In older men, resveratrol - a natural antioxidant found in red grapes blocks the cardiovascular benefits of exercise, suggests study.
Resveratrol has received widespread attention as a possible anti-aging compound and is now widely available as a dietary supplement; much has been made of its role in explaining the cardiovascular health benefits of red wine, and other foods.
But now, new research at The University of Copenhagen surprisingly suggests that eating a diet rich in antioxidants may actually counteract many of the health benefits of exercise, including reduced blood pressure and cholesterol.
In contrast to earlier studies in animals in which resveratrol improved the cardiovascular benefits of exercise, this study in humans has provided surprising and strong evidence that in older men, resveratrol has the opposite effect.
Lasse Gliemann, a PhD student who worked on the study at The University of Copenhagen, said that they studied 27 healthy, physically inactive men around 65 years old for 8 weeks.
He said that during the 8 weeks all of the men performed high-intensity exercise training and half of the group received 250 mg of resveratrol daily, whereas the other group received a placebo pill.
The study design was double-blinded, thus neither the subjects nor the investigators knew which participant that received either resveratrol or placebo.
He asserted that they found that exercise training was highly effective in improving cardiovascular health parameters, but resveratrol supplementation attenuated the positive effects of training on several parameters including blood pressure, plasma lipid concentrations and maximal oxygen uptake.
Ylva Hellsten, the leader of the project, said that they were surprised to find that resveratrol supplementation in aged men blunted the positive effects of exercise training on cardiovascular health parameters, in part because our results contradict findings in animal studies.
The research has been in The Journal of Physiology.