Two new studies in the journal Nutrients suggest that watermelon consumption can increase nutrient intake and overall diet quality in both children and adults, and protect vascular function during hyperglycemia.
Watermelons. Image credit: Jorge Furber.
Watermelon (Citrullus lanatus) is a member of the gourd family Cucurbitaceae and falls under the Food patterns equivalents database (FPED) category of citrus, melons, and berries.
While in the past watermelon was typically thought of as a seasonal fruit in the United States, now watermelon is available year-round.
It contributes certain nutrients, with 100 g providing 112 mg of potassium, 8.1 mg of vitamin C, 28 µg of vitamin A, 10 mg of magnesium, 3 µg of folate and 0.4 g of dietary fiber contributing upwards of 4% of daily potassium, 11-37% of vitamin C, and 4-10% of vitamin A as well as greater than 1% of magnesium and dietary fiber recommendations in adults and children.
Additionally, watermelon has high bioavailability of antioxidant components including lycopene and l-citrulline.
While the nutrient intake and diet quality benefits of fruits has been well studied, a focused study of the impact of watermelon intake on these variables is lacking.
“Our goal was to assess the differences in nutrient intake and diet quality of watermelon consumers and non-consumers in a large sample size representative of the U.S. population,” said Nutrition Impact researchers Kristin Fulgoni and Victor Fulgoni III.
In their study, the researchers analyzed data from the National Health and Nutrition Examination Survey (NHANES) and found that total diet quality was higher in watermelon consumers as compared to non-consumers.
According to their results, children and adult watermelon consumers had higher intakes of dietary fiber, magnesium, potassium, vitamin C and vitamin A as well as lycopene and other carotenoids, while they had lower intakes of added sugars and total saturated fatty acids.
In addition to the study, another new study builds on previous work in this area of research to show that watermelon juice supplementation protects vascular function during hyperglycemia.
In this randomized, double-blind, placebo-controlled crossover trial, Louisiana State University researchers Rachel Matthews and colleagues tested the effects of 2 weeks of daily watermelon juice supplementation.
They specifically looked at the potential beneficial modulating effects of l-citrulline and l-arginine — two compounds found in watermelon — on nitric oxide bioavailability and heart rate variability.
“We acknowledge that while the sample size was small (18 healthy young men and women) and more research is needed, this study adds to the current body of evidence supporting regular intake of watermelon for cardio-metabolic health,” said Louisiana State University’s Professor Jack Losso, co-author of the second study.
“In addition to l-citrulline and l-arginine, watermelon is a rich source of antioxidants, vitamin C and lycopene — all of which can help reduce oxidative stress and play a role in heart disease prevention.”
Kristin Fulgoni & Victor L. Fulgoni III. 2022. Watermelon Intake Is Associated with Increased Nutrient Intake and Higher Diet Quality in Adults and Children, NHANES 2003-2018. Nutrients 14 (22): 4883; doi: 10.3390/nu14224883
Rachel Matthews et al. 2023. 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. Nutrients 15 (4): 810; doi: 10.3390/nu15040810