Mental States and the Stomach.—The typical example of the influence of the mind on the digestive tract is to be found in the experiences of Flaubert, the French novelist, while writing "Madame Bovary." When he was writing the scene in which he describes the effects of the arsenic which Madame Bovary takes, he himself suffered from practically all the symptoms due to the drug. In order to describe it faithfully he had studied it carefully. He had the pains, the vomiting, the burning feeling and even the garlicky, metallic taste in his mouth. Such an incident is extremely exceptional, yet its possibility is recognized, and it illustrates how sensitive some people are to the action of mental states upon the body, and how large a role a strongly excited imagination can play in producing definite physical symptoms. There are many more such realistic imaginations than we have, perhaps, been inclined to suspect. It is over these particularly that the psychotherapeutist can exert his influence by helping to modify the cause of their symptoms, the mental attitude which exists, rather than by trying to change the symptoms which are only effects, for diseases must, as far as possible, be treated in their causes.
Disgust and Disturbance of Digestion.—Max Müller's story, told in his book on "Language," to show how language might have been a human invention from imitation of natural sounds, illustrates the influence of an unfavorable state of mind in disturbing digestion. An Englishman, traveling in China, fearful lest he should not be able to obtain food that he cared for, because of his lack of knowledge of the language of the country, was rather surprised on his first day's journey into the interior, to be served with a stew made of some kind of dark meat that tasted very well indeed and with which he was so much pleased that he asked for a second helping. Just as he was about to eat the second portion, he thought it well to ask the waiter what sort of meat it was, as he wished to be able to obtain the same kind at other places. Calling the waiter to him, he said, pointing to the dish of meat with a questioning tone, "Quack, quack?" The waiter at once shook his head and said, "Ugh! bow wow!" The Englishman pushed the second portion away and got up from the table.
Under the same circumstances nearly everybody would feel the same qualmishness—at least all who had been brought up according to our Western notions. Reason has little or nothing to do with it. It is a question of feeling. The dog is much more cleanly in its habits than the hog, but we in the West are used to the idea of eating hog-meat just as they in the East are used to eating dog-meat. The objection, of course, might be urged that the difference between the hog and the dog is that we do not eat carnivorous but only herbivorous animals. But the slop-fed hogs from the neighborhood of our large cities, constituting a goodly portion of those brought to market, eat meat quite ravenously. They certainly are not exclusively herbivorous. There is no [{244}] principle behind our objection to dog meal then—only the unfamiliarity of the idea of eating it.
The treatment of patients with digestive disturbances requires a careful analysis of the conditions of mind towards foods. If prejudice exists with regard to certain foods, there will be no relish for them, and unless these prejudices can be removed, the foods either will not be taken, though they represent important nutritional elements, or else they must be taken in such small quantities and digested with so much consciousness of their presence and such difficulty as to be a disturbing factor for health. Persuasion, the custom of the country, habit, training, mean much for this modification of mental attitude.
Custom and Food.—In recent years many parts of animals, not generally eaten before, have come to be consumed with a relish because of the removal of prejudices against them. It might be thought that organs like the kidney, the essential function of which is excretory, and through which so much of the offensive waste products of the body pass, could not be a relished article of food. But it has become quite a dainty. The liver, owing to the peculiar nature of its function, its very special flavor, and the staining with bile, might be expected to be objectionable. It is not, but, strange to say, a third organ of the abdominal cavity, the spleen, which has none of the external objectionable features of kidney or liver, is not yet eaten, and most people would probably find it rather difficult to eat it. This difficulty would result, not because of anything in the organic substance itself, but because of the lack of accustomedness to it. There are a number of people who now have trained themselves to eat it. Such apparently impossible portions of the animal as the intestines, even those of the hog, are eaten with relish by a great many people, though there are others who have never been able to get used to them. The dainties of some peoples are utterly repulsive to others. The French like brains and other special portions of animals that are not much eaten by Anglo-Saxons. Fried brains in black butter sauce are enough to turn the stomach of some people by the very thought of it, though it is a highly prized dish in the south of France.
In Italy most visitors eat snail soup with relish before they know what it is. It seems to be a special kind of gumbo soup. Down at Marseilles, gourmets occasionally eat angle-worms and find them to be a very appetizing dish. In all of these things the question of relish and peaceful, happy digestion depends entirely on the attitude of mind. The first men who ate eels must have been looked upon with considerable suspicion by their neighbors as viper eaters, and probably they themselves were not comfortable over the feat. It has been said that the first man who ever swallowed an oyster performed as great a feat as any of our important inventors or discoverers.
Gastric Antipathies.—To the great majority of mankind the idea of eating horseflesh is repulsive. Numbers of people in various parts of Europe have found, however, that after the initial repugnance is conquered, it is quite as pleasant to eat as cow's meat. To my taste, at least, it is much more palatable than venison or bear meat. At the beginning, its sweetish taste has a curious reflex effect. Taken in connection with the thought that this is horse meat, the taste is apt to produce a sensation of nausea. This is readily overcome, though the first time it is necessary to keep constantly inhibiting [{245}] the mind from acting unfavorably upon the stomach during the course of eating and digestion. Custom, I learned from many, soon made it quite as savory as beef.
Food Varieties and the Mind.—How easy it may be to overcome many prejudices in the matter of food digestion under the stress of necessity and the influence of example, was well illustrated during the siege of Paris. The Parisians, though a most delicate people in the matter of eating, were able to accommodate themselves to the conditions, and practically every kind of animal was eaten with a relish. Before the siege, to most of them it would have seemed quite impossible, that they should sit down with complacency to the dishes which afterwards were so appetizing. At the beginning there was a definite attempt to conceal the eating of rats, mice, cats and dogs under various names, and by various modes of preparation. But it was not long before there was an end of this pretense. The animals in the zoological garden proved a veritable life-saving store of meat. Every one of them was eaten, people were glad to get them, and paid high prices for them. Camel steaks, elephant cutlets, lion and tiger stews, appeared under their own names, even at the banquets of the wealthy.
What is true of the mental attitude for meats influencing not only the relish for them, but their digestion, is also true for many vegetables. There are unfavorable suggestions in the minds of many with regard to the supposed indigestibility of potatoes, turnips, carrots, beans and occasionally with regard to tomatoes, lettuce, or the like. A few definite physiological idiosyncrasies against these vegetables, or certain of them, do actually exist. The attitude of mind, however, is largely responsible for the discomfort that occurs after the consumption of most of them. Patients who ought to consume more starchy substances, or whose bowels need the residual materials that are contained in these vegetables, for the sake of their effect upon peristalsis, should be persuaded to take these vegetables, first in small quantities and then in gradually increasing amounts. Many of them can thus be brought to a diet at once more nutritious and more likely to help out intestinal function. Their objection to them is usually but a fancy.
Genuine Food Idiosyncrasies.—There are certain genuine idiosyncrasies with a physiological basis which prevent the taking of certain kinds of food, or cause disturbance if they are taken, but these are rare. Their presence should never be considered as demonstrated by subjective signs alone for these are eminently fallacious. In certain cases, however, so rare as to be almost always curiosities in medical practice, there are definite objective symptoms of the idiosyncrasy. These consist of urticarial rashes, tendencies to vomiting, or diarrhea, or both. Sometimes these result from the most bland and nutritious of foods. I have notes of the cases of two children—whose father could not eat eggs without vomiting—and to whom fresh eggs fed at the age of two and three years, always produced this same effect. Even small portions of egg would cause it. It mattered not how the egg was prepared, nor even whether it was carefully concealed in custard or in cake provided there was a certain amount of it, the food eaten with it would be vomited. There are many such idiosyncrasies for shell fish, cheese, and such fruits as strawberries, pineapples, pomegranates and the like, but they are demonstrated by objective signs. But by far the greater number of food dislikes are entirely [{246}] subjective and the subjective feelings can probably always be overcome by habit and training.