We are often being told – especially by sellers of food supplements and skin creams – that antioxidants slow down the aging process. Antioxidants would delay aging by mopping up harmful free radicals which otherwise would damage our DNA. These free radicals are generally produced as a side effect of our metabolism.
But mounting evidence shows that most antioxidants don’t slow down aging. And that free radicals aren’t always the bad guys.
Free radicals can even function as a beneficial warning sign, revving up the cell’s defense mechanisms, like detoxification enzymes and repair proteins, protecting our cells against age-related damage.
For example, studies have shown that genetically modified worms which produce more free radicals, actually live 32% longer.
Giving worms a weed-controlling herbicide that creates a surge in free radical production makes worms even live 58% longer.
While free radicals aren’t always bad, antioxidants can sometimes be damaging.
A large meta-analysis of 230,000 people has shown that antioxidants don’t extend lifespan, and in some cases can even shorten lifespan.
In conclusion, taking antioxidants isn’t always a good thing. Of course, when you are deficient in certain antioxidants, taking them can help to replenish the ranks.
But taking extra antioxidants to slow down aging doesn’t seem to work unfortunately.
Meanwhile, aging seems much more complex than just free radicals damaging our cellular machinery.
A Mitochondrial Superoxide Signal Triggers Increased Longevity in Caenorhabditis elegans. Wen Yang, Siegfried Hekimi. PLoS Biology, 2013.
Is the oxidative stress theory of ageing dead? Pérez VI et al. Biochim Biophys Acta, 2009. Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis. Bjelakovic, G. et al. JAMA, 2007. Picture: cc Wikicommons