Dr. Dora Il’yasova, associate professor of epidemiology at Georgia State University School of Public Health, explains why everything you thought you knew about antioxidants is wrong.
Your research focuses on oxidative stress, which you say is largely misunderstood. Can you explain?
The normal, natural processes in your body — breathing air, metabolizing your food — create what are known as reactive oxygen species. These species can bind to molecules in the body and oxidize, or damage, them. Sometimes, this ends with one damaged molecule, but other times, it can initiate a chain reaction causing more widespread damage known as oxidative stress.
Yet if this is happening all the time, why aren’t our bodies being damaged beyond repair? The answer: antioxidants, which can absorb these reactive species, almost like a bulletproof vest.
Scientists have found that the more antioxidants — like vitamin E and beta carotene — you have in your blood, the lower your risk of disease. The assumption was that high levels of antioxidants was also correlated with low amounts of oxidative stress. But we didn’t really know. Still, experts just ﬁgured giving people antioxidants would make them healthier. It turned out that wasn’t the case.
In the early 1990s, there was a clinical trial in which researchers gave vitamin E and beta carotene pills to smokers. But what they found was that people who took the pills were more likely to develop lung cancer. When the results were published back in 1994, a similar trial was ongoing in the U.S. When the American researchers began to ﬁnd the same effect, they stopped the trial.