BOONE, N.C.Quercetin, a flavonoid antioxidant found in plants such as apples, onions and broccoli, may help reduce illness and maintain mental performance in physically-stressed test subjects, according to new research out of Appalachian State University. Using high-purity quercetin, supplied by Quercegen Pharma, researchers provided 1,000 mg/d of quercetin (plus niacin and vitamin C) for five weeks to trained cyclists; another group of 20 cyclists received a placebo. Three weeks into the study, participants rode a bicycle three hours a day for three days to the point of exhaustion; blood and tissue samples were taken to track physiological changes.

Following the extreme exercise, 45 percent of the cyclists taking the placebo reported illness, while only 5 percent of the quercetin group did so. The immune-boosting properties of quercetin did not appear to take effect until after the three-day intense exercise period. Lead researcher David Nieman, Ph.D., suggested this means it takes significant stress to bring out quercetins infection-fighting properties. In addition, the athletes taking quercetin better maintained their ability to react to an alertness test when exhausted.

The research was funded by a $1.1 million contract awarded through the U.S. Department of Defenses high risk research and development organization, and was presented at the Southeastern Regional Meeting of the American College of Sports Medicine on Feb. 9 in Charlotte, N.C.