Research published last week indicates that it may be time to pop the corks on wine bottles and toast to longevity — or, at the very least, to a substance found in wine thought to reduce the effects of obesity in mice.
A team of researchers at Harvard Medical School and the National Institute of Aging (NIA) published a study in last Wednesday’s online edition of “Nature” showing that a plant compound called resveratrol lowers the rate of diabetes, liver problems and other side effects of a fatty diet in obese mice. Spearheaded by Harvard researchers David Sinclair and Joseph Baur and NIA researcher Rafael de Cabo, the study found that, among obese mice on a high-fat diet, a daily supplement of resveratrol — the equivalent dosage of over 100 glasses of wine — cut obesity-related deaths by 31 percent.
A control group of mice, which was not given the drug, exhibited signs of enlarged livers as well as high levels of glucose, insulin and insulin-life growth factor, all of which are precursors to diabetes in humans. Mice in the experimental group put on as much weight as their counterparts but did not show signs of diabetes or liver damage.
“Mice on a high-calorie diet stayed healthier and showed less evidence of age-related diseases, despite getting just as fat as the control animals,” Baur said.
Even more surprising, he said, the resveratrol extended the lives of the mice to which it was administered, so that they outlived mice on only the high-calorie diet.
The researchers said they also tried to gauge the effect of the substance on the subjects’ quality of life by testing their ability to walk on a rotating rod before falling off, an indication of their motor skills.
“The mice [in the experimental group] not only showed improved insulin sensitivity and led healthier lives free of aberrant fat deposits, but also had better motor coordination,” Baur said.
While the scientific mechanism behind these findings is still not completely clear, Sinclair said, his team thinks resveratrol might be increasing the function of a group of enzymes called sirtuins that seem to control lifespan in lower organisms. Studies suggest these enzymes can increase the rate of metabolism and expand the role of fat within cells, he said.
Baur said that although this hypothesis has stood up to tests on a variety of organisms, including yeasts, worms, and fruit flies, more research is needed to fully understand the relationship between resveratrol and sirtuins.
If the study can be extrapolated to humans, which Sinclair said he thinks is likely, its novel findings seem to point to very large daily supplements of resveratrol as an answer to the growing challenge of obesity in the United States, he said.
But there still remains much research to be done before this leap can be made, the researchers said.
NIA Director Richard Hodes said it is too early for people to start taking resveratrol diet supplements, especially since safety issues have yet to be sorted out.
“It should be cautioned that this was a study on male mice, and we have much to learn about resveratrol’s safety and effectiveness in humans,” Hodes said.
The research team said the community must also be cautious about directly linking red wine to longevity, especially since a person would need to consume copious amounts of wine daily to take in the same amount of the resveretrol as the mice did in their study.
Sirtris, a Cambridge-based pharmaceutical company co-founded by Sinclair and affiliated with Harvard, is currently starting clinical trials with the substance on diabetics, with the goal of developing an effective drug for diabetes patients within five to seven years, Sinclair said. He does not anticipate using resveratrol to develop an anti-aging drug.