Watermelon is a refreshing, summertime staple that is beloved for its explosive sweetness and thirst-quenching capabilities. While most people enjoy it purely for its flavour, this vibrant fruit is actually a nutrient-dense powerhouse.
Historically cultivated in tropical regions, watermelon has found its way into diets globally. It is far more than just water and sugar; it is packed with essential vitamins, minerals, and potent plant compounds that can positively impact your health.
From supporting heart health to reducing muscle soreness after exercise, the benefits of adding this fruit to your diet are extensive. Whether you enjoy it sliced, cubed, or blended into a smoothie, you are doing your body a favour with every bite.
In this article, we explore the top 9 health benefits of watermelon, supported by science, and provide tips on how to incorporate it into your daily routine.
Comprehensive Overview: What Makes Watermelon So Healthy?
Watermelon (Citrullus lanatus) is a large, sweet fruit originally from Southern Africa. It is related to cantaloupe, zucchini, pumpkin, and cucumber.
One of the most defining characteristics of watermelon is its high water content. As the name suggests, it is approximately 92% water. This makes it an incredibly effective food for maintaining hydration, which is crucial for every bodily function.
However, the nutritional profile extends beyond hydration. It is one of the lowest-calorie fruits available, containing only 30 calories per 100 grams. Despite the low calorie count, it delivers a substantial amount of nutrients.
It is an excellent source of vitamin C, vitamin A (in the form of beta-carotene), and several B vitamins. Furthermore, it contains significant amounts of copper and potassium.
Perhaps most importantly, watermelon is rich in carotenoids, including lycopene. Lycopene is the antioxidant responsible for the deep red colour of the fruit. In fact, fresh watermelon contains more lycopene than raw tomatoes, which are often cited as the primary source of this compound.
Combining high fibre, high water content, and a rich antioxidant profile, watermelon is a functional food that fits well into almost any diet.
9 Evidence-Based Health Benefits
Here is a detailed breakdown of why watermelon is beneficial for your health.
1. Helps You Stay Hydrated
Staying hydrated is important for your body to function properly. Bodily processes, including temperature regulation, organ function, and nutrient delivery to cells, rely on adequate water intake.
Eating foods with a high water content can help give your body the water it needs to function properly. Watermelon contains 92% water, making it one of the best foods for hydration.
Furthermore, a high water content is one of the reasons why fruits and vegetables help you feel full. The combination of water and fibre means you are eating a good volume of food without unnecessary calories.
According to the NHS Eat Well guide, fluids from food contribute to your overall hydration status, helping to prevent dehydration headaches and fatigue.
2. Packed with Nutrients and Beneficial Plant Compounds
Watermelon is relatively low in calories but boasts a robust nutritional profile. It contains several plant compounds that function as antioxidants.
Antioxidants are substances that help protect your body against oxidative stress and free radical damage. Key compounds in watermelon include:
- Vitamin C: An antioxidant that helps prevent cell damage from free radicals.
- Carotenoids: Plant compounds that include alpha-carotene and beta-carotene, which your body converts to vitamin A.
- Lycopene: A type of carotenoid that does not change into vitamin A. This potent antioxidant gives the fruit its red colour.
- Cucurbitacin E: A plant compound with antioxidant and anti-inflammatory effects.
3. May Have Anti-Cancer Effects
Researchers have studied lycopene and other individual plant compounds in watermelon for their anti-cancer effects. Though lycopene intake is associated with a lower risk of some types of cancer, study results are mixed.
The strongest link so far seems to be between lycopene and cancers of the digestive system. It 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.
Additionally, cucurbitacin E has been investigated for its ability to inhibit tumour growth. For detailed information on cancer-fighting foods, Cancer Research UK provides extensive resources on how diet impacts risk.
4. Improves Heart Health
Heart disease is the number one cause of death worldwide. Lifestyle factors, including diet, may lower your risk of heart attack and stroke by reducing blood pressure and cholesterol levels.
Several nutrients in watermelon have specific benefits for heart health. Lycopene may help lower cholesterol and blood pressure. It can also help prevent oxidative damage to cholesterol.
According to studies cited by the British Heart Foundation, diets rich in fruits and vegetables are essential for maintaining cardiovascular health.
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.
5. Reduces Inflammation and Oxidative Stress
Inflammation is a key driver of many chronic diseases. Because watermelon is rich in the anti-inflammatory antioxidants lycopene and vitamin C, it may help lower inflammation and oxidative damage.
In one study, rats fed watermelon powder to supplement an unhealthy diet had lower levels of C-reactive protein (a marker of inflammation) and less oxidative stress compared with the control group.
As an antioxidant, lycopene may also delay the onset and progression of Alzheimer’s disease. For more on the importance of antioxidants, you can refer to government guidelines on Public Health England.
6. May Help Prevent Macular Degeneration
Lycopene is found in several parts of the eye where it helps protect against oxidative damage and inflammation.
It may also prevent age-related macular degeneration (AMD). This is a common eye problem that can cause blindness in older adults. Lycopene’s role as an antioxidant and anti-inflammatory compound may help keep your eyes healthy and prevent AMD from developing.
7. Helps Relieve Muscle Soreness
Citrulline, an amino acid found in watermelon, may reduce muscle soreness. Interestingly, watermelon juice appears to enhance the absorption 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.
Researchers also conducted a test-tube study investigating the absorption of citrulline. Their findings suggest that citrulline absorption is most effective when it is consumed as a component of watermelon juice.
For those interested in sports nutrition, Healthline offers an in-depth look at citrulline supplements and their impact on exercise performance.
8. Aids Skin and Hair Health
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. The British Dietetic Association highlights the vital role vitamins play in maintaining dermatological health.
9. Can Improve Digestion
Watermelon contains lots of water and a small amount of fibre, both of which are important for healthy digestion.
Fibre can provide bulk for your stool, while water helps keep your digestive tract moving efficiently. Eating water-rich and fibre-rich fruits and vegetables, including watermelon, can be very helpful for promoting normal bowel movements.
However, if you have digestive issues like IBS, be aware that watermelon is high in FODMAPs, which are fermentable carbohydrates that can cause distress in some people. Consult The IBS Network for guidance on fruits suitable for sensitive stomachs.
Nutritional Breakdown
The following table outlines the nutrient composition for 100 grams of raw watermelon.
| Nutrient | Amount per 100g |
|---|---|
| Energy | 30 kcal |
| Water | 92 g |
| Protein | 0.6 g |
| Carbohydrates | 7.6 g |
| Sugar | 6.2 g |
| Fibre | 0.4 g |
| Fat | 0.15 g |
| Vitamin C | 8.1 mg |
| Potassium | 112 mg |
| Magnesium | 10 mg |
Tips for Management: Selection and Risks
To get the most out of your watermelon, knowing how to choose a ripe one is essential. Look for a firm, symmetrical fruit that feels heavy for its size. The “ground spot”—where it rested on the soil—should be a creamy yellow colour, not white.
Potential Risks
While generally safe, there are minor risks for certain groups:
- Blood Sugar: People with diabetes should monitor portions, as watermelon has a high Glycaemic Index (GI), though a low Glycaemic Load (GL). See Diabetes UK for advice on managing fruit intake.
- Digestion: As mentioned, the FODMAP content can cause bloating in sensitive individuals.
Creative Ways to Eat It
- Salads: Combine cubes with feta cheese, mint, and cucumber.
- Smoothies: Blend with lime juice and ice for a refreshing drink.
- Grilled: Grilling slices caramelises the natural sugars.
- Soup: A chilled gazpacho is perfect for hot days.
For more culinary inspiration, BBC Good Food offers excellent recipes.
Frequently Asked Questions
Is watermelon high in sugar?
Compared to other fruits, watermelon is lower in sugar. A cup of diced watermelon contains about 9 grams of sugar. While it tastes very sweet, its high water content dilutes the sugar load.
Can you eat watermelon seeds?
Yes, you can. While most people spit them out, sprouted watermelon seeds are actually quite nutritious, packed with magnesium and protein. The white seeds found in “seedless” varieties are empty seed coats and are perfectly safe to eat.
Is the rind edible?
The green rind is tough and unappealing, but the white part of the rind is edible and contains high concentrations of citrulline. It can be pickled or stir-fried.
Does watermelon make you gain weight?
It is unlikely. Because it is low in calorie density, you can eat a large volume without consuming many calories, which typically aids in weight management rather than weight gain. Information on energy density can be found via the British Nutrition Foundation.
The Bottom Line
Watermelon is a surprisingly healthy fruit. It has a high water content and delivers many essential nutrients, including lycopene, citrulline, and vitamins A and C.
Studies suggest that this sweet, red melon may boost heart health, reduce muscle soreness, and decrease inflammation. It is also a versatile addition to your diet, working well in savoury salads, sweet desserts, or simply on its own.
For most people, it is a safe, delicious way to improve dietary quality and hydration. Next time you are looking for a snack, cut a slice of watermelon—it is a choice your body will thank you for.
Read more about hydration and health at NHS.uk.
