No Benefit For The Obese From Resveratrol In Red Wine, Danish Scientists Say

Resveratrol is the miracle supplement of the 1990's that has not yet proven its potential in reversing the diseases of aging.

In the 1990's, scientists discovered a major challenge to the prevailing theory that high-fat and high-cholesterol diets invariably cause heart disease. What came to be known as the French paradox showed that some groups of people who eat high-fat diets, such as the French, tend to have less heart disease, rather than more.

It couldn't possibly be that the cholesterol hypothesis of heart disease was wrong, so researchers began to look for other explanations of the relative health of the butter- and cheese-loving French. Researchers found their answer in red wine. So it was natural for them to assume that the chemical in the skins of red grapes that makes red wine red must be the magic bullet against the ill effects of obesity and high-fat diets that protects the French from the effects of their diet.

A $750 Million Investment in a Supplement Before It Was Proven

A tiny start-up company called Sitris announced that it had found the explanation for the healing properties of resveratrol. The red grape phytochemical activated a gene called SIRT1, as later science has confirmed, and this gene held the key to longevity, a proposition that later science has not yet confirmed. Pharmaceutical giant GlaxoSmithKline was not going to let the potential multi-billion dollar market for a plant-based rejuvenator get away, however, so in 2006 it bought Sitris for $750 million.

Unfortunately, even though resveratrol has potent effects on individual cells in Petri dishes and test tubes, and it may have some benefits for some people under experimental conditions, no clinical trial found clear-cut benefits of resveratrol for any human health condition, and that study was not published until February of 2013.

In 2013, a group of Spanish scientists released their findings of a study of the use of a "resveratrol-rich" grape extract (that is, the supplement didn't just contain resveratrol) for volunteers who already had coronary artery disease. The scientists found that taking the grape extract supplement resulted in greater production of an anti-inflammatory hormone called adiponectin. Levels of this hormone are lower in people who are obese. The scientists had to explain away, however, a finding that increased levels of adiponectin are sometimes associated with increased risk of death, not a ringing endorsement for the use of resveratrol as a supplement for heart disease. And when resveratrol was not combined with other red grape antioxidants, as in a recent Danish study, there were no benefits at all.

"Pure" resveratrol, by the way, isn't extracted from red wine. It's extracted from plant called knotweed.

Another Failure In Resveratrol Research

If resveratrol is of questionable value in treating heart disease, maybe it is of value in treating diabetes. That was the working hypothesis of a team of researchers working at Aarhus University Hospital in Denmark.

Recruiting 24 obese but otherwise healthy men, the Danish scientists gave them resveratrol or a placebo for a month. The research team monitored blood pressure, weight, body fat percentages, bloodstream markers of inflammation, and insulin resistance, the ability of cells, especially fat cells to respond to insulin so that the pancreas does not eventually "burn out" to cause diabetes. The volunteers for this study were overweight, but were not yet diagnosed with either diabetes or pre-diabetes.

And at the end of this most recent clinical trial, what were the proven benefits of resveratrol? As it turns out, none. So naturally the resveratrol establishment has tried to spin the results for damage control. Resveratrol experts have suggested:

• The participants in the study in Denmark did not show any improvements in metabolic markers because they were actually healthy, just obese. Maybe it's necessary to be sicker to benefit from resveratrol. 
• Maybe the problem was that these metabolically healthy, young men were given too much resveratrol. In the Danish study, participants who got resveratrol received 1,500 mg per day. A smaller, less tightly controlled study of middle-aged men found benefits when they were given 150 mg per day. Perhaps it is best not to take more than 300 mg per day. (The pharmaceutical company won't mind. They can still charge the same price for the smaller capsule.)
• Or maybe it is necessary to restrict future studies to people who have a pre-defined health issue. Resveratrol may not be a life extension agent for everyone, but surely there is some ailment it is good for.

Or maybe scientists have been looking at the wrong red wine chemical. Researchers in Austria have found that resveratrol is only one of over two dozen potent antioxidants in red wine, and resveratrol is not even a particularly potent antioxidant. There are other compounds in red wine that are up to 6,000 times more effective for removing free radicals of oxygen. 

And if red grape extract produces benefits, but resveratrol does not, then maybe it's drinking actual red wine that makes the difference in health. A knotweed-derived resveratrol supplement just can't do the same thing.

Red grape juice does not have the same, potent antioxidants as red wine. Some of the antioxidant compounds in red wine are created by interactions of the fermenting wine with the oak in the barrels in which it is stored. However, non-alcoholic wines contain the same range of antioxidants as regular wine, and should hold similar benefits for good health.