Context: Supplementing with fruits high in anthocyanins to reduce exercise-induced oxidative stress and inflammation has produced mixed results. Objective: This systematic review and meta-analysis aims to discuss the impact of whole fruits high in anthocyanins, including processing methods and the type and amount of fruit, on inflammation and oxidative stress. Data Sources: PICOS reporting guidelines and a customized coding scheme were used to search 5 databases (SPORTDiscus, Science Direct, Web of Science [BIOSIS], Medline [Pubmed], and the Cochrane Collaboration) with additional cross-referencing selection. Data Extraction: A random-effects meta-analysis was used to measure effects of the fruit supplements with 3 statistics; the QTotal value based on a χ2 distribution, τ2 value, and I2 value were used to determine homogeneity of variances on 22 studies (out of 807). Outliers were identified using a relative residual value. Results: A small significant negative summary effect across the sum of all inflammatory marker outcomes (P < 0.001) and a moderate negative effect for the sum of all oxidative stress marker outcomes (P = 0.036) were found. Moderator analyses did not reveal significant (P > 0.05) differences between subgrouping variables. Conclusions: Results indicate that consumption of whole fruit high in anthocyanins can be beneficial for reducing inflammation and oxidative stress.

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 VO_2max. 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-α 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-α either with exercise or the intervention. This study demonstrates that a single bout of exercise at 70% of VO_2max 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.

Wild blueberries (WBs) have been documented to decrease oxidative stress in active and sedentary populations as well as influence lipolytic enzymes and increase the rate of fat oxidation (FAT-ox) during rest. To examine the effect of WBs on the rate of FAT-ox and lipid peroxidation during submaximal exercise, 11 healthy, aerobically trained males (26 ± 7.5 years, 74.9 ± 7.54 kg, 10.5 ± 3.2% BF) completed a 2-week washout avoiding foods high in anthocyanins, then completed a control exercise protocol cycling at 65% of VO_2peak for 40 min. Participants then consumed 375 g/d of anthocyanins for two weeks before repeating the exercise protocol. WBs increased FAT-ox when cycling at 65% of VO_2peak by 19.7% at 20, 43.2% at 30, and 31.1% at 40 min, and carbohydrate oxidation (CHO-ox) decreased by 10.1% at 20, 19.2% at 30, and 14.8% at 40 min of cycling at 65% of VO_2peak. Lactate was lower with WBs at 20 (WB: 2.6 ± 1.0, C: 3.0 ± 1.1), 30 (WB: 2.2 ± 0.9, C: 2.9 ± 1.0), and 40 min (WB: 1.9 ± 0.8, C: 2.5 ± 0.9). Results indicate that WBs may increase the rate of FAT-ox during moderate-intensity activity in healthy, active males.