Intense athletic activity leads to oxidative stress, where the production of free radicals, exceeds what the body can eliminate. Free radicals tend to attack our cells and damage our DNA. Antioxidants quench free radicals by reacting with them and, thereby, saving our cells. Sun-dried raisins are an excellent source of antioxidants.

In this study, the effect of consuming sun-dried raisins during a triathlon event on a compound found in the urine known to be an indicator of DNA damage due to oxidative stress was investigated The higher the concentration of this compound in the urine, the greater the DNA damage.

Eight trained athletes, four men and four women, ages 28-42 years, ran a triathlon twice, two weeks apart. The triathlon consisted of a 1500 m swim, 40 Km bicycle ride, and a 10 Km run.

The athletes were randomly divided into two groups. Half the subjects received a total of 170 g (about 6 oz) of sun-dried raisins prior to the swim, at midpoint of the bike ride, and at midpoint of the run. The other half received a glucose (sugar) drink of equivalent energy (520 Kcal), at the same three points. During the second triathlon the group who had taken sun-dried raisins switched to the sugar drink, and vice versa.

At the end of the triathlon, six of the eight athletes (all the women and two of the men) showed lower or no DNA damage after consuming sun-dried raisins, compared to when they consumed the sugar drink.

This study suggests that foods rich in antioxidants, such as sun-dried raisins, when used as a source of energy before and during intense athletic activity, can protect the body from DNA damage due to oxidative stress.

Spiller G, Schultz L, Spiller M, Ou B. Sun-dried raisins help prevent oxidative DNA damage during intense athletic activity. J Am Coll Nutr 21 (5): 482, 2002 (Abstract 64).