A well-known biochemist, Albert P. Matthews, has said of the importance of water to life:
"It is little short of astounding that living matter with all of its wonderful properties of growth, movement, memory, intelligence, devotion, suffering, and happiness should be composed to the extent of from 70 to 90 per cent of nothing more complex or mysterious than water. Such a fact as this is most perplexing, especially when all experiment shows that this water is playing a profoundly important part in the generation of the vital phenomena. Any interference with the amount normally present makes a change at once in the activities of the cells. In fact, we might say that all living matter lives in water."
All the cells and tissues of the body contain an abundance of water, and in this liquid medium, all the numerous chemical processes take place. These chemical processes generate heat, which must be eliminated or the body temperature will rise above the normal level. Elimination of heat is effected by the blood, which absorbs it and carries it to the body surface. The surface is cooled by radiation of heat and by the evaporation of the watery perspiration from the skin. An adequate water supply is therefore essential for the proper regulation of the body temperature. In the modern treatment of fevers, an abundance of water is important, and much of it may be supplied in the form of fruit juice, which also furnishes fruit sugar and vitamins.
The blood, composed largely of water, is the carrier of nourishment from the gastrointestinal tract to all of the body cells. The red cells of the blood, floating in this watery medium, carry oxygen to the tissues. Carbon dioxide is transported away from the tissues by the blood to the lungs for elimination. Other waste material is conveyed in watery solution to the kidneys for excretion. It is therefore apparent that the life of the body as a whole, and of all of its cells and tissues individually, is dependent upon an adequate water supply.
It is generally conceded that the daily water intake should be six to eight glasses. It is best to take most of this liquid between meals. Fluid with meals tends to wash down the food incompletely masticated and poorly mixed with saliva. The primary stages of starch digestion are thereby greatly hindered. It is a good practice to drink one or two glasses of water before breakfast.
Caffeine-Containing Beverages
The caffeine-containing beverages are coffee, tea, and the cola beverages. Coffee, as it comes to us, is the dried and roasted seed of the tree Coffea arabica. Tea is the dried young leaves of the tea tree, supposed to be a native of the province of Assam in India. Kola is the dried seed of the Cola acuminata. The fresh seed is chewed extensively by some of the natives of Africa. A cup of strong coffee or tea contains about a grain and a half of caffeine. In tea, considerable tannin is found, as well as caffeine. Cola contains about 1.2 grains of caffeine to the glass, and a very small amount of theobromine. In addition to caffeine, coffee has aromatic oils which give the aroma to the beverage. These aromatic oils are of importance as a cause of digestive disturbances. Sollmann, who has made a study of the subject, says:
"The volatile aromatic constituents produce local irritation and reflex stimulation, in the same manner as the condiments. The hot water contributes to this effect; and possibly the greater reactivity induced by the caffeine heightens the reflex response. The local irritation stimulates peristalsis, and with excessive use, tends to nervous dyspepsia. It is doubtful whether the quantities (of the volatile substances) taken in the beverage cause any direct central stimulation." 2
Pharmacologists tell us that the caffeine of tea, coffee, and cola "produces stimulation of the higher functions of the brain, with quicker and clearer thought; disappearance of drowsiness and fatigue; more sustained intellectual effort; more efficient appreciation of sensory impressions, and more perfect association of ideas." 3 This statement applies to moderate doses. A professor of therapeutics in a large medical school has made the following statement:
"While caffeine is perhaps the best cerebral and mental stimulant we possess, and inhibits mental fatigue and allows longer continued work, it, of course, cannot take the place of the cerebral rest caused by sleep. Consequently, while it stimulates, it leaves the brain more fatigued after its action is over, and when it is used repeatedly as a cerebral stimulant and to prevent sleep when it is necessary for a person to be awake, it can do nothing but cause general nerve and brain fatigue unless adequate sleep is obtained. There is no question but that a caffeine habit can be acquired, whether as such or as a tea or coffee habit. Coca cola, tea, and coffee 'fiends' are of common occurrence."
More recent studies, 5, ', 9, of the effect of caffeine on the nervous system confirm this last statement that fatigue follows its period of stimulation. Two of these studies indicated that the accuracy of a simple movement (jabbing a point at the center of a target) was increased for one or two hours after taking caffeine or coffee, but twenty-five hours later usually showed a definite impairment. Highly skilled movements acquired by weeks of practice were impaired immediately, and on up to forty-nine hours after taking the drug or beverage. One of these authors remarked, "Evidently caffeine affects the neuromuscular mechanism so that the execution of tasks requiring great precision is impaired, but the performance of tasks requiring chiefly rapidity of movement is facilitated." The other studies indicate a similar impairment of muscular accuracy and speed. These studies show the very important fact that the period of stimulation of the central nervous system by caffeine is followed by a period of fatigue.
The use of caffeine-containing beverages is particularly bad for the sensitive nervous systems of children. In various surveys over the United States, it was indicated that over 5o per cent of school children drink coffee. In some localities as high as 90 per cent of children of foreign parentage use this beverage. A psychologist in a study of 464 school children to determine the effect of coffee on grades concluded: "In all, it might be said that there were lower and lower grades as the amount of coffee taken each day increased. For instance, those drinking four or more cups a day average 63.8 per cent for their lessons, a great difference from the 73.4 per cent of those drinking no coffee." A very important consideration is the fact that these caffeine-containing beverages crowd milk out of the child's diet.
Osborne i° recently stated that tea and coffee accentuate the ailments of old age, and consequently should not be used by elderly people. They cause increased nervousness, palpitation, sleeplessness, excessive urination, and nervous and muscular irritability and trembling, which are common accompaniments of old age.
Caffeine has for a long time been considered a stimulant to muscle. A recent study " made on a group of soldiers in Germany showed that men who received coffee had 23 per cent less endurance than men who did not receive it. A muscle removed from a frog's leg and treated with caffeine has less endurance than one not so treated.' The apparent lessening of fatigue by the drinking of tea or coffee or cola beverages is due to the stimulating effect on the nervous system, rather than to any increased ability of the muscle itself to do work.
A number of years ago it was shown" that the use of tea and coffee placed extra work on the kidneys, since caffeine is changed to uric acid in the body and must be excreted by the kidneys as such. Not only so, but caffeine also causes the kidneys to work harder by stimulating them directly when such stimulation is not needed. Other members of the caffeine group of drugs are sometimes used to increase kidney function when this seems desirable in certain diseases.
More commonly than is generally recognized, caffeine causes pain in the heart." '
, , .
A few days ago I saw a young married woman who complained of pain in the region of her heart, and of insomnia and headache. Though she was drinking only two cups of coffee a day, leaving it entirely out of her diet gave her almost immediate relief from her symptoms. Some people tolerate tea and coffee much better than do others, and appear to get few symptoms from their use, while more susceptible and nervous individuals develop unpleasant effects from relatively small quantities. The fact remains that even though outspoken symptoms are not produced, these caffeine-containing beverages stimulate the nervous system when rest is needed.
A number of cases are on record of acute and chronic poisoning by tea, coffee, cola beverages, and caffeine itself. ", Some of these patients showed actual mental derangement from taking caffeine for mental stimulation. Others presented the more common symptoms of dizziness, headache, insomnia, nervousness, tremor, nausea, visual disturbances, vomiting, heart pain and irregularities. Many of these patients took only two or three cups of coffee a day. The digestive symptoms are due to the volatile substances in coffee and the tannin in tea, as well as to caffeine. A recent study indicates that caffeine is excreted in small quantities in the milk of nursing mothers who drink as little as one or two cups of coffee or tea a day.
Apple and Other Fruit Juices
Strictly speaking, the term cider means fermented apple juice containing 3 to 6 per cent alcohol. This is the accepted meaning of the term in England and France, the world's largest producers of the beverage. In the United States, the terms "cider," "sweet cider," and "hard cider" are used; the term "cider" sometimes indicates unfermented apple juice, and at other times the alcoholic variety. Fermented apple juice is capable of producing definite intoxication, since its alcoholic content is similar to that of beer. Such intoxication will have the same characteristics as those caused by the stronger liquors.
Fresh, unfermented apple juice made from clean, fresh, ripe apples is a wholesome drink, but if allowed to stand it readily begins to ferment. Fresh fruit juices in general are healthful beverages, and contain easily assimilated sugars, mineral salts, and vitamins. The citrus fruit juices and tomato juice are our best sources of vitamin C.
Bibliography
Matthews, Albert P., "Physiological Chemistry," p. 12, Wood, 1916.
Sollmann, Torald, "Manual of Pharmacology," p. 271, Saunders, 1936.
'Id., p. 256.
Osborne, "Principles of Therapeutics," p. 214, Saunders, 1921.
5 Horst, Robinson, Jenkins, and Bao, Journal of Pharmacology and Experimental Therapeutics, 52: 307, 1934.
Horst, Buxton, Robinson, Journal of Pharmacology and Experimental Therapeutics, 52 :322, 1934.
T Horst and Jenkins, Journal of Pharmacology and Experimental Therapeutics, 53 :385, 1935.
Cheney, Journal of Pharmacology and Experimental Therapeutics, 53 :304, 1935.
'Irvin, Medical Journal and Record, 123 :434, 1926. 1.° Osborne, Medical Journal and Record, 120 :163 SUPPI. 1924.
" Voigt, Deutsche Medizinische Wochenschrift, 62:169, 1936, also abstracted in Journal of the American Medical Association, 106:1136, 1936.
Saslow and Webster, Journal of Pharmacology and Experimental Therapeutics, 52:142, 1935.
" Mendell and Wardell, Journal of the American Medical Association, 68:1805, 1917.
" Krehl, "Die Erkrankungen des Herzmuskels," p. 97, Holder, 1913.
" Albutt, "Disease of the Arteries," p. soo, Macmillan, rgr5.
"Levy, Annals of Internal Medicine, ii :833, 1937. Orendorff, Journal of the American Medical Association, 62:1828, 1914.
" Brandenburg, Medizinische Klinik, 16:1921, 1920. Powers, Medical Journal and Record, 121 :745, 1925.
McManamy and Schube, New England Journal of Medicine, 215:616, 1936.
Starr, Medical Record, 99 :463, 1921.