Alpha-lipoic acid supplements enhanced weight loss in the women, compared to the reduced calorie diet alone, according to a study with 77 women published in Obesity .
Adding EPA to the supplementation regime was found to counter the reductions in levels of leptin (the satiety hormone) that occur during weight loss, said scientists from the University of Navarra.
“Our data suggest that alpha–lipoic acid supplementation at a dose of 300 mg/day combined with an energy-restricted diet might help to promote weight loss and fat mass reduction in healthy obese women,” they wrote. “Although EPA supplementation did not have any additional effect on the reduction of body and fat mass, it prevents the fall of leptin during weight loss.”
Alpha-lipoic acid, a naturally occurring antioxidant and co-factor for mitochondrial enzymes, has been reported to have potential anti-obesity properties, such as reducing body weight and fat, and boosting satiety.
“However, studies in humans with alpha-lipoic acid supplementation are limited and with controversial outcomes, and it is difficult to reach firm conclusions regarding the proper dose and its potential role in the treatment of obesity,” explained the researchers.
To expand current knowledge in this area the researchers recruited 97 overweight and obese women to participate in their short-term double-blind placebo-controlled study. All of the women were prescribed a reduced calorie diet, and divided into four groups: Control (no supplements); EPA only (1.3 grams per day, provided by Solutex); alpha-lipoic acid only (0.3 grams per day, Nature's Bounty), or EPA + alpha-lipoic acid for ten weeks. Seventy-seven women completed the study.
Results showed that the control group lost an average of 5.2 kg on the reduced calorie diet. Similar weight loss was seen in the EPA only group (5.4 kg), while the alpha-lipoic acid only group lost significantly more (an average of 7 kg). The EPA + alpha lipoic acid group lost an average of 6.5 kg, but this difference was not statistically significant compared to the control.
Leptin levels were found to decrease in the control and alpha-lipoic acid only group, but these reductions were attenuated when EPA was also consumed, said the researchers.
Commenting on the potential mechanism, the researchers rejected a role for increased satiety from alpha-lipoic acid since leptin levels decreased unless EPA was also consumed, and because there were no differences in energy intake between the groups.
“Adipose tissue is a target organ whereby alpha-lipoic acid exerts its anti-adiposity effects by inhibiting lipogenesis, increasing lipolysis and inhibiting adipogenesis,” wrote the researchers. “Therefore, these mechanisms could be also contributing to the body weight- and fat mass-lowering actions of alpha-lipoic acid, without necessarily involving an increment of energy expenditure.”
“It is essential that these observations be further explored and the underlying mechanisms better elucidated,” they concluded.
February 2015, Volume 23, Issue 2, pages 313-321, doi: 10.1002/oby.20966
“Effects of alpha-lipoic acid and eicosapentaenoic acid in overweight and obese women during weight loss”
Authors: A.E. Huerta, S. Navas-Carretero, P.L. Prieto-Hontoria, J.A. Martinez, M.J. Moreno-Aliaga