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Sunday, November 15, 2026Nov 15

Doctor behind ‘free radical’ aging theory dies

OMAHA, Neb. (AP) – The scientist who developed the most widely accepted theory on aging that’s used study cancer and other diseases has died in Nebraska.

Dr. Denham Harman 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.

Harman officially retired in 1986, but he worked 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. He was 98.