Choline is rarely recognized by the public as a vitamin, and is excluded from most popular multivitamin supplements. Although choline is sometimes added to animal feeds to insure good nutrition, there has been no Minimum Daily Requirement or Recommended Daily Allowance established for humans. Yet this member of the B complex is not only concerned with the body’s general health, it is needed for the proper functioning of the all-important nervous system. In fact, because it is needed by the nervous system, it is tied in with every bodily function: without it, even the heart would stop beating.
Choline is an essential ingredient of the nerve fluid acetylcholine, which is needed to jump the gap between nerve cells so that impulses can be transmitted. This phenomenon is particularly apparent at the point where a nerve cell all but joins the muscle cell which it controls. In order for the muscle to carry out the instruction coming from the brain, it must first receive the message. However, a small gap or "synapse" separates the nerve cell from the muscle, acetylcholine bridges the gap and gets the message across.
Acetylcholine is stored in the "synaptic vesicles" of every nerve cell where it waits passively to relay the message it will receive. The inactive acetylcholine, when jolted by a nerve impulse rippling through that cell, rushes into the synaptic gap to allow the message to cross over to the next nerve or muscle cell. When it does, the acetylcholine reaching the next cell comes into contact with receptor sites, where another chemical, cholinesterase, breaks acetylcholine down into its components, allowing the cells once again to come to rest after the message has passed.
The ability of acetylcholine to relay an impulse is essential to healthy nerve functioning, and choline is an essential component of acetylcholine. If there is a shortage of the substance, the muscles cannot be properly stimulated and will become damaged. If that happens, the whole body will become weak and listless. A severe deficiency can result in paralysis, cardiac arrest, and death.
In order to stay healthy, the liver also needs choline. Otherwise, fatty deposits build up inside that vital organ, blocking its hundreds of functions, and throwing the whole body into a state of ill health. This fact was brought out at an Atlantic City symposium of the American Institute of Nitrition, the results of which were reported in Federation Proceedings (January-February 1971).
"It is known from histological and biochemical evidence that withdrawal of choline from the diet in one single meal causes accumulation of lipid in the liver," wrote Sailen Mookerjea, of the medical research department of Charles H. Best Institute, University of Toronto. He stated that experiments conducted by him and his colleagues, as well as those reported in the Journal of Lipid Research (7: 10, 1966) show that "the increase of liver lipids within one or two days of choline deprivation, uncomplicated by unnecessary manipulations, has always been an irreproachab1e fact."
Richard H. Follis. Jr., M.D., explained why in his book, Deficiency Diseases (Springfield. Illinois: Charles C. Thomas, 1958). He noted that fats must leave the liver in the form of phospholipids. When choline is deficient in the diet, this phospholipid turnover is reduced. Choline, he added, also enables the liver to burn up fatty acids. "By these two mechanisms," wrote Dr. Follis, "the liver cells are normally able to clear themselves of fatty acids which are brought to them by the bloodstream. whether from ingested lipids or from the breakdown of fats elsewhere, particularly in the deposits of subcutaneous tissues and other areas."
But if choline is not available, fat droplets settle within the liver cells, where they may form cyst-like structures. This fatty infiltration inhibits the liver’s ability to detoxify substances that enter the bloodstream, to metabolize proteins and carbohydrates, or to regulate the electrolyte balance in the body’s tissues. In time, the whole body may eventually become diseased by poisons that the liver has been unable to eliminate.
Such a situation is less likely to occur if the diet contains a maximum of choline and a minimum of fats. A study demonstrating the combined effect of choline deficiency and excessive fat upon the liver was conducted by N.W. King, D.V.M., an assistant pathologist at the United States Army Medical Research and Nutrition Laboratory in Denver, Colorado. The American Journal of Clinical Nutrition (January 1965) gave an account of the significant experiment.
Dr. King observed that rats fed a choline-deficient diet developed "severe" damage - 30 to 40 percent of the cells composing the liver lobules became infiltrated with fat. Half the rats in this group also received fat injections which caused 75 to 80 percent of these cells to fill with fat droplets. When choline was added to the diet, the changes were not as severe. The livers of rats fed a diet rich in choline throughout the duration of the experiment appeared normal in every way.
In humans, also, choline supplements have been found to diminish a fatty condition called liver steatosis. The American Medical Association Journal (24 Fehruary 1951) reported that two groups of infants suffering from this ailment were put on a high protein, low fat diet. One group also received choline supplements, and was reported to have "had less fatty infiltration after a given length of time."
A choline deficiency may also cause a rise in blood pressure which can be reduced by adding choline to the diet, as shown by a report in the Journal of Vitaminology (vol. 3, 106, 1957). When 158 patients suffering from hypertension were given choline, those who suffered from headaches, dizziness, palpitations, and constipation got partial or complete relief within ten days. Blood pressure in all the patients dropped by the third week, at which time it was down to normal in one third of the patients. Had those patients been getting enough choline throughout their lives, they might well have avoided hypertension and its accompanying discomforts altogether.
The American Journal of Public Health (March 1966) published a paper by W. Stanley Hartroft, M.D., Ph.D., professor of physiology at the University of Toronto, which was first presented at the ninety-third annual meeting of the American Public Health Association in Chicago in October, 1965. In it, Dr. Hartroft reported that lack of choline was found to set young rats on the path to high blood pressure. More important, such a deficiency probably does the same thing to human infants.
Common Foods Rich in CholineNo standard food composition tables are available as yet from the United States Department of Agriculture for this vitamin, but the following foods are generally recognized as the richest sources. Brewers yeast
Beef liver Fish Soybeans Peanuts Eggs Wheat germ Lecithin |
Choline is also one of the three B-complex factors identified by a team of researchers at the Massachusetts Institute of Technology as being of enormous importance in building life-long resistance to disease. Reporting in Science News (17 August 1974), Paul Newberne. M.D., and his associates named choline, folic acid, and vitamin B12, along with the amino acid methionine as key nutrients in the development of the immune system.
Dr. Newberne’s studies have shown that it only takes a slight deficiency of these nutrients in pregnant animals to shortchange the immune system of their offspring. Although they appear perfectly normal at birth, in later life they turn out to be more susceptible to infections than the offspring of plentifully nourished mothers. Also, there is reason to believe that they are also more likely to succumb to cancer.
What is true of these laboratory animals, is very probably true of humans, too. "Even a subtle impairment in the immune system may open a child to disease later in life," said Dr. Newberne. "The many unexplained illnesses in children, and the wide variation among children in their susceptibility to illness may very possibly be explained by what their mothers ate during pregnancy."
From a biochemical standpoint, all four nutrients are classified as lipotropes, and are involved in a very basic metabolic process known as the transfer of methyl groups. Perhaps more to the point, all four substances are also needed for the synthesis of nucleic acids in the formation of new cells. That means that even a slight shortage of these nutrients could - theoretically - interfere with the extremely rapid growth of the fetus.
In fact, Dr. Newberne and his research team found just such retarded growth in the thymus glands and other organs of the lymph system in their test animals. The lymph system, and especially the thymus, is crucial to the body’s immune response in fighting infection.
Although the animals born to mothers marginally deficient in these nutrients appeared to be normal, later autopsy revealed that their thymus glands were only three-fifths the size of the glands in animals born to properly nourished mothers.
This reduction in thymus size was linked to an even more dramatic difference in resistance. When the control (well-nourished) animals were infected with salmonella bacteria, three out of 20 died. Among the animals whose mothers were just slightly deficient. 14 out of 20 died - almost five times as many.
Choline is a basic constituent of lecithin, the emulsified phospholipid (combination of fatty acids and phosphorus). Its most common source in the average diet is egg yolk, although abundant supplies of lecithin are also contained in soybeans.
It is very important to note that human breast milk also contains lecithin, while cow’s milk is lacking in it. Apparently, the infant whose mother does not nurse him, but raises him on a cow’s formula, has a vastly increased chance of developing a deficiency in choline, which is in short supply at birth. In light of the studies just discussed - Dr. Hartroft’s study linking an early choline deficiency with high blood pressure, and Dr. Newberne’s study demonstrating choline’s importance in the early development of the immune system - breast feeding would appear to be an important step in insuring a child against a host of possible ills.
Breast feeding is just the beginning of a lifetime of good nutrition. As far as choline is concerned, eggs and soybeans should become important in one’s diet. Liver and brewer’s yeast are also good sources. Each gram of desiccated liver contains about 10 mg. of choline, while brewer’s yeast contains 2.4 to 3.6 mg. per gram. While no official intake of choline has been set, estimates of the amount contained in a good diet vary from 500 to 900mg. a day.
Choline should be taken as part of the B complex, because of its interaction with other B vitamins. It is closely related to inositol, another constituent of lecithin, and its relationship with folic acid and B12 has been pointed out.
What should not be in a diet is just as important as what should be in it. According to Adelle Davis, too many calories, particularly from alcohol and refined sugar, greatly increase the need for choline. Alcohol inhibits normal blood flow and keeps fat from being absorbed the way it normally would, while it dumps extra calories into the body and uses up vital supplies of several nutrients, including choline.