Phosphatidyl choline is a phospholipid, which is a polar ionic compound composed of an alcohol and a diacylglycerol, or sphingosine, linked by a phosphodiester bridge. It is a part of the membrane of cells and acts as an essential component of bile, aiding the solubilization of cholesterol. Supplementation with lecithin (which contains high levels of phosphatidyl choline) has been shown to decrease bile cholesterol levels. All animal cells have a phospholipid bilayer that is principally composed of phosphatidyl choline. This phospholipid compound is also a main component of circulating lipoproteins.
Some sources confuse phosphatidyl choline with lecithin and use the two terms interchangeably. However, these are distinct compounds with lecithin being a mix of phospholipids and other fats. Lecithin is the primary dietary source of phosphatidyl choline. Supplements of lecithin that is formulated to contain more than 30% phosphatidyl choline are considered phosphatidyl choline concentrates.
Phosphatidyl choline, the main component of lecithin, can be found in various food sources, most notably legumes (especially soybeans), egg yolks, whole grains, fish, and brewer’s yeast.
Applications of phosphatidyl choline are diverse. For many years, it was thought to be useful for dementia, but the bulk of evidence does not support this use. Phosphatidyl choline supplementation is most commonly employed for treatments of bipolar disorder, gallstones, and conditions of the liver.
Phosphatidyl choline as soybean lecithin has demonstrated the ability to dissolve gallstones when used in combination with cholic acid. Bipolar disorder has also been treated with phosphatidyl choline. This use is based on its ability to raise acetyl choline levels, which is a proposed mechanism of action for the effectiveness of lithium therapy.
Although a number of studies have been conducted to examine the effect of phosphatidyl choline in cases of dementia, the majority were poorly designed. Many trials showed only a modest effect or demonstrated no physiological effect at all.
A novel application for phosphatidyl choline is in the treatment of infraorbital fat pad hernaition. This condition results when fat deposits contained in a specific location under the eye has herniated.
Other conditions for which phosphatidyl choline may be beneficial include; peptic ulcers, sprains, strains, and contusions. Double-blind studies have also confirmed the utilization of phosphatidylchoine for hepatic/alcoholic steatosis and Hepatitis B and C.
Synthesis of phosphatidylcholine in the body requires choline, which can be obtained from the diet or from catabolism, or the breakdown of phospholipids in the membrane of all cells. If choline is not readily available from either of these sources it can be synthesized in the body from two different amino acids, either methionine or serine. Biosynthesis of choline takes place in the liver.
Low levels of choline may be associated with fatty liver, gastric ulcers, kidney and liver impairment, cardiac symptoms, hypertension, and difficulty with fat digestion. Lower levels of phospholipids in general, may also result in the formation of gallstones.
Phosphatidyl choline is generally considered a safe therapeutic agent. Daily doses of up to 18 grams have been well tolerated in humans. When adverse effects occur, it is a sign of intolerance and appears as gastrointestinal discomfort. Patients often experience symptoms of diarrhea, nausea, and fullness.