— High doses of a compound found naturally in grape skins and red wine can improve muscle endurance in mice, and the compound also keeps them slim, a new study shows.
The effects of resveratrol are so pronounced that endurance athletes may one day take it as a performance enhancer, experts speculate.
Johan Auwerx at the Institute of Genetics and Molecular and Cell Biology in Illkirch, France, and colleagues placed mice on a high-fat diet. Half of those mice received daily amounts of up to 400 milligrams of resveratrol per kilogram of body weight. A person would have to drink about 100 glasses of wine in just one day to obtain a similar dose of resveratrol, Auwerx says.
After three weeks, the mice on the resveratrol supplements weighed only about 20% more than mice on a standard diet. But those on the high-fat diet that did not receive the supplement weighed 60% more than the control mice. The resveratrol also improved the rodents endurance in fitness tests, and seemed to have no toxic side effects.
Mice on the high-fat diet that also took resveratrol were able to run twice as far on a treadmill as those on the same diet but without the supplement, even after the animals weight differences were taken into account.
Resveratrol boosts muscle endurance by increasing the energy-producing components within muscle cells, called mitochondria, the researchers believe. Auwerx says that high-doses of resveratrol are needed to trigger the pathway that gives cells more mitochondria. At very low doses you dont activate the cell machinery to burn energy, he explains, banishing the idea that the odd glass of wine might improve athletic prowess.
Mitochondria play a crucial role in burning fat to provide fuel for endurance exercise, perhaps explaining why mice on the supplement were slimmer in the study, Auwerx says.
Resveratrol might also be used to prevent muscle wasting in the elderly, says David Sinclair at Harvard Medical School in Massachusetts, US, who was not involved in this study.
Previous studies have shown the compound can extend the lifespan of mice by around 15%. And resveratrol is also being used in a clinical trial involving people with diabetes.
Journal reference: Cell (DOI: 10.1016/j.cell.2006.11.013)