Quercetin is a dietary supplement that has been touted for its antioxidant and anti-inflammatory powers. It's popular with some cancer patients and athletes and is found in FRS Energy, the sports drink promoted by cyclist Lance Armstrong. But a new study shows that it doesn't improve athletic performance.
Researchers funded by the Coca-Cola Co. tested the supplement in 30 recreational cyclists. Half received 1 gram a day of quercetin in a sports drink while the others received a drink that did not contain the substance. The men's performance on a maximum-effort cycling test was recorded at the start of the study and again after using the sports drink for seven to 16 days. There was no difference in the performance in the two groups in several measures, including peak oxygen consumption, metabolic changes and strength loss following the test. The study was published online this week in the Journal of Applied Physiology.
Quercetin is found naturally in the skins of fruits, leafy vegetables, berries, black tea and red wine. Lab tests in mice have demonstrated a positive effect on running endurance while studies in humans have been mixed.
The results were disappointing, said the lead author of the paper, Kirk Cureton, a kinesiologist at the University of Georgia in Athens. "Our hypothesis, based on previous studies in mice, was that we would see positive effects. But our findings are important because they suggest that results from the animal studies shouldn't be generalized to humans," Cureton said in a news release.
-- Shari Roan
Photo credit: Genero Molina / Los Angeles Times