Evil Effect Resulting from the
Use of Sugar
BY J. H. KELLOGG, M. D.
RECENTLY several correspondents have asked for an opinion as to the dietetic properties of sugar. Claude Bernard proved long ago by careful experiments that sugar alone is not a food, and that an animal fed entirely upon sugar soon loses its strength and vigor, and dies of starvation. Sugar is one of the constituents of a perfect food, but must be associated with the other elements found in food — at least with the nitrogenous — to render it capable of sustaining life.
The love of sweet substances is unquestionably a really natural instinct, since saccharine flavors abound in those food substances which constitute the most natural diet for the human family; and if our diet were wholly composed of natural foods, there would be no occasion for writing this article, for no natural food contains so great an excess of sugar as to be capable of producing harmful effects when eaten by a healthy person. When, however, sugar is separated from its natural association with other food elements, and presented in a concentrated form, as that made from the ordinary sugar- cane it becomes capable of producing injurious effects of a very decided character. The following are the chief injurious results which may arise from the excessive consumption of sugar in its concentrated form: —
1. Acid Dyspepsia. — Acidity, or sour stomach, is a very common result of the use of sugar in its ordinary form, or in the form of candy, sweetmeats, etc. Under the action of certain germs, sugar is converted first into alcohol and carbonic acid gas, and later the alcohol is decomposed into acetic acid and water or vinegar. It is in this way that vinegar is made from cider, wine, and other sweet liquids. When taken into the stomach, sugar undergoes this same change. The first symptoms of this form of fermentation in the stomach are eructations of gas and distention of the stomach due to the alcoholic fermentation. Sometimes months or years may elapse without the appearance of other symptoms, but sooner or later the stomach will become sufficiently disabled from frequent distention and the overstretching of its muscles, to prevent the prompt discharge of its contents; and the longer retention of the food substances within the stomach will give opportunity for the acetous, or acid-forming, fermentation, the symptoms of which are soreness and burning at the pit of the stomach, and sometimes vomiting or regurgitation of sour liquids.
2. Catarrh of the Stomach. — In its concentrated form, sugar gives rise to an excessive formation of mucus in the stomach. By constant repetition this may in time become a habit, and then catarrh of the stomach will be established. The irritation of the mucous membrane by the products resulting from the fermentation of sugar is also provocative of catarrh. The free use of sugar is unquestionably one of the most common causes of gastric catarrh. Some of the worst cases of this disease which the writer has ever met have been from this source. In one well-marked case the lady had been in the habit of eating a three-pound box of highly flavored candy regularly every week.
3. Indigestion of Starch. — Physiologists have demonstrated the interesting fact that in order that the ptyalin, or starch ferment, should continue its work of converting the starch into sugar, it is necessary that the sugar resulting from the action of the ptyalin should be absorbed as rapidly as formed. When absorption does not take place with sufficient rapidity, and the sugar in solution is allowed to accumulate, the action of the ptyalin ceases. The same principles applies to the action of the other ferments — pepsin, pancreatin, etc. It thus appears that when sugar is taken with starchy foods, its effect is to interfere with their digestion, as it will at once render the mixture so highly saccharine that the ptyalin will not act upon the sugar as efficiently as it would otherwise do. Cane-sugar cannot be absorbed as such, but must be digested. It is converted by the action of the intestinal juice into grape or malt sugar, which prepares it for absorption; but this action does not take place until after it enters the intestine, consequently cane-sugar is neither absorbed nor digested in the stomach; and so long as the food substances remain in the stomach, it is also present, interfering with starch digestion. Further interference with digestion is occasioned by the fermentation of the sugar, which, under the influence of the germs which are always present in the stomach, may ferment, although it does not digest; and the fermentation thus started may extend to other of the food substances, vitiating the products of digestion, and interfering with the whole digestive process.
4. Disturbance of the Liver Functions.— A condition commonly known in this country as torpid liver, called by the French, hepatism, is very generally present in persons who consume sugar in large quantities. The condition is characterized by general disturbance of all the functions of the liver, which are so numerous that we can do little more than barely mention them here. They may be briefly stated, together with the effects of sugar upon the several processes, as follows: —
(1) Bile Making.— Bile produced by the liver contains a considerable amount of waste substances, or dregs of the body, some of which are exceedingly poisonous in character, so that when retained in sufficient quantities, a state of poisoning results. This condition is not indicated by jaundice, but by a dingy appearance of the skin, dulness of the white portion of the eye, specks before the eyes, metallic taste in the mouth, and when extreme, by light or clay-colored stools or fecal discharges, and a very dark color of the urine. In some cases, however, what is known as infectious jaundics results from catarrh of the biliary passages. This always begins with catarrh of the stomach. From the stomach the catarrhal inflammation extends to the upper portion of the small intestine, or the duodenum, from which it extends to the liver itself through the ducts which convey the bile from the intestine.
When this catarrhal process becomes intense enough to cause closure of a biliary passage of considerable size, a sufficient amount of bile will be absorbed into the system to make the skin and the white of the eye saffron or yellow-colored, and the patient is said to have jaundice. This sort of jaundice is different from the jaundice produced by gallstones. In the latter form of the disease the occurrence of jaundice is sudden, and is accompanied by severe pain, or hepatic colic, due to the passage of a gallstone. When the stone has passed from the gall-duct, the bile flows again, and the jaundice disappears. Infectious jaundice is preceded by catarrh of the stomach, and often by a dull pain beneath the ribs of the right side in the region of the duodenum. It is also characterized by chills occurring daily or irregularly, accompanied by fever. These chills often continue for several months, and are usually attributed to malaria. The excessive use of sugar is a very common cause of this disease.
(2) Sugar-making and Regulating Function.— One of the most curious functions of the liver is its sugar- making and regulating function. All the sugar and starch taken as food are, after digestion and absorption, carried to the liver by the portal vein. Only a very small portion is allowed to pass through the organ, the greater part being stored up in the liver cells by conversion into a form of starch known as glycogen. This glycogen is subsequently, in the intervals between meals, slowly digested by means of a ferment derived from the blood-corpuscles, and thus converted into sugar again. By this arrangement the sugar is passed out of the body regularly and in small amounts, instead of being thrown into the blood in great quantities as rapidly as it is digested. This regulation of the supply of sugar is of great importance for the reason that sugar is chiefly used in the body for the production of force and heat, the demand for which is more or less regular, as in the case of the furnace or locomotive. This function of the liver may be compared to the automatic stoking, or fuel-feeding arrangement, sometimes connected with large boilers.
When sugar is used in large quantities, as is likely to be the case when it is taken in its free form, so great a quantity is sometimes carried to the liver that it is unable to retain as large a portion as is necessary, and more than the usual amount escapes into the blood. The blood normally contains only two or three parts of sugar to one thousand parts of blood. When the sugar rises above three parts in one thousand, the kidneys, which are always on the alert to regulate the condition of the blood, take alarm, and, seizing upon the excess of sugar, throw it out of the body in the urine, so as to protect the blood-corpuscles and other delicate tissues of the body from the injurious effects certain to follow an excess of sugar in the blood. When sugar is thus present in the urine, the case is said to be one of diabetes. It is a well-recognized fact that this disease is more frequently produced by an excessive use of sugar, or saccharine substances, than by any other cause. The liver apparently becomes exhausted in its effort to retain the excessive amount of sugar taken in, and lets a portion slip through, and as the disease advances, a larger and larger quantity of the sugar eaten passes through in this manner; and thus the amount of sugar in the urine increases from a few grains per diem at the outset to several ounces, or, as the writer has sometimes seen, nearly a pound.
(3) The destruction of ptomains and poisons of animal or vegetable origin, the conversion of tissue poisons into less dangerous forms, the retention of mineral poisons, — in other words, the protection of the body against poisoning. These are very important and interesting functions of the liver. When a man takes alcohol, a part of it goes to the liver, which destroys what it can of the poisonous substance, allowing only a portion to escape into the body. The same is true of nicotin, strychnia, and other poisons. Poisons which are constantly produced in the alimentary canal, the healthy liver is able to destroy, wholly or in part, thus protecting the body against their injurious effects. Poisons produced by the tissues as the result of tissue activity, are, by the action of the liver, converted into less poisonous substances, and prepared for elimination through the kidneys. When the liver becomes disabled as the result of excessive consumption of sugar, so that it is no longer able to perform these important and delicate functions efficiently, systemic poisoning appears as the result of the accumulations of the tissue poisons and the absorption of those formed in the alimentary canal by decomposition of the food under the action of germs. This poison is increased when the liver is in a state of disease, for the reason that the bile is an antiseptic. When it becomes vitiated or diminished in quantity, its antiseptic power is lacking, and the intestinal contents, especially those of the colon, undergo decomposition to an unusual extent, throwing into the blood great quantities of intensely poisonous substances. It is the presence of these poisons which gives to the fecal discharges of persons suffering from a diseased liver their intensely loathsome odor.
Persons whose livers have been disabled by the excessive use of sugar, or otherwise, are much more subject to injury from alcohol, tobacco, and other poisons which may be taken into the body, than are those who are in a normal state. For this reason, cheese, oysters, meat, and other foods especially likely to contain poisonous substances, or to encourage their development within the body, may be injurious in such cases. Meat was formerly recommended as the principal article of diet for patients suffering from diabetes, but the more critical observations made of this disease in recent times have shown that systematic poisoning and death are very likely to result from a diet largely composed of meat in the cases of those suffering from this disorder. This is doubtless due to the disabled condition of the liver.
(4) Blood Functions of the Liver.— Before birth, the liver is active in the production of blood-corpuscles; after birth it is supposed to be a grave for the blood-corpuscles, being one of the organs in which corpuscles are destroyed when they become old and incapable of further usefulness. This delicate function, like others in which the liver is concerned, must be seriously interfered with by the excessive use of sugar or other foods which impair the integrity of this important organ.
(5) Excessive Fat Production.— All the sugar used as food must be utilized in the body in one of three ways,— for heat production, for force production, or for the production of fat. When a larger amount of sugar is taken than can be utilized in connection with the other elements of food in heat or force production, if not eliminated by the kidneys as sugar, it may be deposited as fat; thus the use of sugar tends to obesity. An excessive accumulation of fat gives rise to many inconveniences. Its accumulation in the chest and abdomen causes shortness of breath by diminishing the capacity of the chest. It sometimes accumulates about the heart, overburdening this organ so that it cannot perform its functions properly. Its general accumulation throughout the body imposes a burden upon the muscles which may be so exhausting as to seriously interfere with a person's usefulness. The condition of a man obliged to carry another man of half his own weight or of equal weight upon his shoulders continually, wherever he went, would be indeed pitiable, but it is not an uncommon thing to find very fleshy persons weighing fifty per cent more than they should, or even twice their natural weight. There is no substance more capable of producing a rapid accumulation of fat than is sugar.
Accumulation of fat in the body also induces a tendency to fatty degeneration,— a diseased condition in which the normal tissues are replaced by fat. This is particularly liable to take place in the muscles, which thus lose their strength, and in the walls of the blood-vessels, which may become so weakened as to rupture, causing apoplexy of the brain or of some other part of the body, with resulting paralysis or other form of disablement.
In conclusion, it should be noted that the sugar of commerce is doubtless in some way physiologically different from the saccharine element as it naturally exists in sweet fruits. The writer has been convinced of this by observing the fact that persons who are unable to eat sour fruits sweetened with sugar without suffering from acid dyspepsia, arising from fermentation of the sugar, are able to eat such fruits as sweet apples, figs, etc., with impunity. We have, in the use of sugar, an excellent illustration of a principle which is very wide in its application; namely, that in departing from the simple ways of nature we always incur a risk of injury.
The only apology for the use of sugar in its ordinary state is the gratification of an abnormal or exaggerated taste. We can well dispense with this element altogether. The acidity of acid fruits may be modified by a suitable admixture of sweet fruits. Certainly, the addition of sugar to starchy foods, as cakes and other sweet pastries, and to grains, is not only wholly unnecessary, but physiologically inexcusable, since starch itself is by the process of digestion converted into sugar; so that, in adding sugar to starch or starchy foods, we are practically adding sugar to sugar, the sugar constituting not only a redundancy, but interfering with the digestion of the starchy foods, as previously pointed out. The less sugar taken in its free state, the better for digestion.