Title: Strategies for fighting aging can be complex: resveratrol, low-cal diets don't work the same way.(Genes & Cells).
Author(s): Tina Hesman Saey.
Source: Science News 174.3 (August 2, 2008): p14(1). (430 words)
A substance found in red wine and touted as the chemical equivalent of the fountain of youth probably acts more like a well-spring of health--with warning signs.
Resveratrol, as the chemical is known, does a pretty good job mimicking some age-defying effects found in studies of animals on calorie-restricted diets. But the substance doesn't make animals live longer, a new study shows.
At the same time, boosting levels of an enzyme believed responsible for resveratrol action and for life-extending benefits of calorie restriction does protect mice fed high-fat diets from heart problems.
But a third report links activity of the enzyme, Sirtl, and vulnerability of brain cells to damage.
The research indicates that resveratrol and low-calorie diets don't necessarily confer their benefits the same way.
"You have to carefully study the reality, and the reality is, it's complicated," says Valter Longo, a molecular geneticist at the University of Southern California.
For instance, two new studies show that each organ in the body may react differently to calorie restriction, to resveratrol or to different actions of proteins called sirtuins shown to regulate aging in yeast, roundworms and fruit flies.
Increasing levels of the mouse sirtuin Sirtl prevents mice from developing heart problems and fatty livers even when they are fed high-fat diets, researchers at the University of Cincinnati College of Medicine and the Spanish National Cancer Research Center in Madrid reported online June 30 in the Proceedings of the National Academy of Sciences. These mice with higher levels of Sirtl eat more but also burn more calories than do mice with normal levels of the enzyme.
But Longo's group reported in the July Cell Metabolism that Sirtl may affect the brain differently. Neurons grown in the laboratory were sensitive to oxidative damage when they made normal amounts of Sirtl, but reducing levels of the enzyme helped the brain cells resist stress.
An international team of researchers led by Rafael de Cabo at the U.S. National Institute on Aging reported in the August 6 Cell Metabolism that mice fed resveratrol had similar patterns of gene activity as mice fed only every other day. The resveratrol-treated mice had better bone health, less cataract formation and improved coordination compared with other mice their age.
Resveratrol also lowered the mice's cholesterol and made their hearts function better compared with aged mice fed a standard diet.
Ripe Old Age
Two different ways
to age gracefully
Caloric restriction Resveratrol *
Fights diabetes ** **
Improves cholesterol ** **
Increases longevity **
* The small quantities of resveratrol in wine have not been shown
to achieve these benefits