Log In / Join Now

Resveratrol May Reverse Cognitive Decline Associated with Diabetes

Diabetes-associated brain damage was reversed in rats treated with the red-wine compound

Jacob Gaffney
Posted: July 6, 2011

A team of cellular biologists are suggesting that red wine may help reverse some of the symptoms of cognitive decline in diabetics.

Published June 10 in the American Journal of Physiology, the study by scientists from Louisiana State University and the University of Nebraska Medical Center reported that diabetic rats that consumed the red-wine compound resveratrol experienced a restoration in brain function. Resveratrol, a polyphenolic compound that is abundant in red wine, has in the past been linked to reduced risk of diabetes, heart disease and certain cancers, as well as numerous other health benefits.

The rats in the study consumed 10 milligrams of resveratrol per kilogram of weight per day, and the study's authors reported that, based on the success of the study, even less could still be as effective.

The risk of stroke and other brain disorders is higher in diabetics, regardless of type. Resveratrol is known to act as an anti-inflammatory and an antioxidant, the study states, which are associated with better circulation and a lower risk of cognitive decline. However, no previous studies explore whether resveratrol may potentially reduce risks associated with diabetes through its ability to regulate cerebral blood flow.

In order to test the potential connection, the researchers separated the rats into four groups. The scientists induced diabetes in two of the groups, one of which received daily doses of resveratrol. To serve as a point of comparison, the other two groups remained healthy, one of which received resveratrol.

After several weeks of testing the circulation in the rats, before and after introducing resveratrol, the brains were harvested and examined. Brain tissue in diabetic rats treated with resveratrol showed that some of the brain damage associated with diabetes actually reversed after exposure to the red-wine compound.

"We speculate that resveratrol may be a potential therapeutic treatment for the prevention of cerebrovascular dysfunction during diabetes," the study states, concluding that there are three new findings to the research.

The first being that reservatrol appears to relax the arteries in the brain. In the case of rats with diabetes, without the resveratrol, blood vessels were comparatively more restricted.

Also, oxygen levels normalized in the diabetes-afflicted rats which consumed resveratrol, bolstering the assertion that the red-wine compound works as both an anti-inflammatory and antioxidant.

The third conclusion was that "resveratrol can decrease blood glucose concentration very modestly, less than 5 percent to 10 percent [in diabetic rats]," said Mayhan. "The mechanism is not known. We saw a small decrease in blood glucose concentration, but not enough to account for the effects of resveratrol."

Nonetheless, by controlling heavy levels of oxygen and keeping blood flowing to the brain, resveratrol may help control the stress factors that can lead to strokes in diabetics, the study speculated. However, the reactions of the diabetic brain to resveratrol may not be limited to the three factors observed, the scientists wrote.

There could, in fact, be much more going on that science has not yet discovered, and further study is necessary, as "it was beyond the scope of the present study to examine all such possibilities," the text read.

Richard Gangel
San Francisco —  July 6, 2011 1:55pm ET
As is usually the case, the operative words in this study are "may" and "can." Furthermore, the question arises is to how much wine one must drink in order to achieve the possible beneficial effects that resveratrol might offer. My guess is that if one may derive any benefits from resveratrol, the amount of wine imbibed necessary to bring about such benefits will probably have other deleterious effects on the brain.
James P Cobb
Utica NY —  July 7, 2011 12:03pm ET
This seems to be another in a long series of studies indicating that the consumption of red wine has several beneficial effects. As this particular study appears to be an initial exploratory investigation, the possible conclusions obviously need more in-depth research to identify the mechanisms involved and begin to quantify the amount of red wine that a human would require to attain the benefits implied by the initial study. Even if the implied benefits are proved accurate it would be quite inappropriate to assume that more than 1 or 2 glasses of red wine per day would be needed -- perhaps 1/2 of a glass of red wine would be adequate, perhaps 4 glasses would be inadequate -- it's too early to speculate about quantities. As Mr. Gangel previous comment pointed out -- imbibing too much wine could have negative impacts, so, moderate or light consumption levels should probably prevail until more hard research is completed.
Robert Lauder
Auckland, NZ —  July 12, 2011 5:33pm ET
"10 milligrams of resveratrol per kilogram of weight per day" for the rats!! Translate that to human consumption and it is hugely excessive, putting the dose at a level way above that of a natural diet and where it has often been stated that excessive doses are NOT proven in the long term to be safe. All wines are not equal in their resveratrol content and several studies have shown there is very little resveratrol in most wines. The famous quote is you need 1000 glasses of wine per day to get the concentration given to the rats in the study that started all the interest in resveratrol. In my observation that's why most supplements use knot weed and other plants, rather than grape extracts, as the source of resveratrol.

Would you like to comment? Want to join or start a discussion?

Become a WineSpectator.com member and you can!
To protect the quality of our conversations, only members may submit comments. Member benefits include access to more than 315,000 reviews in our Wine Ratings Search; a first look at ratings in our Insider, Advance and Tasting Highlights; Value Wines; the Personal Wine List/My Cellar tool, hundreds of wine-friendly recipes and more.

WineRatings+ app: Download now for 340,000+ ratings.