When a vegetable grown above the ground, such as spinach, is cooked as it is, without the addition of any water, one will be surprised at the quantity of fluid that will gather in the cooking utensil. This is the water which is present in considerable quantities in spinach and all of the vegetables that are grown above ground; in fact, they consist principally of water: 80 to 92 per cent. It is for this reason that an animal which feeds upon leaves and green vegetables does not need to drink water; when rabbits and guinea-pigs are fed in this way they do not drink, but if they are fed upon grains they must have water. Very much the same thing is the case with man, and consequently in diabetes large quantities of green vegetables should be taken. Normal persons can also with such a diet prevent thirst in the summer; another advantage is that the fluid in vegetables enters the circulation gradually, so that it is not suddenly overcharged, as it is when the liquid is taken all at once in the form of water or beer. In cases where the addition of large amounts of fluid is contraindicated, as in heart affections or arteriosclerosis, vegetables may prove beneficial, but care should be exercised in selecting those which do not cause flatulence.
The nutritive substances contained in the leaf vegetables grown above ground include only small amounts of nitrogen,-f rom 2 to 4 per cent.,-which, when we include the unripe leguminous vegetables, may amount to 7 per cent.,-also small quantities of sugar (up to 2 per cent.) and other carbohydrates, -6 to 10 per cent. in some varieties. Unfortunately the cellulose content is quite large, so that the assimilation is poorly accomplished. Since the process of cooking removes a considerable portion of these nutritive substances and also of the nutrient salts, the nourishing properties of these vegetables are greatly diminished; indeed, such leafy vegetables are less chosen for their nutritive value than for other desirable properties we shall now mention.
The great quantity of nutrient salts contained in these vegetables plays a more important part than the nitrogen or carbohydrate content.
Head salad contains much lime, about 37.63 in the pure ash, and also much iron-5.31 per cent. Owing to their high content in alkaline salts, green vegetables exert a considerable influence upon the composition of the blood, which they alkalinize. In very acid urine, this increased alkalinity of the blood greatly diminishes the acidity, and with large quantities of such food the urine may even become alkaline. A similar result is brought about by the large amounts of organic acids which occur either in the free state or in combination with alkalies, and are converted into carbohydrate combinations by combustion in the body. The juice of head salad contains potassium citrate: tomato juice also contains mainly citric acid.
In order, however, that the important nutrient salt content of such vegetables shall not be lost, a proper method of cooking is required. When boiled in water-especially pure waterwithout salt, the nutrient salts are drawn out, and frequently this water is then thrown away. The best way would be to cook such vegetables in utensils in which the water does not come into contact with the vegetables, and where it is principally the steam which acts upon the foodas is the case with the Wolf cooking apparatusor when the vegetables are steamed according to the English custom. In Austria and Hungary they are prepared with much browned butter and very little water, which is quite to the purpose, as very little of the nutrient salts is thus lost.
Proper cooking is all the more important for such foods, since the intestinal assimilation is dependent upon it. When some of the nutrient properties are lost in cooking, and others through the insufficient assimilation in the intestine, these foods lose much of their value.
The more raw fiber vegetables contain, the less they are assimilated in the intestine. Experiments were made by Rubner with curled Savoy cabbage and green beans in respect to their assimilation, with the result that of the harder portion of the Savoy cabbage 14.9 per cent. of the nitrogen and 15.4 per cent, of the carbohydrates were lost, and of the beans 15 per cent, of nitrogen and 15 per cent. of the carbohydrates of the hard portions remained unassimilated.
It is of the greatest importance that green vegetables be thoroughly cleansed before using them, since a number of bacteria and unclean substances of all kinds adhere to them. The thorough washing of the salads which are eaten raw is of the greatest importance. Worms are often found in carelessly cleaned vegetables. When not sufficiently cooked, tiny snails, which are sometimes found in vegetables, may prove injurious. In this way the green vegetables instead of benefiting the health may prove detrimental.
When well prepared and properly cooked, green vegetables may often be very useful as remedial herbs. We have already shown that they increase the alkalinity of the blood; in this way affections like gout and diabetes, in which there is acidity of the blood, may be much benefited. We might add that, as remedial agents, vegetablesin addition to this important in-crease of alkalinityexert, owing to their cellulose, a very favorable action upon the intestines, thus preventing or benefiting constipation. Since the most remote times many curative properties have been ascribed to green vegetables, and the medicinal treasures o,f the old masters of healing contained many o,f the vegetables now in use. In the progress of the science of medicine, with the painstaking experiments of the present day, their claims have been set aside. Nearly all of the green vegetables, however, have the property of alkalinizing the blood and improving the action of the bowels; the majority also have a more or less favorable effect upon diuresis, and some contain substances which stimulate the digestion. In this way they exert more of a curative action than almost any other food substance. In the diet of diabetics, gouty patients, and those suffering from arteriosclerosis, green vegetables occupy a first place.
As regards the very useful and nutritive salt content, it would be well if one could extract the juices of the vegetables as is done with fruits. Should the taste not prove very agreeable, other substances might be added, for instance a few drops of lemon juice, or whenever practicable a little of some other fruit syrup. These extracts could then be taken as curative substances. This would present the advantage that the indigestibility of certain vegetables need not at all be taken into account. The exclusion of certain substances and a thorough cleansing before the pressing out of the juices would be an obvious necessity. Since the nutrient value of such vegetables is rather limited to begin with, the nutrient salts would in this way be fully utilized.
We must, however, not overlook the fact that in addition to their many good properties green vegetables also possess some undesirable ones. Some herbs, such as sorrel, contain much oxalic acid, and the alkalinizing property is also not always desirable, as for instance in phosphaturia. The indigestibility of certain vegetables must also be taken into account, as is the case with roots, stalks, etc., which contain much cellulose. The most easily digested are the tender fresh vegetables and those cultivated in greenhouses, and also in gardens. Those growing in the wild stateas is also the case with wild animalsare less tender, and often contain more pungent sub-stances. These varieties, digested with difficulty, may be rendered more suitable for consumption by keeping them in dark places, as in a cellar from which the light is excluded; in this way, although they lose their color, the chlorophyll, the fibers become more tender. Thus, salad when raised in a cellar is very much more easily masticated and digested, and the taste is also less acrid.
Some vegetables, and in particular those of the cabbage family, cause considerable flatulence. Among these, cauliflower is probably the most easily digested. We may mention here that vegetables have the property of taking up a large amount of fat, their nutritive quality being thereby much increased.
We shall now refer to certain individual vegetables, al-though only the most important varieties, the scope of this work not permitting us to dwell upon all of them.
One of the most important of the leaf vegetables is spinach, which is in general very easily digested; for this it is necessary that the spinach be prepared as a smooth purée, and not served with the leaves entire, as is the custom in some countries, in which form it is less digestible.
Spinach very readily gives off its coloring matter, and is consequently well adapted for the coloring of soups, etc. It absorbs large amounts of fat, and tastes very good when goose-fat is added to it, as was so often proven to his guests by the writer Alexander Dumaswho prepared it in person. It is said that spinach tastes better when warmed over. By the addition of eggs the nutritive value is increased. A very practical method and one o,f much dietetic value is to add the yolks of two eggs to the spinach, stirring them in; this also greatly improves the taste. There is scarcely any other vegetable which is so prized in the practice of dietetics as spinach, and in cures, as at Carlsbad, it plays, an important rôle. It greatly favors the action of the bowels, and certainly induces less flatulence than most other vegetables of the cabbage group. But even so desirable an article of diet as spinach is not with-out its drawbacks. It is frequently the cause of oxalic acid formation. I have very often observed the presence of oxalic acid in the urine of my patients at Carlsbad. In healthy persons, of course, this is of no importance, especially in those who often show oxalic acid in the urine.
Much more oxalic acidthe largest amount contained in any vegetableis present in sorrel, which fact should be taken into account when the latter is used. This vegetable has a very sour taste. It is best eaten in purée form. Sorrel some-times causes intestinal or gastric disturbances when taken in combination with sour fruit.
Water cress also contains an acrid substance. It has long been credited with the property of stimulating the secretion of saliva and cleansing the mouth, for which reason it has often been used in ulcers of the mouth. Cress stimulates the appetite, and is often served with fine roasts. It is digested the most easily when taken in the form of a purée. This vegetable was in great favor among the ancient Persians, as well as the Greeks and Romans, not only as a food, but also as a medicinal agent. The name “santé du corps” (health of the body), which was given to it by the French, shows how greatly it was esteemed by them. It is an interesting fact that this vegetable, which was first cultivated in Germany at Erfurt, was seen there by an officer of Napoleon’s army named Cardon, who introduced it into France. In the latter country it is eaten in considerable amounts at almost every meal ; in Austria and Germany, on the other hand, it is used comparatively seldom.
Water cress requires much water in order to thrive. It should be mentioned, however, that when the watery soil in which it grows becomes contaminated with drain water containing the bacilli of typhoid fever, as is not infrequently the case, it may transmit the disease. Cress is sometimes used for its medicinal properties. It contains important substances, such as iodine, iron, etc. Its juice is claimed by certain authors to be useful in many skin diseases : very stubborn cases of eczema are said to have been cured with it. In constipation it has a favorable action, and also stimulates the appetite.
Another vegetable which improves the appetite is parsley. It stimulates the sense of taste and helps the digestion; it is much used for soups, sauces, and as an addition to many foods that would seem rather tasteless without it. It also promotes the flow o,f urine and augments the perspiration. Apiol, which is used in menstrual disorders, hysteria, etc., is obtained from parsley.
A much-used vegetable is celery, which also has a stimulating action. As a remedial agent it is beneficial in flatulence, and for this purpose a kind of preserve is made from celery stalks. It is also a generally accepted fact, especially in the Latin countries, that celery exerts a stimulating effect upon sexual activity.
In some countriesas in Englandcelery is frequently eaten raw at the end of the meal. In this form it is certainly not very easily digested. In England and America it is also used as a salad; during my stay in America I often had occasion to take it mixed with grapes in a sort of mayonnaise.
Owing to a bitter substance contained in it, chicory also has a favorable action upon the appetite. It is interesting to see with what avidity animals, especially pigs, will devour chicory growing wild. Probably their instinct tells them that it is a useful plant. The roots in particular are very bitter. Animals which feed upon these plants are thereby protected against skin diseases. Chicory has a strengthening influence upon weak animals. In some countries, as in Belgium, especially in Brussels and its vicinity, this plant is extensively cultivated. A special variety is raised there which, when kept in the dark, becomes more digestible, having tender fibers and also a finer taste; Brussels chicory is renowned for this reason. Owing to the bitter substance contained in it, chicory, when well cooked, has a favorable action upon the digestive processes, but if eaten as a salad it is very indigestible. When the roots have been dried, then roasted and finely ground, a well-known, although not universally liked, substitute for coffee is obtained. It is surprising that this substitute, which so frequently gives rise to much disappointment when a good cup of coffee is expected, should have been placed upon the market in the very country where generally the best coffee in Europe is drunk, viz., in Holland.
Endive is a variety of chicory which is even more bitter. It is cultivated chiefly in Holland. It contains 2.78 per cent. of nitrogen, 0.76 per cent. of sugar, 1.19 per cent. o,f other carbohydrates, and o.82 per cent. of cellulose.
Two varieties o,f herbs have already been mentioned that are rich in oxalic acid ; we shall now add rhubarb, which, like celery, is much used in England. Rhubarb is, however, not easily digested; owing to its acid content, it, like sorrel, very often has an unfavorable action upon the stomach. Owing to the acid contained in it, its use should be forbidden in kidney affections and particularly in oxaluria. According to König, it contains 0.82 per cent. of nitrogen, 0.18 per cent. of sugar, and 0.52 per cent. of cellulose, together with 0.78 per cent. of oxalic acid in the fresh substance and 14.23 per cent. in the dry substance, and malic acid in the stalks and leaf-stems; 3.28 per cent. of sugar is also contained in the dry substance.
A very delicious vegetable, and probably one of the most prized of all, is asparagus. As a nourishing food it is not, to be sure, of very great value, since it only contains 0.47 per cent. of sugar, 2.80 per cent. of other carbohydrates, and a rather large amount1.54 per cent.of cellulose. The young shoots are most easily digested, as are also the tips and upper portions of the asparagus; the lower portion contains much fiber and is therefore indigestible.
Already in the time of the ancient Greeks, asparagus was held in great esteem among high livers, as stated by Theophrastos, and its high price even now practically restricts its use to such circles. It is a luxury among vegetables, having almost no nutritive value. When added to other foods, as in a mixture of eggs with asparagus tips, it improves the taste, stimulates the appetite, and is, in this way, useful. Asparagus contains a considerable amount of iron, which constitutes about 3.38 per cent. of the ash. It is also rich in certain other nûtrient saltscontaining, according to König, in the ash 24.04 per cent. of potash, 17.07 per cent. of soda, 10.85 per cent. of lime, 4.32 per cent. of magnesia, 3.38 per cent. o,f iron oxide, 18.57 per cent. of phosphoric acid, 6.18 per cent. of sulphuric acid, and 10.9 per cent, of silicic acid. It very often contains even much more potash than the amount stated.
Asparagus contains an amido-compoundasparagin to which an influence upon glycogen formation is ascribed, and which is said to exert a favorable action in diabetes. It should be remembered, however, that asparagus greatly increases the flow of urine, and, when diabetics pass very much urine, asparagus is not to be recommended for them. The same may be said of its use in kidney affections, catarrh of the bladder, strangury, and diseases of the prostate. When asparagus has been eaten the urine has a peculiar, unpleasant odor, but when a few drops o,f turpentine are added this is changed into an agreeable violet perfume.
Asparagus when freshly cutparticularly in Mayhas rather an agreeable aroma, and., even though cut for some little time, it will preserve this aroma when kept in a damp place, standing in sand with the tips up. The property of promoting sexual activity has frequently been ascribed to it. Asparagus tips in syrup were used by Broussais to quiet cardiac action.
Asparagus tastes much the best when freshly cut. It soon loses its flavor, and when used canned or bottled is not nearly so good. It is pretty rich in extractives and promotes the formation of uric acid, as it contains o.25 per cent. of purin bodies. It is consequently not well adapted for gouty patients.
In the treatment of gout, obesity, and often in diabetes, the above-named vegetables are useful, since, because of their bulk, they appease hunger without greatly increasing metabolism as they contain only small amounts of nutritive substances. Some varieties contain more o,f these than others, but besides these so much cellulose that the intestinal juices cannot well act upon them. They are consequently not readily taken up into the blood. The oyster plant belongs to this class. It contains 80.39 per cent, of water, only 1.09 per cent. of protein, but 2.29 per cent. of sugar and 12.61 per cent. of other carbohydrates. The cellulose content is large, amounting to 2.27 per cent. In the dry substance this vegetable contains 5.31 per cent. of protein and 75.97 per cent. carbohydrates. Notwithstanding the considerable carbohydrate content, it is not injurious for diabetics, since it contains much inulin, the primary substance of fruit-sugar, which is frequently much better borne. This vegetable is also poorly assimilated, which is usually an advantage in diabetes. After its use I have frequently noticed quite normal looking fragments of oyster plant in the feces, which would indicate that it should be classed among the least nutritious vegetables. Of the 14.81 per cent. of carbohydrates only 12.44 per cent. are assimilated (König). It has still another advantage, namely, that it is very satisfying; when fried in plenty of butter it is a very palatable food. For gouty patients and obese persons, it would be a desirable food, since not very much of it can be eaten, but in obesity not much butter should be added. The young shoots of hops are also a very good food.
Artichokes are very rich in carbohydrates, especially in the lower portions of the vegetable. They contain 15 per cent. of carbohydrate, of which 0.57 per cent. is glucose and 2.84 per cent. dextrose. The nitrogen content is 1.68 per cent. The lower part of the vegetable’ contains 0.21 per cent. glucose and 2.06 per cent. dextrose, with 2.54 per cent. of protein.
The lower portion of the artichoke is that chiefly used. It may be prepared in the form of a purée, and is easily digested in this way. We may here mention the rather large content of tannic acid, which turns the knife black.
The cabbage family is poorer in carbohydrates, but con-tains more protein than the above-named vegetables, some-times as much as 9 per cent. or even more. Their content of nutrient salts is even more important. The various kinds of cabbage occupy a prominent place among our vegetable, foods, but have the disadvantage that they are, in general, not easily digested. The top of the cauliflower is the best in this connection, and when it is well cooked it almost melts in the mouth. The lower part is more difficult to digest, and the upper portion is all that should be eaten. Cauliflower, like all the cabbage variety, has the property of causing considerable flatulence; indeed, this class of vegetable does so more than almost any other food.
When the ground has been well fertilized, cauliflower sometimes attains an almost incredible size. Specimens of this sort can be seen in the neighborhood of Frankfort and Nassau. Cauliflower is rich in potash, lime, phosphorus (13 per cent.), with 12.81 per cent. of silicic acid in the ash.
A rather easily digested variety of cabbage is Brussels sprouts; the finest specimens are found in Belgium, which country is, so to speak, really one large vegetable garden. Here and in Holland probably the best vegetables in the world are grown. Brussels sprouts are a very interesting variety among the cabbages ; the plant shoots up like a tree among its brothers in the vegetable patch, and clustering around its stalk are found the little rose-like flowers. In the German language it is called “rose cabbage.” The taste, like that of the cauliflower, is very pleasant, and it is quite nourishing, since it contains 4.81 per cent. of protein. In this connection, however, it should be remembered that a considerable part of this vegetable is not made up of protein combinations and is consequently not assimilated. Of the 6.22 per cent. of carbohydrates only about 5.22 per cent, is absorbed. But, even so, Brussels sprouts are nourishing and easily digested, and probably cause rather less flatulence than the other varieties of cabbage. It would be desirable to have this very useful vegetable cultivated to, a greater extent in Austria. The nutritive properties o,f both the cauliflower and Brussels sprouts are greatly enhanced by the customary addition of a good deal of butter, of which Brussels sprouts in particular take up a considerable quantity. For diabetics the cabbage family are excellent vegetables, and cauliflower in particular should occupy a prominent place in the bill o,f fare of diabetic patients.
The red and white cabbages are poorer in nutritive properties than the above-named varieties. They contain less than 2 per cent. of protein, with 2 per cent. of sugar, and 3 to 4 per cent. other carbohydrates. They must be well cooked, for they are hard to digest; when thoroughly cooked, red cabbage is somewhat improved in this respect. Since these two vegetables are not nourishing, it is rather necessary to, add some fat to them. They contain quite an amount of the nutritive salts. The outer leaves of white cabbage contain much lime (27.88 per cent.), and the heart contains 37.82 per cent. of potash and 12.30 per cent. of phosphorus. Neither the taste nor the digestibility of white cabbage is calculated to make it a popular vegetable. It is only made so when, by a process of fermentation, it has been converted into sauerkraut. In this way it becomes a useful vegetable, which we shall now consider.