Choline, an amino acid, may protect the brain throughout life -- from the womb to very old age. Indeed, if your mother eats enough choline to satiate your fetal brain, you may enjoy a lifetime of superior intellect and not even have to worry about a declining memory as you get old. That's a remarkable new finding from laboratory animals, that researchers say may translate to humans, although such human studies have not been done.
What researchers have found is phenomenal: That giving rats choline halfway through pregnancy makes a permanent mark on the fetal brain -- dictating how its cells organize to mold and wire the brain, essentially building in an "excess memory capacity" that endures throughout life. In a series of experiments, scientists at Duke University Medical Center fed pregnant rats normal choline, extra choline, or no choline and then studied the mental functioning and brains of their offspring.
Clearly, the rats that got the extra choline in the womb had vastly superior brains; as infants and adults they displayed better memory and learning capabilities. Indeed, postmortem examinations revealed superbly efficient brain circuits for transmitting messages. The neurons in their hippocampus, the brain's memory processlng center, responded instantly to the tiniest electrical probe, indicating their brains were primed to learn rapidly. Awesome as it seems, the extra infusion of a single nutrient, choline, enabled nature to assemble a brain of extraordinary quality.
On the other hand, rats deprived of choline in utero had sluggish brains and impaired memory when they grew up.
Even more startling, as the high-choline offspring entered old age, their brain function remained undiminished. Their memory did not fade, as it did in rats not given choline prenatally. In very old age, choline-primed rats made only half as many memory errors when searching through mazes for food as did geriatric rats whose pregnant mothers had not been given extra choline.
"The ramifications of this could be profound. We've found that manipulating one single nutrient for a few days during gestation has a lifelong effect on how brains function. In theory, we could develop ways to significantly reduce age-related memory deficits." -- Dr. Scott Swartzwelder, neuropsychologist, Duke University
How could choline received before birth possibly be so powerful and long-lasting as to prevent memory deterioration in old age? Researchers speculate that choline might slow down the entire aging process, the brain included. Or, more probable, choline helps construct a brain with such a superior anatomical network of neurons and connections -- a large reserve of brain power and efficient memory processing -- that age-related erosion is insignificant to memory functioning later in life.
Choline does dramatically change the very structure of memory centers in the hippocampus and septum of the developing fetal brain, declares Dr. Steven Zeisel, M.D., a world expert on choline, and chairman of nutrition at the University of North Carolina School of Medicine at Chapel Hill. Dr. Zeisel and colleagues found that when choline is lacking, cell division in the fetal brain is reduced, cells migrate abnormally, and increasing numbers of brain cells die prematurely. "For the first time, we have shown that the very structure of the brain is influenced by what mothers eat during pregnancy. Mainly, the specific nutrient choline appears to be critical."
But what if your mother failed to give your fetal brain lots of choline? Will eating choline later as a child, adult, or in old age improve your mental functioning? It's a good bet, say experts, although you cannot count on choline to completely reorganize the way your brain circuits work. Still, birth does not put an end to the brain's need for choline.
Choline is particularly essential for infants, whose brains are still developing. So if a mother missed providing lots of choline in the womb, there is a second chance, Not surprisingly, breast milk, also depending on a mother's diet, is very rich in choline, which is one more brain-boosting reason to breast-feed. Infant formulas made from both cow's milk and soy are required to add choline, but they do not contain as much as human breast milk.
Breast-feeding is definitely preferred, and may make a difference in your baby's brain. "Because infant formulas vary so much from human breast milk," says Dr. Zeisel, "it's not unreasonable to worry that some differences in intellectual performance that we see could be due to changes in the availability of choline in utero and shortly after birth in some kids."
Besides building strong brains, choline is also vital in keeping brain cells functioning throughout life. For one thing, choline is a precursor (building block) for acetylcholine the neurotransmitter vital to encoding memory. When choline is in good supply, your neurons are more apt to make and release acetylcholine. Blocking production of acetylcholine in brain cells impairs memory; flooding brain cells with acetylcholine may overcome some memory deficits. That's the theory of some drugs used to treat Alzheimer's and dementia. Choline is a critical constituent of fat in brain cell membranes, influencing their structure and facilitating transmission of signals from the cell exterior to the nucleus, a momentous task. Additionally, choline helps suppress homocysteine in the blood that is associated with brain disturbances, memory damage, and even Alzheimer's, and strokes.
According to extensive research, choline improves memory and learning in many species, including rats, mice, mollusks, and humans. Of course, tests in laboratory animals do not prove that humans build brains the same way. But decades of research have been eerily accurate in making the leap from what happens in the brains of small mammals to how the human brain works. It's probable that if scientists discover a brain secret in other mammals, it will eventually be confirmed in humans. Growing new brain cells is a prime case in point: Thirty years before it was detected in humans, scientists had demonstrated it in laboratory animals.
It's unclear to what extent taking supplemental choline later in life may boost human memory or intellectual performance. Some studies find benefits; others do not. One recent experiment with eighty college students found improvement on tests of explicit memory in those who took 25 grams of lecithin that supplied 3750 milligrams of choline. There was no memory benefit from taking just ten grams of lecithin. Specifically, the students were better able to memorize a series of nonsense syllables about an hour and a half after taking the choline. Interestingly, the memory boost was greatest in "slow learners," leading researchers to suspect that the slow learners had subnormal levels of choline to begin with. Thus, a supplement corrected a slight deficiency.
This may mean, they said, that choline works best to improve memory in slow learners and the elderly who may have abnormally low choline. The double-blind controlled study was conducted by psychologists at several California universities, including Stanford.
Choline has boosted memory in older adults. Florence Safford, D.S.W., of Florida International University, had forty-one healthy people, ages fifty through eighty, take 500 milligrams of choline (found in two tablespoons of lecithin granules) every day for five weeks. She says they reported diminished memory lapses, such as forgetting names, misplacing items, remembering names on the tip of their tongue. Indeed, their memory lapses were about half those of comparable subjects not getting choline-lecithin--down from an average 35 lapses per week to 19 per week.
However other more rigorous double-blind studies have not found mental benefits in adults taking choline. One explanation: The choline in food or supplements that gets 1nto your bloodstream may not make it into your brain. Around middle age, the ability to transport choline from the blood to the brain tends to decline, say brain experts.
Regardless of whether high doses of choline hypes memory in adults, everybody still needs choline in the diet or through supplements for optimal brain functioning. Experts now consider choline an essential or required nutrient for all ages. Your body cannot make enough choline for optimum health.
You may be surprised to learn that egg yolk's are one of the highest and most reliable sources of choline. Thus, avoiding or severely restricting eggs may be harmful to brain functioning. The consumption of eggs has plummeted in the last thirty years due to warnings that the yolk is high in artery-clogging cholesterol. Consequently, intake of choline dropped sharply, since egg yolk is a major source of choline. Now, much new evidence shows that the amount of cholesterol in food is not a primary cause of raising cholesterol in the blood. High cholesterol is caused mainly by eating saturated fats, as in milk, butter, cheese, and meat.
Indeed, the egg is being exonerated. In April 1999, Harvard researchers proclaimed that an egg a day is unlikely to increase the risk of heart disease or strokes, according to a new analysis of the Harvard Nurses' Health Study and the Health Professionals Follow Up Study. Research tracked the egg consumption of 100,000 people for more than a decade. Harvard's Frank B. Hu,M.D., and colleagues, concluded that a daily egg is not harmful -- and may even help prevent heart disease, because eggs contain nutrients, including antioxidants, folic acid, other B vitamins, and unsaturated fat that may counteract any ill effect from the yolk's high cholesterol. Another one of those beneficial nutrients is choline.
How Much Choline Do You Need Daily?Adult menAdult women Pregnant women Lactating women |
550 mg 425 mg 450 mg 550 mg |
How Much Is Too Much?Upper tolerable upper daily intake for: ChildrenAdults |
1000 mg 3500 mg |
|
SOURCE: National Academy of Sciences. |
Best food sources: Egg yolks, peanuts, wheat germ, liver, meat, fish, milk, cheese, vegetables -- mainly broccoli, cabbage, and cauliflower.
What about supplements? If you want to take choline supplements, the best bet is lecithin rather than straight choline. High doses of pure choline leave you smelling "fishy," say experts. Lecithin, which is 20 percent choline, is a far better source. Lecithin comes in various forms (the scientific name is phosphatidylcholine), including granules that you can dissolve in a liquid, such as juice or milk, or sprinkle on cereal. A tablespoon of lecithin granules supplies about 250 milligrams of choline.
Lecithin supplements appear very safe, even at high doses, according to government tests.
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.