For decades, lecithin has been a popular treatment for high cholesterol (although there is surprisingly little evidence that it works). More recently, lecithin has been proposed as a remedy for various psychological and neurological diseases, such as Tourette's syndrome, Alzheimer's disease, and bipolar disorder (also known as manic depression).

Lecithin contains a substance called phosphatidylcholine (PC) that is presumed to be responsible for its medicinal effects. Phosphatidylcholine is a major part of the membranes surrounding our cells. However, when you consume this substance it is broken down into the nutrient choline rather than being carried directly to cell membranes. Choline acts like folate, TMG (trimethylglycine), and SAMe (S-adenosylmethionine) to promote methylation. (See the article on TMG for further discussion of this subject.) It is also used to make acetylcholine, a nerve chemical essential for proper brain function.

This article discusses lecithin and phosphatidylcholine. For more information on the effects and possible benefits of Choline alone, see the full article on that subject.

Neither lecithin nor its ingredient phosphatidylcholine is an essential nutrient; however, choline has recently been recognized as essential. For use as a supplement or a food additive, lecithin is often manufactured from soy.