SAGE KE Bulletin Board

Free Radicals and Aging

19 November 2001

Peter H Proctor

Aging and Free Radicals

There are really two distinct free radical theories of aging, the "Weak" and the "Strong". The Weak theory holds that there is a free radical component in age-related degenerative diseases. This includes stuff like arthritis, altzheimers, atherosclerosis, cancer etc. Many of these do shorten lifespan.

The evidence for the weak theory is abundant and not really much in dispute. For one thing, reactive oxygen species act as signalling molecules in the degenerative processes behind these diseases. E.g., see ( he says modestly ).

On the other hand, with a nod toward Denham Harman, the "strong" theory holds that aging per se is a free radical disease, distinct from degenerative diseases. The evidence for this is less solid. For one thing, it is generally difficult to distinguish between and effect of an antioxidant, etc. on aging itself ( whatever that is ) and some degenerative process. BTW, personally, I concur with Aubrey and the mitochondrial mafia that there is a separate role.

Peter H Proctor, PhD, MD

Science of Aging Knowledge Environment. ISSN 1539-6150