Lecithin

Scientific Name(s):1,2-diacyl-sn-glycero-3-phosphatidylcholine

Common Name(s): Lecithin , lecithol , vitellin , kelecin , granulestin

Uses

Lecithin is used for its emulsifying properties in the food, pharmaceutical, and cosmetic industries. Pharmacological use of lecithin includes treatment for hypercholesterolemia, neurologic disorders, and liver ailments. It has also been used to modify the immune system by activating specific and nonspecific defense systems.

Dosing

Studies of lecithin in cognitive impairment have used a wide variety of doses, from 1 to 35 g daily. A systematic review has been published.

Contraindications

Contraindications have not yet been identified.

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

None well documented.

Adverse Reactions

Adverse effects are usually not associated with lecithin. However, there have been reports of anorexia, nausea, increased salivation, other GI effects, and hepatitis.

Toxicology

Research reveals little or no information regarding toxicology with the use of this product.

Lecithin is found in many animal and vegetable sources including beef liver, steak, eggs, peanuts, cauliflower, and oranges. 1 Commercial sources for lecithin can come from soybeans, egg yolk, or brain tissue. 2 , 3 Some commercial lecithin and lecithin supplements contain between 10% and 35% phosphatidylcholine. 1

History

Lecithin originated from the Greek “Lekithos,” referring to egg yolk. Lecithin is used today to treat liver ailments, hypercholesterolemia and neurologic diseases. 1 , 4 It is also used in the food processing industry. 2 , 5 Lecithin is a common compound found in cells of all living organisms, its presence being required for proper biological function. 6

Chemistry

Lecithin is a phospholipid mixture of acetone insoluble phosphatides consisting mainly of phosphatidylcholine, phosphatidyl ethanolamine, phosphatidyl serine, phosphatidyl inositol combined with various other substances including fatty acids and carbohydrates. 4 Lecithin is the common name for a series of related compounds called phosphatidylcholines. 5 Lecithin is defined chemically as a mixture of the diglycerides of stearic, palmitic, and oleic acids, linked to the choline ester of phosphoric acid (eg, soybean lecithin contains 4% stearic, 11.7% palmitic, 9.8% oleic acids, along with others). Lecithins also contain phosphorous and nitrogenous (eg, choline) compounds. 5

Physical properties of lecithin can vary depending upon acid value. It is a waxy mass at acid value 20 and a thick pourable fluid at acid value 30. The color is white when freshly made but turns yellow to brown in air. It is an edible and digestible surfactant and emulsifier. 2

Uses and Pharmacology

Use

Lecithin is used as an emulsifying and stabilizing agent in the food (eg, margarine, chocolate production), pharmaceutical, and cosmetic (eg, creams, lipsticks, conditioners) industries. 2 , 4 , 5

Pharmacological use of lecithin primarily includes treatments for hypercholesterolemia, neurologic disorders, and liver ailments.

Hypercholesterolemia

Lecithin seems to possess beneficial properties in reducing cholesterol levels and controlling or preventing atherosclerosis. However, studies done in the late 1970's to early 1980's provide insufficient clinical or epidemiologic evidence to entirely support its positive effects against atherosclerosis. Although other studies from this time appear promising and have found results such as “18% cholesterol reduction,” or “lowered cholesterol levels along with changes in lipid metabolism,” no study was definitive with respect to atherosclerosis progression. 5

Animal data

Research reveals no animal data regarding the use of lecithin for hypercholesterolemia.

Clinical data

Four months of soybean lecithin administration was found to reduce total serum lipids, cholesterol, and triglycerides in 21 hyperlipidemic patients. 6 The mechanism appears to be enhancement of cholesterol metabolism in the digestive system.

Neurologic disorders

Variable results occur using lecithin supplementation for treatment of neurologic disorders.

Lecithin is a good source of choline for treatment in dementias. 4 Phosphatidylcholine is thought to be a precursor for acetylcholine (Ach) synthesis. 5 Choline increases the accumulation of Ach within the brain. Ach is important for many brain functions including memory, so increasing concentration of this neurotransmitter can result in improved memory. 1

Animal data

Research reveals no animal data regarding the use of lecithin for neurological disorders.

Clinical data

Positive effect on long-term memory has been demonstrated after administration of 35 g lecithin for 4 to 6 weeks. 5 However, another report shows no improvement from lecithin in memory disorders when taken in 30 mg/day dosages. 7

Lecithin supplementation has also been studied in Alzheimer disease, starting with memory difficulties. Three of 7 Alzheimer patients receiving 25 g lecithin showed improvement in learning ability (coinciding with peak choline levels). 8 Combination tacrine and lecithin therapy conducted in a 32-patient double-blinded trial yielded poor results. 9 In a multicenter study, this combination did not improve mental status in 67 Alzheimer patients. 10

Acetylcholine deficiencies are also associated with other neurological disorders including tardive dyskinesia, Huntington chorea, Friedreich ataxia, myasthenia gravis, and other brain atrophies. In 2 patients with tardive dyskinesia, lecithin administration reduced abnormal movements. Ten cases of Friedreich ataxia were also improved by lecithin supplementation. 11 One study failed to show any beneficial response in 12 patients with Friedreich ataxia taking 25 g lecithin daily. 12

Liver disease

In Germany, a product called Essentiale (phosphatidylcholine) is marketed for liver disorders including acute and chronic hepatitis, cirrhosis, diabetic fatty liver, and toxic liver damage. Documentation supporting these claims have been authorized by the BGA (the German equivalent of the FDA).

Animal data

One report describes supplementation with phosphatidylcholine and protecting against alcoholic cirrhosis in baboons. 1

Clinical data

Research reveals no clinical data regarding the use of lecithin for liver disease.

Other

Lecithin has also been used for immune modulation, activating specific and nonspecific defense systems in 20 patients receiving 1 teaspoonful 3 times daily for 30 days. 13 Another report discusses gallstone dissolution in 2 of 7 patients treated with lecithin and oral cholic acid. One patient experienced stone size reduction. 14

Dosage

Studies of lecithin in cognitive impairment have used a wide variety of doses, from 1 to 35 g daily. A systematic review has been published.

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

None well documented.

Adverse Reactions

Adverse effects generally have not been associated with lecithin as a nutritional supplement. 5 Some studies had no observable side effects as well. 2 , 6 , 11 Six of 12 patients complained of anorexia and nausea when taking 25 g lecithin daily; 1 of these patients also noted excessive salivation. 12 Gastrointestinal side effects and hepatitis were experienced from the study in Alzheimer patients taking both tacrine and lecithin. 10

Toxicology

One report in rats observes biochemical alterations and impaired sensorimotor development in offspring of rats fed a diet including 5% crude lecithin, suggesting its consumption is inadvisable during pregnancy. 5

Bibliography

1. Murray M. Encyclopedia of Nutritional Supplements . Rocklin, CA: Prima Publishing, 1996.
2. Budavari S, ed. The Merck Index, ed. 11. Rahway, NJ: Merck and Co., 1989.
3. Venturella US. Natural Products. Gennaro AR, ed. Remington: The Science and Practice of Pharmacy , ed. 19. Easton, PA: Mack Publishing Co., 1995.
4. Reynolds J, ed. Martindale, The Extra Pharmacopoeia , ed. 31. London, Eng.: Royal Pharm. Society, 1996.
5. DerMarderosian A, et al. Natural Product Medicine , Philadelphia, PA: George F. Stickley Co., 1988;121-22,140,313-15.
6. Saba P, et al. Current Therapeutic Research, Clinical & Experimental . 1978 Aug;24:299-306.
7. Caine E. NEJM . 1980 Sep 4;303:585-86.
8. Etienne P, et al. Lancet . 1978 Dec 2;2:1206.
9. Maltby N, et al. BMJ . 1994 Apr 2;308:879-83.
10. Chatellier G, et al. BMJ . 1990 Feb 24;300:495-99.
11. Barbeau A, et al. NEJM . 1978 Jul 27;299:200-1.
12. Pentland B, et al. BMJ . 1981 Apr 11;282:1197-98.
13. Pawlik A, et al. Herba Polonica . 1996;42(1):42-46.
14. Toouli J, et al. Lancet . 1975 Dec 6;2:1124-26.
15. Higgins JP, Flicker L. Lecithin for dementia and cognitive impairment. Cochrane Database Syst Rev. 2003;(3):CD001015.

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