Digestion and Food : Part 1

Hygienic Physiology: with Special Reference to the Use of Alcoholic Drinks and Narcotics
by Joel Dorman Steele, Ph.D.

(Page 6 of 16)

"A man puts some ashes in a hill of corn and thereby doubles its yield. Then he says, 'My ashes have I turned into corn.' Weak from his labor, he eats of his corn, and new life comes to him. Again, he says, 'I have changed my corn into a man.' This also he feels to be the truth.

"It is the problem of the body, remember, that we are discussing. A man is more than the body; to confound the body and the man is worse than confounding the body and the clothing."

- John Darby.

Why We Need Food. - We have learned that our bodies are constantly giving off waste matter - the products of the fire, or oxidation, as the chemist terms the change going on within us. A man without food will starve to death in a few days the oxygen will have consumed all the available flesh of his body. To replace the daily outgo, we need about two and a quarter pounds of food, and three pints of drink.

Including the eight hundred pounds of oxygen taken from the air, a man uses in a year about a ton and a half of material.

Yet during this entire time his weight may have been nearly uniform.

What Food Does. - We make no force ourselves. We can only use that which nature provides for us. All our strength comes from the food we eat. Food is force - that is, it contains a latent power which it gives up when it is decomposed. Oxygen is the magic key which unlocks for our use this hidden store. Putting food into our bodies is like placing a tense spring within a watch; every motion of the body is only a new direction given to this food force, as every movement of the hand on the dial is but the manifestation of the power of the bent spring in the watch. We use the pent-up energies of meat, bread, and vegetables which are placed at our service, and transfer them to a higher theater of action.

Kinds of Food Needed. - From what has been said it is clear that, in order to produce heat and force, we need something that will burn with which oxygen can combine. Experiment has proved that to build up every organ, and keep the body in the best condition, we require three kinds of food.

1. Nitrogenous Food. - As nitrogen is a prominent constituent of the tissues of the body, food which contains it is therefore necessary to their growth and repair. The most common forms are whites of eggs - which are nearly pure albumen; casein - the chief constituent of cheese; lean meat; and gluten - the viscid substance which gives tenacity to dough. Bodies having a great deal of nitrogen readily oxidize. Hence the peculiar character of the quick-changing, force-exciting muscle.

2. Carbonaceous Food - food containing much carbon - consists of two kinds, viz., the sugars, and the fats.

(1) The sugars contain hydrogen and oxygen in the proportion to form water, and about the same amount of carbon. They may, therefore, be considered as water, with carbon diffused through it. In digestion, starch and gum are changed to sugar, and so are ranked with this class.

(2) The fats are like the sugars in composition, but contain less oxygen, and not in the proportion to form water. They combine with more oxygen in burning, and so give off more heat.

The non-nitrogenous elements of the food have, however, other uses than to develop heat. Fat is essential to the assimilation of the food, while sugar and starch aid in digestion and may be converted into fat. Fat and carbonaceous material both enter into the composition of the various tissues, and when, by the breaking up of the contractile substance of the muscle, their latent energy is set free, they become the source of muscular force, as well as heat. While the tendency of the albuminous food is to excite chemical action, and hence the release of energy, the fats and carbonaceous food may be laid up in the body to serve as a storehouse of energy to supply future needs.

3. Mineral Matters. - Food should contain water, and certain common minerals, such as iron, sulphur, magnesia, phosphorus, salt, and potash. About three pints of water are needed daily to dissolve the food and carry it through the circulation, to float off waste matter, to lubricate the tissues, and by evaporation to cool the system. It also enters largely into the composition of the body. A man weighing one hundred and fifty-four pounds contains one hundred pounds of water, about twelve gallons - enough, if rightly arranged, to drown him.

Iron goes to the blood disks; lime combines with phosphoric and carbonic acids to give solidity to the bones and teeth; phosphorus is essential to the activity of the brain. Salt is necessary to the secretion of some of the digestive fluids, and also to aid in working off from the system its waste products. These various minerals, except iron - sometimes given as a medicine, and salt - universally used as a condiment, are contained in small, but sufficient quantities in meat, bread, and vegetables.

One Kind of Food Is Insufficient. - A person fed on starch alone, would die. It would be a clear case of nitrogen starvation. On the other hand, as nitrogenous food contains carbon, the elements of water, and various mineral matters, life could be supported on that alone. But such a prodigious quantity of lean meat, for example, would be required to furnish the other elements, that not only would it be very expensive, but it is likely that after a time the labor of digestion would be too onerous, and the system would give up the task in despair. The need of a diet containing both nitrogenous and carbonaceous elements is shown in the fact that even in the tropical regions oil is relished as a dressing upon salad. Instinct everywhere suggests the blending. Butter is used with bread; rice is boiled with milk; cheese is eaten with macaroni, and beans are baked with pork.

The Object of Digestion. - If our food were cast directly into the blood, it could not be used. For example, although the chemist can not see wherein the albumen of the egg differs from the albumen of the blood, yet if it be injected into the veins it is unavailable for the purposes required, and is thrown out again. In the course of digestion the food is modified in various ways whereby it is fitted for the use of the body, into which it is finally incorporated. We call this change of food into flesh assimilation, a name for a work done solely by the vital organs, and so mysterious in its nature that the wisest physiologist gets only glimpses here and there of its operations.