The effect of wild blueberry (Vaccinium angustifolium) consumption on oxidative stress, inflammation, and DNA damage associated with exercise

The present study examined the effect of wild blueberries on oxidative stress, the inflammatory response and DNA damage associated with exercise in untrained individuals. Ten sedentary males, aged 21-26 years, completed two single bouts of treadmill exercise at 70% of their VO2max. One bout occurred prior to, and one occurred following daily consumption of 300 g of wild blueberries for eight weeks. Blood samples were drawn during both exercise bouts and assayed for measures of oxidative stress (manganese-superoxide dismutase: Mn-SOD), inflammation (tumour necrosis factor-alpha: TNF-a and interleukin-6: IL-6) and DNA damage (comet assay). Blood samples were obtained immediately pre-exercise, and post exercise at 0, 30 and 60 min, and 3 and 6 h. A significant interaction between pre- and post-intervention over time was detected in plasma Mn-SOD concentration. Post hoc comparisons showed no significant differences between time points pre- and post-intervention, although plasma Mn-SOD concentration showed a moderate trend 30 min after exercise with wild blueberry consumption (P=0.072). A significant increase in IL-6 was observed for time (at 30 min and 1 h) following exercise, both pre- and post-intervention. No significant differences were seen in DNA damage or TNF-a either with exercise or the intervention. This study demonstrates that a single bout of exercise at 70% of VO2max is sufficient to cause a significant increase in inflammation in untrained individuals. The trend for Mn-SOD concentration to decrease after exercise post-intervention indicates a potential benefit of wild blueberries to increase antioxidant capacity and reduce oxidative stress.