General Description
Lecithin is an oily substance belonging a group of nutrients known
as phospholipids, which are water-soluble compounds composed of
fatty acids, phosphorus, and nitrogen. The fatty acid portion of
lecithin consists of linoleic acid or a combination of linoleic
and linolenic acids, both of which are essential in the human diet.
The phosphorus portion of lecithin is in the form of phosphatidylcholine
(PC), and the terms "lecithin" and "phosphatidylcholine" are used
interchangeably in medical literature. PC is generally considered
to be the most beneficial compound found in lecithin because it
is a rich source of choline, a member of the B-vitamin complex involved
in many vital biological functions.
Food sources
Dietary sources of choline are found primarily in the form of
phosphatidylcholine from lecithin. Good sources of lecithin include
liver, red meat, whole grains, legumes, and egg yolks (in fact,
the term "lecithin" is derived from the Greek word for egg yolk,
lekithos). Free choline (without the phosphatidyl group) is found
in whole grains, liver, soy, and in some vegetables (especially
cauliflower and cabbage). Supplemental sources of PC labeled as
"lecithin" usually contain 10-20 percent PC. More concentrated
supplements (containing about 35 percent PC) are usually labeled
as "phosphatidylcholine." Other supplemental forms of choline
include choline salts such as choline bitartrate, citrate, or
chloride.
Health applications
Functions and uses
Choline is a crucial component of acetylcholine, a neurotransmitter
essential for normal brain function. Phosphatidylcholine is a
key structural component of cellular membranes and also plays
an important role in the transport of fats throughout the bloodstream.
As a constituent of bile, PC helps control cholesterol levels,
prevent fatty buildup in the liver, and maintain gallbladder function.
Mental function
Because choline is known to play a key role in brain chemistry,
studies have been conducted to determine the efficacy of choline
and lecithin supplements in various mental disorders including
Alzheimer's disease, tardive dyskinesia, depression, and bipolar
disorder. While it appears to have no effect on the progression
of Alzheimer's, studies indicate that lecithin supplementation
may be helpful in some cases of mania1 and
tardive dyskinesia.2-4
Liver health
Phosphatidylcholine is essential for healthy liver function, and
a concentrated PC formulation is used in Germany to treat a variety
of liver disorders. Studies have shown that PC supplementation
can provide significant improvement in some forms of hepatitis,5-9
and may also be beneficial for patients with alcoholic cirrhosis.9-11
Cardiovascular
health
Lecithin's role in fat transport can make it a useful supplement
for promoting cardiovascular health. Research indicates that lecithin
can help lower serum cholesterol12-16 and
triglyceride16 levels while raising HDL 13,16
(the "good cholesterol") levels„factors that inhibit the progression
of atherosclerosis. Lecithin can also reduce the tendency of blood
platelets to clump together and form clots, therby promoting healthy
blood flow.15,16
Dosage/toxicity
The recommended dosage for lecithin varies according to its PC
content and its intended use. Consult a nutritionally-oriented
healthcare professional to determine the appropriate dosage. Many
people prefer lecithin or PC concentrates over choline salts because
high doses of choline may cause gastrointestinal discomfort and
a "fishy" odor. In addition, research indicates that lecithin
may be more effective than choline salts in raising serum choline
levels.17 There is currently no evidence that
lecithin or choline salts are toxic to humans. |
