Resveratrol, found in grape skin, was given in a purified form to 6 obese men in daily doses of 150mg for 30 days. Another 6 in the same group were given a placebo as a method of control. For increased control, the placebo group were switched with the resveratrol group after 4 weeks.
Regular measurements of the resveratrol group showed a decrease in blood sugar levels, an improvement in insulin sensitivity and a decrease in triglycerides. Triglycerides, like cholesterol, are a fatty substance that can build up and cause blockages, leading to cardiac disease and heart attack. Resveratrol was also found to reduce sleeping and resting metabolic rate and reduce blood pressure.
Resveratrol works in a similar way to calorie restriction by triggering the production of a protein known as SIRT1. This is known to improve metabolic function and keep cells healthy. Previous research has shown that calorie restriction can extend the lifespan of laboratory animals; however, more research needs to be conducted to reach any conclusive evidence.
There is no evidence to suggest that resveratrol in small doses, such as in grape skins or red wine, has the same effect as it does in a purified form.
Professor Schrauwen, leader of the experiment, admitted: “This is small, proof of principle study, but the results are so promising that I think it is important that we conduct a bigger study.”
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