Narrator: This is Science Today. An antioxidant supplement can make a big difference in the diets of those who are not getting enough of these crucial nutrients. Lynn Wallock, an assistant research scientist at the University of California, Berkeley, recently conducted a study that included the diets of male smokers.

Wallock: The focus really was to find out what it is about fruits and vegetables that is healthful. One reason for including smoking in the group is because it's easier to see differences with smokers and non-smokers and it's easier to see a change when you look at smokers and you do something to try to improve their health.

Narrator: The smokers in this particular study were eating three or less servings of the recommended five to nine servings of fresh fruits and vegetables.

Wallock: What we were trying to do was to simulate a better diet. When we gave these men the supplement, which they took daily for ninety days, we found that their vitamin C concentrations in their blood increased dramatically.

Narrator: Still, Wallock says supplements should not be a substitute for fresh fruits and vegetables. For Science Today, I'm Larissa Branin. .