Lipoic acid supplements help some obese but otherwise healthy people lose weight

A compound given as a dietary supplement for overweight but otherwise healthy people in a clinical trial caused many of the patients to lose weight, according to research from Oregon State University and Oregon Health & Science University.

The study, published in the Journal of Nutrition, analyzed the effects of 24-week daily 600-milligram doses of lipoic acid supplements on 31 people, with a similarly large control group receiving a placebo.

“The data clearly show a loss in body weight and body fat in people taking lipoic acid supplements,” said Balz Frei, director emeritus of OSU’s Linus Pauling Institute and one of the scientists on the study. “Especially among women and in the most difficult participants.”

Produced by both plants and animals, lipoic acid stores in the mitochondria of cells, where it is normally attached to proteins involved in energy and metabolism of amino acids. A specialized, medium-chain fatty acid, it is unique in having two sulfur atoms at one end of the chain, allowing the transfer of electrons from other sources.

The body generally produces enough lipoic acid to supply the enzymes whose proper function it requires. When taken as a dietary supplement, lipoic acid shows additional properties that may not be related to function in the mitochondria. They include stimulating glucose metabolism, antioxidant defenses and anti-inflammatory responses – making it a potentially complementary treatment for people with diabetes, heart disease and age-related cognitive decline.

“Scientists have been researching for decades about the potential health benefits of lipoic acid supplements, including how it could improve healthy aging and cardiovascular disease,” said Alexander Michels, another scientist at the Linus Pauling Institute involved in the study. “In both rodent models and small-scale human clinical trials, LPI researchers have demonstrated the beneficial effects of lipoic acid on oxidative stress, lipid metabolism, and circadian rhythms.”

The OSU / OHSU project addresses two issues often ignored by previous human trials, said Tory Hagen, a professor of biochemistry and biophysics at the OSU College of Science and the corresponding author of the study.

“Many existing clinical studies using lipoic acid have focused on volunteers with pre-existing conditions such as diabetes, making it difficult to determine if lipoic acid supplements simply act as a disease treatment or have other beneficial health effects,” he said. Hagen, principal investigator and Helen P. Rumbel professor of healthy research into age at the institute. “Another issue is the formulation of the supplement. Many previous studies have used the S-form of lipoic acid, which is a product of industrial synthesis and not found in nature. We have only used the R-form of lipoic acid – the form that is natural in the body. “

Contrary to what was expected by the researchers, reduced levels of triglycerides – a type of fat, like lipid, found in the blood – were not seen in all participants taking lipoic acid.

“The effect of lipoic acid supplements on blood lipids was limited,” said Gerd Bobe, another LPI scientist who collaborated on the study. “But people who lost weight on lipoic acid also reduced their triglyceride levels in blood – that effect was obvious.”

Other effects of the lipoic acid supplements were also measurable.

“At the end of the study, some markers of inflammation decreased,” Hagen said. “The findings also suggest that lipoic acid supplementation provides a slight reduction in oxidative stress. It is not a perfect panacea, but our results show that lipoic acid supplements may be beneficial.”

Identifying which patients benefit most from lipoic acid supplementation, and how much they need, is important for both clinical and economic reasons, he added.

“Lipoic acid supplements are often quite expensive,” he said. “That understanding how we can maximize benefits with smaller amounts of the supplement is something we are interested in striving for.”