First clinical trial of resveratrol indicates important metabolic shifts
The study, published in Cell Metabolism, is the first to report the clinical effects of resveratrol, reporting that obese men receiving a daily dietary supplement containing 150 milligrams of a 99 percent pure trans-resveratrol (resVida, DSM) have improved energy metabolism – to the extent that they appear to have similar metabolic changes as people on severe calorie restriction.
“This is a real scientific breakthrough,” said Professor Patrick Schrauwen of Maastricht University in The Netherlands, who led the study. “For the first time, we demonstrated the health effects of resveratrol in humans. We also gained insight in how this occurs.”
"We saw a lot of small effects, but consistently pointing in a good direction of improved metabolic health," he added.
Schrauwen said that the study “marks a starting point” for further research to help improve the health of the still rising number of people suffering from obesity and type 2 diabetes.
The study was carried out by researchers at Maastricht University, in collaboration with TI Food and Nutrition, Wageningen University, DSM, and Ecole Polytechnique Fédérale de Lausanne (EPFL).
Resveratrol potential
Resveratrol is a natural polyphenolic compound present in various foods and fruits – most famously in red win and grapes, but also in mulberries and peanuts.
Animal studies already previously shown that resveratrol activates ‘sirtuins’ (SIRT), proteins that are involved in energy metabolism, the same sirtuins are also activated when calorie intake is reduced.
It is therefore suggested that resveratrol supplementation could have the same beneficial effects as calorie-intake reduction, without actually lowering the calorie intake. However, until now, no research has systematically examined the metabolic effects of resveratrol in humans in order to test such a theory.
Study details
Schrauwen and his team randomly assigned 11 obese men to receive either a placebo or a dietary supplement containing 150 mg per day resveratrol, over a 30 day trial. After a four week washout period, the trial was repeated (crossed over) with all participants receiving the opposite supplement.
During the trial the team measured metabolic rate (energy expenditure), fat storage, fat burning, blood sugar levels and blood pressure, in order to assess any changed in metabolism due to the resveratrol.
The authors reported that the resveratrol supplement lowered total energy expenditure and improved measures of metabolism and overall health.
Schrauwen and his team said that the results demonstrated that resveratrol (ResVida) affects energy metabolism through activation of the ‘AMPK-SIRT1’ pathway – resulting in a decrease of blood glucose and insulin levels, less fat storage in the liver, enhancement of the mitochondrial function and reduction of levels of inflammation markers in blood.
They added that supplementation also lowered energy expenditure during sleep, suggesting it improves the total body efficiency.
"The immediate reduction in sleep metabolic rate was particularly striking," said Schrauwen, who noted that whilst it is “not entirely clear” whether burning fewer calories is a good or a bad thing for obese people, “it does suggest that participants' cells were operating more efficiently, as they do following calorie restriction.”
The metabolism expert explained that whilst ResVida – and other resveratrol supplements – are already widely available, further work is needed to establish whether they in fact have the potential to overcome the long term metabolic deviations associated with obesity and aging.
"I don't see a reason for particular caution, but we do need long-term studies," said Schrauwen.
Source: Cell Metabolism
