Researchers say mice on a high fat diet that were also fed a compound derived from red wine lived 20 percent longer than overweight mice that did not get the compound.  The research suggests that a pill may some day be available to help people who cannot lose weight.

The study by Harvard University aging researcher David Sinclair and colleagues is the latest outgrowth of work that goes back about 10 years.  Sinclair says researchers are looking into ways to control the aging process.

"Now, we are trying to manipulate that anti-aging pathway in mice," said Mr. Sinclair.  "And we are having a look at whether we can have health benefits and lifespan extension in mice.  And so far, the results are really promising."

Sinclair's team has zeroed in on a group of genes they believe are involved in life extension, called SIR2 or "sirtuins."  Previous work by the researchers has shown that in a simple organism like yeast, the sirtuin pathway is stimulated by resveratrol, a molecule found in the skin of grapes and red wine.

In a study published in Nature, Sinclair and colleagues took the work a step farther, showing that in higher animals, resveratrol prevents many of the diseases associated with old age and that are hastened by obesity.

Chemical structure of resveratrol

"We are reporting that just with a simple molecule sprinkled in the food of mice, you can reduce most of the negative impact of obesity, even if you do not lose weight," he explained.

These negative impacts include diseases such as cancer, diabetes and heart disease that can eventually kill people who are overweight.

In the study, the researchers took one-year old mice and fed them either a normal, healthy diet or a 60 percent, high fat diet.  The diets of some of the overweight mice included resveratrol.

While they were initially sluggish and unfit, the health status of the fat mice on the resveratrol diet quickly outpaced that of the overweight mice that did not get the compound, and their vital signs soon began to mirror those of the lean mice.

Researchers noted the untreated mice slowed down as they aged and showed signs of developing diabetes and heart disease.  But the resveratrol mice had organs that looked identical to the normally-fed mice.

Sinclair says the study is the first of a number of papers his group plans to publish on resveratrol. 

There are lean mice in the study who are still alive and getting the compound.  Sinclair says researchers want to see how much longer, if at all, the molecule extends their lives. 

Sinclair bristles slightly when people suggest that he is working on a pill to let them eat whatever they want without getting sick, or that he is devoting his time on an anti-aging drug for healthy people.

Sinclair says there's a serious need for something to help overweight individuals.

"We can lecture as much as we want as doctors to patients, and some people are are just unable to lose weight," he said.  "And there are 2 billion people on the planet in this situation.  And I do not think we can continue to hope that lecturing is just sufficient."

The amount of resveratrol used in the mouse experiments is many times higher than one would get by simply drinking a glass of wine. 

While resveratrol supplements are available at many health food stores, experts caution that no one knows whether the compound will work the same way for humans and, perhaps more important, whether high doses of resveratrol are harmful in the long run.