RESEARCH Original Research Daily Blueberry Consumption Improves Blood Pressure and Arterial Stiffness in Postmenopausal Women with Pre- and Stage 1-Hypertension: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial Sarah A. Johnson, PhD, RD, CSO; Arturo Figueroa, MD, PhD, FACSM; Negin Navaei; Alexei Wong, PhD; Roy Kalfon, MS; Lauren T. Ormsbee, MS; Rafaela G. Feresin, MS; Marcus L. Elam, MS; Shirin Hooshmand, PhD; Mark E. Payton, PhD; Bahram H. Arjmandi, PhD, RD ARTICLE INFORMATION Article history: Accepted 27 October 2014 Available online 8 January 2015 Keywords: Blueberries Flavonoids Nitric oxide Pulse wave velocity Vasodilation Supplementary materials: Podcast available at www.andjrnl.org/content/ podcast 2212-2672/Copyright ª 2015 by the Academy of Nutrition and Dietetics. http://dx.doi.org/10.1016/j.jand.2014.11.001 ABSTRACT Background Postmenopausal women have a high prevalence of hypertension and often develop arterial stiffness thereby increasing cardiovascular disease risk. Although antihypertensive drug therapies exist, increasing numbers of people prefer natural therapies. In vivo studies and a limited number of clinical studies have demonstrated the antihypertensive and vascular-protective effects of blueberries. Objective To examine the effects of daily blueberry consumption for 8 weeks on blood pressure and arterial stiffness in postmenopausal women with pre- and stage 1- hypertension. Design This was an 8-week, randomized, double-blind, placebo-controlled clinical trial. Participants/setting Forty-eight postmenopausal women with pre- and stage 1- hypertension recruited from the greater Tallahassee, FL, area participated. Intervention Participants were randomly assigned to receive either 22 g freeze-dried blueberry powder or 22 g control powder. Main outcome measures Resting brachial systolic and diastolic blood pressures were evaluated and arterial stiffness was assessed using carotid-femoral pulse wave velocity and brachial-ankle pulse wave velocity. C-reactive protein, nitric oxide, and superoxide dismutase were measured at baseline, 4 weeks, and 8 weeks. Statistical analyses performed Statistical analysis was performed using a split plot model of repeated measures analysis of variance. Results After 8 weeks, systolic blood pressure and diastolic blood pressure (13117 mm Hg [P<0.05] and 759 mm Hg [P<0.01], respectively) and brachial-ankle pulse wave velocity (1,401122 cm/second; P<0.01) were significantly lower than baseline levels (13814 mm Hg, 807 mm Hg, and 1,498179 cm/second, respectively), with significant (P<0.05) grouptime interactions in the blueberry powder group, whereas there were no changes in the group receiving the control powder. Nitric oxide levels were greater (15.3511.16 mmol/L; P<0.01) in the blueberry powder group at 8 weeks compared with baseline values (9.117.95 mmol/L), whereas there were no changes in the control group. Conclusions Daily blueberry consumption may reduce blood pressure and arterial stiffness, which may be due, in part, to increased nitric oxide production. J Acad Nutr Diet. 2015;115:369-377. H YPERTENSION IS A KNOWN MAJOR, YET preventable, risk factor for the development of cardiovascular disease (CVD), the leading cause of death in the United States. According to the American Heart Association, in the United States approxi- mately 77.9 million, or one in three adults, have hyperten- sion. 1,2 Although the prevalence of hypertension is associated To take the Continuing Professional Education quiz for this article, log in to www.eatrightPRO.org, go to the My Account section of My Academy Toolbar, click the “Journal Quiz” link, click “Journal Article Quiz” on the next page, and then click the “Additional Journal CPE Article” button to view a list of available quizzes. ª 2015 by the Academy of Nutrition and Dietetics. JOURNAL OF THE ACADEMY OF NUTRITION AND DIETETICS 369