New research states that an antioxidant called resveratrol counteracts exercise benefits, especially in older men.
Resveratrol, a natural antioxidant compound found in red grapes and wine, blocks the cardiovascular benefits attained through exercise. This was seen primarily in older men, according to the Journal of Physiology.
The finding contradicts recent similar research that suggests the health benefits of exercise could be acquired in a pill made with high concentrations of resveratrol.
Resveratrol is a type of phenol, an antioxidative substance produced naturally by several plants. It is primarily found in both red grapes and in the roots of the Japanese Knotweed, from which it is extracted commercially.
To clarify, an antioxidant is a molecule that inhibits the oxidation of other molecules. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When the chain reaction occurs in a cell, it can cause damage or death to the cell.
Antioxidants terminate these chain reactions, and are thought to aid in maintaining the integrity of cells.
The effects of resveratrol are currently under study in numerous animal and human trials. However, the anti-aging and health effects of the antioxidant have been controversial. Resveratrol shows different results in various organism models.
In mouse and rat studies, resveratrol has shown positive health benefits against cancer, inflammation, blood-sugar, and improved cardiovascular response. In humans, however, while reported effects are generally positive, resveratrol may have lesser benefits.
New research at The University of Copenhagen suggests that eating a diet rich in antioxidants may actually counteract many of the health benefits of exercise, including reduced blood pressure and cholesterol.
Researchers studied 27 healthy, physically inactive men around 65 years of age for eight weeks. During the eight weeks all of the men performed high-intensity exercise training. Half of the group received 250 mg of resveratrol daily, whereas the other group received a placebo pill. A placebo is a pill that contains no active ingredient.
“The study design was double-blinded, thus neither the subjects nor the investigators knew which participant that received either resveratrol or placebo,” according to Lasse Gliemann, a PhD student who worked on the study – quoted in Science Daily.
The results revealed that exercise training was highly effective in improving cardiovascular health. But resveratrol supplementation attenuated the positive effects of physical training on blood pressure, plasma lipid concentrations, and maximal oxygen uptake.
Ylva Hellsten, who led the project, said in Medical Xpress, “We were surprised to find that resveratrol supplementation in aged men blunts the positive effects of exercise training on cardiovascular health parameters, in part because our results contradict findings in animal studies.”
This research adds to the growing body of evidence questioning the assumed positive effects of antioxidants.
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