Lecithin

Overview

Lecithin is a complex mixture of naturally occurring compounds called phosphatides or phospholipids. The principle components of lecithin are phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol. The kind and portion of the various polar lipids, especially the phospholipids, primarily determine the physiological properties of lecithins. Phosphatidyl choline (PC) is generally thought to be the primary active ingredient in lecithin and frequently the two terms are used interchangeably.

Phospholipids are responsible for maintaining the surface tension of the cell membranes. With insufficient lecithin, the cell wall may harden, and does not easily allow nutrients in or wastes out of the cell. This situation contributes to premature aging of the cells. Certain phospholipids play a role in generating second messengers for cell membrane signal transduction. This can involve cell transport, metabolism, growth, function, or gene expression.

Phosphatidylcholine (PC) may help reduce high cholesterol levels by enhancing the metabolism of cholesterol and aiding its transport through the circulatory system. It acts as an emulsifier to break down the fats and cholesterol into tiny particles and holds them in suspension, preventing them from sticking to blood platelets or arterial walls.

Lecithins are mixtures or fractions of phospholipids, which are obtained from animal or vegetable matter by physical process.

Dosage Info

Dosage Range

1-10 grams daily.

Most Common Dosage

2 grams daily.

Dosage Forms

Liquids, softgels, capsules, and loose granules.

Adult RDI

None established

Adult ODA

None established

RDA

Active Forms

Lecithin.

Absorption

Lecithin is well absorbed orally.

Toxicities & Precautions

General

There is no known toxicity associated with choline and lecithin.

Functions in the Body

Acetylcholine Synthesis:

The phosphatidyl choline content in lecithin provides choline, which is necessary for the synthesis of the neurotransmitter acetylcholine.

Emulsification of Cholesterol:

Lecithin (PC) is the primary phospholipid in bile, forming a lecithin-bile salt micelle, which solubilizes cholesterol so that it can be transported via the bile duct to the intestines.

Nervous System:

Radio-labeled studies report that the choline-containing phospholipids in lecithin are incorporated into the myelin sheath of nerves, which may help to improve nerve conduction and prevent damage to the nervous system.

Transmembrane Signaling:

Phosphatidyl choline and other phospholipids function as important regulators of transmembrane signaling among cells.

Clinical Applications

Elevated Homocysteine

Choline lowers homocysteine level, which in turn lowers risk of heart disease. (1)

High Serum Cholesterol

Linoleic acid in lecithin seems to be responsible for the cholesterol-lowering effect of lecithin. (2)

Intestinal And Stomach Protection

Orally administered lecithin may protect the stomach against exogenous damaging substances. (3) Lecithin has been reported to protect the GI tract when undergoing therapy with NSAIDS and numerous medications affecting liver function. (4)

Cirrhosis

Phosphatidylcholine, PC, is a building block of liver cells. PC potentially helps the liver to recover after damage from alcohol, pollutants, viruses, and other toxic agents. (5)

Alzheimer’s Disease

Certain lipids in lecithin have been shown to help mental function in patients with Alzheimer’s. (6)

Endurance

Choline has reported benefit in improving performance over extended periods of physical activity. Choline has reported some benefit in improving performance over extended periods of physical activity. (7)

Psoriasis

Oral doses of lecithin used during a 10-year study demonstrated positive response in 118 of 155 subjects. (8)

Symptoms and Causes of Deficiency

Although lecithin is not considered an essential nutrient, the FDA classified choline (a component of lecithin) as an essential nutrient in 1998. Because many Americans have decreased consumption of fatty foods, their intake of lecithin and choline may be inadequate.

Animal studies have shown a choline-deficient diet promotes liver carcinogenesis. (9) , (10) , (11) The disease begins with early signs of lipid accumulation in the liver because lecithin is required to synthesize very-low-density lipoproteins (VLDLs), the liver’s major export route for triglycerides. (12)

Choline deficiency has been reported to result in liver cancer in the absence of exposure to carcinogens (13) , (14) and to promote cancer in the presence of various carcinogens. (15) , (16)

Dietary Sources

Lecithin is found in egg yolks, soybeans, nuts, and organ meats.

References

  1. View Abstract: Emmert JL, et al. Hepatic Betaine-homocysteine Methyltransferase Activity in the Chicken is Influenced by Dietary Intake of Sulfur Amino Acids, Choline and Betaine. J Nutr. Aug1996;126(8):2050-58.
  2. View Abstract: Knuiman JT, et al. Lecithin Intake and Serum Cholesterol. Am J Clin Nutr. Feb1989;49(2):266-68.
  3. View Abstract: Anand BS, et al. Phospholipid Association Reduces the Gastric Mucosal Toxicity of Aspirin in Human Subjects. Am J Gastroenterol. Jul1999;94(7):1818-22.
  4. View Abstract: Leyck S, et al. Improvement of the Gastric Tolerance of Non-steroidal Anti-inflammatory Drugs by Polyene Phosphatidylcholine (Phospholipon 100). Eur J Pharmacol. Oct1985;117(1):35-42.
  5. View Abstract: Paniachik J, et al. Dilinoleoylphosphatidylcholine Decreases Hepatic Stellate Cell Activation. J Lab Clin Med. Apr1999;133(4):342-48.
  6. View Abstract: Guan ZZ. Activity of Phosphatidylethanolamine-N-methyltransferase in Brain Affected by Alzheimer’s Disease. Neurochem Int. Jan1999;34(1):41-47.
  7. Marriott BM, ed. Institute of Medicine. Conclusions and Recommendations. Food Components to Enhance Performance. Washington, DC: National Academy Press; 1994:47-61.
  8. Abramovich AI. Use of the Preparation Essentiale for Treating Psoriasis Patients. Vestn Dermatol Venerol. Jul1984;(7):54-56.
  9. View Abstract: Goshal AK, Farber E. The Induction of Liver Cancer by Dietary Deficiency of Choline and Methionine Without Added Carcinogens. Carcinogenesis. 1984;5:1367-70.
  10. View Abstract: Creasia D, Hoover KL, Mikol YB, et al. Hepatic DNA Methylation and Liver Tumor Formation in Male C3H Mice Fed Methionine- and Choline-deficient Diets. J Natl Cancer Inst. 1986;77:213-17.
  11. View Abstract: Locker J, Lombardi B, Reddy TV. DNA Methylation and Hepatocarcinogenesis in Rats Fed a Choline-devoid Diet. Carcinogenesis. 1986;7:1309-12.
  12. View Abstract: Vance JE, et al. The Role of Phosphatidylcholine Biosynthesis in the Secretion of Lipoproteins from Hepatocytes. Can J Biochem Cell Biol. Aug1985;63(8):870-81.
  13. View Abstract: Locker J, Lombardi B, Reddy TV. DNA Methylation and Hepatocarcinogenesis in Rats Fed a Choline-devoid Diet. Carcinogenesis. 1986;7:1309-12.
  14. View Abstract: Creasia D, Hoover KL, Mikol YB. Hepatocarcinogenesis in Rats Fed Methyl-deficient, Amino-acid Defined Diets. Carcinogenesis. 1983;4:1619-29.
  15. Newberne PM, Rogers AE. Labile Methyl Groups and the Promotion of Cancer. Ann Rev Nutr. 1986;6:407-32.
  16. View Abstract: Rogers AE. Methyl Donors in the Diet and Responses to Chemical Carcinogens. Am J Clin Nutr. 1995;61:659S-65S.