“This is not weak evidence at this point,” said Leonard Guarente, a biologist at the Massachusetts Institute of Technology who trained Sinclair and several of his critics. “You would really bet the ranch on this one.” Guarente also serves on the Sirtris scientific advisory board.
The latest advance by Sinclair’s team isn’t likely to have the mass appeal of earlier studies that showed resveratrol could improve heart function in people, make obese mice as nimble as thin ones and cause flies, fish and worms to live longer. Those splashy results fueled the rise of high-dose resveratrol supplements, which have not been vetted in clinical trials the way drugs are. Interest in the compound has also boosted sales of red wine, though scientists have cautioned that oenophiles would have to drink about 100 bottles of wine each day to get anywhere near a workable dose of resveratrol.
But the new work in effect put to rest contentions that earlier laboratory results were unlikely to occur in nature.
Detractors had claimed Sinclair’s data were influenced by a fluorescent chemical — one that doesn’t occur in nature — that he used to measure the activation of sirtuin proteins by resveratrol-like compounds. For the new study, Sinclair and his colleagues essentially repeated the experiment with naturally occurring amino acids instead. The reaction worked.
A major branch of anti-aging research centers on the effects of calorie restriction, which can send cells into a crisis mode that prompts them to repair damage and stave off hazardous changes in cellular activity. Resveratrol, found in such foods as grapes, peanuts, cocoa and berries, provokes similar reactions.