Transcript: Resveratrol Impairs Exercise Benefits
If one searches the Internet for anti-aging interventions, a vast array of techniques is offered, from starvation to supplements. All are for sale, but none, so far, has been proven, despite the exorbitant claims on many of the websites. Resveratrol is one you’ll likely come across, a component of red wine, which gained notoriety as a possible explanation for the so-called French Paradox, which turns out is not so paradoxical after all.
Turns out that countries with high wine consumption are coincidentally those in which saturated fat consumption used to be low but increased in recent years; so, the low mortality from ischemic heart disease may just reflect the earlier low levels of saturated fat consumption—the wine may just be a confounding factor. But it did help spark interest in resveratrol, the purported active ingredient of red wine, on which scientific papers are now published every day.
More than a hundred of those papers have been called into question, though, as one of the leading researchers in the field was found guilty of taking millions in taxpayer money only to fabricate and falsify his data.
Hundreds of studies remain, though; so, can pills now replace a healthy diet? Even a group of resveratrol scientists don’t think resveratrol is worth supplementing. In contrast to the lacking data on resveratrol in humans, they say the animal data are promising and indicate the need for further human clinical trials. In rodents, resveratrol supplementation decreased cardiovascular risk factors, improved cardiovascular function and physical capacity and decreased inflammation, leading to improved vascular function. So, it was put to the test in people, and almost the exact opposite was found.
Specifically, taking resveratrol with athletic training abolished the reduction in blood pressure, cholesterol, and triglycerides, had a more arterial constricting effect than a dilating effect, and led to a significantly lower increase in the training-induced increase in maximal oxygen uptake.
Rodents on resveratrol get enhanced exercise performance, but in people, compared to those taking the sugar pill, the resveratrol induced a 45% lower increase in maximum aerobic capacity. Here, the guys are working out like crazy, and the resveratrol is undercutting their efforts.
This raises a larger issue, though. Mouse models are the cornerstone of modern biomedical research; yet, systematic studies as to their usefulness are rarely done. This one was done on inflammation after nearly 150 human clinical trials testing drugs that looked promising in mice failed without exception. The result was surprising, almost shocking. The correlation was not only poor, it was virtually absent for the main study areas: burns, trauma, and endotoxemia. Turns out, for example, mice may be up to a million times less sensitive to inflammatory endotoxins.
But anyway, the negative effects they found add to the growing body of evidence questioning the positive effects of resveratrol supplementation in humans.
Maybe that was the problem, though. It was resveratrol supplementation, giving people capsules containing 50 times the resveratrol they would normally get eating grapes, berries, peanuts, or chocolate. Maybe it was just too much of a good thing. To see if the amount one gets drinking red wine would be beneficial, we can look to the Chianti region of Tuscany, to determine whether resveratrol levels achieved with diet help protect against inflammation, cancer, cardiovascular disease, and death. And the answer is, none of the above. Although annual sales of resveratrol supplements have reached $30 million in the United States alone, there is limited and conflicting human data demonstrating any human benefits, and there are no data concerning its long-term safety.
The exercise study was supported in part by a manufacturer of resveratrol supplements; yet, to their credit, the researchers responded this way to an angry letter by a supplement company consultant: “It is our opinion that we, as scientists, have a responsibility to report what we find, and not to twist our findings to fit the commercial interests.”
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
Please consider volunteering to help out on the site.