The Effect of Watermelon Juice Supplementation on Heart Rate Variability and Metabolic Response during an Oral Glucose Challenge: A Randomized, Double-Blind, Placebo-Controlled Crossover Trial.

Heart rate variability (HRV) provides a simple method to evaluate autonomic function in health and disease. A reduction in HRV may indicate autonomic dysfunction and is strongly associated with aspects of cardiometabolic disease, including hyperglycemia. Reduced nitric oxide (NO) bioavailability is also implicated in the development of cardiometabolic disease and autonomic dysfunction.

Supplemental Watermelon Juice Attenuates Acute Hyperglycemia-Induced Macro-and Microvascular Dysfunction in Healthy Adults.

Background: Acute hyperglycemia reduces NO bioavailability and causes macro- and microvascular dysfunction. Watermelon juice (WMJ) is a natural source of the amino acid citrulline, which is metabolized to form arginine for the NO cycle and may improve vascular function.

Objectives: We examined the effects of 2 weeks of WMJ compared to a calorie-matched placebo (PLA) to attenuate acute hyperglycemia-induced vascular dysfunction.