June 17, 2008 -- An antioxidant found in red wine and grapes known as resveratrol -- already thought to help keep the heart healthy and ward off cancer -- may also turn out to be a fat fighter, according to new research.
In the laboratory, exposure to resveratrol prevented pre-fat cells, termed pre-adipocytes, from increasing and from converting into mature fat cells, according to Martin Wabitsch, MD, PhD, a researcher from the University of Ulm in Ulm, Germany. Wabitsch presented the findings this week at ENDO 08, The Endocrine Society's 90th annual meeting in San Francisco.
"We have to show it works in the same way in human beings," Wabitsch tells WebMD.
The hope, he says, is to continue the research and, if it bears out, develop drugs that will use the same mechanism as the resveratrol in controlling the fat cells.
Health Benefits of Resveratrol: Study Details
In previous research, Wabitsch and his colleagues had found that the resveratrol protected lab mice fed a high-calorie diet from the health problems brought on by obesity by mimicking the effects of caloric restriction.
So the next step, they thought, was to see if the substance could mimic the effects of caloric restriction in human fat cells by changing them.
"We used a human fat cell strain," Wabitsch says, a stable cell strain that can be used over and over in the laboratory.
They exposed some fat cells to resveratrol and did not expose a comparison group of fat cells to the antioxidant. "Forty hours is the normal doubling time [of pre-fat cells]," Wabitsch says. "At 48 hours, the pre-fat cells in the control dish had more than doubled. In the resveratrol dish, the number of pre-fat cells had decreased by 40% to 45%," he tells WebMD.
The volume of fat cells exposed to the resveratrol was also less, he says, in effect producing skinnier fat cells. Exposure to the resveratrol also reduced the secretion of substances called interleukin 6 and 8, which may be linked to the development of diabetes and clogged arteries, both thought to be obesity-related problems.
Wabitsch says the finding is consistent with the theory that red wine's resveratrol explains the so-called French paradox -- the observation that French people, who eat a relatively high-fat diet but enjoy their red wine, have a low death rate from heart disease.
Health Benefits of Resveratrol: What's the Mechanism?
The resveratrol affects the fat cells in many ways, Wabitsch says. "There's not just one mechanism."
"The reduction of the number of pre-fat cells works through SIRT1," says Wabitsch, referring to the activation of a gene associated with metabolism and aging.
When they "silenced" SIRT1 in animal studies, the resveratrol had no effect on the proliferation of the pre-fat cells, he says.
The study was partly funded by the German Research Association and the Ministry of Science, Research and Arts in Germany.
Health Benefits of Resveratrol: More Research Needed
The study is interesting, says Katherine Tallmadge, RD, an American Dietetic Association spokeswoman. "But we need more studies," she says.
She says that not enough is known about caloric restriction. Caloric restriction reduces body fat, which has multiple benefits, she says. But if it is too severe it can also be accompanied by health problems, including osteoporosis, she says.
Health Benefits of Resveratrol: The Future
When more is known about how resveratrol might inhibit fat, the hope is to develop a drug that will mimic the resveratrol's action, Wabitsch says. The pharmaceutical industry is already working on the concept, he says.