Watermelon has long been a summer favorite, but research suggests this refreshing fruit may offer benefits far beyond hydration. Studies published in Nutrients found that people who regularly eat watermelon tend to have healthier overall diets and may also support better heart and blood vessel function.
Researchers say watermelon provides an impressive mix of nutrients, antioxidants, and naturally occurring compounds linked to cardiovascular and metabolic health. Its high water content and low calorie count also make it an easy way to add more fruit to your diet.
Watermelon Linked to Better Diet Quality
One study examined data from the National Health and Nutrition Examination Survey (NHANES) to compare the diets of watermelon eaters and non-consumers across the United States. The analysis found that both children and adults who consumed watermelon generally had higher-quality diets overall.
According to the findings, watermelon consumers took in more dietary fiber, magnesium, potassium, vitamin C, vitamin A, lycopene, and other carotenoids. At the same time, they consumed lower amounts of added sugars and saturated fat. The study was originally published in Nutrients in 2022.
That combination is notable because many Americans still struggle to meet recommended fruit intake goals. The Dietary Guidelines for Americans (DGA) recommend between 1.5 and 2.5 cups of fruit daily, yet most adults and children consume only about half that amount.
Compounds in Watermelon May Support Heart Health
A separate clinical trial from Louisiana State University explored whether watermelon juice could help protect blood vessel function during periods of elevated blood sugar. The randomized, double-blind, placebo-controlled crossover study involved 18 healthy young adults who consumed watermelon juice daily for two weeks.
Researchers focused on two naturally occurring watermelon compounds, L-citrulline and L-arginine, which are involved in nitric oxide production. Nitric oxide helps blood vessels relax and expand, an important part of healthy circulation and cardiovascular function.
The study found evidence that watermelon juice supplementation helped maintain vascular function during hyperglycemia and influenced 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. 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,” said Dr. Jack Losso, Ph.D., professor at Louisiana State University’s School of Nutrition and Food Sciences.
Follow Up Research Continues to Explore Benefits
Since those studies were published, additional reviews and meta-analyses have continued investigating watermelon’s role in vascular and metabolic health. Researchers have reported that watermelon consumption and L-citrulline supplementation may improve measures tied to blood vessel flexibility and circulation, including pulse wave velocity and endothelial function.
Scientists are especially interested in watermelon because it is one of the richest natural food sources of L-citrulline. Recent reviews have highlighted the fruit’s potential role in supporting nitric oxide production, healthy blood flow, and cardiovascular function, although experts stress that larger long-term studies are still needed.
Watermelon is also packed with lycopene, a powerful antioxidant associated with reduced oxidative stress and potential heart health benefits. Red watermelon varieties tend to contain especially high levels of lycopene.
A Hydrating, Low Calorie Fruit
Beyond the research buzz, watermelon remains a nutrient-dense fruit that is easy to enjoy year-round. A 2-cup serving contains only 80 calories and provides 25% of the daily value for vitamin C along with 8% of the daily value for vitamin B6. The fruit is also made up of about 92% water, making it a hydrating option during hot weather or after exercise.
Whether served at a summer barbecue, blended into smoothies, or added to salads, watermelon offers a simple way to increase fruit intake while adding vitamins, antioxidants, and hydration to your diet.