A review on the clinical significance of betaine

Betaine is an essential osmolyte and source of methyl groups and comes from either the diet or by the oxidation of choline. Its metabolism methylates homocysteine to methionine, also producing N,N-dimethylglycine. Betaine insufficiency is associated with the metabolic syndrome, lipid disorders and diabetes, and may have a role in vascular and other diseases. Betaine is important in development, from the pre-implantation embryo to infancy. Betaine supplementation improves animal and poultry health, but the effect of long-term supplementation on humans is not known, though reports that it improves athletic performance will stimulate further studies. Subsets of the population that may benefit from betaine supplementation could be identified by the laboratory, in particular those who excessively lose betaine through the urine. Plasma betaine is highly individual, in women typically 20-60 [mu]mol/L and in men 25-75 [mu]mol/L. Plasma dimethylglycine is typically < 10 [mu]mol/L. Urine betaine excretion is minimal, even following a large betaine dose. It is constant, highly individual and normally < 35 mmol/mole creatinine. The preferred method of betaine measurement is by LC-MS/MS, which is rapid and capable of automation. Slower HPLC methods give comparable results. Proton NMR spectrometry is another option but caution is needed to avoid confusion with trimethylamine-N-oxide.

Lever and Slow (2010). "The clinical significance of betaine, an osmolyte with a key role in methyl group metabolism." Clinical Biochemistry 43(9): 732-744.

Ergogenic effects of betaine on strength and power

Twelve men completed two 14-day experimental trials separated by a 14-day washout period, in a balanced, randomized, double-blind, repeated measures, crossover design. Prior to and following 14 days of twice daily betaine (B) or placebo (P) supplementation, subjects completed two consecutive days (D1 and D2) of a standardized high intensity strength/power resistance exercise challenge (REC). Performance included bench, squat, and jump tests.

Following 14-days of B supplementation, D1 and D2 bench throw power and isometric bench press force were increased during REC compared to pre-supplementation values and corresponding P values. Compared to pre-supplementation, vertical jump power and isometric squat force increased on D1 and D2 following B supplementation. However, there were no differences in jump squat power or the number of bench press or squat repetitions.

Therefore, B supplementation increased power, force and maintenance of these measures in selected performance measures, and these were more apparent in the smaller upper-body muscle groups.

Lee et al (2010). "Ergogenic effects of betaine supplementation on strength and power performance." Journal of the International Society of Sports Nutrition 7(1): 27.