In the prescribed doses betaine [structural formula shown below] doesn't make men stronger. Nor does it do so when combined with creatine, sports scientists from the University of Sao Paulo conclude in an article in Amino Acids.
Betaine is trimethylglycine, an amino acid. It's a substance that occurs naturally in meat and grains, and we make it ourselves too. Betaine is a methyl donor: it converts the once controversial but now forgotten amino acid homocysteine into methionine and gives cells methyl groups from which they can make creatine and turn their DNA on and off.
Because betaine is a by product from sugar refining, the giant sugar company Danisco is financing studies on positive health effects of betaine, in the hope of finding new markets. These have shown for example that a daily 2.5 g betaine has a weak subtle ergogenic effect in strength athletes – they are able to perform a few more reps after taking the stuff. The most recent Danisco study we've seen was published in 2010. [J Int Soc Sports Nutr. 2010 Jul 19; 7:27.]
The Brazilians were not financed by betaine sellers. They gave 34 men aged between 18 and 30 who did not do weight training a daily placebo [PL], 20 g creatine [CR], 2 g betaine plus 20 g creatine [BET+CR] or just 2 g betaine [BET] for a period of 10 days.
Before and after the experiment the researchers measured the concentration of phosphocreatine in the subjects' muscles. As you can see from the figure below, betaine supplementation had no effect, not even when combined with creatine.
The subjects were made to do squats before they started taking the supplements and at the end of the experiment. The researchers measured the amount of power the men developed, and found that betaine had no effect.
So the subjects did no weight training. But is that so important here? Not really, say the researchers. They maintain that betaine doesn't work. Not if you take 2 g a day for 10 days. But what if you were to take 10 g a day for a month? Who knows.
Amino Acids. 2011 Jul 9. [Epub ahead of print].