Purpose: Bilberries are abundant in polyphenols. Dietary polyphenols have been associated with strategies for prevention and treatment of chronic inflammatory diseases. We investigated the effect of bilberry juice on serum and plasma biomarkers of inflammation and antioxidant status in subjects with elevated levels of at least one risk factor for cardiovascular disease (CVD).
Methods: In a randomized controlled trial, participants consumed either bilberry juice (n = 31) or water (n = 31) for 4 weeks.
Results: Supplementation with bilberry juice resulted in significant decreases in plasma concentrations of C-reactive protein (CRP), interleukin (IL)-6, IL-15, and monokine induced by INF-gamma (MIG). Unexpectedly, an increase in the plasma concentration of tumor nuclear factor-alpha (TNF-alpha) was observed in the bilberry group. CRP, IL-6, IL15, MIG, and TNF-alpha are all target genes of nuclear factor- kappa B (NF-kappaB), -a transcription factor that is crucial in orchestrating inflammatory responses. Plasma quercetin and p-coumaric acid increased in the bilberry group, otherwise no differences were observed for clinical parameters, oxidative stress or antioxidant status. Furthermore, we studied the effect of polyphenols from bilberries on lipopolysaccharide (LPS)-induced NF-kappaB activation in a monocytic cell line. We observed that quercetin, epicatechin, and resveratrol inhibited NF-kappaB activation.
Conclusions: These findings suggest that supplementation with bilberry polyphenols may modulate the inflammation processes. Further testing of bilberry supplementation as a potential strategy in prevention and treatment of chronic inflammatory diseases is warranted.