Part 4

In one thing medical authorities do agree, however, coffee and tea are not beverages for children. Moralists to the contrary notwithstanding, this is again beside the point when we are considering the reasonable use of coffee by adults. Adults and children are essentially different animals using their food intake differently--the one for upkeep and repair the other for new construction as well as upkeep and repair. They differ basically in metabolism. They have different metabolic rates and different expenditures of energy. The child is turning food into flesh and bone and blood at a much greater rate than a fully-grown adult organism is ever required to do. Diets which would amply sustain an adult may easily be detrimental to or deficient for young and growing children. We shall, then, restrict ourselves herein to the rational use of coffee by average adults. What can coffee, or its active principle caffeine, do to harm adults?

Caffeine definitely increases the force of the heart beat. Yet Wood, “Notice of Judgment Under the Food and Drugs Act No. 1455 1912,” says such an effect may be desirable since a slower rate and increased force induce cardiac efficiency. Heavy coffee drinking may produce a frequent, hard pulse and palpitations, but this again goes over into the territory of abuse.

Coffee tends both to dilate the vascular system and to constrict it, the net result being a mass movement of the blood without increased blood pressure. Coffee has repeatedly been suspected of damage to the heart and blood vessels but such suspicions are common in therapy and evidence is entirely lacking to prove this point scientifically. Suspicion is here probably no more legitimate than in many lay superstitions. While patients with definite heart trouble should avoid all stimulants the normal use of coffee by an adult cannot be said to have an insidious effect upon the heart and blood vessels.

While coffee is a diuretic it cannot be convicted of renal injury as yet. Indeed it is quite probable that the kidneys become accustomed to caffeine while A. R. Cushny (J. Pharmacol. & Experimental Therapy 4 363) declares that caffeine does not injure the kidneys even when given in large dosage over long periods.

But how about digestion? Years ago Fraser (J. of Anatomy & Physiology 184 13 1883) said that coffee and tea hindered the digestion of protein foodstuffs with the exception of ham and eggs! This very fortunate immunity renders the typical American dish a safe breakfast in any case. In general, however, observations in vivo indicate that the amounts of the beverage usually taken have no evil effects upon digestion. Indeed some investigators have found a pronounced increase in gastric secretion following tea and coffee.

Hutchinson in his “Food and Dietetics” says that the digestive disturbance caused by such infused beverages is negligible in health. Others have held that the aromatic constituents of coffee, or the “empyreumatic oil,” upset digestion. There may be some reason for this; at least certain individuals tolerate much better coffee from which these substances have been removed.

Caffeine is of course a stimulant to the central nervous system, particularly that part of it intimately associated with the gastric function. How far is its use as such a cerebral stimulant advisable? Like all stimulants this will result in greater fatigue on excessive usage. But as “The Medical Review of Reviews” once said, “When tea and coffee are made moderate in strength and partaken of in sober quantities they are gentle stimulants and their effect upon the nervous system is salutary.” A too constant reliance on coffee as a goad may of course result in nervous irritability.

Coffee speeds up the metabolism, increases the body heat and heat elimination, and perhaps urges us on to greater activity. But, as the English pharmacologist Dixon remarks in his “Manual of Pharmacology,” “Caffeine decidedly facilitates the performance of all forms of physical work.” Yet certain athletes are reported to have had their performances injured by coffee drinking, while Osborn holds that coffee interferes with the best muscular efforts. Take Hobson’s choice here, you have an authority either way and we do love some one to give our opinions an affidavit. It may be observed that coffee also increases the rate and depth of our respiration.

The following gracefully and euphoniously named aromatics have been found in roasted coffee--pyrol, quinol, methylamin, acetone, furfuryl alcohol, a derivative of saligenin, phenols, valeric acid, pyridin and trimethylamin. You are no doubt much surprised and edified to know that. Some of these compounds are toxic, but they occur in coffee in amounts far too small to be dangerous to health. Some have accused these formidably named derivatives of bad effects but the work existing shows caffeine to be the only coffee constituent of importance in its physiological effects. It is agreed that caffeine is very rapidly changed by the body into less active substances and disposed of, so there can be no cumulative effect even of that. In old age, as in youth, coffee, like other stimulants, should be used in moderation if at all.

As a whole then what can we conclude about the use of coffee by adults? Science has not found it harmful when taken in non-excessive amounts. Heart patients, neurotics, the young and the aged should avoid it. It has not been proven to cause pathological changes in the heart, blood vessels or kidneys. It is a valuable cerebral stimulant and antidote for mental fatigue, lacking as it does the bad effects of most stimulants. It also stimulates respiration and speeds up the metabolism, while its effects on digestion cannot be said to be definitely deleterious. Tea, because of its tannin content, is probably worse than coffee gastrically. Finally caffeine is rapidly oxidized and has no cumulative poisonous effect.

Most important of all we must remember that individuals differ. They are constructed of different proteins and have cellular and glandular processes differing from individual to individual. What one can do with impunity another will find bringing him nearer to the undertaker daily. In this as in all other matters dietetic common sense and sound judgment in appraising our own state of health and the reactions of our organism to various stimuli will always surpass slavish subservience to systems or morbid efforts to avoid all harm and achieve an impossible all good.

Then if we are to drink coffee let us consider momentarily how best to make it. One basic fact stands out--freshly ground coffee is best. Ground coffee loses its flavor on standing. It also loses its content of carbon dioxide. These two factors are definitely related but exactly how and why we do not know.

In considering coffee-making precise scientific methods are everything. Our mothers, more energetic than the decadent women of today, made their own bread. They often appraised various flours by such rude methods and declared this brand better than that. How much could they have known about it? Did they keep every factor constant except the flour when making their tests? You know they did not.

Go into the laboratory in the U. S. Bureau of Chemistry, where flour bought by the government is tested, and what do you see? You see an apparatus enabling the investigator to make bread from that flour holding every factor constant except the flour. All other materials used are precisely the same and all materials are carefully weighed. The dough is kneaded mechanically and timed exactly. Fermentation takes place in a cabinet at a constant temperature and for a definite time for all loaves. The same holds for the time and temperature of baking. The loaves are cooled just alike on wire meshes for the same time. They are weighed and their volumes measured. Then the investigator positively knows which flour makes the best loaf of bread and the government buys that flour for its hospitals and penitentiaries.

It is exactly the same with coffee. To test coffees they must be infused in very precise ways. How is it done? In the first place pulverized coffee must pass a 30 mesh sieve and be like fine cornmeal, medium ground coffee must pass a 10 mesh sieve and be like steel cut; coarsely ground coffee must pass an 8 mesh sieve and appear like the rude, home ground bean of our childhood.

Then boiling, boiling with egg, percolation and filtration must be tried on each by precise methods. A 40c. Mocha-Java coffee may be used with 12 grams of coffee and 240 cc. of water, except in the case of percolation which requires 480 cubic centimeters of water for 12 grams of coffee. In boiling with egg 10 grams of egg white were added. The infusion must be governed precisely.

Boiling takes place in a seamless white enamel pot, cold water being poured over the coffee, the whole brought to a boil and boiling continued for three minutes; the infusion then stood five minutes and was ready. It was strained through cheese cloth. Percolation was carried out in the usual manner with an ordinary percolator, the water being cold at the start and boiling being continued for five minutes. In filtration a wire strainer was put across the top of the pot covered with a piece of tennis flannel upon which the coffee lay. Boiling water was poured through once.

The brews were tested hot, for strength, color, and flavor by various people who did not know the methods of preparation. Six degrees of strength were observed with specific gravities of the brew by test as shown in the table--

Very weak 1.0045 Specific Gravity Weak 1.0055 Specific Gravity Moderately strong 1.0060 Specific Gravity Standard 1.0065 Specific Gravity A little too strong 1.0070 Specific Gravity Much too strong 1.0080 Specific Gravity

The specific gravity was taken on the cold brew and a standard, 1.0065 was selected for further tests. The following table indicating condition of coffee, method of brew, weight of coffee used and cost per cup is of considerable interest--

S. G. 1.0065 Cost Condition Method Weight Coffee per cup of infusion Grams cents

Pulverized Boiling 12.05 .63 Pulverized Percolated 12.78 .71 Pulverized Boiled with egg 12.85 1.05 Pulverized Filtered 12.31 .72 Medium Boiling 15.89 .83 Medium Percolated 22.94 1.29 Medium Boiled with egg 16.71 1.29 Medium Filtered 30.00 1.73 Coarse Boiling 19.79 1.03 Coarse Percolated 27.52 1.54 Coarse Boiled with egg 21.27 1.56

Hence it is apparent that pulverizing is the most efficient method of grinding. The best brew is made by filtration. Boiling with egg is second best while plain boiling and percolation are the poorest of all. In general, strength and color of the brew are quite independent of the blend and price but depend upon the grind. The flavor, however, varies markedly with the coffee brand and price. Java, Sumatra and Bogota give weaker infusions under the same conditions than do Mocha and Santos. The order of preference for flavor stood--Java, Sumatra, Santos, Bogota and Mocha. It was also observed that coffee which had stood long after grinding gave an infusion of a lower specific gravity and hence of impaired strength.

The effect of adding sugar and cream to coffee is not well understood. Some assert that the fat of cream and the fats of the coffee bean form indigestible compounds, but there is scarcely sufficient experimental evidence to justify this. The tannin compounds in coffee are apparently not precipitated, as has frequently been stated, by the addition of sugar and cream. Testing a centrifuged cream from a beverage coffee gave no appreciable evidence of tannin while the remaining coffee infusion gave the normal positive tests for tannin. It is certainly true, however, according to one authority that black coffee without any additional substances, with the possible exception of a portion of sugar, is the most beneficial form of the beverage.

Transcriber’s Note:

Words and phrases in italics are surrounded by underscores, like this; those in bold are surrounded by equal signs, =like this=. Obvious printing errors, such as partially printed letters and punctuation, were corrected. Three misspelled words were corrected.