Grape Expectations

ATHLETES WHO believe in better living through chemistry were surely heartened by a recent breakthrough by a group of unheralded French distance runners. They followed a training regimen that you might expect in a weight-loss infomercial: They took an oral supplement found in red wine, ate whatever they wanted and didn't exercise before competing. Still, they ran farther than their opponents and, despite indulging in high-fat foods, gained only slightly more weight than runners with healthy diets.

The story sounds far-fetched, but it isn't science fiction. It's science: the runners in question were lab mice at the Institute of Genetics and Molecular and Cellular Biology in Illkirch, France. Their experience might offer a glimpse into the future of doping, especially for distance athletes such as marathoners and cyclists.

Right now, those who want to artificially enhance their endurance have few options. They can take EPO, a hormone that increases one's level of oxygen-carrying red blood cells, or they can add red cells through blood transfusions. Both methods are banned by the International Olympic Committee and other authorities. But researchers think that resveratrol, a chemical found in grape skins and red wine, might do for endurance what steroids do for muscles. In a study published in Cell in December, a group of mice were given high doses of resveratrol and made to run on a treadmill. On average, mice that weren't given the supplement tired after just over a kilometer. Mice on resveratrol ran nearly twice as far.

Another group of mice was put on a high-fat diet. Those among them that were also given resveratrol gained much less weight than those that weren't—and they ran nearly two kilometers before tiring, 56% farther than the mice not given resveratrol. "That was even a little beyond our expectations," says Dr. Johan Auwerx, one of the authors of the study. Auwerx's team also found changes in the leg muscles of the resveratrol-fed mice. They were brimming with mitochondria, organelles that produce energy in cells. That made their muscles extremely efficient. The rodents had developed the muscles of elite athletes, if not in size and shape, then in function. "It's like they were marathoners without ever exercising," Auwerx says.

Binge drinking before a race won't help runners or cyclists—to get a dose of resveratrol equal to what the mice received, a person would would have to swill 70,000 glasses of wine. (Low-dose resveratrol pills can be purchased in health-food stores; the substance is also being studied as a treatment for muscle deterioration and diabetes.) But it's possible that someday highly concentrated doses might aid endurance athletes. And, unlike many of today's performance enhancers, resveratrol has no known negative side effects. "Almost everything that can enhance an athlete, you can argue it might harm him as well," says Dr. H. Lee Sweeney, a physiology professor at Penn. "With resveratrol, there doesn't seem to be a safety issue."