Watermelon is a delicious and refreshing fruit that's also good for you.
It contains only 46 calories per cup, but is high in vitamin C, vitamin A and many healthy plant compounds.
Here are the top 9 health benefits of eating watermelon.
Drinking water is an important way to keep your body hydrated.
However, eating foods that have a high water content can also help.
Interestingly, watermelon is 92% water (1).
A high water content is one of the reasons that fruits and vegetables help you feel full. The combination of water and fiber means you're eating a good volume of food without a lot of calories.
Bottom Line: Watermelon has a high water content. This makes it hydrating and helps you feel full.
As far as fruits go, watermelon is one of the lowest in calories — only 46 calories per cup. That's lower than even "low-sugar" fruits such as berries (2).
A cup (154 grams) of watermelon has many other nutrients as well, including these vitamins and minerals:
- Vitamin C: 21% of the RDI.
- Vitamin A: 18% of the RDI.
- Potassium: 5% of the RDI.
- Magnesium: 4% of the RDI.
- Vitamins B1, B5 and B6: 3% of the RDI.
Watermelon is also high in carotenoids, including beta-carotene and lycopene. Plus, it has citrulline, an important amino acid.
Here's an overview of watermelon's most important antioxidants:
Vitamin C is an antioxidant that helps prevent cell damage from free radicals.
Carotenoids are a class of plant compounds that includes alpha-carotene and beta-carotene, which your body converts to vitamin A.
Lycopene is a type of carotenoid that doesn't change into vitamin A. This potent antioxidant gives a red color to plant foods such as tomatoes and watermelon, and is linked to many health benefits.
Cucurbitacin E is a plant compound with antioxidant and anti-inflammatory effects. Bitter melon, a relative of watermelon, contains even more cucurbitacin E.
Bottom Line: Watermelon is a low-calorie fruit high in some nutrients, especially carotenoids, vitamin C and cucurbitacin E.
Researchers have studied lycopene and other individual plant compounds in watermelon for their anti-cancer effects.
Although lycopene intake is linked to a lower risk of some types of cancer, the results are mixed. The strongest link so far seems to be between lycopene and cancers of the digestive system (1).
Lycopene appears to reduce cancer risk by lowering insulin-like growth factor (IGF), a protein involved in cell division. High IGF levels are linked to cancer (3).
Bottom Line: Some compounds in watermelon, including cucurbitacin E and lycopene, have been studied for their potential to prevent cancer.
Heart disease is the number one cause of death worldwide (6).
Lifestyle factors, including diet, may lower the risk of heart attacks and strokes by reducing blood pressure and cholesterol levels.
Several nutrients in watermelon have specific benefits for heart health.
Studies suggest that lycopene may help lower cholesterol and blood pressure. It can also help prevent oxidative damage to cholesterol (1).
Watermelon also contains citrulline, an amino acid that may increase nitric oxide levels in the body. Nitric oxide helps your blood vessels expand, which lowers blood pressure (9).
Other vitamins and minerals in watermelon are also good for your heart. These include vitamins A, B6, C, magnesium and potassium (1).
Bottom Line: Watermelon has several heart-healthy components, including lycopene, citrulline and other vitamins and minerals.
Inflammation is a key driver of many chronic diseases.
Watermelon may help lower inflammation and oxidative damage, since it's rich in the anti-inflammatory antioxidants lycopene and vitamin C (1).
In a 2015 study, lab rats were fed watermelon powder to supplement an unhealthy diet. Compared with the control group, they developed lower levels of C-reactive protein (a marker of inflammation) and less oxidative stress (10).
In an earlier study, humans were given lycopene-rich tomato juice with added vitamin C. Overall, their markers of inflammation went down and antioxidants went up. Watermelon has both lycopene and vitamin C (11).
As an antioxidant, lycopene may also benefit brain health. For example, it may help delay the onset and progression of Alzheimer's disease (12).
Bottom Line: Lycopene and vitamin C are anti-inflammatory antioxidants found in watermelon. Inflammation is linked to many chronic diseases.
Found in several parts of the eye, lycopene helps protect against oxidative damage and inflammation.
It may also help prevent age-related macular degeneration (AMD). This is a common eye problem that can cause blindness in older adults (1).
Lycopene's role as an antioxidant and anti-inflammatory compound may help prevent AMD from developing and getting worse.
Bottom Line: Lycopene may help keep eyes healthy and protect against AMD through its antioxidant and anti-inflammatory functions.
Citrulline, an amino acid in watermelon, may reduce muscle soreness.
Interestingly, watermelon juice appears to enhance the bio-availability of citrulline.
One small study gave athletes plain watermelon juice, watermelon juice mixed with citrulline or a citrulline drink. Both watermelon drinks led to less muscle soreness and quicker heart rate recovery, compared to citrulline on its own (13).
The researchers also conducted a test-tube experiment, investigating the absorption of citrulline. Their findings suggest that citrulline absorption is most effective when it's consumed as a component of watermelon juice.
Other research has also looked at citrulline's potential to improve exercise endurance and performance. So far, citrulline doesn't seem to improve exercise performance in the amounts studied, but it's still an area of research interest (14).
Bottom Line: Watermelon juice has some potential as a recovery beverage after exercise. Citrulline may be partially responsible for its effect of easing muscle soreness.
Two vitamins in watermelon — A and C — are important for skin and hair health.
Vitamin C helps your body make collagen, a protein that keeps your skin supple and your hair strong.
Vitamin A is also important for healthy skin since it helps create and repair skin cells. Without enough vitamin A, your skin can look dry and flaky.
Both lycopene and beta-carotene may also help protect your skin from sunburn (15).
Bottom Line: Several nutrients in watermelon are good for your hair and skin. Some help keep skin supple while others protect against sunburn.
Watermelon contains lots of water and a small amount of fiber — both of which are important for healthy digestion.
Fiber can provide bulk for your stool, while water helps keep your digestive tract moving efficiently.
Eating water-rich and fiber-rich fruits and vegetables, including watermelon, can be very helpful for promoting normal bowel movements.
Bottom Line: Fiber and water are important for healthy digestion. Watermelon contains both.
Watermelon is a surprisingly healthy fruit. It has a high water content and also delivers many other important nutrients, including lycopene and vitamin C.
These nutrients mean that watermelon isn't only a tasty low-calorie treat — it's also very good for your health.