( Originally Published Early 1925 )
The foregoing deductions of Hawk are apparently opposed to ordinary human experience, but are not for that reason to be rejected. Hawk, it seems, was not satisfied, for he continued his experiments and published them in 1919. In quoting his later conclusions the reader will note that his phrase "flushed out of the system" can apply to the urinary as well as the bowel function. If you are normal, Hawk says, by all means drink all the water you wish at your meals. The food is thus more thoroughly digested and its digestion products are more quickly and completely absorbed. Various materials which are poisonous in character are flushed out of the system and harmful bacteria do not thrive so well in the large bowel. All these things promote increased mental and physical efficiency. Some types of kidney disorders have been shown to be benefited by drinking large volumes of water whereas other types might possibly not be so benefited.
The drinking of water immediately before a meal is a good practice. It will cause the appearance of digestive fluid in the stomach. Therefore when the food reaches the stomach it is more rapidly digested than it would have been if no water had been taken.
It is also good practice to drink water immediately after a meal. The stimulation thus afforded permits the stomach to handle its burden more efficiently).
We often hear the expression "on an empty stomach." As a matter of fact the human stomach is never empty. In the early morning before breakfast, the normal stomach contains on the average about a fifth of a glass of fluid that generally possesses at least a faint blue, green or yellow color, due to the bile or other fluids that have passed from the bowel up into the stomach during the night. If the individual was the victim of a banquet or party the night before the stomach may contain nearly a glassful of the residuum filled with undigested and indigestible residues of the so-called food he was called upon to eat.
A glass of water, either hot or cold, serves to stimulate the formation of fresh gastric fluid as well as the motor action of the stomach. Consequently, this colored residuum which has been diluted by the water is passed quickly from the stomach into the bowel, leaving normal gastric juice in the stomach ready to digest the food to be eaten at breakfast.* It has been shown by experiment that very soon after water is drunk its presence may be demonstrated far down in the intestine."
Some individuals derive the most satisfactory results from hot water. It raises somewhat the bodily temperature, which is slightly subnormal in the early morning.'
The amount of water one should drink a day depends on such factors as body weight, vocation, season of the year, character of diet, etc. One general statement, how-ever, can be made with certainty the great majority of people drink far too little water. It has been claimed that three pints of water are sufficient for the average man or woman per day. This is rather low. In order to derive the maximum benefit from our food we should drink at least three pints of water at meals alone, that is two glasses with each of the three meals.'
In order to further facilitate absorption and the general flushing of the system, with its consequent removal of poisonous substances, at least one pint additional should be drunk between meals, in the early morning and before retiring. In other words the water schedule of the average man or woman should call for at least two quarts of water per day (eight glasses) rather than three pints. In case one drinks considerable milk, which is 87 per cent water, the water quota may be appreciably lower. If one eats freely of fruits and vegetables less water is required, since these foods have a high water content. If one exercises vigorously in a warm climate the water ingestion should be considerably increased).
For example, Hawk has known a man weighing 150 pounds to lose eight pounds in the three hours of a fatiguing tennis contest on a scorching hot day.
In the Biological Bulletin for April-July, 1914, Hawk goes into details on the large percentage of water in the human body; that the gastric juice is 98 per cent water, the blood over 90, the intestinal juice 98 and that efficient intestinal digestion is greatly promoted by a large in-take of water; that even where the stomach is full the water will not be retained in the mixture but pass on through a channel. ' Much misinformation is current on this subject. He also points out that a large intake of drinking water, whether distilled or ordinary, acts as a deterrent of intestinal putrefaction, and also calls attention to the improvement in the character of the urine under full intakes of water. Of this more anon.
Kellogg in his "New Dietetics," says of the foregoing theories of Hawk (whom he designates as a Chemist of Philadelphia) that they have been particularly misleading and dangerous. He says the author would have us believe that drinking freely of even ice water at meals does not involve risk of indigestion. The professor's experiments simply demonstrate how much abuse a healthy stomach is able to endure before it surrenders to disease. Because, Kellogg says, it seems to make little difference to a healthy stomach whether bread is stale, and hence quickly digested, or fresh and slowly digested, it cannot be assumed it makes no difference to a weakened stomach. This principle applies to all sorts of unhygienic practices including excessive water drinking with meals. Prof. Pavlow showed that taking a quantity of water into the stomach gives rise to the production of an increased amount of gastric acid. The increase is not so great as to cause any serious disturbance in a healthy stomach, but in the case of a stomach which is already making an excess of gastric acid, the drinking of a quantity of water may be the means of greatly increasing the difficulty. Thus it is an easy inference that the habitual use of liberal quantities of water in connection with meals, like other gastric stimulants, will in time produce pronounced hyper-acidity. A glass of water at meal time is not harmful to the ordinary person, but the practice of drinking water to wash food down is very injurious. Those whose stomachs are already producing an excess of acid, which class is a large one, Kellogg says elsewhere, should avoid water drinking at meals, as well as the use of broths and thin soups. In the feeding of milk to many hundreds of patients subjected to the milk regimen, experience has shown that the taking of milk slowly is so important that the patient is required invariably to draw it through a straw or a small glass tube. In this way a person may take as much as six quarts a day without difficulty which may otherwise result in the production of dangerous curds. In one such case where the patient had swallowed several glasses of milk this curd, in the form of a rope, was felt in his throat several hours after. Reaching in, the author succeeded in getting hold of it with his fingers and pulled it out. The distinguished English surgeon, Dr. Lawson Tait, told Kellogg of a case in which he was obliged to remove a similar mass of curds which had lodged low down in the intestine.
While Kellogg does not mention it, Hawk at page 401 of the Journal of Experimental Medicine, volume 12, quotes with approval the statement of Foster and Lambert that when water is added to the diet, the gastric juice is not only increased but becomes more acid.
At page 482, Kellogg says, the daily loss of water from the body is about 4 1/2 pints. Ordinary food, as eaten at the table, contains water to the extent of about one half its weight. About 12 ounces of water are produced in the body by the reactions which occur in the processes of digestion, assimilation and dissimilation. To supply the daily loss at least 2 to 4 pints should be drunk.
Referring elsewhere to the practice of Priessnitz, of Grafenberg, Germany (the originator of hydrotherapy, or water cure), in requiring the drinking of as high as 20 to 40 glasses a day, which is still recommended by German water-cure empirics, Kellogg approves the practice up to 6 to 10 glasses a day as a method of treatment. He says water drinking is especially indicated in all cachexias (a depraved condition of general nutrition) and diatheses (a predisposition to certain diseases like tuberculosis, gout, etc.). In rheumatism it is useful in diluting the blood so that it can dissolve and carry out of the body a larger amount of waste matters.* As a means for encouraging activity of the skin and kidneys and diluting the urine free water drinking not only promotes the elimination of excess sugar in the blood in diabetes but lowers the specific gravity of the blood and aids in the elimination of acetone (found in the blood in diabetics) and diacetic acid (some-times associated with diabetes). In insipient diabetes the disposition to drink large quantities of water should be resisted to a moderate extent, water being taken only when the thirst becomes very intense. In fevers water drinking aids the kidneys and skin in eliminating body poisons to which the rise of temperature is due, in aiding the liver in its work of destroying fever poisons and promoting the reductions of temperature by causing increased evaporation from the skin.
In health when the amount of water supplied to the body is insufficient the condition of the body can be compared to a stagnant pool, while an abundance of liquid so encourages its activities that it may be compared to the flowing mountain stream. It is one of the most effective means of relieving a common cold by aiding in the elimination of tissue poisons.