Population-Based Study Shows Vitamin C May Be Antioxidant

EDMONTON -- A population-based study of vitamin C's antioxidant properties, conducted by University at Buffalo epidemiologists, has shown that people with higher levels of vitamin C in their blood serum have lower levels of a marker for oxidative stress.

"It is well known that oxidative stress (cell damage caused by free radicals) plays a role in atherosclerosis, cancer, pulmonary disease and other chronic conditions," said Holger Schunemann, M.D., research assistant professor of social and preventive medicine at the University at Buffalo and lead author on the study. "In this population, vitamin C was negatively associated with oxidative stress, suggesting it may play a role in protecting against these diseases."

Schunemann presented results of the study today (Friday, June 13) at the annual meeting of the Society for Epidemiologic Research.

This study differs from most other attempts to determine Vitamin C's potential as an antioxidant, Schunemann said, because it was population-based, and because researchers measured the actual level of the vitamin in each participant's blood, rather than relying on dietary records.

The study involved 187 women and 206 men, selected randomly from residents of Erie and Niagara counties in Western New York State. Participants were between the ages of 35 and 73, and all were non smokers.

The researchers collected fasting blood samples from participants, and measured the amount of vitamin C in the serum. They also measured the concentration of thiobarbituric acid-reactive substances, or TBARS -- products generated by oxidative stress to lipids (fats). The level of TBARS in serum is an indicator of an individual's oxidative stress.

Analysis of the samples showed that persons with low serum levels of vitamin C had high levels of TBARS, indicating high oxidative stress and the potential for significant cell damage from free radicals. High levels of vitamin C were associated with low oxidative stress and a lower risk of cell damage.

Also participating in the study were Maurizio Trevisan, M.D.; Jo L. Freudenheim, Ph.D.; Paola Muti, M.D; Nina Markovic, Ph.D., and Ann Marie Carosella, Ph.D., from the UB Department of Social and Preventive Medicine, and Douglas Armstrong, Ph.D., from the UB Department of Clinical Laboratory Sciences.