Wild blueberry consumption and risks for cardiovascular disease

Abstract

Hitchner Hall, Orono, ME, 04469-5735 Wild blueberries are a rich source of dietary antioxidants, yet few human studies have been reported. Anthocyanins and other flavonoids in blueberries may reduce inflammation and free radicals, which are two possible risk factors for cardiovascular disease (CVD). This pilot study was designed to explore the potential health benefits of consuming wild blueberries for persons with high low-density lipoprotein levels (LDL) (between 130–189 mg/dl). The University of Maine Institutional Review Board for the Protection of Human Subjects approved the protocols. Subjects from the Bangor, ME area were randomized to either a positive control group (n=9) or a blueberry treatment group (n=17). All subjects were instructed to follow the Therapeutic Lifestyle Changes diet (TLC) that was customized to each subject's gender, age, BMI and activity level. Subjects in the blueberry group were asked to consume two pre-packaged servings (~ 70 g) of frozen wild blueberries. Weight, blood pressure and fasting serum assays were performed at the start of the study and at 4 and 8 weeks. Three-day food records were submitted on testing days. No significant differences between groups were found for serum triglycerides, HDL, LDL and total cholesterol and blood pressure. High-sensitivity C-reactive protein levels were inconsistent, suggesting that infection or other factors confounded treatment effects. Some subjects in the blueberry group had significant weight loss, but most subjects’ weight changed very little. Poor compliance with the TLC by both groups contributed to relatively low improvement in CVD markers. Future work will evaluate the benefits of wild blueberry consumption for reduction of other risk factors for CVD, and for site-specific losses in body fat. Financial support was provided by the Wild Blueberry Commission of Maine.