The new study was published in the Journal of Dietary Supplements. It was the work of a team led by Hunter S. Waldman, PhD of Human Performance Research Laboratory at the University of North Alabama.
Betaine is a zwitterionic compound which refers to its property of having both positively and negatively charged groups (‘zwitter’ is a German word meaning ‘hybrid’ or ‘hermaphrodite’). It is commonly isolated from molasses during sugar beet refinement.
It is present in both plants and animals, being found for example in both wheat bran and shellfish in addition to beets. It has been marketed as both a weight management ingredient and as sports performance ingredient, though the evidence in favor of its use is not overwhelming.
The researchers noted that betaine intake in the standard American diet is low at less than 350 mg a day. Studies have found it to be safe and well tolerated at doses of as high as 15 grams a day or even more, though most studies have found effects at 2 grams to 5 grams.
Little know about betaine’s effects in women
Many sports nutrition studies use men for subjects, because without the confounder of menstrual cycles men are easier and cheaper to study. The researchers noted that for this reason little is known about the effects of betaine supplementation on performance outcomes in women. Only one other recent study has been conducted, which found that betaine given at a rate of 2.5g/day to college age women engaged in a resistance training protocol helped them lose fat, but did not boost their absolute strength.