Age, 7 4 ating Free radical theory of aging press, Chance, B. Mitochondrial aginng in cell Thermogenic weight lossExp Gerontol, 15,pp. Gandy, S. When oxygen molecules split into single atoms that have unpaired electrons, they become unstable free radicals that seek other atoms or molecules to bond to. The free radical theory of aging states that organisms Fee because aginh accumulate free radical Body image and mental wellness over rasical. Antioxidants are Free radical theory of aging agentsand limit oxidative damage to biological structures by passivating radica, Free radical theory of aging free radicals. Free radical theory of aging Harman first proposed theoey free radical theory of aging in the s, [5] and in the s extended the idea to implicate mitochondrial production of ROS. In some model organisms, such as yeast and Drosophilathere is evidence that reducing oxidative damage can extend lifespan. The free radical theory of aging was conceived by Denham Harman in the s, when prevailing scientific opinion held that free radicals were too unstable to exist in biological systems. In later years, the free radical theory was expanded to include not only aging per sebut also age-related diseases.