Back in the mid-’60s and early ’70s, bodybuilders didn’t have the huge variety of supplements that are now available—like “fat burners.” While numerous supplements now tout their ability to help you burn up excess bodyfat, bodybuilders of yesteryear turned to lipotropics for that purpose. Lipotropic literally means “fat loving.” From a medical perspective, a lipotropic was something that helped to clear fat out of the liver. In fact, one of the earliest signs of liver failure is an excessively large fat content in the organ. The liver uses lipotropics to help clear out excess fat. So, when you’re deficient in them, you can accumulate excess fat in your liver.
Most nutritional lipotropics work by donating a methyl group, which is the base for the production of many vital body substances, such as creatine. The primary nutrient lipotropics are lecithin and phosphatidylcholine, choline and betaine, which is produced from choline. Choline and inositol were sold as “lipotropic supplements” 40 years ago, and bodybuilders referred to them as “fat burners.” While they were not actually directly involved in fat oxidation, they played important roles in the liver synthesis of lipoproteins, which helped to transport fatlike substances in the blood. A lack of choline and other methyl donors led to a drop in the production of lipoproteins, causing a backup of fat in the liver. So you can see how the thinking went: Because choline helped the liver rid itself of excess fat deposits, using choline would do the same for excessive fat elsewhere in the body.
Besides helping the liver control fat storage, choline plays a number of other important roles in the body. Choline and other methyl donors, such as S-adenyl methionine, a.k.a. SAMi, help the body to break down homocysteine, a by-product of the metabolism of the essential amino acid methionine. Homocysteine is toxic in large quantities, however, and is linked to cardiovascular problems and other diseases.
Choline and lecithin also are vital for the maintenance of cellular membranes—a lack of choline leads to cellular death. Choline plays important roles in brain health as well, not only in relation to cellular membrane repair and production but also because it’s the precursor of acetylcholine, a brain neurotransmitter. Acetylcholine is low in someone who has a degenerative brain disease, such as Alzheimer’s. In fact, Alzheimer’s disease seems to target neurons that produce acetylcholine. The lack of acetylcholine is responsible for the typical memory and learning problems of those who have degenerative brain diseases.
In addition, acetylcholine is the primary neurotransmitter at the motor neuron, meaning that it’s required to transmit messages from the central nervous system to your muscles, enabling them to contract. Some studies show that exhaustive exercise can deplete the body’s choline, leading to deficits in muscular function. More recently, several studies have shown that betaine, which is a by-product of choline metabolism, helps to maintain exercise intensity. Betaine is also efficient at helping to convert excess homocysteine back into methionine.
Until 1998 choline wasn’t officially considered an essential nutrient, but based on a review of ongoing research, the Institute of Medicine recognized it as being essential in human nutrition that year. The reason choline was overlooked for so many years was that scientists believed that it could be synthesized in the body in sufficient amounts from SAMi, but that turned out to be highly inefficient, most likely because of the many other functions related to SAMi. One study of healthy adults deprived of choline found that 77 percent of men and 80 percent of women developed clear signs of choline deficiency, including fatty liver and muscle damage. Another 10 percent still showed deficiency symptoms even when they got the recommended daily intake, which indicates that the requirement for choline may differ widely due to genetic factors. The current suggested intake for adults aged 19 and over is 425 milligrams a day for women and 550 milligrams for men.
Most choline that we take in is converted in the body into lecithin, which, in turn, is the predominant phospholipid in cell membranes. It makes up more than 50 percent of the content of such membranes, which also contain cholesterol.
More recent studies show that subjects who got the most choline and betaine also had the lowest levels of several inflammatory markers. That’s important because out-of-control inflammation is now known to be the underlying cause of most degenerative diseases, including cardiovascular disease, cancer and brain disease. Inflammation tends to increase with age, and choline and other methyl donors may help to offset the effects of what’s been called “inflamaging.”
Cancer is linked to cellular mutations caused by damage to DNA, which is needed for orderly cell replication. Full DNA repair processes require sufficient methyl donors—the implication being that without sufficient methyl donors such as choline available, the risk of cancer increases. Indeed, several preliminary studies suggest that a high choline intake is associated with lower rates of breast cancer.
Rich food sources of choline include liver, eggs and wheat germ. Egg yolks are probably the best source, containing an average of 125 milligrams per yolk. Yet the practice of discarding egg yolks in favor of eating only egg whites continues to be popular among bodybuilders. The thought is that the yolk contains all the fat and cholesterol found, while the white is nearly pure protein. The problem with that theory: Besides containing choline, the yolk also contains all the other nutrients found in eggs—including half the protein. Studies show that the fat contained in eggs has no harmful effects on human health, and even the cholesterol content is overplayed. For most people, eating whole eggs doesn’t adversely affect blood cholesterol. In fact, cholesterol is actually good for building muscle, as it’s not only a constituent of cell membranes but also the precursor of testosterone synthesis in the body.
As with other nutrients, it is possible to get too much choline. Doses of 7.5 grams have produced nausea, diarrhea and a drop in blood pressure in some people. Doses of up to three grams a day are considered safe. Some people lack an enzyme that causes the buildup of a choline metabolite called trimethylamine in the body. More specifically, gut bacteria convert choline into trimethylamine, then the enzyme (which is lacking in about 1 percent of the population) converts trimethylamine into trimethylamine-N-oxide. Without the enzyme, trimethylamine builds up in the body and is excreted in urine, sweat and breath; however, the increased amounts cause a disgusting odor akin to rotting fish. Having certain types of viral hepatitis can also lead to the buildup of trimethylamine in the body. Cases are on record of marriages ending because one spouse smelled like rotten fish, which was traced to the buildup of trimethylamine from normal choline intake.
More recently, a far more serious effect related to trimethylamine has been reported.1 Researchers found that depending on the content of intestinal bacteria, or flora, some people produce excessive amounts of trimethylamine-N-oxide from lecithin and choline. When fed to mice, lecithin and choline promoted an increase in foam cells, which are cells laden with fat and cholesterol. An increase in such cells is considered the first stage in the development of atherosclerosis, the buildup of plaque in arteries that leads to cardiovascular disease. Betaine was also found to be involved in the process. Based on those preliminary findings, the authors question the wisdom of taking supplemental betaine, choline or lecithin. They note that “excessive” amounts of those nutrients could lead to cardiovascular disease though the activity of gut bacteria.
That raises a number of questions. How do we know who has the precise balance of gut bacteria that would produce the negative effect? Also, since many people, including bodybuilders, avoid eating egg yolks, the primary food source of lecithin and choline, what will happen if they don’t use choline or lecithin supplements? As noted above, one such effect could be fatty liver.
While the main cause of fatty liver used to be excessive alcohol intake, more recently cases in which alcohol wasn’t a factor have shown up. That type of fatty liver is linked to insulin resistance and the metabolic syndrome, itself a precursor of cardiovascular disease and diabetes. Since choline is needed to clear the liver of excessive fat, not getting it in some form would make a bad situation even worse. Taking a special type of probiotic supplement could restore the balance of intestinal bacteria, preventing the cardiovascular side effects of taking choline or lecithin.
Perhaps the most prudent thing you can do in the meantime is to stop discarding egg yolks. They won’t blunt any fat-loss efforts, but they may help protect your long-term health.
1 Wang, Z., et al. (2011). Gut flora metabolism of phosphatidycholine promotes cardiovascular disease. Nature. 472.