“The research is out there that you can cure all of it by diet!” Not so fast.  One of the most popular theories of aging is that aging results from accumulation of damage from oxidative stress – destruction of tissues by free radicals.  Hence oxidation creates havoc on cells over time and causes tissues and organs to age as a result.  The theory suggests that consuming antioxidants is the key to anti-aging and curing disease.

Last March, I wrote an article based on several findings that puzzled me. “There are small but consistent findings that vitamins and supplements may cause harm – even use of a multivitamin in those who are well nourished may slightly increase the risk of premature death.”  Additionally, taking more than 400 IUs of vitamin E may pose health risks including premature death.  Vitamin A may increase the risk of hip fracture in postmenopausal women and high doses of vitamin A are potentially toxic.  Folic acid supplementation may increase the risk of premature death.  Vitamin B-6 – doses of greater than 100 mgs can cause nerve damage.  Vitamin B-3 (niacin) – high doses of niacin can lower cholesterol but may also damage the liver.

An article, “The Myth of Antioxidants” by Melinda Wenner Moyer (Scientific American, February, 2013, pp. 62-67) clarified my confusion.  In an experimental test of the antioxidant theory conducted by David Gems, roundworms were genetically modified so that naturally occurring antioxidants were deactivated.  Sure enough, the mutation caused free radicals to rise dramatically.  According to the free radical theory, these worms should have a shortened life expectancy when compared to their normal counterparts.   “Contrary to Gem’s expectations, however, the mutant worms did not die prematurely.  Instead they lived just as long as normal worms did” (p 64).

Ms. Moyer goes on to present several additional studies that contradict the oxidative stress theory of aging.  She also reports two studies in humans where antioxidant vitamins increased the risk of death.  First, antioxidants (beta-carotene and retinol) were associated with an increased rate of death from lung cancer.  Second, a review of a large number of studies of vitamins concluded that beta-carotene, vitamin A, and vitamin E are associated with increased risk of death.  Additionally, exercise reduces the effects of aging despite the fact that it produces free radicals.

Like the amyloid theory of Alzheimer’s disease, the antioxidant theory of aging is too simplistic.  Both the American Heart Association and the American Diabetes Association have cautioned against taking antioxidant supplements unless you have a vitamin deficiency.  Be cautious of taking supplements – even vitamins and minerals – without consulting with your physician first.