Time course of blueberry ingestion on measures of arterial stiffness and blood pressure

BACKGROUND: Blueberries possess anthocyanins which exert cardiovascular benefits but little is known about the timeframe of these benefits. OBJECTIVES: Examine effects of blueberry (BB) or placebo (PL) on variables of blood pressure (BP), augmentation index (AIx), and pulse wave velocity (cPWV) each week for three weeks for chronic assessment and within 1 h and 2 h to assess acute effects in sedentary individuals. METHODS: Participants (N = 22), 40 to 70 years old were randomized into BB ( n = 10) or PL ( n = 12). Baseline values were obtained, participants consumed 38 g BB or PL/d for three weeks, and BP, AIx, and cPWV were measured weekly. At the end of week three, 38 g of BB or PL were ingested and acute measures taken at one and two hours post-consumption. RESULTS: Chronic and acute ingestion resulted in significant Treatment-Time Interaction for systolic BP (SBP) ( p = 0.030 and p = 0.017, respectively) with BB group being lower. Diastolic pressures were not affected. Chronic and acute Time ( p = 0.029 and p = 0.021, respectively), but not Treatment or Interaction, effects existed for AIx. Acute Time effects existed for cPWV ( p = 0.020) but not for Treatment or Interaction. CONCLUSIONS: Change in SBP was not mediated by vessel distensibility but was likely due to an unknown physiologic factor not examined.