(
http://www.forbes.com/lifestyle/2005/02/02/cx_vg_0202feat_ls.html?partner=netscape)
"Not all free radicals are bad. They're byproducts of normal cell activity, and without them, oxygen couldn't react with other molecules to maintain basic biological functions. An integral part of turning calories into energy, for example, is free radical production (that explains why overeating and the overproduction of free radicals go hand-in-hand). Our immune system even relies on free radicals to kill invading organisms. Getting rid of free radicals all together would clearly be a bad thing.
It's when free radicals don't do what they are supposed to do (and
the more calories you consume, the more likely that is to happen) that problems arise."
Вся статья целиком представляет некоторый интерес, не только эта цитата.