Part 17 (1/2)
Providence intended the different digestive organs of the human body to work, and there is no possibility of condensed or concentrated foods taking the place of ordinary victuals, as has been suggested. The stomach must have some bulky material on which to work, and similarly the intestine must be comfortably filled in order to exert its forward movements. It is in the same way intended that each organ shall supply the necessary digestive juices to take care of the different kinds of foods taken into the system. It is just as important that the liver should be called upon to act on a certain amount of fat as that the gastric juice should break up the molecules of the proteid, and just as important as both of these is the fact that the saliva should flow freely to decompose the starch before it enters the stomach. It is not intended, however, that the healthy individual should deliberately overload any part of the digestive system.
If a child, in a hurry to get to school, swallows bread and milk without chewing and without allowing the starch to be acted upon in the mouth, then an overburden is placed on the pancreatic gland, making that organ less capable of its regular work. And if, again, the food is drenched in fat, if everything is fried, or if b.u.t.ter is used in large quant.i.ties, the liver becomes overworked and cannot keep up with the demands, and digestive troubles follow.
_Effect of individual habits._
a.s.suming that the amount and quality of food have been properly adjusted, that each of the several const.i.tuents is in proper proportion, and that a suitable variety is maintained, there are still other phases to be considered before the nourishment of the individual may be considered satisfactory. Nature has furnished man with a guide both to the quant.i.ty and quality of food that should be taken into the system,--that is, his desire for food, or his appet.i.te,--and, in general, this guide may be safely trusted both as to the quant.i.ty and quality, although, in the latter, the appet.i.te is not so trustworthy as that of the lower animals.
Unfortunately, the appet.i.te is easily distracted by the general conditions of health, and when once the healthy tone of the system has been relaxed, the appet.i.te becomes misleading. For instance, a person not indulging in muscular exercise, but sitting still all day and eating candy or other sweets, has no desire for food, and the lack of appet.i.te in this case indicates, not a failure of the need of food, but abnormal conditions of the system. Also the conditions of housing, lack of ventilation, excessive heat, excess in the use of stimulants or of food, all affect and interfere with the guidance of a normal appet.i.te. Some persons go to the other extreme, and, having been in their earlier years accustomed to heavy exercise and generous feeding, forget that in a more quiet life, less breaking down of the tissue occurs and therefore less food is required. Their appet.i.te is a poor guide since it leads them to immoderate eating, resulting in time in an overloading of the organs and the probable poisoning of the system.
_Cooking._
Good cooking is as important as any other part of the process of digestion, and, in fact, cooking may be said to be the first step, since there the breaking down of the food tissue occurs, whereby subsequent action by the juices of the body is made easier. For instance, beef may be cooked so long and in such a way as to dry and harden the fibers, making it almost impossible for subsequent digestion; and on the other hand, it is possible to so stew or boil or steam tough meat as to make it quite easily absorbed by the stomach. Cereals, if properly boiled at the right temperature, and for the right length of time, will have the starch granules so broken up that the saliva will act easily on the broken granules. Raw vegetables containing starch are not acted upon in the mouth and are digested afterwards only with great difficulty, while cooked vegetables are a most desirable article of diet.
A great deal is said nowadays about overeating, and Horace Fletcher affirms that the average man would be much healthier and much stronger if he ate not more than two meals and generally only one meal a day. The relation between the amount of food eaten or the amount of food absorbed or utilized and the need for food cannot be determined for the average but only for the individual. There is no doubt but that men or women doing muscular work require greater amounts of food than those not so engaged. It is a common practice to increase the amount of oats which a horse consumes when the horse has hard work to do and to cut down the amount of grain when the horse stands in the stable. It is curious that this practice, so well known to give good results, is not applied to the human animal as well. But very few men will be found voluntarily to diminish the amount of their breakfast or dinner because on that day or on the following day they are going to stay in the house instead of engaging in vigorous outdoor labor.
No discussion on foods would be complete without a repet.i.tion of the frequently given warning, against fried meats and vegetables. Frying coats the outside of the food with a layer of fat not easily penetrated by the digestive juice and not acted on in the stomach. Therefore, all fried food, unless thoroughly chewed and then only when the frying is done in very hot fat so that it remains on the outside of the whole piece, will pa.s.s through the stomach without being acted upon. Frying is a quicker process than roasting, an advantage which appeals to the American notion of haste, but it is better to begin the preparation of the meal earlier and cook the meat by roasting or stewing and the vegetables by boiling or baking rather than to postpone the preparation of the meal until ten minutes before the hour and then fry everything.
_Muscular and psychic reactions._
Another factor in the power of the body to utilize the food values is the condition of the body at the time of the meal. If the individual is exhausted or even tired, no complete digestion is possible, and particularly is this true if the exercise has involved excessive perspiration. So in hot weather, a heavy meal should not be eaten until after a half hour's rest and after copious water drinking to compensate for that loss of perspiration.
Studies on the digestion of foods and on other matters pertaining thereto have shown that the smell of food, or the mere suggestion of food, stimulates the organs for the production of the digestive juices.
It is directly and literally correct, therefore, to say that one's mouth waters for this or that food because the thought or antic.i.p.ation of the food, if pleasant, will actually cause the saliva to form and flow in the mouth. This is true of the other digestive juices as well, so that an appetizing fritter, for instance, showing the rich, brown crust will stir up the bile, and when the fried cake reaches the opening into the intestine, the bile will be there ready to act. This has been demonstrated by putting into the stomach of sleeping dogs various kinds of foods and finding that no digestive juices whatever were produced, although with the dog awake and seeing the food before eating, the juices began to flow in the usual fas.h.i.+on.
It follows, then, that the enjoyment of food is quite as important as any other digestive function, and on the contrary, the eating of all sorts of foods with no interest or attention is the best way to induce subsequent indigestion. The fact, then, that a business man eating at a quick-lunch counter does not get the full enjoyment and benefit from his meal as compared with those who sit leisurely over a well-appointed table does not result altogether from the difference in the viands, but rather in the different att.i.tude toward the meal. It would undoubtedly be a great gain in every household if more attention could be given to a cheerful intercourse at meal times--not for the better relations.h.i.+p which would follow, but merely for the effect on the digestion.
After meals, violent exercise is not desirable because thereby vitality is taken away from the muscles of the stomach and intestines and is used up in the other muscles; but it is vigorous exercise after heavy meals only that is condemned, since moderate exercise after ordinary meals is not objectionable. Nor is there any evidence, unless the meal has been excessive, that mental exercise after a meal does any harm. The amount of mental tissue used up in the ordinary processes of mental work is not great enough to call for any large diminution of the supply of blood to other parts of the body.
_Consumption of water._
A move in the right direction to-day undoubtedly is the tendency to increase the quant.i.ty of water to drink. The body is nine-tenths per cent water, and while a large part of the water in the tissues is made chemically by combinations of hydrogen and oxygen, there must be a constant replenis.h.i.+ng of the liquids of the body.
The ordinary person ought to drink, or consume with his food in some way, at least two quarts of water a day, and many difficulties with the liver, kidneys, and other organs would be avoided if this amount of water daily were imbibed. Probably the contention that water should not be taken at meals is not particularly tenable except as the continual swallowing of water increases the tendency to swallow food without chewing, a childish habit sure to lead to distress later. But, to eat one's dinner or part of one's dinner and then drink a gla.s.s of water cannot reasonably be a.s.sumed to interfere with any digestive process. It is quite likely, in fact, that the greater dilution of the ma.s.s in the stomach will tend to easier absorption later on.
_Condiments and drinks._
There are certain kinds of foods which, though not strictly included in the four elements of food already named, yet are so common as to deserve special mention. Chief among these are the condiments and drinks, particularly coffee and tea. So far as the nutritive value of such materials as salt and pepper, vinegar or spices, goes, they are practically negligible, and yet, undoubtedly, these flavors play an important part in the suggestion of pleasure and therefore in the excitement leading to the excretion of the digestive juices. If one ate salt pork and boiled potatoes always, eating would be a tiresome affair, and it is quite likely that such a sameness of food would fail to excite subsequent digestion, merely from the monotony of the affair.
Salt, however, has a particular role in that the human body craves this mineral, and, while its exact value in the body is not clearly known, a certain amount of it must always be provided. The wild tribes of Africa, for instance, away from deposits of salt consider it their most valuable possession and will go to great lengths to procure it. Animals, in the same way, go great distances for a supply of salt.
Coffee and tea are generally consumed merely for the pleasure which the warm drink gives. Both, however, have a certain stimulating effect on the nervous system, and when a tired woman refuses food but drinks cup after cup of strong tea, the exhilarating effect can be produced only at the expense of nerves and muscular tissue which must be later atoned for. Similarly, when a man under stress drinks strong black coffee to keep up, he must pay the penalty for the stimulant. The natural forces of the human body are able to do normally a certain amount of work, their ability to perform this work being directly proportioned to the energy derived from the food-supply taken into the body.
No amount of tea, coffee, or alcohol will add to the living tissue of the system; it merely goads the nerves and muscles to further action, however tired and unwilling they may be. When the stimulant is stopped, or after a time in spite of the stimulant, the exhausted nerves and muscles refuse to continue, and the depleted body stops work and may even die. A certain amount of stimulants at infrequent intervals for particular occasions may do no harm, but the pity of it is that the habit once started, the ultimate effects are forgotten in the apparent relief of the moment. In the case of tea, besides the stimulating effect, a certain substance known as tannin is developed, particularly when the tea is boiled, and this substance is really harmful on account of its strong astringent property, which acts injuriously on the membrane of the stomach. The bitter taste of the tannin is disguised when milk is used with the tea, and it has been pointed out that tea used without milk or cream is safer than tea with milk, because without the milk the bitter taste would prevent the tea being boiled so long.
Alcohol is stimulating in its nature, because of its setting free from their usual control by the will the unconscious elements of the brain; while the effect of alcohol on the system as a whole is, as has been carefully proved by scientific investigation, unfortunate in every respect. Whether the alcohol be in the form of whisky or brandy or gin or in such milder forms as wines, beers, and hard cider, the continued use of even a small quant.i.ty acts adversely on the memory, on the will, on the intellect, on the inventive power, and on all the mental processes. It has a deteriorating effect on all the muscular tissue throughout the body, and while this is sufficiently deplorable, its effect on the mind is by far the more serious. No idea is more false than that a small amount of alcohol aids in the performance of work of any sort, and experience in the army, navy, and in exploring expeditions all go to show that the use of alcohol in any form reduces the capacity, both for activity and endurance. As a protection against cold, it is worse than useless, and the feeling of warmth which drinking alcohol in any form produces, does not manufacture heat in the body, but is rather a source of danger on account of the reaction of the whole system.
_Tobacco._
The use of tobacco may or may not be injurious to the human system, and it is said by those accustomed to its use that it is for them a source of great enjoyment and comfort. The essential poison of tobacco is known as nicotine, and experiments are very readily made with this substance, extracted from the plant, to show its deadly character on the heart and nerve cells of animals. It is easy to demonstrate that the use of tobacco affects the heart, since the common ”out-of-breath feeling”
which comes to users of tobacco when climbing hills or running is well known. No young man training for an athletic event would think of smoking, on account of the danger to his wind.