This juicy melon may have several health benefits of watermelon, including lower blood pressure, improved insulin sensitivity, and reduced muscle soreness.
The watermelon (Citrullus lanatus) is a large, sweet fruit originally from southern Africa. It’s related to cantaloupe, zucchini, pumpkin, and cucumber.
Watermelon is packed with water and nutrients, contains very few calories, and is exceptionally refreshing.
Watermelons are mostly water — about 92 percent — but this refreshing fruit is soaked with nutrients. Each juicy bite has significant levels of vitamins A, B6 and C, lots of lycopene, antioxidants and amino acids. There’s even a modest amount of potassium. Plus, this quintessential summer snack is fat-free, very low in sodium and has only 40 calories per cup.
“Foods that are high in antioxidants and amino acids allow your body to function optimally,” said Angela Lemond, a Plano, Texas-based registered dietitian nutritionist and spokesperson for the Academy of Nutrition and Dietetics. “Antioxidants help prevent damage, and cancer. Amino acids are the basic building block for protein, and protein is used in virtually every vital function in the body.”
What’s more, it’s a good dietary source of both citrulline and lycopene, two powerful plant compounds.
Watermelon, one of summer’s most iconic fruits, is low in calories and rich in water. Watermelon is often eaten on its own as a sweet snack (think: every picnic and BBQ of the season), but it can be a versatile ingredient in many recipes. It’s also an excellent source of lycopene and vitamins A and C and is less acidic than citrus fruits and tomatoes, other well-known providers of lycopene and vitamin C.
There are five common types of watermelon: seeded, seedless, mini, yellow, and orange.
Did you know that March is National Nutrition Month®? It’s true! National Nutrition Month is sponsored by the Academy of Nutrition and Dietetics and started almost 50 years ago. What better way to celebrate, than with a beloved watermelon, which provides us with unique nutrients and health benefits of watermelon?
In this article, learn more about the possible health benefits of watermelon and nutritional content of watermelon, some tips for serving it, and who should limit it.
What Is Watermelon Exactly, and Where Does It Come From?
Watermelon may be a summertime must-have in the United States, but its origins are in the African continent. Historians and archaeologists have long argued about where exactly watermelons originated, with some of the possibilities including northeastern, western, and southern Africa. Watermelon seeds have been found in Egyptian tombs and ancient Libyan settlements dating back as far as 4,000 and 5,000 years.
Before making its way to North America, the watermelon appeared elsewhere, too! Watermelon started showing up in the Mediterranean region sometime between 400 BCE and 500 CE. (1) From there it made its way to China in the 10th century, and then to the rest of Europe during the 1200s. (1,2) It is thought that watermelon was brought to North America on ships that also bore African slaves.
The watermelon Americans have come to love today isn’t the same as the fruit once used in African cultures. The original watermelon is said to have possibly evolved from the South African citron melon, which had an extremely hairy rind and inedible flesh. Other possible watermelon ancestors include gurum and egusi melons from northern and western Africa. The Greeks referred to watermelon as “pepon.” Its modern relatives include other members of the gourd family, such as squash, cucumbers, and pumpkins.
While no one is exactly sure about the true origins of the watermelon, it’s a fact that this fruit has been prized by generations Americans. Its high water content is refreshing on a hot summer day, and its sweetness rivals that of ice cream and other calorie-rich and processed snacks. This perhaps explains why the watermelon is the most widely consumed melon in the country. (2)
Today, there are more than 200 varieties of watermelon grown in North America, but China is the top producer worldwide. (2) In the U.S., bright-red flesh varieties are the most popular, but watermelon also comes in yellow- and orange-flesh versions.
Nutrition Facts
The following nutrition information is provided by the USDA for 1 cup (154g) of raw, balled watermelon.
- Calories: 46
- Fat: 0.2g
- Sodium: 1.5mg
- Carbohydrates: 11.6g
- Fiber: 0.6g
- Sugars: 9.5g
- Protein: 0.9g
- Vitamin C: 12.5mg
Carbs
The carbohydrates in watermelon are mostly sugars, with only a little fiber. If you are counting carbohydrates, it’s best to measure watermelon carefully.
- 1 cup diced watermelon (152g): 0.6 grams fiber, 9.4 grams sugars, 11.5 grams total carbohydrates, 10.9 grams net carbohydrates
- 1 medium-sized wedge of watermelon (286g): 1.1 grams fiber, 18 grams sugars, 22 grams total carbohydrates, 21 grams net carbohydrates
Half of the sugar in watermelon is fructose, one quarter is glucose, and less than one quarter is sucrose, with other sugars making up minor fractions.
Watermelon has an average glycemic index of 76, which ranks it as high.2 This means it could give you a faster rise in blood sugar than foods of a lower glycemic index. Watermelon looks better when considering glycemic load, which takes into account how much you eat per serving. A glycemic load under 10 is considered low and a half a cup of chopped watermelon is 4.2
Fats
You will get almost no fat in watermelon, making it similar to other melons such as cantaloupe or honeydew. The fat that is present is evenly split between saturated, monosaturated, and polyunsaturated fat. For dietary tracking purposes, you can consider watermelon a non-fat food. If you concentrate the seeds (yes, they are edible), they are a source of omega-3 fatty acids.
Protein
Watermelon has only a little protein, with just under 1 gram (g) per 1 cup serving. Interestingly, some companies are producing watermelon seed protein by sprouting and shelling the seeds. You won’t be able to get that level of protein from fresh seeds, however, because the shell of the seed prevents digesting the protein inside.
Vitamins and Minerals
A fully ripe red watermelon contains higher levels of nutrients than less-ripe pink watermelon. A single serving of watermelon is a good source of vitamin C and vitamin A, providing a significant percentage of your daily requirement for each.
Vitamin C can aid in wound healing and is said to have anti-aging and immune-boosting properties,3 whereas vitamin A is important for eye health.4 A one-cup serving of watermelon also provides about 7% of your daily needs of copper and pantothenic acid, 5% of biotin, and 4% of vitamins B1 and B6.
Health Benefits of Watermelon
Watermelon is around 90% water, which makes it useful for staying hydrated in the summer. It can also satisfy a sweet tooth with its natural sugars.
Watermelon also contains antioxidants. These substances can help removeTrusted Source molecules known as free radicals, or reactive species, from the body. The body produces free radicals during natural processes, such as metabolism. They can also develop through smoking, air pollution, stress, and other environmental pressures.
If too many free radicals stay in the body, oxidative stress can occur. This can result in cell damage and may lead to a range of diseases, such as cancer and heart disease.
The body can remove some free radicals naturally, but dietary antioxidants support this process.
Below are some of the ways antioxidants and other nutrients in watermelon may help protect a person’s health.
Asthma Prevention
Some expertsTrusted Source believe that free radicals contribute to the development of asthma. The presence of certain antioxidants in the lungs, including vitamin C, may reduce the risk of having asthma.
Studies have not confirmed that taking vitamin C supplements can help prevent asthma, but a diet that is rich in vitamin C may offer some protection.
A cup of watermelonTrusted Source balls weighing around 154 grams (g) provides 12.5 milligrams (mg) of vitamin C, or between 14% and 16%Trusted Source of a person’s daily needs.
Lower Blood Pressure
High blood pressure is a major risk factor for chronic disease and premature death (25Trusted Source).
Watermelon is a good source of citrulline, which is converted into arginine in your body. Both of these amino acids aid nitric oxide production.
Nitric oxide is a gas molecule that causes the tiny muscles around your blood vessels to relax and dilate. This leads to a reduction in blood pressure (26Trusted Source).
Supplementing with watermelon or its juice may reduce blood pressure and arterial stiffness in people with high blood pressure (27Trusted Source, 28Trusted Source, 29Trusted Source, 30Trusted Source).
Heart health
Watermelon’s high levels of lycopene are very effective at protecting cells from damage and may help lower the risk of heart disease, according to a study at Purdue University. A study published in the American Journal of Hypertension found that watermelon extracts helped reduce hypertension and lower blood pressure in obese adults.
Watermelon may be especially important for older women. A study published in Menopause found that postmenopausal women, a group known to have increased aortic stiffness, who took watermelon extract for six weeks saw decreased blood pressure and arterial stiffness compared to those who did not take watermelon extract. The authors of the study attributed the benefits to citrulline and arginine.
Arginine can help improve blood flow and may help reduce the accumulation of excess fat.
Watermelon Can Help You Stay Hydrated
At 92% water, watermelon is an excellent and delicious way to help hydrate your body.[5] Proper hydration is one of the most important aspects of health. We need water in order for our bodies to function properly. Water carries nutrients and oxygen to cells, moves waste products out of our body, and helps lubricate joints allowing us to exercise and play![6] Eat watermelon all-year-round to up your hydration!
Blood Pressure
In a 2012 study, researchers found that watermelon extract reduced blood pressure in and around the ankles of middle-aged people with obesity and early hypertension. The authors suggested that L-citrulline and L-arginine — two of the antioxidants in watermelon — may improve the function of the arteries.
Lycopene — another antioxidant in watermelon — may help protect against heart disease. A 2017 reviewTrusted Source suggested that it might do this by reducing inflammation linked with high-density lipoprotein (HDL) or “good” cholesterol.
Phytosterols are plant compounds that may help manage low-density lipoprotein (LDL) or “bad” cholesterol. Some guidelinesTrusted Source recommend consuming 2 grams (g) of phytosterols each day. 154 g of watermelon balls provides a small amount, at 3.08 mg.
Reducing LDL cholesterol may help prevent high blood pressure and cardiovascular disease (CVD), but the precise impact of phytosterols on CVD remains unclear.
Reduced Insulin Resistance
Insulin is a vital hormone in your body and involved in blood sugar control.
Insulin resistance is the condition in which your cells become resistant to the effects of insulin. This can lead to elevated blood sugar levels and is linked to metabolic syndrome and type 2 diabetes.
Watermelon juice and arginine intake are associated with reduced insulin resistance in some studies.
Reduced Muscle Soreness After Exercise
Muscle soreness is a well-known side effect of strenuous exercise.
One study showed that watermelon juice is effective at decreasing muscle soreness following exercise (34Trusted Source).
Research on watermelon juice (or citrulline) and exercise performance gives mixed results. One study found no effect, while another observed improved performance in untrained — but not well-trained — individuals.
Anti-Inflammatory Properties
“The lycopene in watermelon makes it an anti-inflammatory fruit,” Jarzabkowski said. Lycopene is an inhibitor for various inflammatory processes and also works as an antioxidant to neutralize free radicals. Additionally, the watermelon contains choline, which helps keep chronic inflammation down, according to a 2006 article published in Shock medical journal.
Reducing inflammation isn’t just good for people suffering from arthritis. “When you’re sick, you have cellular damage, which can be caused by a variety of factors including stress, smoking, pollution, disease, and your body becomes inflamed,” Jarzabkowski said. “It’s called ‘systemic inflammation.'” In this way, anti-inflammatory foods can help with overall immunity and general health.
Melon Potential for Reducing Risk of Certain Chronic Diseases
Research suggests that people who eat more vegetables and fruits as part of an overall healthy diet are likely to have a reduced risk of some chronic diseases, including heart disease and some cancers.[7] Watermelon is a wonderful addition to a heart-healthy diet and is proudly American Heart Association Heart-Check Certified. It is cholesterol-free, fat-free, sodium-free, and only 80 calories per 2 cups.2 It also contains an antioxidant-rich phytonutrient, Lycopene (12.7 mg per 2-cup serving).
Lycopene has been studied for its potential role in reducing blood pressure (in those with prehypertension or hypertension) and reducing the risk of prostate cancer. Further research is needed with a larger sample size and longer duration in order to fully determine the clinical implications.
Skin and Hair Benefits
Vitamin A is stellar for your skin, and just a cup of watermelon contains nearly one-quarter of your recommended daily intake of it. Vitamin A helps keep skin and hair moisturized, and it also encourages healthy growth of new collagen and elastin cells, according to the Cleveland Clinic. Vitamin C is also beneficial in this regard, as it promotes healthy collagen growth.
Cancer
The National Cancer Institute (NCI) note that free radicals can play a role in the development of some types of cancer. The oxidative stress they cause can result in DNA cell damage.
Dietary antioxidants in watermelon, such as vitamin C, may help prevent cancer by combatting free radicals.
Some studiesTrusted Source have also linked lycopene intake with a lower risk of prostate cancer.
Muscle Soreness & Athletic Performance
Watermelon-loving athletes are in luck: drinking watermelon juice before an intense workout helps reduce next-day muscle soreness and heart rate, according to a 2013 study published in the Journal of Agricultural and Food Chemistry. This can be attributed to watermelon’s amino acids citrulline and arginine, which help improve circulation.
A 2015 study published in the Journal of Applied Physiology suggests that watermelon’s citrulline may also help improve athletic performance. Study participants who took citrulline supplements saw a boosted performance with more power production in high-intensity exercise like cycling and sprinting.
Watermelon Can Improve Digestion
Watermelon contains both water and fiber (4% DV). These two compounds are important for healthy digestion. Fiber increases bulk in the digestive tract and may keep the frequency of bowel movements regular. Water keeps the food in your digestive tract moving so that nutrients can be properly absorbed and fully digested. Eating fruits and vegetables that contain both fiber and water, including watermelon, can be very helpful for promoting normal bowel movements.
Brain and Nervous System
Choline is another antioxidant that occurs in watermelon.
It contributesTrusted Source to the following functions and activities:
- muscle movement
- learning and memory
- maintaining the structure of cell membranes
- the transmission of nerve impulses
- early brain development
One theory suggests that choline may help slow the progression of dementia in Alzheimer’s disease, but there is not enough evidence to confirm this.
Metabolic Syndrome
In 2019, researchers published findingsTrusted Source indicating that watermelon may improve features of metabolic syndrome, including obesity and cardiovascular measures. In the study, 33 people with overweight or obesity consumed either 2 cups of watermelon or low-fat cookies each day for 4 weeks.
The people who ate watermelon reported feeling less hungry and more satisfied for longer than those who ate the cookies.
In addition, after 4 weeks, those who ate watermelon had:
- higher levels of antioxidants in their blood
- lower body weight and body mass index (BMI)
- lower systolic blood pressure
- improved waist-to-hip ratio
Those who ate the cookies had higher levels of oxidative stress than the watermelon group. Their blood pressure and body fat also increased.
The results suggest that watermelon may be a good choice of snack for people with obesity and metabolic syndrome.
Can people with diabetes eat watermelon? Find out here.
Diuretic Properties
Some people use diuretic drugs to help their body remove excess water and salt. This can be useful for people with kidney problems, high blood pressure, and other conditions.
A 2014 mouse study concluded that watermelon’s diuretic action might be as effective as that of furosemide, which is a well-known diuretic. This could make it a natural option for people with excess fluid. Never stop taking a prescription diuretic without talking to your healthcare provider.
Health Risks
If eaten in reasonable amounts, watermelons should produce no serious side effects. If you eat an abundance of the fruit daily, however, you may experience problems from having too much lycopene or potassium.
The consumption of more than 30 mg of lycopene daily could potentially cause nausea, diarrhea, indigestion and bloating, according to the American Cancer Society.
People with serious hyperkalemia, or too much potassium in their blood, should probably not consume more than about one cup of watermelon a day, which has less than 140 mg of potassium. According to the National Institutes of Health, hyperkalemia can result in irregular heartbeats and other cardiovascular problems, as well as reduced muscle control.
Loading up on water-dense foods like watermelon can be tempting for those looking to lose weight because they help you feel full, but Lemond cautions against going to extremes. “Eating more fruits and vegetables of any kind naturally helps decrease overall calories (energy) of the diet,” she said. “We know that people that eat higher quantities of fruits and vegetables typically have healthier body weights However, I do not recommend eating only watermelon … You will lose weight, but that weight will be mostly muscle.”
Jarzabkowski also warned watermelon lovers to be mindful of their sugar intake. “Though watermelon’s sugar is naturally occurring, [watermelon] is still relatively high in sugar.”
“My recommendation is always to vary your selections,” said Lemond. “Watermelon is a great hydrating food, so keep it in along with other plant foods that offer other benefits. Variety is always key.”
