Chapter 8

FOOD-VALUE OF VEGETABLES

In recent times we hear much of vegetarianism, which has its advocates among many highly intelligent people, and which, as a consequence, has achieved a certain vogue throughout the civilized world. It is rarely the case, however, that those who affect to practice this cult in reality live exclusively on a vegetable diet. As a rule it will be found that they are milk-drinkers, and not infrequently add eggs to their dietary. It is, of course, absurd to regard as vegetarians those who simply avoid meat, since it is true that the nitrogenous substances contained in milk and eggs differ in no essential particular from similar substances found in flesh of all kinds.

Experiments on a somewhat extended scale have shown within recent years that young and vigorous individuals at least may live and thrive on a diet composed largely of vegetables; no one has yet shown that a strict vegetable diet is that best adapted to the average individual, and no competent authority on this subject at the present time advocates a diet purely of this kind. It is true that the vegetables ordinarily eaten contain all of the elements that are essential to the animal system, such as starch, sugar, fat and albumins. Unfortunately, however, the amount of the last-named substance is usually so small in food-plants that the quantity that would have to be eaten by a normal individual taking active exercise would cost considerably more than if a reasonable proportion of animal food were included, and--which is of even greater importance--the digestive powers of the individual who attempted to live only on food of this character would be severely taxed, and, in the long run, probably seriously impaired. Furthermore, vegetables and fruits contain substances, usually in great quantity, that are scarcely acted upon at all by the digestive juices. Chief among the latter is cellulose, which, while forming the great bulk of the food of herbivorous animals, is scarcely suited to the weaker digestive capacity of the human being; practically none of it is converted to the uses of the body. It is thus seen that in the average man or woman a dietary consisting largely of vegetables would result in the presence in the intestines of a greater or less bulk of indigestible materials, which could subserve no good purpose other than that they would by their mechanical presence have a tendency to cause the bowels to act; as is the case with fruits, however, it is unfortunately true that this large residue of undigested food, in one way or another, often gives rise to considerable irritation of the mucous membrane of the intestine, and frequently produces dyspeptic disturbances, among which looseness of the bowels is common.

This brings us to a consideration of the digestibility of vegetables in general, which is always the paramount consideration when dealing with the value of any substance to be used as a food. It has been before remarked that young and vigorous persons seem to thrive on a dietary largely of vegetable character, but the case is certainly quite different with older people, particularly where their digestive powers are impaired. In the latter we often find that severe intestinal disturbances follow even after moderate indulgence in vegetable foods--particularly where they are served with vinegar, or some other fruit acid. Another peculiarity of foods of this kind that makes decidedly against their digestibility lies in the fact that, being soft and containing a large proportion of water, they are scarcely ever properly chewed, and as a consequence they are swallowed in comparatively large masses without having been adequately insalivated.

Vegetables may be roughly classified as legumes, roots and tubers, and green vegetables, and will now be considered briefly in the order named.

_Legumes,--Beans, Peas, Lentils, and Peanuts._--With the exception of the cereals, the legumes are the most valuable of all vegetable foods. Their nutritious properties are mainly due to their relatively high percentage of nitrogenous material, though they also contain starch and fat. Hence these vegetables contain the ingredients necessary to supply all the needs of the human economy; unfortunately, however, when eaten alone in sufficient bulk to furnish the nourishment required, they often--even in healthy individuals--give rise after a little time to dyspeptic disturbances.

Of beans, a large number of different varieties are in common use including string-beans (or snap-beans), lima-beans, kidney-beans, red beans, the frijole, and the Soya bean. String-beans are exceedingly palatable, and are very much prized as an article of diet by the peoples of all countries. When gathered young and thoroughly cooked while still fresh they are exceedingly wholesome, and are very well assimilated, when properly chewed, by even those whose digestions are considerably impaired. The other beans named are generally eaten dry after having been removed from the pod in which they grow. When they are soaked in water until they become soft and then thoroughly cooked they make an excellent food, and, when not taken in too great quantities, are fairly digestible. When cooked with onions, parsley, and red pepper in proper proportions they make a very delicious dish. In Japan the Soya bean forms the basis for a kind of vegetable cheese which is eaten with rice, and furnishes the nitrogenous materials in which the latter is deficient. Peas are wholesome when young and fresh and when properly cooked, and as they come on in the early spring when other fresh vegetables cannot be obtained, they furnish a most acceptable addition to the dietary. When old, after their skins become tough, they cease to be digestible, and should not be eaten except in the form of purees, during the preparation of which the hull is removed.

Lentils are scarcely eaten at all in America, but are much prized in some portions of the Old World, as the basis of soups.

Peanuts belong to the group of legumes, though, unlike the others that serve as food, they grow beneath the surface of the ground. They are highly nutritious, but are, unfortunately, indigestible, owing largely to the high percentage of oil that they contain. The latter is extracted, and is sometimes sold as olive-oil; in a somewhat different form it is made into a sort of butter which is quite palatable.

_Roots, Tubers, and Yams._--Sweet and Irish potatoes, which constitute the most important members of this group, have already been discussed under the head of breads. Of those that remain, some few, as beets and artichokes, may be regarded as related to those just referred to, while others, such as carrots, turnips, radishes, parsnips, etc., are generally reckoned among the succulent tubers on account of the large proportion of juice that they contain. Irrespective of the beet, which furnishes a considerable portion of the sugar of commerce, none of them may be looked upon as foods of a very important character, as they contain only relatively small proportions of sugars, starches, and nitrogenous materials. Beets, however, do contain a very high percentage of that which makes potatoes so popular,--about eighty-five per cent. of starches and sugars, with only a trifle of nitrogenous material. When young and tender they are often eaten as a salad, either alone or mixed with other vegetables, and are generally regarded as being wholesome and highly nutritious. They should not be eaten by dyspeptics when pickled, on account of the vinegar.

Artichokes are occasionally eaten, but are not nutritious, although they agree well with many persons.

Carrots, when young and fresh, are fairly digestible, but like other vegetables are exceedingly apt, particularly if old, to produce intestinal disturbances in dyspeptics. They are not very commonly eaten in the United States, but where selected with care we would profit by their more frequent use. They contain a small percentage of starches, with an insignificant proportion of vegetable albumin.

Turnips are exceedingly unwholesome, contain very little nourishment, and may be eaten with impunity only by persons in vigorous health. The same remarks apply to radishes, and to parsnips.

_Green Vegetables._--Vegetables of this class are of much more value from the standpoint of their agreeable taste, and the consequent stimulating effect upon the appetite, than from the nutritive materials that they contain. Some of them are eaten cooked, while others are usually consumed in a raw state. They are all much less indigestible if eaten when quite young and fresh--drying seemingly having the effect of producing alterations in them that predispose to dyspeptic disturbances in those so inclined.

Spinach is one of the most digestible of the entire group, and is much eaten in all parts of the world.

Turnip-tops differ in no essential particular from spinach. They have a somewhat bitter taste, but when young and fresh are highly palatable, and if thoroughly cooked cause comparatively little intestinal trouble, but like spinach they contain practically no nourishment. The same may be said of the leaves of various other plants commonly served as greens, among them beet-tops, and dandelion-tops.

Cabbages, many different kinds of which are habitually eaten as food in civilized countries, have comparatively little nutritive value, and are, generally speaking, decidedly indigestible, although young and vigorous persons, particularly where they take abundant out-door exercise, find no difficulty in assimilating the inner portions of the fresh cabbage "head." As in the case with other vegetables, the soil and locality in which the cabbage is grown largely influences its taste, and to some extent its digestibility. It should never be given to infants. Sauerkraut is a preparation of cabbage leaves produced by adding salt, and later crushing them with considerable pressure; after a time alterations occur of a fermentative character, and the product is generally regarded as more wholesome than fresh cabbage.

Cauliflower consists of masses of the somewhat modified flowers of a plant closely related to the cabbage, and is, when properly prepared, palatable, and perhaps somewhat more digestible than cabbage. Cole, and Brussels sprouts, are plants of the cabbage family, and are perhaps even more indigestible.

_Salad Plants._--The leaves of the lettuce are usually eaten raw, most commonly being served as a salad in combination with oil and vinegar, or lemon juice. That the leaves possess, when treated in this way, a very palatable taste all will perhaps agree, but they cannot be said to be of any nutritive value, nor are the acids just referred to conducive to their digestibility.

On account of their somewhat pungent taste, watercresses are used in many parts of the world as ingredients of salads, but they are, of all vegetables, the ones that are most liable to transmit disease to man, for in addition to the possibility of contracting in this way typhoid fever, dysentery, cholera, and the ordinary intestinal worms, the human being is apt to receive with them the eggs of the flukes, and the spores of the amoebae that produce chronic tropical dysentery. As they are probably never grown under such conditions as to preclude the possibility of this danger, it would be the part of wisdom to absolutely refrain from their use.

_Onions, Leeks, Shallots, and Garlic._--Vegetables of this group are eaten either raw or cooked, and of all those consumed in the former state are least liable to transmit disease, owing to the fact that they are nearly always thoroughly peeled before being eaten. They have the advantage, furthermore, that they may be preserved for long periods of time in such a way as to be fit for food, and when properly cooked have a delicate flavor, and are quite wholesome although furnishing little food for the body. Garlic is never eaten as a vegetable, but serves as the basis for many of the delicate sauces for which the French cooks are so justly celebrated.

The tomato has been used as a food only within comparatively recent times, it having been formerly thought to be poisonous. Like the onion it may be eaten either raw or cooked, and if taken in moderation does not, as a rule, produce any serious harm. When eaten in greater quantities, both on account of the acid that it contains and its relatively small proportion of assimilable nutriment, the tomato is exceedingly prone to cause intestinal disturbances, and should rather be regarded as a fruit than a vegetable. Growing at some distance from the ground, it is rather less apt to convey diseases than the majority of vegetables eaten in a raw state.

While celery is generally eaten raw, it furnishes a palatable dish when cooked in milk. It should not be eaten by dyspeptics or children, particularly if raw. Similarly the cucumber has a well-merited reputation for producing dyspeptic disturbances. It is only eaten raw, is frequently served as a salad, and should be used only when very young and fresh, and eaten only by persons of sound digestion.

Okra is much prized in the Southern States as the principal ingredient of a very palatable soup, but is not as a rule looked upon with favor by the uninitiated. It is also much eaten boiled and served with a little butter and pepper. When fresh and young it is fairly digestible, and furnishes a very agreeable addition to the dinner.

In addition to those already referred to, there are a number of vegetables that are very popular either alone, or in combination as salads--particularly in the South; among them are green peppers, parsley, mint, capers, endive, and chicory. The remarks already made concerning green vegetables apply equally to these just mentioned, and it should here again be particularly insisted upon that salads containing acids are unwholesome for infants and children, and should be used sparingly even by those in health. None contains much nourishment.

Among easily digestible vegetables asparagus probably takes front rank, and in addition to this has the merit of being exceedingly agreeable to the taste. It possesses little nutritive value, but when young, fresh, and well cooked, it may be taken even by infants without harm.

Rhubarb, or "pie plant," is eaten stewed, and made into pie. It is said to be somewhat laxative, and is decidedly more wholesome than many others. The squash, when properly cooked is comparatively wholesome, but contains little nourishment, and is of no particular value as a food, and the pumpkin is not much better, although useful during the winter for making pies after the ordinary vegetables and fruits are gone.

Cranberries, when thoroughly cooked and separated from the hulls, form the basis of a delicious jelly that is widely eaten in the winter over all portions of the United States. Like all sweets it is not entirely wholesome for dyspeptics or infants, but as it is usually eaten with meats and not in great quantities, it may be looked upon as being one of the most wholesome of all foods of this class. It does not seem to have such a tendency to produce sour stomach in many dyspeptics as is so frequently done by other foods containing vegetable acids.