Researchers from the University of Louis Pasteur, in collaboration with colleagues from Harvard and Kuopio Universities and Sirtis Pharmaceuticals, observed first that administering a dietary supplement of resveratrol to mice had an effect on the muscles of mice.
The muscle fibres used up a lot of oxygen and therefore had high energy expenditure during exercise, and they demonstrated a high level of endurance both during exercise and during in activity.
A look at the signalling pathway
They went on to study the signalling pathway at a molecular level, in the mitochondrion organelle, which is responsible for energy production within the muscle cells. The resveratrol was seen to activate a protein in the sirtuin family, which in turn stimulated the activity of another protein involved in mitochondrial function.
Thus, by enhancing energy expenditure, the researchers surmised that resveratrol led to a reduction in weight gain.
What is more, since the study found a link between sirtuins and energy expenditure, the researchers say there is a possibility that they may prove useful in the prevention or treatment of metabolic disorders – in particular certain pathologies related to mitochondrial dysfunction, as is often the case with obesity, type 2 diabetes and other age-related disorders.
The findings of the mice study are published in the peer reviewed journal Cell.
Diabetes trial underway
With view to substantiating the results in humans, Sirtris Pharmaceuticals has initiated a clinical trial on diabetes sufferers. However, it is using a “confidential formulation of resveratrol, which has better bioavailability”.
Although this means that the outcome cannot necessarily be transposed to commercially available resveratrol in dietary supplements, this is the latest in a string of studies indicating that resveratrol packs a powerful health punch.
Last month, Harvard researchers reported in Nature that resveratrol was seen to extend survival rates of mice and prevent the negative effects of high-calorie diets – findings described by an independent expert as “the breakthrough of the year”.
Other recent research has linked resveratrol and red wine to a reduced risk of colorectal cancer and to slowing the progression of Alzheimer’s disease.
Better consumer awareness
The ingredients industry has welcomed more research in this area. Moreover, such studies are likely to have an accumulative effect on consumer awareness of resveratrol, whether gleaned from supplements or from natural food sources.
The amount of resveratrol in a bottle of red wine can vary between types of grapes and growing seasons, and can vary between 0,2 and 5,8mg per litre. But nearly all dark red wines – merlot, cabernet, zinfandel, shiraz and pinot noir – contain resveratrol. - (Decision News Media, December 2006)