Although there aren't any immediate reasons for concern, a common additive found in food and cosmetics might affect the aging process of human cells, a new study carried out by researchers at the University of California said.
The study found that dihydrocoumarin (DHC), a compound found naturally in sweet clover and synthetically manufactured for use in foods and cosmetics, inhibited the activity of Sir2p and SIRT1, forms of sirtuin found in yeast and humans, respectively.
Increased sirtuin activity is known to
increase longevity in yeast, roundworms and fruit flies. The opposite effect in yeast has also been shown when the sirtuin enzyme is either deleted or reduced, the lifespan decreases by as much as 30 percent.
"Although studies on sirtuins and longevity have not been done in humans, there is reason to suspect that sirtuins play a role in the aging process of human cells, so identifying sirtuin inhibitors becomes important," said Martyn Smith, professor of toxicology at UC Berkeley's School of Public Health and principal investigator of the study.
DHC is added as a flavoring agent to a wide variety of foods, including soft drinks, yogurt and muffins, and is used as a common fragrance in cosmetics, lotions and soaps. It can be found in concentrations as high as 100 parts per million in such foods as gelatins, puddings and frozen dairy products.
"It's still a long jump from test tube to person, but our findings may imply that humans are exposed to chemicals in the diet and environment that block an important enzyme involved in longevity," said Smith.
"Our study raises some concern about the potential effects of DHC on humans," said Andrew Olaharski. "However, I would not be alarmed at this point, since we currently do not have any evidence that exposure to DHC in the diet accelerates the human aging process."