Effects of watermelon supplementation on aortic blood pressure and wave reflection in individuals with prehypertension: a pilot study.
Am J Hypertens. 2011 Jan;24(1):40-4. Epub 2010 Jul 8. PMID: 20616787
Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, USA. email@example.com
BACKGROUND: Oral L-citrulline is efficiently converted to L-arginine, the precursor for endothelial nitric oxide (NO) synthesis. Oral L-arginine supplementation reduces brachial blood pressure (BP). We evaluated the effects of watermelon supplementation on aortic BP and arterial function in individuals with prehypertension.
METHODS: Heart rate (HR), brachial systolic BP (bSBP), brachial pulse pressure (bPP), aortic SBP (aSBP), aortic PP (aPP), augmentation index (AIx), AIx adjusted for HR of 75 beats/min (AIx@75), amplitude of the first (P1) and second (P2) systolic peaks, reflection time (Tr), and carotid-femoral pulse wave velocity (PWV) were evaluated in the supine position in nine subjects (four men/five women, age 54± 3 years) with prehypertension (134/77 ± 5/3 mm Hg). Subjects were randomly assigned to 6 weeks of watermelon supplementation (L-citrulline/L arginine, 2.7 g/1.3 g/day) or placebo followed by a 4-week washout period and then crossover.
RESULTS: There was a significant treatment effect (change in the value of watermelon minus placebo from baseline to 6 weeks) on bPP (-8± 3 mm Hg, P<0.05), aSBP (-7± 2 mm Hg, P<0.05), aPP (-6± 2 mm Hg, P<0.01), AIx (-6± 3%, P<0.05), AIx@75 (-4± 2%, P<0.05), and P2 (-2± 1 mm Hg, P<0.05). There was no significant treatment effect (P>0.05) on bSBP, brachial diastolic BP (DBP), aortic DBP, Tr, P1, HR, and carotid-femoral PWV.
CONCLUSIONS: This pilot study shows that watermelon supplementation improves aortic hemodynamics through a decrease in the amplitude of the reflected wave in individuals with prehypertension.