Blueberry Enhances Activity and Cognition Through Increased Vascular Efficiency

Recent evidence suggests that increased berry intake results in a variety of health benefits, across multiple health domains. This 3-month randomized, double-blind, placebo-controlled trial assess the effects of combining daily blueberry intake with weekly exercise (BB-EX) on cardiovascular function, as well as physical activity and cognitive function, in sedentary older adults (\>60 years). We will compare these effects to the same outcomes with a control group consuming a blueberry placebo (P-EX) at 0, 4, 8 and 12 weeks.

A 12-week randomized, double-blind, placebo-controlled physical activity intervention will be administered in sedentary older (\>60 years) women and men randomized to either lyophilized blueberry powder, rehydrated and consumed as a beverage twice daily with meals (BB-EX; n = 25), or an indistinguishable placebo powder, taken in the same manner (placebo control; P-EX; n = 25). Vascular function (primary outcome), 24-hr ambulatory blood pressure, cognitive performance, and related secondary measures will be assessed at 0 and 12 weeks; berry and nutrient intake and function are assessed every 4 weeks; and physical activity as step counts will be continuously monitored using a mobile device (Garmin). Blood, urine (24-hr), and stool samples will be collected at 0 and 12 weeks and archived for later analysis. The 12-week study duration is based upon the timing of vascular responses seen in other trials, as well as the minimal time needed to expect a change in cognitive performance in an older adult population. The blueberry dose of 36 grams per day in a split dose consumed with meals is based on (1) a 33% increase in dose over that previously used in a longer (6-month) trial; (2) delivering the most effective dose of blueberry bioactives; and (3) reduced likelihood of any gastrointestinal symptoms.