Betaine is found in most microorganisms, plants, and marine animals. Its main physiologic functions are to protect cells under stress and as a source of methyl groups needed for many biochemical pathways. Betaine is also found naturally in many foods and is most highly concentrated in beets, spinach, grain, and shellfish.
Betaine supplementation has historically been used in the treatment of homocysteinuria due to genetic deficiencies in the cystathione beta synthase and methylenetetrahydrofolate reductase genes.
Betaine supplementation may reduce circulating levels of homocysteine, a potential risk factor for heart disease, stroke, cancer, and Alzheimer's disease.
Betaine supplementation has been thought to improve hepatic steatosis, from both alcoholic and nonalcoholic etiologies. While many animal studies have provided plausible mechanisms, data from human studies are limited.
Betaine in the form of cocamidopropylbetaine has been identified as a cause of contact allergy in some skin care products. In this same form, betaine has been studied as a potential replacement for sodium lauryl sulfate in toothpastes to reduce dry mouth, ulcers, and other mucosal irritations.
Since the 1980s, betaine has been used as a treatment option for subjects who have homocystenuria, due to a genetic defect in the cystathione beta-synthase (CBS) gene. Pyridoxine (vitamin B6) was beneficial in only 50% of CBS patients, and betaine was a therapeutic option for homocysteine reduction in these unresponsive patients. Benefit was also seen among pyridoxine-responsive patients.
Early anecdotal reports showed that among CBS variants, treatment with betaine, in addition to B6 and methionine restriction, prevented or delayed clinical complications of the disease, including cardiovascular disease before age 30.
Abromine, alpha-earleine, betaine, betaine glucuronate, BetaPureTM, Cystadane®, glycine, glycine betaine, glycocoll betaine, glycylbetaine, hydroxide, inner salt, lycine, inner salt, oxyneurine, TMG, trimethylammonioacetate trimethylbetaine, trimethylglycine, trimethylglycocoll.
Note: This monograph covers betaine anhydrous, which should not be confused with betaine hydrochloride.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Cardiovascular disease (in homocysteinuric patients)
Homocystinuria is a severe form of hyperhomocysteinemia caused by genetic defects in homocysteine-metabolizing genes, most commonly the cystathionine beta-synthase (CBS) gene. Patients with severely elevated homocysteine due to a genetic deficiency can use betaine treatment, in combination with other vitamins and diet restrictions, to reduce the risk of vascular events. Further studies are needed to determine whether betaine supplementation can lower cardiovascular risk within the general population.
Overall, betaine supplementation has shown significant reductions in both fasting and postmethionine load homocysteine. However, additional studies are needed to make a strong recommendation.
Hyperhomocysteinemia (in chronic renal failure patients)
Hyperhomocysteinemia is a complication found in 80% of end-stage renal failure patients and may contribute to the progression of atherosclerosis among these patients. The effect of betaine supplementation on reducing homocysteine concentrations within this population has only been studied in addition to folic acid. Additional study investigating betaine alone is needed to make a firm recommendation.
Betaine raises S-adenosylmethionine (SAM) levels that may in turn play a role in decreasing hepatic steatosis. Additional studies are needed to confirm these results.
Limited evidence from human trials suggests betaine supplementation increases total cholesterol, LDL cholesterol, and triglycerides, which may offset any benefit in CHD risk received through homocysteine lowering. However, the increase in cholesterol is relatively small. More study is warranted to confirm these results.
There is currently insufficient available evidence supporting betaine for weight loss.