Watermelon is a fruit that grows on a vine-like flowering plant native to Southern Africa. It was cultivated in the Nile River Valley, in Egypt, and eventually in China, roughly 1,000 years ago. Now, watermelon is grown around the world, and in 44 of the 50 states in America. It is specifically selected to grow larger and juicier, resulting in the huge fruits that many of us are familiar with. The green outer rind is hard and fleshy, and rarely eaten, while the interior is soft, red or pink flesh containing many seeds; this is the part of watermelon which is typically eaten.
Nutritional Value of Watermelon
|Nutritional Value per 100 g (3.5 oz)|
|Energy||127 kJ (30 kcal)|
|Dietary fiber||0.4 g|
|Vitamin A equiv.
|Pantothenic acid (B5)||
|†Percentages are roughly approximated using US recommendations for adults.
Source: USDA Nutrient Database
Uses/ Health Benefits of Watermelon
- Diuretic activities – Traditionally, Citrullus lanatus is known to have protective properties in kidney diseases and for having the ability to clear urine. The current study aims to validate the traditional uses of C. lanatus by evaluation of anti-urolithiatic and diuretic activities using in vivo and in vitro experiments. Male Wistar rats were used for in vivo anti-urolithiatic and diuretic activities. The supersaturated solution of calcium and oxalate was used for in vitro crystallization study. Hematoxylin & eosin staining was used for histopathological evaluation of kidney. In the in vivo rat model of urolithiasis, the pulp extract reduced calcium oxalate (CaOX) crystal count in both kidney and urine. The pulp extract also increased the urinary pH and output and prevented the weight loss. Serum analysis showed elevation in creatinine clearance and reduction in urea and creatinine levels. Urinary analysis demonstrated that pulp extract restored altered phosphate, calcium, oxalate, and nitrate levels. In the in vivo rat model of diuresis; the pulp extract produced diuresis, reduced serum chloride levels, and elevated urinary sodium and chloride levels. In the in vitro crystallization experiment, pulp extract inhibited the aggregation phase. Seed extract failed to show any convincing results. GC-MS analysis revealed the presence of steroids and alkanes as the major constituents of pulp extract, which might be responsible for anti-urolithiasis activity; however, further studies are required for isolation and identification of active constituents. Current study validated the traditional uses of watermelon and demonstrated that pulp extract possessed significant anti-urolithiasis and diuretic activities.
- Keeps Your Heart Healthy – According to research, having a slice of watermelon every day can halt the accumulation of bad cholesterol, thereby preventing heart disease (1). Regular consumption of watermelon has also been linked to fewer fatty deposits inside the blood vessels. These heart-healthy properties of watermelon can be attributed to citrulline, a chemical found in the fruit. As per a Kentucky study, citrulline can have beneficial effects on atherosclerosis (2). Citrulline has also been found to reduce arterial stiffness in postmenopausal women (3).
- Helps Treat Inflammation – Another primary compound found in watermelons is lycopene, which has great benefits. In one American study, lycopene was found to exhibit anti-inflammatory properties (4). Amongst the different carotenoids, lycopene is considered the best (5). In fact, the beneficial effects of lycopene for inflammation are considered even better than beta-carotene, an important carotenoid (6).
- Keeps You Hydrated – Wondering what percentage of watermelon is water? As the name of the fruit implies, watermelon is 90% water, making it one of the best sources of hydration (7). It is far better than alcohol or caffeine in terms of being a diuretic. As it is a natural source, it increases urination without stressing the kidneys (8).
- Helps Combat Cancer – Lycopene gets the credit, again. According to a study, lycopene in watermelons has been found to reduce the extent of cancer insurgence (9). Lycopene is the pigment that renders watermelons their characteristic red color, and since it is a powerful antioxidant, it prevents the onset of certain cancers (10). A two-cup serving of watermelon contains about 20 milligrams of lycopene, which battles free radicals and protects against numerous types of cancer (11). According to a Chicago study, lycopene exhibits chemopreventive properties, especially in prostate cancer cells (12). Lycopene has also been found useful in the treatment of HPV (human papillomavirus) infection, which might otherwise lead to uterine cancer (13).
- Might Help Relieve Muscle Soreness – If your sore muscles trouble you after a workout, watermelon might hold the key. The fruit is packed with electrolytes and the amino acid citrulline, which help soothe sore muscles after a heavy workout (14). And as per an Iranian study, citrulline in watermelons can help reduce muscle fatigue (15). Citrulline has also been externally added to watermelon juice to check its effects, and it has been proven that it is only the naturally occurring citrulline in watermelons that have any effect on muscle soreness (16). Citrulline has been found to accelerate the process of lactic acid removal, thereby relieving muscle soreness (17). Drinking watermelon juice can also help your muscles receive more oxygen – this helps them recover faster (18).
- Aids Digestion – Watermelon, as we have seen, contains huge amounts of water, and hence can aid digestion. It also contains fiber, thus promoting digestion and preventing constipation.
- Is Good For Pregnant Women – Watermelon eases heartburn, a common condition during pregnancy. It also helps alleviate morning sickness (19). The minerals in the fruit can help prevent third-trimester muscle cramps.
- Might Prevent Macular Degeneration – As we have seen, watermelons are an excellent source of lycopene – which was found to reduce the risk of macular degenerative disease (20). According to Mayo Clinic, lycopene has been suggested as a potential treatment for eye disorders like macular degeneration (although further studies are required in this regard) (21). Antioxidants are essential for eye health as they offer protection against free radicals. The effect of free radicals can be scary – they might lead to the deterioration of the eye lens, and can even cause blindness. Lycopene, being a potent antioxidant, prevents this (22).
- Prevents Asthma – Hail lycopene, again! Being one of the key antioxidants, lycopene helps with the body’s reaction to cold and flu. And what’s more interesting is this antioxidant has been found to reduce asthma flare-ups in children (23). Watermelon also allows people who have asthma to breathe properly, without them having to take each breath in panic (24). A study conducted on 17 asthmatic adults showed that lycopene might have a therapeutic effect on the disease (25). As per a report, adequate intake of lycopene and vitamin A could be beneficial for asthmatic patients (26).
- Controls Blood Pressure – Watermelon is the richest natural source of citrulline. And according to a study published by the Florida State University, citrulline is closely related to arginine, which is an amino acid essential for maintaining healthy blood pressure (27). Another study that had volunteers consuming concentrated watermelon juice found increased levels of arginine in them, which was likely to have been converted from citrulline (28). Watermelon also is a good source of potassium, the nutrient that is known to lower high blood pressure (29). Potassium is also an electrolyte that regulates blood pressure during physical exercise (30).
- Improves Skin And Hair Health – Watermelon is a good source of vitamin C, the nutrient that is essential for collagen synthesis (31). Collagen keeps your skin supple and strengthens your hair. According to a German study, lycopene and beta-carotene can protect the skin against sunburn (32). Beta-carotene is also known to prevent certain skin conditions like psoriasis and vitiligo (33). The vitamin A in watermelon is another important nutrient that contributes to skin health – it repairs and creates new skin cells. Without the nutrient, your skin would appear dull and flaky.
- Improves Bone Health – Vitamin C plays a major role here as the nutrient is good for the bones and aids wound healing (34). A Switzerland study suggests that lycopene supplementation can prevent osteoporosis and bone fractures (35). Vitamin A in watermelons has been linked to bone growth (36).
- Aids Weight Loss – One of the best watermelon health benefits is that it aids in healthy weight loss too. Yes, given its high water content, watermelon can fill you up for fewer calories (37). Water has also been found to speed up metabolism and flush out toxins and fats, which eventually might contribute to weight loss (38). One wedge of watermelon has just about 86 calories, less than 1 gram of fat, and no cholesterol. It provides 22 grams of carbs and 5% of your daily fiber requirement, making it a great food for fat burning and weight loss (39).
- Offers Kidney Support – Though watermelons could be good sources of potassium, the percentage is lower compared to most other foods. This is why it can be good for people suffering from chronic kidney disease (40). However, in some individuals suffering from chronic kidney disease, the kidneys may not be able to remove the excess potassium from the blood. This can raise potassium levels in the blood and lead to complications.
- Strengthens Immunity – Watermelon, being rich in vitamin C, strengthens the body’s immune system (41). The fruit also contains vitamin B6 that helps the immune system produce antibodies (42). The vitamin also aids in the formation of red blood cells. The fruit has vitamin A that regulates the immune system and protects it from infections (43).
- Helps Treat Diabetes – What is the link between watermelon and diabetes? Although watermelon has a high glycemic index, it has a lower glycemic load (the value by which a particular food will raise an individual’s blood glucose levels), and hence is good for diabetics. In a Nigerian study, watermelon was found to have anti-diabetic properties (44). Another study showed the beneficial effects of watermelon pomace juice – it increases the mass of brown adipose tissue and reduces excess white fat mass, which eventually helps treat diabetes (45). However, take your doctor’s advice in this regard – as certain small-scale studies have stated otherwise.
- Can Promote Sexual Health – The amino acid citrulline in watermelon relaxes and dilates the blood vessels and might aid in the treatment of erectile dysfunction (46). Citrulline is converted into arginine, which is a precursor for nitric oxide that helps in blood vessel dilation. According to an Italian study, oral citrulline supplementation has been found to improve erection hardness in men suffering from mild erectile dysfunction (47). Watermelon can also act as a natural viagra (48). The ingredients in watermelon, especially the phytonutrients, react with the human body and trigger such reactions.
- Can Prevent Cell Damage – Watermelon, being rich in lycopene, protects the cells from damage associated with heart disease. Lycopene fights the free radicals and prevents cell damage (49).
- Prevents Heat Stroke – Given its high water content, watermelon is known to prevent hyperthermia (50). It has a lot of significance in Chinese medicine as well – watermelon is one of the few fruits that clears heat and relieves irritability and thirst. It also relieves heat exhaustion, for which the outermost layer of the rind is used (51).
- Promotes Healthy Gums – The vitamin C in watermelon keeps the capillaries and gums healthy (52). The deficiency of vitamin C can cause bleeding gums and gingivitis (inflammation of the gums), and watermelon can prevent these conditions (53). The vitamin C in watermelon can also kill the bacteria in the mouth that might otherwise lead to gum disease and other gum infections.
- Boosts Energy Levels – Watermelon is a good source of vitamin B, which is responsible for energy production in your body (54). The fruit is low in calories and high in energy, and it can help you stay active for the better part of the day (55). Another reason you must have a watermelon to stay at the top of your game is potassium. Potassium is an electrolyte that keeps you from feeling tired after an exhausting day (56). Watermelon, as we have seen, is not just replete with water – but with great benefits as well. You will be surprised to know interesting facts about watermelon
- Protection Against Diabetes – When you consume watermelon, your kidneys convert one amino acid, L-citrulline, into another amino acid, L-arginine. The one-two punch of these two amino acids has many health benefits, not the least of which is protection against the development of diabetes. Studies show that L-arginine supplementation is beneficial in regulating glucose metabolism and insulin sensitivity. While you might not be able to get as much of the amino acid from watermelon as you might through supplementation, it is noting that foods that contain this compound can be a beneficial part of a diet designed to fight against diabetes.
- L-citrulline for Recovery – The next time you reach for a post work out drink that contains L-citrulline, reach for a wedge of watermelon instead. The restorative amino acid helps accelerate the rate of lactic acid removal from your muscles, giving you a quicker recovery time after your tough workout. Watermelon also has a high water content, so it will help you rehydrate in one of the most delicious ways possible.
- Heart Healthy Summertime Treat – Lycopene is responsible for the pinkish-red hue of watermelons. It is also responsible for every shade of red tomato from the palest pink to the most garnet like reds. Did you know that there is more lycopene in watermelon than tomatoes? Almost one and half times more. Lycopene has been proven to reduce cholesterol levels and the occurrence of cardiovascular disease in people who either take supplements or consume lycopene-rich foods on a regular basis.
- Reduction of Severity and Frequency of Asthma Attacks – Interesting new research is pointing towards a connection between vitamin C and asthma. Current research indicates that low levels of vitamin C correlate to an increase of asthma attacks, while higher levels of vitamin C are tied to a reduction in asthma symptoms. Eat more vitamin C rich foods, such as watermelon which has nearly 40% of the recommended daily intake of vitamin C in just one thick, juicy wedge.
- Helps You Lose Weight Faster – If you are trying to lose weight, you know that we all have those triggers that send us down the road of temptation, longing after something that we know isn’t the healthiest option. For many people, that thing is sweets. It isn’t just about the sweetness of sugary treats, but also about the texture and the mouthfeel. This is one reason why a strawberry might not satisfy you mentally in the same way as cheesecake. However, watermelon brings something new to the dessert table. The texture of watermelon is almost like that of a dessert that melts in your mouth. It can be sliced and presented on a plate just like a piece of cake or pie. Watermelon satisfies the emotional craving as well as the physical one.
- The Potassium in Watermelon Protects Nerve Function – Watermelon is rich in potassium, which helps to regulate nerve function by facilitating the passage of electrical impulses and messages. Too little potassium can cause lack of nerve function, numbness, and tingling. If you suffer from nighttime leg cramps, a potassium deficiency might also be the cause. Steer clear from these unpleasant side effects by enjoying a cup of watermelon which has approximately 170 mg of potassium.
- Eradicate Inflammation – Chronic, systemic inflammation is known to be a precursor to many of the serious diseases that we suffer from today including diabetes, heart disease, fibromyalgia, and even cancer. Because inflammation can have such a detrimental effect on the body, it is necessary to take steps to fight it in every possible way. One of the most effective means of fighting inflammation is through dietary sources. Watermelon contains the amino acids L-arginine and L-citrulline, two known powerful anti-inflammatory agents. Keeping cool with watermelon can help cool down inflammation as well.[ 60]
- Helps Balance Your pH – The foods we eat and the drinks we enjoy all fall somewhere along the pH scale. Some are considered acidic, while others are considered basic or alkaline. The human body regulates itself at a very specific 7.4. On a scale of 0-14, the lower the number the more acidic it is. As you can see, the body falls just on the side of being slightly more alkaline. The problem is that the average diet filled with saturated fats, sugars, and processed foods tends to be more acidic, which can throw off the balance of the body’s pH. Major pH imbalances are rare and serious, but minor shifts into the acidic zone can leave you feeling off. Watermelon is an alkaline food, which helps to neutralize the acidic components in our diets and thereby helping our bodies maintain a proper pH level.
- Prevents Heat Exhaustion and Heat Stroke – Every summer, thousands fall victim to heat stroke, with more than two hundred people died from the condition annually in the united states. Heat stroke is not just about being a little overheated. It is a serious condition that requires medical attention. Watermelon, which is mostly water and contains electrolytes can help negate the effects of the heat in the summertime and potentially reduce the risk of suffering heat stroke. If someone looks like they aren’t handling the heat well, offer them some watermelon. If they appear to be suffering from the symptoms of heat stroke, seek medical attention immediately.
- Reduces Your Risk of Developing Periodontal Disease – Periodontal disease is a condition that is suspected of affecting anywhere from 20-25% of the population. Periodontal disease can lead to tooth loss, infection and has even been connected to other health conditions such as heart disease. Proper oral hygiene and regular dental checkups are your primary tools against periodontal disease, but adequate amounts of vitamin C in the diet has been shown to inhibit the development or worsening of the disease. Watermelon is a great source of vitamin C. Sink those teeth into a slice of watermelon to keep your smile healthy and bright.
- Digestive Aid – So many of us go through the day not taking the time to drink enough water so that we are in a perpetual state of mild dehydration. You might not really notice it because you are not necessarily thirsty, however, you might suffer from mild, chronic health side effects like headaches, fatigue, and uncomfortable constipation.