Study Finds Evidence That With Age,Free Radical Production And Damage Increase

WASHINGTON, D.C. -- Researchers at the University at Buffalo have shown that humans produce more free radicals as they grow older, and experience increased damage caused by these unstable molecules after the age of 70.

The findings lend credence to the widely held hypothesis that free-radical oxidation is one of the primary causes of many health conditions associated with old age.

Results of the research were presented here today (June 16, 1995) at the annual meeting of the Endocrine Society.

Free radicals -- molecules within cells that have an unpaired electron -- are by-products of normal metabolism. Their unpaired electron makes them extremely unstable, capable of bombarding and damaging surrounding cells. Scientists have speculated for some time that free radicals are a major cause of the physical degeneration associated with aging.

To test this hypothesis, researchers headed by Paresh Dandona, M.D., Ph.D., UB professor of medicine and a specialist in biological endocrinology, assessed the rate of free-radical generation by cells that line the blood vessels. The cells were found in blood samples from subjects ranging in age from 8 to 104.

They also measured concentrations of lipid peroxides and carbonylated proteins -- markers of oxidative damage to fats and proteins --in subjects' blood plasma and serum, and total amount of antioxidants, compounds known to protect against oxidative damage.

Results in the 80 subjects studied to date have shown that persons over the age of 70 generate markedly larger amounts of free radicals than younger participants. They also have shown significantly higher concentrations of the markers for free-radical oxidative damage and significantly lower reserves of antioxidants.

"This is the first really good evidence linking aging to oxidative damage," Dandona said.

"We have shown clearly that cells lining the blood vessels produce more free radicals as people age. Both lipid peroxides and carbonylated proteins also increased. Total antioxidants remained steady until 65 and then decreased. It is the most compelling data to date on aging and free radicals."

Other members of the research team were Kuldip Thusu, doctoral candidate working with Dandona; Ajeet Sharma, M.D., chief resident at Millard Fillmore Hospital, Buffalo; Kshitij Dandona and Ahmad Aljada, graduate students; Usha Khurana, research scientist at Millard Fillmore; Jack Freer, M.D., UB clinical assistant professor of medicine, and Thomas Nicotera, Ph.D., of Roswell Park Cancer Institute, Buffalo.