Watermelon Health Benefits

Normally watermelons are considered to be just a cool fruit that is nice to eat during hot summer months. It’s also seen that it contains a large amount of water as one’s mouth is filled with sweet watery substance while eating a watermelon. Thus, it can be hardly known that this watery-looking fruit contains a surprising amount of nutrients. But it’s true.

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One may be surprised with the fact that a watermelon is richer in a highly esteemed carotenoid named lycopene than tomatoes. But it has been proved by studies that lycopene in an average red-fleshed watermelons is 4-5 mg per 100 grams (around 2/3 cup) while it’s 3-4 mg per 100 grams (around ½ cup) in tomatoes. What’s more, the bioavailability of lycopene in watermelon seems to be higher than that of red tomatoes.

This higher bioavailability is supposed to be because of the presence of cis-isomeric lycopene in watermelon, which is a more readily available form of lycopene.

While a watermelon may not seem to be a food with a high diversity, actually it’s far more diverse than anyone would imagine. It comes in a range of flesh colors including red, pink, orange and yellow, rind patters like striped and solid, sizes ranging from 5 to 30 pounds, shapes like round, oblong and oval, and nutrient patterns.

Recent research has shown its diversity in nutrient patterns. Particularly, vitamin C and total phenols (including total flavonoids) can significantly vary between varieties as well as between degrees of ripening. Thus, it’s not possible to tell the exact concentration of nutrients in watermelon based just on the variety or stage of ripening. But lycopene is an exception to this because its amount can be predicted from the variety of watermelon and its stage of ripening. Yellow- and orange-fleshed watermelons have less lycopene than that in red-fleshed varieties.

Also, the amount of lycopene increases even further in red-fleshed varieties when they are fully ripened. As red-fleshed varieties go on ripening, their flesh color goes on changing from white to pinkish white to pink to red, and with this color change, amount of lycopene goes on increasing. Thus if anyone wants the highest amount of lycopene from watermelon, they should choose fully-ripened red-fleshed watermelon.

However, it should be remembered that all varieties of watermelons contain nutrients, but their amount is optimal in the fully ripened stage; so, such fruits should be chosen if one wants to get full benefits of nutrients in watermelon.

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Health Benefits of Watermelon

Antioxidant Benefits

Watermelon contains a surprising diversity of phytonutrients which contributes to its antioxidant and anti-inflammatory properties. There are so many different types of phenolic phytonutrients in a watermelon, including flavonoids, carotenoids and triterpenoids. Among these, cucurbitacin E (a triterpenoid) and lycopene (a carotenoid) are extremely important from the research perspective as being highly responsible for watermelon’s anti-inflammatory and antioxidant properties. As mentioned earlier, red-fleshed watermelon has higher amount of lycopene than even red tomatoes and is higher in its bioavailability too.

Lycopene has been found to be beneficial in cardiovascular disease and studies have repeatedly found that it lowers the risk of the disease by scavenging reactive oxygen species (ROS) and lipid peroxyl radicals. Decrease in lycopene due to aging is also associated to age-related cardiovascular disease. Therefore, high amount of lycopene in red-fleshed watermelon provides antioxidant protection, especially as it relates to the cardiovascular system.

Cucurbitacin E is another important phytonutrient in watermelon that complements the activities of lycopene. It is a triterpenoid known to reduce unwanted inflammation by preventing the activity of the enzyme cyclooxygenase-2 (COX-2). However, it’s doesn’t seem to scavenge ROS (reactive oxygen species) as effectively as lycopene. However, it’s been found to effectively scavenge RNS (reactive nitrogen species). Thus due to the combined activity of these two phytonutrients, watermelon provides one with increased scavenging of oxygen as well as nitrogen radicals and reduce the risk of unwanted oxidative stress or chronic inflammation.

Cardiovascular Benefits

Regarding its cardiovascular benefits, watermelon contains a third nutrient in unusual amounts. This is amino acid citrulline. Although the amount of this nutrient may vary significantly among watermelons, a cup of fresh watermelon is expected to consist of 200 to 300 mg of citrulline. Citrulline is beneficial to one’s cardiovascular system through its role in a metabolic process called urea cycle. This cycle involves interconversion of three amino acids, viz. citrulline, arginine and ornithine.

During this process, an important cell-signaling molecule, nitric oxide (NO) is produced. NO has a key role in regulation of blood pressure because it has the capability of increasing the expansion of blood vessels, thereby lowering the pressure. Levels of NO also play a key role in determining the regulation of blood sugar levels. Because NO is directly formed from the conversion of arginine to citrulline, scientists are interested in the degree to which citrulline intake (through watermelon, for example) can affect the overall balance of arginine, citrulline, ornithine and NO in metabolism.

But in one recent study, participants were given 3-6 cups of watermelon juice every day for several weeks and it was found that there was a steady increase in the citrulline and arginine in their blood which shows that citrulline from the watermelon juice was converted to arginine and plenty of citrulline was left in the blood and thus watermelon juice increased the balance in this area of metabolism. This is an evidence that watermelon intake can reduce the risk of high blood pressure and diabetes type 2, especially caused by arginine deficiency.

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Anti-inflammatory Benefits

When it comes to the antioxidant benefits of watermelon, the vitamin C and beta-carotene contained in it are important. Watermelon is a very good source of vitamin C providing around 12 mg per cup. Thus two cups can provide one-third of the daily recommended intake of vitamin C. Similarly, watermelon is also a rich source of vitamin A, which is largely due to its beta-carotene content. Beta-carotene is particularly highest in red-fleshed watermelons, though amounts can differ greatly from 5 to 325 micrograms per 100 grams.

However, even in the lower half of this range, one can get valuable antioxidant benefits from watermelon’s beta-carotene content.

Beneficial in Cancer

Watermelon has been extensively studied in animals in various health areas, but notably in cancer risk. The research has often been focused on the types of cancer known as “aerodigestive cancers”. These include cancers of oral cavity (mouth), pharynx (passage that connects nose to mouth and throat), larynx (voice box) and esophagus (tube that connects mouth to stomach). However, this study is in its primary stages.

Hydration

Watermelon being rich in water content is definitely a great hydrating food. Its juice is rich in good electrolytes and can help prevent heat stroke.

Beneficial in Digestion

Since watermelon contains a lot of fiber it maintains a good health of gut and prevents constipation.

Helps in Muscle Soreness and Athletic Performance

Drinking watermelon juice before an intense exercise helps lower next-day muscle soreness and heart rate, according to a study published in the Journal of Agricultural and Food Chemistry in 2013. This beneficial property can be accredited to the amino acids arginine and citrulline in watermelon which improve circulation.

Another study published in the Journal of Applied Physiology in 2015 suggests that citrulline in watermelon may even improve athletic performance as there was an improved performance in the study participants with increased power production in high-intensity workout like sprinting and cycling.

Skin and Hair Benefits

Since watermelon is rich in vitamin A which encourages the building of collagen and elastin, which are essential for the health of skin and hair, watermelon intake promotes the health of skin and hair. Vitamin C in watermelon also promotes skin and hair health.

Health Benefits of Watermelon Seeds

Watermelon seeds are increasingly being interesting for researchers for their anti-inflammatory and antioxidant properties. These seeds are just as nutrient-rich as the flesh of the fruit is, or even more. For example, they contain carotenoids, flavonoids, phenolic acids, saponins, carbohydrates, proteins and fats.

Watermelon Nutrition Profile - 1 cup (152gm)

Note: DRI/DV [Daily Recommended Intake/Daily Value]

- Protein: 0.93gm (DRI/DV 2%)

- Carbohydrates: 11.48gm (DRI/DV 5%)

- Fat: 0.23gm (DRI/DV 0%)

- Fiber: 0.61gm (DRI/DV 2%)

- Vitamin A: 864.88 IU

- Vitamin B1 (Thiamine): 0.05mg (DRI/DV 4%)

- Vitamin B2 (Riboflavin): 0.03mg (DRI/DV 2%)

- Vitamin B3 (Niacin): 0.27mg (DRI/DV 2%)

- Vitamin B5 (Pantothenic Acid): 0.34mg (DRI/DV 7%)

- Vitamin B6 (Pyridoxine): 0.07mg (DRI/DV 4%)

- Vitamin B7 (Biotin): 1.52mcg (DRI/DV 5%)

- Vitamin B9 (Folate): 4.56mcg (DRI/DV 1%)

- Vitamin C: 12.31mg (DRI/DV 16%)

- Vitamin E: 0.08mg (DRI/DV 1%)

- Choline: 6.23mg (DRI/DV 1%)

- Boron: 142.50mcg

- Calcium: 10.64mg (DRI/DV 1%)

- Copper: 0.06mg (DRI/DV 7%)

- Iron: 0.36mg (DRI/DV 2%)

- Magnesium: 15.20mg (DRI/DV 4%)

- Manganese: 0.06mg (DRI/DV 3%)

- Phosphorus: 16.72mg (DRI/DV 2%)

- Potassium: 170.24mg (DRI/DV 4%)

- Selenium: 0.61mcg (DRI/DV 1%)

- Sodium: 1.52mg (DRI/DV 0%)

- Zinc: 0.15mg (DRI/DV 1%)

- Calories: 45.60 (DRI/DV 3%)


Risks

Eating watermelon in reasonable amounts don’t cause any harm. However, eating it too much can cause problems due to excess lycopene or potassium. Intake of more than 30 mg of lycopene every day can cause nausea, indigestion, diarrhea and bloating.

Those who have serious hyperkalemia i.e. excessive levels of potassium in their blood, should better avoid more than one cup of watermelon a day, which contains less than 140 mg of potassium. Hyperkalemia can cause irregular heartbeats and other heart-related problems, and also reduced muscle control.

For those who are looking for reducing weight, watermelon can be tempting because it’s water-laden and make one feel full; however, these people should avoid extremes.

Also excessive consumption of watermelon can cause rise in sugar levels.

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