Phospholipids are the predominant form of fat in our cell membranes. The major phospholipid of the human body is phosphatidylcholine. Commercially available phosphatidylcholine supplements are derived from soy lecithin, an excellent source of phosphatidylcholine. These preparations are used in the treatment of Alzheimer's disease, bipolar disorder, an elevated level of cholesterol, and liver disorders. The beneficial effects are probably due primarily to the essential fatty acid components of phosphatidylcholine and the soy lecithin preparations because the body primarily breaks down phospholipids into free fatty acids that benefit the body. These free fatty acids are used directly as fuel by the cells of the body. Free fatty acids can be long, short, saturated, or unsaturated. The free fatty acids in soy lecithin are the beneficial medium- and short-chain, unsaturated fatty acids.