Wild Watermelon-Extracted Juice Ingestion Reduces Peripheral Arterial Stiffness with an Increase in Nitric Oxide Production: A Randomized Crossover Pilot Study

Wild watermelon contains various nutrients, but the effect of its acute ingestion on arterial stiffness is unclear. This study aimed to investigate whether a single bout of acute ingestion of wild watermelon-extracted juice decreased arterial stiffness concomitant with an increase in nitric oxide (NO) production. Twelve healthy young female participants were tested under two conditions in a randomized, double-blind crossover study: (1) a beverage containing 90 g of wild watermelon extract and (2) a control beverage: a placebo. Pulse wave velocity (PWV), an index of arterial stiffness, blood flow, and plasma nitrate/nitrite (NOx) levels were measured in the supine position at 30, 60, and 90 min after the intake of each beverage. The changes in femoral-ankle PWV were significantly reduced after wild watermelon-extracted juice intake compared to those in the placebo group. Additionally, the changes in blood flow in the posterior tibial artery and plasma NOx levels after intake of wild watermelon-extracted juice were significantly increased compared to those in the placebo group. These data show that acute ingestion of wild watermelon-extracted juice reduces peripheral (lower limb) arterial stiffness and increases NO bioavailability. To confirm these associations, more detailed investigations of the nutrients that influence these effects should be conducted.