults. An obese individual, or one suffering from the results of imperfect oxidation, as manifested in rheumatism, neuralgia, and myalgia, may do well for a time on as low an allowance as one thousand one hundred to one thousand two hundred food units daily, experiencing marked relief from symptoms, and if obese, a reduction in weight of from one to four pounds a week.
It should be kept in mind that the amount of protein needed is quite constant, and does not vary with one's state of activity, as does the demand for the fats and the carbohydrates. From two hundred to two hundred fifty calories of this element are needed daily, even though the total ration be low. If one does well on the low ration suggested above, the protein should not be lowered proportionately, as would be the tendency. This is the repairsubstance, which the body, not being able to store up, must have supplied to it in regular daily amounts.
Excess in eating is often due to the use of certain concentrated foods. A teaspoonful of olive oil contains forty calories; the ordinary pat of butter (one fourth ounce), fifty calories; a heaping teaspoonful of sugar, forty calories; one English walnut, thirty-three calories; a fair sized olive, twenty calories. While these are good foods, they should be eaten with due regard for their high energy value, that the proper food balance be not disturbed. After eating a good square meal, the average individual calls for the dessert, which, with its accompaniments, actually constitutes a second meal; as, for example, a serving of pie, three hundred fifty calories; its cheese accompaniment, another one hundred calories; a few stuffed dates, another one hundred calories; a few nuts and raisins and a cup of chocolate bringing the total value of this second meal forced upon the body up to seven hundred or eight hundred calories.
Vegetables of themselves are low in caloric value, their importance being due to the cellulose, salts, and vitamines they contain. But they are usually prepared with so much butter or cream that as served they have a high caloric value in fat. Lean meat is practically pure protein, and the tendency of the meat eater is to get an excess of this element. The vegetarian often goes to the other extreme, his diet showing a deficiency in protein, with an excess of fats and carbohydrates. That the protein balance be kept normal is an important matter, for a person may at one and the same time be suffering from the results of a deficient diet and also from the effects of overeating. The protein needed daily is from ten to thirteen per cent of the total ration. If the total daily ration is but one thousand five hundred calories, the protein should still be two hundred calories, and therefore thirteen per cent of thetotal. Thus if a person is living on foods containing less than ten per cent, there is danger of not getting enough of this important element. Much of the food eaten is less than ten per cent protein, because of the addition to it of fat and sugar in large amounts.
So-called meat substitutes should be high in the percentage of protein, in order to make up for the butter, sugar, oils, olives, desserts, fruits, and other very low protein foods that enter so largely into one's dietary. The question has been asked, Why object to the addition of fat to a meat substance, since it does not actually reduce the quantity of protein, though it does relatively? In reply, it may be said that the relative reduction makes necessary an excess of the nonnitrogenous foods, to get enough protein; and even though one's capacity should receive it comfortably, still the objection to the excess aliment remains.
A study of food composition and values will enable the housewife so to plan her meals that the various elements may be served to her family in the proper proportions. A knowledge of calories, and an intelligent application of the principles involved in these questions of nutrition, will enable any housewife to reduce the cost of feeding her family from twenty-five to fifty per cent, which would be worth while from an economical standpoint, not to mention the advantage to be realized healthwise.
Vitamines
Says Lusk, "It has thus far been shown that nutrition means fuel for the machinery, new parts with which to repair the machine, and minute quantities of vitamines, which produce a harmonious interaction between the materials in the food and their host."
In the words of another investigator, "The study of dietetics from the standpoint of the vitamines has onlyjust begun." Sufficient has been learned and demonstrated about them, however, to show that they play a most important part in nutrition and in vital tissue processes. Since they are so little understood, a complete definition is not yet possible. The pure vitamine, it seems, cannot be isolated, so their exact chemical nature is not known. The chemical process necessary to free it is no sooner begun than the vitamine is apparently decomposed, and all trace of it is lost. One is reminded of the efforts of some early investigators to submit living protoplasm to a chemical analysis, they hoping thereby to reveal the mysteries of physical life itself; but at the first intrusion, this subtle something flees, taking its secrets with it, and leaving us only the empty shell of dead protein matter. While the activities and manifestations of life are seen on every hand in animal and plant, we are but little the wiser as to what life really is.
Vitamines seem to stand closely related to the living process in the tissue cells. Some investigators have thought them to be the mother substances of the various bodily ferments and internal secretions, any disturbance of which produces serious constitutional troubles. Therefore the continuous use of a diet lacking in any of these mother substances would of necessity lead to a deficiency of these absolutely essential vital secretions and ferments.
Vitamines and Disease
Years were spent in investigation before it was found out that beriberi, a disease of the Orient, could be cured and prevented by the addition, to the diet, of certain nutritive elements in the covering of the rice, that are ordinarily removed in the polishing process, and thrown away. Just what these nutritive elements were, was not understood; but the fact remained that a diet of polished rice resulted in symptoms of beriberi, while a diet of theunpolished grain was sufficient to prevent any manifestations of the disease. In Java, where the people lived largely on whole rice, beriberi was unknown. For years, the fact had been recognized, that sailors living on canned and preserved foods sooner or later developed scurvy, which could be quickly cured by an addition of fresh vegetables or the juice of fruits, especially lemons and oranges, to the diet. In 1535, when all but three of Cartier's one hundred ten sailors had scurvy, he cured them all by giving them a decoction of fresh pine needles. Babies fed on Pasteurized milk often develop infantile scurvy.
Convincing Experiments
Vitamines are made only in nature's laboratory. The body cannot make them, therefore mother's milk is deficient in vitamine if her diet is. This is demonstrated in a decided way in the Philippine Islands, where the diet is deficient in the vitamine preventing beriberi. Among the Filipinos, one half the deaths take place before the end of the first year of age; and in these infants, one half the deaths are due to beriberi. Pellagra, a disease of obscure ætiology, or cause, manifests itself principally among a class of people who live on a monotonous diet of corn bread, bacon, soda biscuit, and sirup. Some authorities are quite convinced that it is a "deficiency" disease. Also rickets, eczema, pyorrhea, and a number of other diseases of obscure cause are beginning to be regarded as being, in part at least, deficiency diseases. A predisposition to tuberculosis and other infections may be of similar cause. There are probably a number, possibly many, of these vitamine substances. At least two have been quite fully demonstrated,—the one preventing scurvy, and the one preventing beriberi.
The experiments of Cosimir Funk, a Russian, are convincing. He was able to produce experimental beriberiin pigeons by feeding them for three weeks on polished rice, then readily to cure them of the disease by feeding the polishings from the same rice, showing that in the rice polishings are certain elements absolutely essential to life. He finally isolated what appeared to be this substance, one pound of the polishings yielding about three grains of the material. Injecting under the skin of pigeons dying of beriberi one third of a grain of this crystalline substance, he was able not only to make them perfectly well in a few hours, but to keep them in health for three weeks with but the one dose, even though they were continued on a diet of polished rice. Funk named this wonderful life-giving substance vitamine, because its effects were life-giving, and chemically it seemed to belong to the amines.
Where Found
Vitamines are found in plants, and especially in their seeds. Fresh meat and raw milk contain them, although animals seem incapable of making them. In summer, milk is richer in them than in winter, because of the difference in feed for the cattle. They are contained also in yolks of eggs, whole grains, potatoes, carrots, beans, peas, lentils—in fact, practically all green garden vegetables, and fruit. In the grains, they are found in the dark layer near the outer surface or branny layer, and in the germ. In potatoes and other vegetables, they lie immediately under the skin. Yeast bread contains more than baking powder breads.
Vitamines are lost by the processing of grains; that is, by the removal of the outer layers, which contain most of these substances. Hence the whole grain should be included in the flour. They are also destroyed by the subjection of foods to too high a temperature. It is therefore best to cook cereals at a low temperature, as in afireless cooker. The vitamines are sacrificed in the drying of foods, and in the paring of vegetables. If potatoes are boiled, there is great advantage in boiling them in their "jackets," in which case the vitamines and the salts are not lost. If they are pared before they are boiled, the potato water should not be thrown away, as it is rich in vitamines, salts, and protein. Parboiling of other vegetables is objectionable for the same reason. Soda and baking powder and similar chemicals seem to destroy the vitamines. This is one reason why yeast breads are better than baking powder breads. Furthermore, in yeast fermentation, the vitamine preventing beriberi is actually formed, but not the vitamine preventing scurvy. The natural foods that require cooking to make them edible and wholesome contain vitamines which are not destroyed thereby if the cooking is done in the most wholesome and hygienic way.