blueberry enhances activity and cognition through increased vascular efficiency

Conditions: Sedentary Lifestyle; Blood Pressure; Arterial Stiffness; Overweight and Obesity

Summary: 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.

Eligibility criteria:
inclusion criteria: * age 60 and older * overweight (bmi ≥25 to 35 kg/m2) * well-controlled blood pressure (\< 150/90 mmhg) * able to speak and understand spoken and written english * cognitively normal (mini-cog score 3-5) * able to walk independently * social security number (required for compensation) * own a smartphone or other mobile device capable of downloading the garmin connect app exclusion criteria: * exercise \> 150 minutes/week * unwillingness or inability to be randomized to any one of two intervention groups without knowing which (double-blind), submit to all study testing, or continuously participate in a randomly assigned diet and exercise intervention for six months. * unwilling to restrict consumption of anthocyanin-rich foods * unwillingness to abstain from mood altering drugs (including marijuana but excluding cbds) for 7 days prior to baseline and endpoint testing. * self-reported vegetarian or vegan. * inability to complete written recording forms including journals of eating and exercise behaviors. * inability to complete written and computerized cognitive tasks (presented in english). * allergy or intolerance to blueberry or placebo powder ingredients placebo ingredients include: maltodextrin, fructose, artificial blueberry flavor, natural blueberry flavor, artificial purple color (water, fd\&c red #40, fd\&c blue #1, malic acid, sodium benzoate) citric acid, and artificial red color (water, fd\&c red #40, malic acid, sodium benzoate, silica dioxide). * gastrointestinal disorders that influence digestion and absorption of food, e.g., ibd * history of frequent urinary tract or clostridium difficile infections * presence of unstable, acutely symptomatic, or life-limiting illness. * regular use of medication that interferes with the measurement of study outcomes as determined by the study physician. * unstable use of medications, other than statins, for conditions associated with metabolic syndrome (hypertension, diabetes, dyslipidemia) during the prior 6 months or during the study. * antibiotic use in the last 3 months. * cigarette smoking, chewing, or use of nicotine replacement products in the past 3 months or during the course of the study. * colonoscopy in last 2 months. * history of stomach or bowel resection (other than appendectomy), gastric bypass or other bariatric weight loss procedure effecting absorption. * history of significant weight instability (defined as \> 10 pounds weight gain or loss over one month prior to study participation). * history of cancer treatment (other than melanoma skin cancer) and not "cancer-free" for at least 1 year. * history of anti-hormonal therapy (eg., for breast or prostate cancer) within the last 6 months.

Keywords: blueberries pulse wave velocity aging exercise cognition