Betaine -- also called betaine anhydrous, or trimethylglycine (TMG) -- is a substance that's made in the body. It's involved in liver function, cellular reproduction, and helping make carnitine. It also helps the body metabolize an amino acid called homocysteine. The US Food and Drug Administration (FDA) approved betaine to treat a genetic condition where too much homocysteine builds up in the body.
Scientists have also proposed betaine as a way to lower homocysteine levels in people who don't have the genetic disease. This is because higher levels of homocysteine are associated with heart disease and stroke. But researchers don't yet know exactly how high levels of homocysteine and heart disease are related. It's unclear as to whether homocysteine itself is harmful, or whether it is just an indicator of increased risk for heart disease.
Studies suggest that betaine, along with vitamins B6, B12, and folic acid, helps reduce higher levels of homocysteine. Some studies show that high levels of homocysteine may encourage atherosclerosis (hardening of the arteries).
Betaine supplements may increase cholesterol levels, which could work against any treatment for heart disease. If you are at risk for heart disease, your doctor may test levels of homocysteine in your blood. Ask your doctor whether taking supplements of betaine, folic acid, and other B vitamins makes sense for you.
Some people have a genetic condition called homocystinuria, in which homocysteine levels build up in the body. They are at much higher risk of developing heart disease and osteoporosis as early as their 20s. Betaine supplements are used to lower levels of homocysteine in people with this inherited health condition.
Studies in rats suggest that betaine may help protect against harmful fatty deposits in the liver. These deposits can be caused by alcohol abuse, obesity, diabetes, and other causes. Preliminary studies in people have shown similar results. More research is needed.
One study found that a toothpaste containing betaine helped relieve dry mouth.
One study found that higher betaine intake protects against lung cancer by minimizing the adverse effects of smoking. A second suggests that betaine intake may lower the risk of breast cancer.
Abdelmalek MF, Angulo P, Jorgensen RA, Sylvestre PB, Lindor KD. Betaine, a promising new agent for patients with nonalcoholic steatohepatitis: results of a pilot study. Am J Gastroenterol. 2001;96(9):2711-2717.
Alfthan G, Tapani K, Nissinen K, Saarela J, Aro A. The effect of low doses of betaine on plasma homocysteine in healthy volunteers. Br J Nutr. 2004;92(4):665-669.
Atkinson W, Elmslie J, Lever M, Chambers ST, George PM. Dietary and supplementary betaine: acute effects on plasma betaine and homocysteine concentrations under standard and postmethionine load conditions in healthy male subjects. Am J Clin Nutr. 2008;87(3):577-585.
Angulo P, Lindor KD. Treatment of nonalcoholic fatty liver: present and emerging therapies. Semin Liver Dis. 2001;21(1):81-88.
Barak AJ, Beckenhauer HC, Badkhsh S, Tuma DJ. The effect of betaine in reversing alcoholic steatosis. Alcohol Clin Exp Res. 1997;21(6):1100-1102.
Barak AJ, Beckenhauer HC, Tuma DJ. Betaine, ethanol, and the liver: a review. Alcohol. 1996;13(4):395-398.
Boushey CJ, Beresford SA, Omenn GS, Motulsky AG. A quantitative assessment of plasma homocysteine as a risk factor for vascular disease. Probable benefits of increasing folic acid intakes. JAMA. 1995;274(13):1049-1057.
Eikelboom JW, Lonn E, Genest J, Hankey G, Yusuf S. Homocyst(e)ine and cardiovascular disease: a critical review of the epidemiologic evidence. Ann Intern Med. 1999;131(5):363-375.
Hanje AJ, Fortune B, Song M, Hill D, McClain C. The use of selected nutrition supplements and complementary and alternative medicine in liver disease. Nutr Clin Pract. 2006;21(3):255-272. Review.
Imbard A, Benoist JF, Esse R, et al. High homocysteine induces betaine depletion. Biosci Rep. 2015;35(4):pii:e00222.
Kanbak G, Arslan OC, Dokumacioglu A, Kartkaya K, Inal ME. Effects of chronic ethanol consumption on brain synaptosomes and protective role of betaine. Neurochem Res. 2008;33(3):539-544.
Kendler BS. Supplemental conditionally essential nutrients in cardiovascular disease therapy. Cardiovasc Nurs. 2006 Jan-Feb;21(1):9-16. Review.
Kishi T, Kawamura I, Harada Y, et al. Effect of betaine on S-adenosylmethionine levels in the cerebrospinal fluid in a patient with methylenetetrahydrofolate reductase deficiency and peripheral neuropathy. J Inherit Metab Dis. 1994;17(5):560-565.
Malinow MR, Bostom AG, Krauss RM. Homocyst(e)ine, diet, and cardiovascular disease. A statement for healthcare professionals from the nutrition committee, American Heart Association. Circulation. 1999;99(1):178-182.
Miglio F, Rovati LC, Santoro A, Senikar I. Efficacy and safety of oral betaine glucuronate in non-alcoholic steatohepatitis. A double-blind, randomized, parallel group, placebo-controlled prospective clinical study. Arzneimittelforschung. 2000;50(8):722-727.
Olthof MR, Bots ML, Katan MB, Verhoef P. Effect of folic acid and betaine supplementation on flow-mediated dilation: a randomized, controlled study in healthy volunteers. PLoS Clin Trials. 2006;1(2):e10.
Olthof MR, Van Vliet T, Boelsma E, et al. Low dose betaine supplementation leads to immediate and long term lowering of plasma homocysteine in healthy men and women. J Nutr. 2003;133(12):4135-4138.
Olthof MR, Vliet TV, Verhoef P, et al. Effect of homocysteine-lowering nutrients on blood lipids: results from four randomised, placebo-controlled studies in healthy humans. PLoS Med. 2005;2(5):e135.
Robinson K, Arheart K, Refsum H, et al. Low circulating folate and vitamin B6 concentrations. Risk factors for stroke, peripheral vascular disease, and coronary artery disease. Circulation. 1998;97(5):437-443.
Sarkar PK, Lambert LA. Aetiology and treatment of hyperhomocysteinaemia causing ischaemic stroke. Int J Clin Pract. 2001;55(4):262-268.
Schwab U, Torronen A, Toppinen L, et al. Betaine supplementation decreases plasma homocysteine concentrations but does not affect body weight, body composition, or resting energy expenditure in human subjects. Am J Clin Nutr. 2002;76(5):961-967.
Schwahn BC, Wang XL, Mikael LG, et al. Betaine supplementation improves the atherogenic risk factor profile in a transgenic mouse model of hyperhomocysteinemia. Atherosclerosis. 2007;195(2):e100-e107.
Soderling E, Le Bell A, Kirstila V, Tenovuo J. Betaine-containing toothpaste relieves subjective symptoms of dry mouth. Acta Odontol Scand. 1998;56(2):65-69.
Song Z, Deaciuc I, Zhou Z, et al. Involvement of AMP-activated protein kinase in beneficial effects of betaine on high-sucrose diet-induced hepatic stenosis. Am J Physiol Gastrointest Liver Physiol. 2007;293(4):G894-G902.
Song Z, Zhou Z, Deaciuc I, Chen T, McClain CJ. Inhibition of adiponectin production by homocysteine: a potential mechanism for alcoholic liver disease. Hepatology. 2008;47(3):867-879.
Stampfer MJ, Malinow MR. Can lowering homocysteine levels reduce cardiovascular disease? N Engl J Med. 1995;332(5):328-329.
van Guldener C, Stehouwer CD. Homocysteine-lowering treatment: an overview. Expert Opin Pharmacother. 2001;2(9):1449-1460.
Wilcken DE, Dudman NP, Tyrrell PA. Homocystinuria due to cystathione beta-synthase deficiency--the effects of betaine treatment in pyridoxine-responsive patients. Metabolism. 1985;34(12):1115-1121.
Ying J, Rahbar MH, Hallman DM, et al. Associations between dietary intake of choline and betaine and lung cancer risk. PLoS One. 2013;8(2):e54561.
Yonemori KM, Lim U, Koga KR, et al. Dietary choline and betaine intakes vary in an adult multiethnic population. J Nutr. 2013;143(6):894-899.
Zeisel SH. Betaine supplementation and blood lipids: fact or artifact? Nutr Rev. 2006;64(2 Pt 1):77-79. Review.
Zhang CX, Pan MX, Li B, et al. Choline and betaine intake is inversely associated with breast cancer risk: a two-stage case-control study in China. Cancer Sci. 2013;104(2):250-258.