Comparison of blood parameters associated with exercise and the total antioxidant power in sled dogs supplemented with blueberries

Thesis (M.S.) University of Alaska Fairbanks, 2003Oxidative damage from free radicals plays an important role in several diseases such as cancer, Alzheimer's disease, and heart disease. Research indicates that exercise may contribute to oxidative stress. Fruits, such as blueberries, are good antioxidants because they contain phenolics that preferentially react with free radicals. Maintaining antioxidant levels by supplementing the diet with blueberries may prevent exercise-induced oxidative damage. Additionally, oxidative damage from exercise can temporarily suppress the immune system. The goal of our study was to compare antioxidant levels in sled dogs supplemented with blueberries. Total antioxidant power (TAP), haptoglobin, isoprostane and other blood parameters were measured in plasma samples from racing sled dogs before exercise, post-exercise, 24 hours post-exercise, and 48 hours post-exercise. Though isoprostane levels did not change throughout the study, creatine kinase levels increased post-exercise for all exercise dogs regardless of blueberry supplementation. Conflicting data makes it unclear as to whether blueberry supplementation reduces muscle damage, adding confusion to the lack of sound antioxidant data available for dogs. Regardless, dogs fed blueberries had a significantly higher TAP than control post-exercise. This suggests that dogs fed blueberries while exercising as compared to dogs fed a control diet while exercising, may be better protected against oxidative damage