A recent study suggests that, at least for worms, free radicals may not be the "bad guys" after all. It turns out that if you are a bacteria-eating worm of the species C. elegans, genetic modifications that raise your free radical levels don't have the negative effect expected, but instead serve to lengthen lifespan. The effect was negated by exposure to known antioxidants such as vitamin C. C. elegans also seems to thrive when exposed to the herbicide Paraquat which is known to dramatically increase free radical levels in animals, so much so that it has been banned in the EU and its use is restricted in most other countries. C. elegans actually lived longer when exposed to Paraquat. It remains unclear what, if any, significance this has for humans so don’t stop eating your antioxidant-rich fruits and veggies just yet.
Free radicals are molecules that are produced by our bodies as it processes oxygen. Many mammalian cell functions consume oxygen, generating free radicals as a by-product, which in turn causes damage to those same cells. This is called “oxidative stress” and has been broadly understood to be a degradative process in cells. This is one of the key reasons antioxidants have become a buzz word in both conventional and complementary medicine in recent years. One of the favored theories of aging suggests that the process is caused by a endless downward spiral involving increasing production of free radicals, leading to cellular damage and a consequent increase in free radicals as a result of that damage. Consuming dietary antioxidants, in food or as supplements, can reverse this spiral.
“These findings challenge our understanding of how free radicals are involved in the aging process,” said Dr. Siegfried Hekimi a researcher at McGill’s Department of Biology responsible for the C. elegans study. “The current theory is very neat and logical, but these findings suggest a different framework for why oxidative stress is associated with ageing. Further experimentation is required to explore exactly how this data might change our theory of ageing. Free radicals are clearly involved, but maybe in a very different way than in the way people used to think.”
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