Q: My blood cholesterol level is high, and I was thinking about using a lecithin supplement to help lower it. Is that a reasonable technique for this purpose?
A: In this era of high-tech nutritional supplements you don't hear much about lecithin anymore. In the past, however, the soybean derivative was popular for both health and bodybuilding purposes. Lecithin is a phospholipid, which means it consists of fatty acids attached to a phosphorus backbone.
Lecithin contains glycerol, too, and is also referred to as phosphatidylcholine. It's still a popular emulsifying agent in food processing. Food sources naturally high in lecithin include liver, soya beans and, especially, egg yolks. Of course, bodybuilders who throw out the yolks in favor of the whites also eliminate the valuable lecithin component. Years ago health pundits used to note that the high lecithin content of a whole egg neutralized the 300 milligrams of cholesterol it contained. The mechanism involved the potent emulsifying activity of lecithin, which was thought to somehow offset any adverse cholesterol effects.
In fact, several poorly designed studies beginning in the 1940s touted lecithin as a virtual cure for high blood cholesterol levels. While that may not be completely accurate, other studies show that infusing lecithin directly into the intestine does appear to inhibit the absorption of cholesterol into the small intestine. A 1986 study suggested that rather than resorting to the obvious impracticality of infused lecithin, people could take the supplement several times a day to get the same effect.
The most recent study on the effects of lecithin on blood fats was published in the European Journal of Clinical Nutrition (52:419-424; 2003). The purpose was to examine the effects of lecithin on serum lipoproteins, plasma fibrinogen and macro-molecular protein cornplex (MPC) levels. Fibrinogen has emerged as an independent risk factor for cardiovascular disease, associated with high levels of total cholesterol, low-density lipoprotein (LDL) and blood triglycerides. High levels of fibrinogen and MPC are linked to a greater risk of internal blood clots, the existence of which in the coronary arteries is the prime cause of most heart attacks.
The new study involved 20 men with high blood cholesterol levels who were randomly assigned to one of three groups, according to what they ate: 1) plain frozen yogurt, 2) frozen yogurt with 20 grams of soya lecithin or 3) frozen yogurt with 17 grams of sunflower oil. The sunflower oil added calories and linoleic acid, an essential fatty acid, as past studies have attributed any cholesterol-lowering effect induced by lecithin to its liberal content of linoleic acid.
The results showed that blood plasma levels of linoleic acid increased with both the lecithin and the sunflower oil treatments. The researchers used a 96 percent lecithin supplement, much higher than anything commercially available. (The highest commercial lecithin sold as a food supplement contains only 55 percent lecithin, while others contain as little as 15 percent.) Despite the high concentration, lecithin had no significant effects on total blood cholesterol, blood triglycerides, high-density lipoprotein, low-density lipoprotein or any other blood fats. Plasma levels of fibrinogen and MPC were also unaffected by lecithin intake. The sunflower oil increased bodyweight and serum triglycerides and lowered MPG levels.
Thus, it would appear that lecithin isn't of much use in lowering elevated blood fat or cholesterol levels. Even so, the body needs it to synthesize HDL in the liver. HDL is considered a protective cholesterol carrier, since it helps ferry cholesterol out of the blood and back to the liver, where excess cholesterol is degraded into bile, then eventually excreted from the body.
Lecithin is also required for the liver synthesis of another lipid carrier in the blood, very low-density lipoprotein (VLDL), which transports triglycerides. That may explain the old idea that choline, which is found in lecithin, helps burn fat. What it actually does is help transport fat in the blood.
Lecithin is so vital to the liver's processing of fat that a cardinal sign of lecithin deficiency is fat buildup in the liver. The fatty liver can lead to the death of liver cells, which in turn results in a type of scar tissue, or fibrotic accumulation, in the liver called cirrhosis. In a worst case scenario the cirrhotic condition predisposes the liver to cancer, one of the consistently fatal forms of the disease.
The 1994 Nobel Prize in Medicine was awarded for the discovery of a process in the body called cell signaling. It begins with the activation of G protein enzymes, breakdown products that activate protein kinase C. The latter acts as a primary cell signal in myriad essential life reactions, such as cellular growth, nutrient uptake, ion transport with in cells and muscular contraction. Abnormal cell signaling is associated with cancer and Alzheimer's disease, among other ailments. Lecithin is vital to the activation of the G protein enzymes that begins the biochemical cascade. Some studies also indicate that lecithin may serve to keep the signaling system stable, thus preventing the diseases that result when the system is disrupted.
While the liver does synthesize lecithin, diet has a great effect on the amount produced. The popularity of lower-fat diets has led experts such as Dr. Richard Wurtman of the Massachusetts Institute of Technology to express concern that many people may not be getting enough lecithin and its product, choline, in their diets. Past studies showed that the average American consumed about six grams of lecithin a day, with an intake of 0.6 to 1.0 grams of choline.
Recent studies show that lecithin and choline may offer benefits for both young and old. For example, a study involving 61 older people with an age range of 50 to 80 found that taking two tablespoons of lecithin a day for five weeks significantly lowered memory lapses by 48 percent. One hallmark of Alzheimer's disease is memory defects that are thought to occur because of a lack of the brain neurotransmitter acetylcholine. While lecithin supplies the raw material for acetylcholine, most studies show no effect of added choline in the treatment of Alzheimer's.
That's probably due to choline's inability to be absorbed into older people's brains. Animal-based studies, however, show that the type of choline found in lecithin, phosphatidycholine, is more easily absorbed into older brains and does reliably increase acetylcholine synthesis. For treatment to be effective, however, it must begin before the onset of mental symptoms, since the cells that synthesize acetyl choline are destroyed with advanced disease. Significantly, most drugs prescribed to treat Alzheimer's disease work by inhibiting a brain enzyme that degrades acetylcholine.
Other recent studies show that giving extra lecithin or choline to an expectant mother provides her unborn child with a boost in brain power that lasts throughout life (I wish this information had been available to my mom!). Choline is required for the formation of neurons in the area of the brain that governs memory and intelligence, and extra choline appears to enhance that process. Some scientists even suggest that the enhanced neuron formation by way of lecithin or choline may protect against Alzheimer's many years later. Talk about giving a gift for life!
While choline and lecithin are often used interchangeably, the preferred supplement is lecithin. For one thing, the phosphatidycholine (PC) is more efficiently absorbed than what occurs with straight choline supplements such as choline chloride or bitartrate. In addition, PC has a slower release effect in absorption than othet choline supplements, which results in greater uptake of choline into the body. An even more interesting point about choline uptake is that about 60 percent of it is converted into trimethylamine, a substance that imparts a disgusting dead fish body odor. That doesn't occur with PC.
Other benefits of lecithin include aiding the formation of a methyl-based substance in the body called S-adenosylmethionine (SAM), which is a hot supplement in Europe. SAM is said to be an effective natural antidepressant and is also used to lessen the pain associated with Iibromyalgia, a syndrome that strikes many young women. Lecithin may also prevent the frequent gasiointestinal side affects off nonsteroidal anti-inflammatory drugs, including aspirin, and some studies suggest that lecithin may work with vitamin B12 and folic acid in neutralizing the effects of the amino acid by-product homocysteine in causing cardiovascular disease.
The upper range of the recommended choline dosage is about 20 grams. Any more than that causes such side effects as nausea, sweating, the dreaded fish odor and heart rhythm disturbances. Excess lecithin may lead to abdominal bloating, diarrhea and vomiting. The suggested dose begins with two tablespoons a day of the granulated version. If you're using 1,200-milligram soft-gel lecithin capsules, 10 caps equals a tablespoon of granulated lecithin.