There is something almost impossible to resist about cutting into a watermelon. That first crack through the rind reveals the brilliant pink-red center, and within seconds, juice is running across the cutting board. On a hot summer day, few foods sound better.

Watermelon is around 90 percent water, but calling it “mostly water” seriously undersells it. Hidden inside all that sweetness and juice are vitamin C, lycopene, potassium, antioxidants, and an amino acid called L-citrulline that has become particularly interesting to researchers studying circulation and cardiovascular health.

For those of us who eat a high fruit diet, watermelon is a great example of how hydration, energy, and nutrition can exist together in one incredibly simple food. It doesn’t require much preparation either. You just cut it open and eat it.

What Are the Health Benefits of Watermelon?

Hydration is probably the first benefit that comes to mind when we think about watermelon. Water makes up the vast majority of the fruit, so eating watermelon contributes to daily fluid intake while also providing vitamins and naturally occurring plant compounds.

Watermelon contains vitamin C, carotenoids such as lycopene and beta-carotene, potassium, polyphenols, and L-citrulline. Together, these nutrients and plant compounds support several functions throughout the body.

Some of the benefits of watermelon include:

• Supporting hydration
• Providing readily available carbohydrates for energy
• Providing antioxidants
• Supporting normal circulation
• Providing vitamin C
• Supporting normal nitric oxide production through L-citrulline
• Providing lycopene and other carotenoids
• Supporting skin health
• Contributing to overall fruit and plant intake

One of the most interesting things about watermelon is its L-citrulline content, something most of us probably never think about while eating a slice.

The Surprising Role of L-Citrulline

Watermelon is one of the best-known food sources of L-citrulline, an amino acid involved in several important processes within the body. In fact, the name citrulline comes from Citrullus, the genus to which watermelon belongs.

Once consumed, L-citrulline can be converted by the body into L-arginine. L-arginine is then involved in the production of nitric oxide, a signaling molecule that helps blood vessels relax and supports normal blood flow and vascular function.

Researchers have explored watermelon and L-citrulline in relation to blood pressure, arterial stiffness, endothelial function, circulation, and exercise performance. While eating watermelon isn’t a treatment for cardiovascular disease, the research gives us another reason to appreciate what is happening nutritionally inside such a familiar fruit.

Why Is Watermelon So Hydrating?

There is a reason juicy fruits are so appealing when the weather gets hot. Our bodies constantly use water to regulate temperature, transport nutrients, support circulation, aid digestion, and remove waste. We lose water throughout the day through breathing, perspiration, and urination, with those losses increasing during hot weather and physical activity.

Drinking water is an important part of staying hydrated, but beverages aren’t our only source of fluid. Fresh fruits and vegetables contribute to our total water intake too, and watermelon happens to package an enormous amount of water inside a naturally sweet, refreshing fruit.

This is one of the things I appreciate about eating seasonally. Summer gives us an abundance of water-rich foods such as melons, berries, peaches, tomatoes, cucumbers, and grapes. A cold plate of watermelon on a hot afternoon seems so simple, but it is simultaneously providing fluid, carbohydrates, vitamins, minerals, and beneficial plant compounds.

What Makes Watermelon Red?

One of my favorite things about plant foods is that their colors often tell us something about their chemistry. Watermelon’s beautiful red and pink color comes largely from lycopene, a carotenoid responsible for the color of several red and pink foods.

Tomatoes are probably the food most commonly associated with lycopene, but watermelon is another notable source. Lycopene has antioxidant properties and has been widely studied for its potential role in protecting cells against oxidative stress.

Watermelon also provides vitamin C, beta-carotene, polyphenols, and other naturally occurring plant compounds. This is one reason eating many different colors of fruits and vegetables is such a simple way to bring variety into your diet. Those reds, oranges, yellows, greens, blues, and purples represent an incredible assortment of plant compounds.

Natural Sugar and Energy

One of the things I love about watermelon is its natural sweetness. Sugar is a source of energy for the body, and the carbohydrates we eat can be broken down into glucose, which our cells use to produce energy. Glucose is especially important for the brain, and carbohydrates also help fuel our muscles and everyday activity.

Fruit is one of my favorite sources of carbohydrates because it gives us so much alongside that natural sugar. Watermelon provides an abundance of water along with vitamin C, potassium, lycopene, carotenoids, and other plant compounds. We get readily available energy and an entire package of nutrients at the same time.

I eat a fruit-rich diet, so naturally occurring sugars are a significant part of the way I fuel my body. I don’t approach the sweetness in watermelon as something that needs to be justified. Sweet fruits have been part of human diets for a very long time, and carbohydrates remain one of the body’s primary sources of energy.

Watermelon is particularly lovely during the warmer months when something juicy, sweet, and hydrating feels exactly right. A cold bowl gives the body fluid, carbohydrates, and an assortment of vitamins and plant compounds in one of the simplest forms possible.

Is Watermelon Good for Skin Health?

Watermelon contains several nutrients relevant to healthy skin, including water, vitamin C, lycopene, and beta-carotene. Vitamin C is particularly important because the body requires it to produce collagen, one of the major structural proteins found in the skin.

Carotenoids and other antioxidants help protect cells against oxidative stress, while adequate hydration supports normal skin function. Healthy circulation also helps deliver oxygen and nutrients throughout the body’s tissues.

This is where I find looking at food from a whole-body viewpoint so interesting. The same fruit providing hydration is also giving us nutrients involved in collagen production, antioxidants that help protect cells, and L-citrulline associated with normal vascular function. Food rarely interacts with only one part of us.

Watermelon, Digestion, and Elimination

Watermelon provides plenty of water along with a small amount of fiber, both of which can contribute to normal digestive function. Adequate hydration is particularly important for healthy bowel function because water helps support the movement of digestive contents through the intestinal tract.

Hydration also supports kidney function. The kidneys continuously filter the blood, regulate fluid and electrolyte balance, and remove waste through urine. Providing the body with adequate fluids supports these normal physiological processes.

I think nutrition can become unnecessarily complicated when we start looking for a different special food, powder, or supplement for every function in the body. So much begins with consistently giving the body what it needs: fresh food, water, carbohydrates, vitamins, minerals, fiber, movement, and rest.

What Body Systems Does Watermelon Support?

Watermelon’s combination of water, carbohydrates, vitamins, minerals, antioxidants, and amino acids means its nutrients are used throughout the body.

Cardiovascular system: L-citrulline is involved in the pathway the body uses to produce nitric oxide, which contributes to normal blood vessel function and circulation.

Digestive system: Water and fiber contribute to normal digestion and bowel function.

Urinary system: Watermelon contributes to fluid intake, which supports the kidneys in their normal filtration and fluid-regulation functions.

Skin: Vitamin C contributes to normal collagen production, while water, carotenoids, and antioxidants support normal skin function.

Muscles: Carbohydrates provide energy for physical activity, while L-citrulline has been studied for its potential relationship with blood flow and exercise performance.

This is one of the reasons I prefer looking at foods as a whole. A piece of fruit isn’t a single vitamin or isolated nutrient. It contains a collection of compounds that the body can use in many different ways.

Can You Eat Watermelon Seeds and Rind?

Most of us eat the bright center of the watermelon and discard everything else, but both the rind and seeds are edible. Watermelon rind can be juiced, or incorporated into recipes, while the seeds provide protein, fats, and minerals. I personally love to juice the watermelon rind in place of cucumber in my Green Juice Recipe.

Researchers studying watermelon have also looked at how compounds such as citrulline are distributed throughout different parts of the fruit. It is interesting to realize how much nutritional value may exist in parts of plants we routinely throw away.

You certainly don’t need to save every watermelon rind that enters your kitchen, but experimenting with different parts of fruits and vegetables can introduce you to foods and preparations you may never have considered before.

Simple Ways to Eat More Watermelon

Watermelon doesn’t require much preparation, which is part of its appeal. A cold bowl of freshly cut watermelon straight from the refrigerator is difficult to improve upon, especially during the hottest days of summer.

When watermelon is abundant, try it:

• Fresh and chilled
• Blended with lime
• Paired with fresh mint
• Frozen into chunks
• Blended into a watermelon slush
• Added to fruit bowls
• Juiced
• Frozen into homemade fruit pops
• Added to smoothies

Frozen watermelon can also be blended into a simple sorbet-like dessert. When the fruit is ripe and naturally sweet, very little needs to be added to it. Here is my recipe to a super fun Watermelon Slushie recipe.

Frequently Asked Questions About Watermelon

Is watermelon good for hydration?

Yes. Watermelon is approximately 90 percent water, making it a naturally water-rich food that contributes to daily fluid intake. It also provides nutrients including vitamin C and potassium.

What are the main health benefits of watermelon?

Watermelon provides water, natural carbohydrates, vitamin C, lycopene, L-citrulline, potassium, carotenoids, and other antioxidants. Its L-citrulline content has attracted particular research interest for its relationship with nitric oxide production and vascular health.

Is the natural sugar in watermelon good for energy?

The carbohydrates in watermelon provide sugars that the body can use for energy. Watermelon also provides water, vitamins, minerals, carotenoids, and other plant compounds alongside those carbohydrates.

Is watermelon good for circulation?

Watermelon contains L-citrulline, which the body can convert into L-arginine. L-arginine is involved in the production of nitric oxide, a molecule that plays an important role in normal blood vessel function and circulation.

Can you eat watermelon every day?

Watermelon can be part of a varied, fruit-rich diet for most people. Eating a range of fruits also provides exposure to different vitamins, minerals, antioxidants, and phytochemicals.

Is watermelon good for your skin?

Watermelon provides water, vitamin C, lycopene, beta-carotene, and other antioxidants that contribute to normal skin function. Vitamin C also plays an essential role in normal collagen production.

A Simple Fruit With a Lot Going On Inside

I think watermelon is a wonderful example of how easy it can be to overlook the complexity of everyday foods. We see a familiar summer fruit without necessarily thinking about the chemistry happening beneath that green rind.

A ripe watermelon gives us water, natural sugars, vitamin C, lycopene, carotenoids, potassium, L-citrulline, antioxidants, and an assortment of other plant compounds. Researchers are still learning more about how some of those compounds interact with our cardiovascular system, circulation, metabolism, and overall health.

Knowing all of that doesn’t make me want to turn watermelon into another food that needs to be measured, optimized, or analyzed every time I eat it. If anything, it makes me appreciate the simplicity of it more. During the summer, I eat watermelon almost every single day because it is no simple, cleansing, sweet and most of all … delicious.