This study aimed to investigate the metabolic fate of bioactive components in watermelon and explore their effect on endothelial function. Six healthy overweight/obese (BMI: 28.7 ± 1.6 kg/m 2 ) adults received 100 kcal of watermelon flesh (WF), rind (WR), seeds (WS), or control meal. l-Citrulline, arginine, and (poly)phenolic metabolites were characterized in plasma over 24 h using UHPLC-MS. Endothelial function was assessed using a flow mediated dilation (FMD) technique over 7 h. Maximum concentration (Cmax) and area under the curve (AUC0-8h) of l-citrulline were significantly higher after WF- and WR-containing test meals compared to control (p < 0.05). Likewise, several individual phenolic metabolites in plasma had significantly higher Cmax after WR, WF, or WS intake compared to control. FMD responses were not different among test meals. Our results provide insights on circulating metabolites from watermelon flesh, seed, and rind and lay the foundation for future clinical trials on vascular benefits of watermelon.
Keywords: arginine; endothelial function; l-citrulline; polyphenols; watermelon.
12 to 18 months old: At this age, you can either serve watermelon in small bite-sized pieces, or in the classic triangular pieces, with the rind on (it is edible, so don’t worry if the child teethes and munches on that part). If the child successfully bites off too-big pieces of the rind, simply cut some of the rind off before serving. In the dead of summer with a teething toddler? Puree watermelon and freeze into small popsicles for a tasty teething treat.
Today, watermelon is the quintessential hot weather treat: brightly colored and refreshingly crunchy and juicy. But in Africa, where the watermelon originated, it served much more practical purposes. In a hot, dry climate, the melon’s thick rind and moisture-rich interior made it a valuable source of water when and where people needed it.
Recipe: Watermelon Dusted with Ground Nuts
Yield: 1 cup (125 grams)
Cooking Time: 5 minutes
Age: 6 months+
Where does watermelon come from?
R. Ruiz, MD, FAAP. Board-Certified General Pediatrician & Pediatric Gastroenterologist