Betaine (or trimethylglycine, to use its technical name) is a crystalline compound that can be found in some plant juices, it is what’s known as a proteinogenic amino acid, meaning it contributes to muscle growth. Betaine has long been thought to potentially reduce the risk of heart disease, researchers had focused almost solely on its potential in this area, but recent research links it with muscle growth and recovery, and hence it is now a sports nutrition and supplement industry staple.
So why is there Betaine in my protein supplement?
Betaine has long been championed by industry experts and researchers as an important component in muscle recovery and growth. It has been added to protein supplements because it supports the benefit of other proteinogenic amino acids such as leucine in promoting muscle protein synthesis. The likely mechanism of action behind betaines ability to promote muscle growth is its function as a methyl donor, meaning it transfers a methyl group to the amino acid homocysteine. Once it receives the methyl group, homocysteine is converted to methionine, an important component in the development of muscle protein synthesis (Cholewa et al. 2013).
The scientific literature out there demonstrates that 10-15 days of betaine supplementation may reduce the levels of transmethylate Hcy, a component in the body that can directly impair insulin signalling by inhibiting insulin receptor substrate- 1 (IRS-1). Insulin is a key anabolic hormone meaning it promotes muscle growth and development, so reduced signalling may be detrimental to muscle gains, hence the addition of betaine to a supplement. Alongside betaines ability to reduce transmethylate Hcy, it also reduces homocysteine thiolactone (HCTL) levels (as mentioned above), an amino acid that may increase the risk of heart disease. HCTL is also thought to be more damaging to insulin sensitivity than even Hcy, this makes betaine key to minimising the risk of losing your hard earned gains!
Industry guru Dr. Jim Stoppani refers to a study presented in the Journal of the International Society of Sports Nutrition which exhibits impressive results thanks to the consumption of betaine. The researchers noticed an increase in muscle mass of 4 pounds, a 10% increase in arm mass, and a 7% decrease in body fat in the group that took betaine, a significant difference compared to the placebo group who showed no difference in muscle mass.
Apicella, J. M., et al. (2013). Betaine supplementation enhances anabolic endocrine and Akt signaling in response to acute bouts of exercise. Eur J Appl Physiol. Mar; 113(3): 793-802.
Cholewa, J. M., et al. (2013). Effects of betaine on body composition, performance, and homocysteine thiolactone. J Int Soc Sports Nutr. Aug 22; 10(1): 39.