CHAPTER IV.. Conditions to Be Observed Before and After Eating.

CONDITIONS TO BE OBSERVED BEFORE AND AFTER EATING.

General laws of organic activity apply to the stomach as well as to other parts--Increased flow of blood towards the stomach during digestion--Hence less circulating in other organs--And consequently less aptitude for exertion in them--Bodily rest and mental tranquillity essential to sound digestion--Rest always attended to before feeding horses--Hence also a natural aversion to exertion immediately after eating--Mischief done by hurrying away to business after meals--Severe thinking hurtful at that time--Playful cheerfulness after dinner conducive to digestion--The mind often the cause of indigestion--Its mode of operation explained--Also influences nutrition--Illustration from Shakspeare.--Importance of attending to this condition of health enforced.

Having now discussed the principles by which the number, quantity, and quality of our meals ought to be regulated, we have next to consider the conditions required for the healthy performance of digestion after the aliment has reached the stomach, and to deduce from them such practical rules as shall tend to facilitate the accomplishment of the process.

Among the circumstances which favour digestion, the observance of bodily rest and mental tranquillity for some time before and after every meal, is perhaps the most important; its influence depends on a well-known law of the animal economy, already frequently alluded to, but to which, that it may be fully understood, I must again shortly refer.

Whenever any living part is called into vivid action, an increased flow of blood and of nervous energy towards it immediately commences, to enable it to sustain the requisite degree of excitement, and continues till some time after the activity has ceased. In accordance with this law, whenever food is swallowed, the lining membrane of the stomach becomes suffused with blood, and, owing to the greater distention of its vessels, its colour changes from a pale pink to a deep red hue. After digestion is completed, and the unusual supply of blood is no longer required, the vessels again diminish, and the colour returns to its original tint. In St Martin’s stomach, these changes were so often seen by Dr Beaumont, as to render their occurrence as fully demonstrated as any circumstance with which we are acquainted. Even had they never been seen, the simple examination of the structure of the stomach would lead us directly to the inference that it receives an additional supply of blood when engaged in digestion; for the very act of its distention by food renders the course of its bloodvessels less tortuous, and the flow of blood through them consequently more easy and rapid. In the case of the stomach, indeed, the increased circulation is doubly required; not only as in other parts to enable it to act with greater vigour, but also to supply the very copious secretion of gastric and mucous fluids necessary for digestion, and which we have seen to commence the moment food touches the mucous coat. The quantity of gastric juice actually secreted at each meal cannot easily be determined; but as more than an equal weight of it is required for the solution of food out of the stomach, its amount must be very considerable. Indeed we know that, on one occasion, when St Martin dined on broiled mutton and bread without any liquids, the gastric secretion was so copious, that half an hour afterwards the “stomach was as full of fluids as when he drank a pint immediately after eating;” and, as the whole of this must have been derived directly from the blood circulating through the vessels of the stomach, they must necessarily have received a very large supply to enable them to furnish it.

It is obvious, however, that the great afflux of blood which takes place towards the stomach and intestines during digestion, cannot occur without a corresponding diminution in the quantity circulating on the surface and in other distant parts of the body, attended of course with a diminished power of action in them. Hence, for some time after a full meal, there is an inaptitude for vigorous thinking and bodily exertion, a depression of respiration, and, in delicate persons, a degree of coldness or chill felt over the whole body. But, under ordinary circumstances, this depression is not of long continuance. After the requisite secretions have been provided for the solution of the food and the formation of the chyle, a reaction and change in the distribution of the blood, now partially renewed by the admixture of nutritive chyle, ensue, and, by the stimulus which they afford, soon fit the person for the active resumption of his ordinary duties.

That this impaired activity of the other functions after a full meal is natural, and intentionally arranged by the Creator, is plain, both from its universality among all kinds of animals, and from the mode in which it is produced. Among the lower creatures, the sluggishness induced by eating increases in proportion to the degree in which they gorge themselves with food. The boa constrictor, after a plentiful repast, slumbers for a week; and the glutton of our own species, in similar circumstances, drops into a stertorous sleep of several hours. If active exertion immediately after a full meal be rendered compulsory by any external cause, such as the presence of danger urging to flight, the aliment often remains for hours in the stomach undigested. Again, the very distention of the stomach inseparable from a hearty meal, necessarily impairs the activity of several of the functions, by directly pressing upon the vessels which supply their organs with blood, and consequently diminishing the stimulus essential to their activity.

The obvious practical inference to be deduced from a consideration of the principle under discussion is, that rest of body and tranquillity of mind for a short time both before and after eating are necessary, and conducive to healthy digestion. If we have been engaged in severe and fatiguing bodily exertion, or anxious meditation, just before sitting down to a meal, the blood which was flowing copiously through the vessels of the muscles or the brain to keep up their unusual action, still continues to do so, because a sufficient interval has not elapsed to allow the excitement to subside, and a new distribution to take place towards the organs concerned in digestion. The consequence is, that the stomach does not receive blood enough to carry on its increased action, and furnish gastric juice with sufficient rapidity, or in sufficient quantity, to mix with the whole of the food; and that the nervous energy, already partially exhausted by over-excitement in the remoter organs, is imperfectly supplied to the stomach, the tone and action of which are thus so far impaired as to render it no longer able to carry on digestion with its usual success. Accordingly, when we are fatigued with mental or bodily labour, we are naturally impelled to seek repose before sitting down to table; and if we yield to this instinctive prompting, and refresh ourselves by a rest, we not only enjoy better what we eat, but also digest it with an ease and comfort unattainable by swallowing our food the moment our labour is at an end--and hence the wisdom and advantage of appropriating half an hour to any light occupation, such as dressing, before sitting down to dinner. If, however, we have previously been engaged only in very moderate exercise, an interval of repose is not required, because then there is no undue excitement elsewhere to retard the necessary flow of blood and nervous energy towards the internal organs.

The practical rule of avoiding serious exertion of mind or body immediately after eating, which is directly deducible from the physiological law above explained, has long been acted upon in our treatment of the lower animals; and no one who sets any value on the lives of his horses or dogs, ever allows it to be disregarded with respect to them. And yet the same man who would unhesitatingly dismiss his groom for feeding his horse immediately after a fatiguing chace or a gallop home, would probably think nothing of walking into the house and ordering dinner to be instantly served for himself in similar circumstances. In the army, the difficulty of managing recruits on a march, in this respect, has often been remarked. Fatigued with the day’s exertions, they are impatient for food, and, when they get it, can scarcely refrain so long from devouring it as to admit of its being even moderately cooked. They consequently labour under the double disadvantage of eating before the system is in a sufficient state of repose to benefit by the supply, and of having the food itself in a condition unfit for easy digestion. The old campaigner, on the other hand, instructed by former experience, restrains his appetite, systematically kindles his fire, cooks his victuals, and makes his arrangements for the night, with a coolness of deliberation which surprises the recruit; and he is amply repaid for his temporary self-denial, by the greater enjoyment and support which he derives from the very same materials which the impatience of the other has caused him in a great measure to waste.

Let any one who doubts the advantages resulting from attention to this rule, consider for a moment its universal and scrupulous observance by postmasters and jockies, and think whether these are persons likely to throw away time and trouble on a useless ceremony. When a horse is taken out of harness, an interval of repose is always allowed, that the excitement of the system may have time to subside; and then not only an eager appetite but an active digestion are sure to follow. Many a valuable horse has been killed by being prematurely fed after fatiguing exercise, and man himself is no exception to the rule. He not only enjoys a meal with superior relish, but digests it better, when due repose has removed the fatigue and excitement of exertion. Even after continued activity of mind, a period of tranquillity or of gentle bodily exercise is eminently conducive to the healthy action of the stomach, precisely because it favours the new distribution of the circulating blood which that process requires.

In accordance with this law of digestion, there is throughout the whole animal creation a marked aversion to activity for some time after a full meal, although man, eager in the pursuit of gain or the gratification of other passions, often sets it at defiance, and engages in bodily or mental labour both immediately before and after meals; but, in return, he receives his reward for despising the authority of Nature, in a severity of suffering from which the animals whom he treats so much better than himself are by his care entirely exempted. No where, for example, does man hurry off to business so immediately as in the United States of America, and no where does he bolt his food so much as if running a race against time. The consequence is, that no where do intemperate eating and dyspepsia prevail to the same enormous amount. Even in England, according to Dr Caldwell, the extent of transgression cannot be compared with what is witnessed among our Transatlantic brethren; and the result shews, that if we in Britain suffer from indulging our fondness for good things, the comparatively deliberate way in which we set about enjoying them serves as a partial safeguard, and exempts us from a portion of the punishment which our brethren bring down upon themselves, by the hurry with which they first devour their food and then set off to work. Rapid eating almost invariably leads to overloading the stomach; and when to this is added a total disregard of the quietude necessary for digestion, what can be expected to follow but inveterate dyspepsia?

The reason why wounds, bloodletting, bathing, and other circumstances which tend to disturb the regularity of the circulation, are so hurtful after a full meal, will now be apparent. The effect of wounds and bloodletting is to give rise to an instantaneous change in the distribution of the blood, and to deprive the stomach of that which is now doubly required. Bathing, whether hot or cold, has an analogous effect; and so, indeed, have all violent and sudden bodily or mental shocks.

It must not, however, be imagined that the period of repose necessary to insure healthy digestion extends over the whole time of the continuance of food in the stomach. After a moderate meal and in ordinary health, the concentration of the vital powers in that organ, and their proportionate depression in other parts of the body, rarely continue, at least in a very marked degree, beyond the period usually allotted to the siesta, or sleep after dinner, in warm climates, and even in Italy and Spain--namely, an hour or an hour and a half. When the meal has not exceeded the bounds of moderation, a sufficient quantity of gastric juice for the digestion of the whole is secreted generally within the first hour; after which time, consequently, the same quantity of blood is no longer required to be directed towards the stomach, but may beneficially be distributed to such other parts as from their activity more immediately require its aid. If the muscular system is to be employed in labour or locomotion, the blood can now be spared to sustain its activity; if the mind is to be engaged in intellectual pursuits, it can be sent to the brain without robbing the stomach. The same principle of course applies to all the other organs; and it is therefore chiefly during the first hour, till all the gastric juice be provided and the chymification of the food be fairly commenced, that tranquillity of mind and inaction of body are so essential.

As already mentioned, the reality of increased circulation in the vessels of the stomach during digestion has been established by ocular demonstration, as well as by analogy. The increase in the supply of nervous energy which takes place at the same time is, however, scarcely less certain, although from its nature incapable of being seen. It is the almost characteristic feature of the nervous system to be excited by stimulus to increased action; and we formerly saw that when the nerves of the stomach are cut, and the flow of nervous influence is arrested, digestion instantly suffers. But the same principle holds in the nervous as in the circulating system. Energetic action cannot be kept up in two distant parts of the body at the same time. If the intellect be intently occupied in profound and absorbing thought, the nervous energy will be concentrated in the brain, and any demands made on it by the stomach or muscles will be very imperfectly attended to. If, on the other hand, the stomach be actively engaged in digesting a full meal, and some subject of thought be then presented to the mind, considerable difficulty will be felt in pursuing it, and most probably both thought and digestion will be disturbed. If the mental effort required be easy and agreeable, and the meal be a very temperate one, there will be much less difficulty in simultaneously proceeding with both, because comparatively little nervous energy will then suffice for them. Still, however, each will go on more efficiently if not interfered with by the other.

When the mind is active and vigorous, and properly exercised in all its departments of feeling and affection as well as of intellect, the nervous influence which the brain produces is not only more abundant, but of a more healthful and invigorating quality. Hence the well-known preservative and restorative influence of cheerful dispositions and gratified activity of mind, and hence the depressing, morbid, and often fatal effects of corroding care, grief, and apprehension, on every organ of the body. Hence, too, the weak digestion and sallow complexions of literary men and hard students, who suffer severely from transgressing this law of the animal economy by habitually engaging in occupations requiring much exertion of mind, not only soon after, but even during the very act of swallowing their meals. Ignorant of the connexion subsisting between the different functions, and of their laws of action, few can be convinced in time of the importance of observing this condition, even after its operation has been explained to them. In the conclusion, however, experience teaches many whose reason is insufficient for their guidance, and forces them to a closer conformity with the dictates of nature, when obedience is almost too late to be of benefit.

The prodigious influence of the nervous system on digestion is familiarly and unequivocally exhibited in almost every case of dyspepsia which each succeeding day brings under the notice of the physician. He knows well from experience that the diet may be selected with every care, its quantity duly proportioned, and exercise rigidly practised, and yet all his curative treatment fail even to relieve, unless his patient be at the same time freed from the pressure of care, and due attention be devoted to the observance of mental and bodily repose after every meal. The heavier the meal the greater is the desire for absolute rest, and the less advantageously can active exertion be encountered. When the stomach is loaded, the whole vital energies seem to be concentrated in it to enable it to cope with the task imposed upon it. But when we eat temperately, there is less necessity for entire quietude of mind and body. Accordingly, if we do not experience the same dislike to exertion after a light forenoon lunch, which we do after a heavy late dinner, the reason is simply, that less gastric juice, less nervous energy, and less vigorous action in the stomach, are required to digest in the one case than in the other.

Among operative manufacturers, who are much within doors, and who are allowed only a few minutes for meals, indigestion is very prevalent. Ordinary labourers are better treated in this respect, as they are allowed one hour for breakfast and another for dinner. To most of them the walk to and from their own houses is almost as good as, if not better, than absolute rest, because it varies their position, is taken leisurely, and costs no effort.

Those who are compelled by circumstances to active exertion immediately after a meal, or whose minds are intently occupied in thought or emotion, will find their only safety in eating less than when differently situated. The stomach, having less labour imposed upon it, will require less blood and less nervous energy, and consequently less of both will be abstracted from the other organs which are also in activity, and requiring their assistance. Travellers, literati, and other actively engaged men, know this rule by experience, and some of them have specially noticed its importance. Richard Cumberland, for example, in speaking of his own habits, says: “Nature has given me the hereditary blessing of a constitutional and habitual temperance, that revolts against excess of any sort, and never suffers appetite to load the frame. I am accordingly as fit to resume my book or my pen the instant after my meal as I was in the freshest hours of the morning.” This compatibility of temperate eating with activity did not escape the acute observation of Hippocrates.

The state of the mind, indeed, exerts a powerful influence not only on the stomach, but on the whole process of nutrition, and greatly modifies the quantity which may be safely eaten. If the mind be gay and joyous, appetite will be comparatively keen, digestion effective and rapid, and nutrition complete. Examples of this kind abound in childhood, and among an easy-minded well-fed peasantry; whereas if the mind be harassed by care and anxiety, or devoured by grief, envy, jealousy, or other troubles and disquieting passions, the healthy calls of appetite will be scarcely known, and digestion and nutrition will be equally impaired, for it is literally true that “indigestion or, to use the term of the day, a Bilious attack, as often arises from over exertion or ANXIETY OF MIND, as from refractory food.” This fact is exemplified on a large scale in every commercial country, and especially in times of public distress and political change. Shakspeare obviously had the principle in view when he made Cæsar exclaim:

“Let me have men about me that are fat, Sleek-headed men, and such as sleep o’ nights. Yond’ Cassius has a lean and hungry look; He thinks too much: such men are dangerous.

Antony. Fear him not, Cæsar, he’s not dangerous; He is a noble Roman, and well given.

Cæsar. Would he were fatter:--But I fear him not: Yet if my name were liable to fear I do not know the man I should avoid So soon as that spare Cassius.--He reads much. He is a great observer, and he looks Quite through the deeds of men; he loves no plays As thou dost, Antony; he hears no music, Seldom he smiles, and smiles in such a sort As if he mocked himself, and scorned his spirit That could be moved to smile at any thing. Such men as he be never at heart’s ease Whiles they behold a greater than themselves, And therefore are they very dangerous.”

Even experience must have taught every one with what zest we sit down to enjoy the pleasures of the table, and how largely we incline to eat, when the mind is free, unburdened, and joyous, compared with the little attention we bestow on our meals when we are overwhelmed with anxiety, or have the whole energies of the mind concentrated on some important scheme. There cannot be a doubt, indeed, that the over-exertion and excitement, or absolute inertness, of mind, in which sedentary people are generally immersed, contributes greatly, along with the want of muscular exercise in the open air, to impair the tone of the digestive organs. In this way, as it is not less justly than forcibly remarked by Dr Caldwell, “dyspepsia commences perhaps as often in the brain as in the stomach. Possibly oftener. That this is true of the disease in Europe will scarcely be denied, after a fair examination of the facts connected with it. It is there almost exclusively a complaint of the studious and the scheming, who, over-tasking their brains, injure them by toil. Among the husbandmen of England, who steadily pursue their tranquil mode of life, regardless of the fluctuations of stock, the bickerings of party, the fate of political measures, and the changes of place, dyspepsia is almost a stranger.” “In the cities, the same is in a great measure true of merchants, manufacturers, and mechanics, who are engaged in a regular and well established business, which is fully understood by them, where the risk is slight and the profits sure, and no disquieting anxiety attends it. Such individuals have a good digestion, and bear the marks of it. But with literary men, officers of state, dealers in scrip, daring adventurers, and anxious and ambitious projectors of improvements, with these and every other brain-worn class of persons, the case is different. Dyspepsia is their torment, and they exhibit deep traces of it in their lean frames and hagard countenances. Yet are they much more select in their diet, both as respects quantity, quality, and cooking, than the classes to whom dyspepsia is unknown. This fact is notorious, and has been so for centuries. Nor can it be attributed, I think, to any other cause but excessive and deleterious cerebral irritation in the one case, and an exemption from it in the other; and this cause seems sufficient to solve the problem.”

In denouncing active exertion of mind or body immediately after eating, as inimical to digestion, it is not meant that we should go to sleep, or indulge in absolute listlessness. A weak constitution may require something like complete repose, but a person in ordinary health may indulge in a leisurely saunter or pleasant conversation not only without injury but with positive benefit; and perhaps there is no situation in which digestion goes on so favourably as during the cheerful play of sentiment in the after-dinner small-talk of a well-assorted circle. The nervous stimulus sent to the stomach is then of the most healthful and invigorating description, and ever the dyspeptic, if on his guard against a heavy meal, forgets his woes amidst the unwonted vigour of his functions.

It is true that thousands who habitually neglect the observance of the condition here adverted to, continue to live and digest for years without appearing to suffer much from their conduct. But it is not less true that there are many more who bring wretchedness and disease upon themselves and their offspring, in the vain attempt to counteract the intentions of Nature, and that there are comparatively few even of the former so happily constituted as to escape entirely unscathed. Most frequently the evil consequences are only accumulating, and when they are summed up at the end of years, the victim finds himself more severely punished than he had ever expected to be. In this respect, the consequence resembles that arising from breathing in a vitiated atmosphere. The effect may not be perceptible for a time; but if God has ordained a pure air to be best adapted for respiration, we have the infallible authority of His omniscience for believing that one which is vitiated must be less wholesome, although His beneficence has so constituted us, that the injury resulting from it is gradual in its infliction, for the very purpose of giving us time to escape. In like manner, if bodily and mental relaxation are favourable to digestion, we have the same infallible guarantee that every departure from them must be in so far hurtful, however slowly the effect may develope itself.