PROBLEM: In today's issue of The Journal of Physiology, researchers led by Dr. Lasse Gliemann at the University of Copenhagen report some unfortunate business that no one wants to hear.
When some plants (like grape vines) are under stress, they produce a polyphenol known as resveratrol, which you may have heard of as the "anti-aging" chemical. Resveratrol has been shown to improve cardiovascular performance and extend the lives of non-mammals and mice -- specifically improving the lipid profiles and longevity of mice who ate a lot of fat. We believe that's because of its work as an antioxidant.
The mice in that study got a boatload of resveratrol, though. Red wine has 1.5 to 3 mg of resveratrol per liter, so an average person would need to drink 1000 liters of red wine daily to get that much. Resveratrol does come in supplement form, but is that good for humans? Some believe that a certain amount of oxidative stress is necessary, so we shouldn't drown ourselves in antioxidants.
METHODOLOGY: 27 healthy physically inactive men (all 65 and older) undertook intense eight-week regimens of CrossFit and circuit training. Some took 250 mg of resveratrol as well, and some took a placebo. The researchers measured numerous metrics of cardiovascular health throughout the exercise program.
RESULTS: By the end of the exercise program, the placebo group had a 45 percent greater increase in maximal oxygen uptake than the resveratrol group. The placebo group also saw a decrease in blood pressure, but the resveratrol group did not. Levels of a vasodilator prostacyclin (a good thing) were also lower in the resveratrol group, and the resveratrol group did not experience the positive effects on cholesterol and triglycerides that the placebo group did.
IMPLICATIONS: This is a small study that adds to a growing body of reasons to question the divinity of antioxidants. The authors' interpretation: "These findings indicate that, whereas exercise training effectively improves several cardiovascular health parameters in aged men, concomitant resveratrol supplementation blunts most of these effects."
It seems most of what we think we know about what's good and bad for our bodies will eventually be disproved. And then proved again. And then ... So just, until we're entirely post-body as a society, moderation in all things.
The full study, "Resveratrol Blunts the Positive Effects of Exercise Training on Cardiovascular Health in Aged Men" is published in today's issue of The Journal of Physiology.