Raisins beat oxidative stress

Early results from a new study show that adults who eat raisins prior to and during intense workouts may modulate their levels of oxidative DNA stress, reports the California Raisin Marketing Board. Oxidative damage is linked to a person's ability to fight chronic diseases, such as heart disease or certain types of cancer.

The research was presented last week at the 43rd annual meeting of the American College of Nutrition in San Antonio, Texas, by Dr Gene Spiller. Spiller and researchers affiliated with the Health Research and Studies Center and the Sphera Foundation of Los Altos, California, which specialise in natural foods research, found that those athletes who ate sun-dried raisins before and during an intense athletic event experienced lower or no DNA damage compared to a control group.

"We knew going into this study that sun-dried raisins are a great source of antioxidants and offer a high oxygen radical absorbance capacity (ORAC),"​ said Spiller. "This data leads one to believe that foods with a high ORAC value, such as California raisins, when used as a source of energy during strenuous exercise, protect most athletes from oxidative damage."​

Along with their antioxidant potential, raisins are recognised by most experts as offering a wide range of other nutritional benefits, adding fibre and potassium to the diet.

For the study, eight healthy adult athletes, (four female and four male), participated in a triathlon (1500m swim, 40km bicycle ride and 10km run) twice, two weeks apart. Subjects were divided into two groups and received either 170g of sun-dried raisins or a glucose drink of equivalent caloric value prior to the swim and halfway through the bike ride and run. During the second triathlon, the groups were reversed.

Urine samples were collected prior to and at the completion of each event. At the end of the triathlon, all four females and two of the four males showed lower or no DNA damage when they ate sun-dried raisins, than when on the glucose drink.

The preliminary data suggests that foods with a high ORAC level, such as sun-dried raisins, when used as an energy source during strenuous exercise, protect most athletes from experiencing oxidative DNA damage, said the board.

Influence of gender, level of training, body antioxidant status, and age need further study according to researchers, together with additional measurements for a few hours following the athletic event.

Further information about the study can be obtained from Dr Gene Spiller on +1-650-941-725.