When it comes to slowing aging, the much ballyhooed properties of antioxidants may have some surprise wrinkles. For more than 40 years, prevailing wisdom has linked aging to cellular oxidative stress. This theory postulates that a build-up of reactive oxygen species, or ROS, molecules overwhelms a cell’s ability to repair damage—causing the cell to age. The theory spawned an industry of alternative antioxidant therapies (such as megadosing on Vitamin E) and gladdened fans of antioxidant-rich tipples like red wine. It just might not be, well, true.
In a study published in the February 2009 issue of the journal PLoS Genetics, McGill professor Siegfried Hekimi, the Strathcona Chair of Zoology and Robert Archibald & Catherine Louise Campbell Chair in Developmental Biology, and postdoctoral fellow Jeremy Van Raamsdonk show that oxidative stress may just as easily be the result—not the cause—of aging. The researchers genetically modified Caenorhabditis elegans worms so they were progressively less able to produce a group of proteins called superoxide dismutases (SOD), which detoxify one of the main ROS molecules. Previous studies seemed to show that decreased SOD production shortened an organism’s lifespan, but the researchers found the opposite to be true: Even though oxidative stress was elevated, none of the mutant worms showed decreased lifespan—and some even lived longer than their unmodified kin.
The researchers hasten to point out that they are not suggesting oxidative stress is good for you. “ROS undoubtedly cause damage to the body,” Hekimi says. “However, they do not appear to be responsible for aging.” So maybe there’s reason to break out the red wine after all.
This research is funded by the Canadian Institutes of Health Research.