Is Watermelon Good for You?

This juicy summer fruit packs plenty of nutritional and health benefits

Watermelon's red color comes from the powerful antioxidant lycopene.

By Julia Calderone

A staple at picnics and backyard barbecues, watermelon is the quintessential summer fruit. Over half of Americans said they purchased it within the last year, according to a survey by The Packer, a produce industry publication. That’s more people than those who bought other seasonal fruit, like peaches, plums, and nectarines.

The fact that it’s sweet and refreshing is probably what makes watermelon popular. But flavor alone isn’t the only reason to include watermelon in your diet.

Watermelon Nutrition

“As with all fruits and vegetables, watermelon is very nutritious, and it’s quite delicious,” says Lisa Sasson, MS, RD, clinical professor of nutrition at New York University. Here are the reasons why watermelon is so good for you:

It’s a Top Source of AntioxidantsWatermelon’s characteristic reddish-pink hue comes from a powerful antioxidant called lycopene. Antioxidants help fight free radicals, which can cause cell damage. “Like all phytonutrients, lycopene appears to protect against some cancers, such as prostate cancer and breast cancer,” Sasson says. “It may also help protect against heart disease.”

In fact, watermelon is unique in that it’s one of the few foods that are packed with this pigment. Tomatoes, pink and red grapefruit, and guava are among the other lycopene-rich foods. According to the USDA, watermelon has an average of about 40 percent more lycopene than raw tomatoes (although cooked tomato products are the best source). The redder and sweeter the flesh, the more nutritious the melon, the USDA says.

It's Hydrating

"As its name implies, watermelon is mostly water [92 percent] and is a great way to hydrate yourself in the warmer weather,” Sasson says. A cup of watermelon has about 5 ounces of water. You can even use it as a post-workout snack to replenish fluids lost during exercise, she says.

It's Low in Calories and Sugar

A cup of watermelon has about 45 calories and 10 grams of sugars. While the sugar naturally found in fruit isn’t a health concern, people who are controlling their carbohydrate intake (sugar is a carbohydrate) may prefer to opt for lower-sugar fruits. Watermelon has less sugars than many fruits, such as cantaloupe and other melons, peaches, cherries, and apples.

It Contains a Variety of Essential Nutrients

A cup of watermelon will give you about 13 percent of the daily value of vitamin C and small amounts of calcium, iron, magnesium, potassium, and vitamin A.

It May Help Keep Blood Vessels Healthy

Watermelon is uniquely rich in a compound called L-citrulline, which can help relax blood vessels, thereby possibly improving blood flow and helping to control blood pressure. You may have heard that watermelon can improve soreness after exercise; L-citrulline is thought to help muscles recover faster. However, the studies have been small and of short duration, and results have been inconsistent.

A Downside of Watermelon

Conventional (non-organic) watermelons grown in the U.S. may pose a high risk from pesticides, according to a recent analysis of pesticide data by Consumer Reports. About 3 percent of the samples in the analysis contained oxamyl, a pesticide that CR’s experts say poses particular health concerns. Choosing organic watermelon would be your best bet, but if you can’t, CR’s analysis finds that it’s okay to eat up to one serving (1 1/3 cups) per day. Imported conventional watermelon was categorized as moderate risk, with a limit of up to 3 servings a day.

You Can Eat Watermelon Rind and Seeds

Watermelon seeds and rind are typically discarded, but they’re edible and highly nutritious. Using them reduces food waste and is good for the environment.

Like other seeds, watermelon seeds are rich in healthy fats and protein, plus they’re a decent source of iron, magnesium, and zinc. The flavor is reminiscent of sunflower seeds, but a little less nutty. You may have a hard time finding a seeded watermelon, though, because 90 percent of what’s grown in the U.S. these days is seedless.

Watermelon rind tastes a little like cucumber (watermelon and cucumber are from the same botanical family) and is crunchy like jicama. It’s even higher in citrulline than the flesh, plus it provides about 14 grams of fiber per ounce.

How to Pick a Watermelon

Watermelons ripen only slightly after harvest, so you want to make sure the one you buy at the store or farm stand is ready to eat. You could use the thump test—knock on the melon and listen for a dull, hollow, muffled sound. But a more reliable approach is to look for a watermelon that’s heavy for its size, has a smooth surface, a slightly dull rind, filled-in and rounded ends, and a yellow or creamy yellow underside.

Watermelon Safety

From a food safety perspective, buying a whole melon is better than buying a container of precut watermelon. It may be a time-saver, but precut melon (not just watermelon, but other melons as well) have been linked to several foodborne illness outbreaks. In commercial facilities, many fruits and vegetables are processed in one place, creating opportunities for cross-contamination.

When you buy a whole watermelon, wash it before slicing into it, because the outside can be contaminated with harmful bacteria, such as salmonella, Sasson says. If bacteria is present, the knife can carry it from the rind to the flesh as you slice. Always be sure to use a clean knife so that you don’t inadvertently transfer bacteria from other foods to the melon.

Whole melons will keep seven to 10 days unrefrigerated. That timing accounts for harvesting and shipping to the grocery store; a locally grown melon may last longer. Cut melon should be refrigerated (and kept cold at picnics) and eaten in three to four days.

What You Can Do With Watermelon

Eat watermelon fresh off the rind, mix it into a cold tomato-watermelon gazpacho, or crush it into juice. You can freeze watermelon chunks or crushed watermelon to make ice cubes to use in drinks or smoothies, or partly freeze it to make a cool, refreshing, slushy treat.

You can also spice it up with salt, pepper, lime, or chili as a snack or to add to a salad. Try combining watermelon with peaches, mint, a little feta cheese, and farro for a summery whole-grain dish. Or, leaving the rind on, grill wedges (about 2 minutes per side) to caramelize the fruit’s sugars, and serve plain or with a sauce made from honey, garlic, and chili oil or chili crisp.

Toast watermelon seeds and add to salads or in place of pumpkin or sunflower seeds in recipes. The rind can be used in a variety of ways (cut the green parts off before cooking). Recipes from the Watermelon Board suggest grating it and using it in place of cabbage in coleslaw, roasting and topping it with Parmesan, or slicing and including it in a stir-fry to add some crunch.

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