The scientist who developed the most widely accepted theory on aging that's used to study cancer and other diseases has died in Nebraska. Dr. Denham Harman, 98, developed the 'Free Radical Theory of Aging' in 1954, though it took years for additional research to prove its importance. The theory essentially says that a byproduct of oxygen utilization is adverse chemical reactions in cells, with the result being aging and, ultimately, death. Dr. Denham Harman (pictured in 2006) is seen on his 90th birthday celebration at the University of Nebraska Medical Center in Omaha . Harman officially retired in 1986, but he worked four days a week into his 90s at the University of Nebraska Medical Center — arriving each day at 7 a.m. He held both medical and doctorate degrees. University of Nebraska Medical Center spokesman Tom O'Connor says Harman died Tuesday at a hospital in Omaha.
Dr. Denham Harman developed the most widely accepted theory on aging - that's used to study cancer . Harman retired in 1986, but he worked four days a week into his 90s . He held both medical and doctorate degrees .