Free Radicals Appear to be Unrelated to Aging

The notion that oxidative stress causes us to age is under fire from McGill University researchers. The scientists question the theory that oxidative stress from free radicals is related to aging. They found that some organisms lived longer when their ability to clear free radicals, or ROS (reactive oxygen species), from the body was disabled in experiments.

Hekimi, McGill's Strathcona Chair of Zoology and Robert Archibald & Catherine Louise Campbell Chair in Developmental Biology says, It is true that the more an organism appears aged, whether in terms of disease, or appearance or anything you care to measure, the more it seems to be suffering from oxidative stress.

Clinical trials have not supported the notion that taking large doses of antioxidant vitamins like co-enzyme Q or vitamin E has a significant effect on aging. The new study from McGill also shows that antioxidant vitamins may be no help for slowing the aging process.

Hekimi explains, "The problem with the theory is that it's been based purely on correlative data, on the weight of evidence. This has really entrenched the theory because people think correlation is causation. But now this theory really is in the way of progress.”

Hekimi and postdoctoral fellow Jeremy Van Raamsdonk studied mutant Caenorhabditis elegans worms. They disabled five genes responsible for detoxifying one of the main reactive oxygen species (ROS).

The researchers discovered that when the genes, collectively known as superoxide dismutases (SODs) were disabled, the lifespan of one worm actually increased. The effect seen in the study is contrary to previous research suggesting that oxidative stress from free radicals shortens lifespan and accelerates the aging process.

Hekimi says that free radicals are not good for us by any means, and they do damage the body. "However, they do not appear to be responsible for aging." The study concludes that antioxidant vitamins may be of no benefit against aging.