During the summer months, there’s nothing quite like freshly cut watermelon. This juicy, vibrant fruit is packed with vitamins A, B1, B6, and C. It’s also a rich source of the phytochemical lycopene and the amino acid L-citrulline. Watermelon even contains small amounts of minerals such as potassium and magnesium. It is made up of 92% water, is low in sodium, and is free of fat and cholesterol. One cup is equal to less than 40 calories. Moreover, the fiber in watermelon will keep your digestive tract healthy and happy.1 What’s not to love?
The Magic Ingredients Of Watermelon
Watermelon gets its attractive red color from lycopene, a pigment that is also present in tomatoes, guavas, grapefruits, and apricots. Historically, tomatoes have always been considered one of the richest sources of lycopene. Research now points at watermelon as a potent source, too. However, what makes watermelon special is lycopene’s availability. Unlike tomatoes, watermelon doesn’t need to be cooked to reap the benefits of lycopene. To top it off, red-fleshed watermelon has about 40% more lycopene than raw tomatoes.2Make sure you eat ripe, pink watermelons to get maximum benefit.
The amino acid L-citrulline is another phytonutrient in watermelon. In the kidneys, it converts to L-arginine. And as arginine levels increase, production of nitric oxide amplifies. The latter is essential for vasodilation (widening of blood vessels.) Thanks to this process, citrulline plays a major role in heart health by promoting blood flow and improving circulation. This action also encourages the liver to eliminate ammonia, lowers blood pressure, and helps sexual dysfunction in men.3
Studies have also shown that watermelon rind, long considered an agricultural waste, is also a rich source of natural citrulline. It might be an even richer source than the flesh.4However, since the rind is not commonly eaten, scientists are trying to breed new varieties of watermelon that have more citrulline in the flesh.5
The Wonders Of Watermelon
1. Cancer Prevention
Lycopene’s strong antioxidant properties have made it a rock star in the health world. This means that it has the potential to fight the formation of free radicals that cause cancer. Many studies speculate that regular lycopene consumption prevents cancers of the breast, lungs, throat, prostate, bladder, ovaries, pancreas, and colon. One study notes that high lycopene consumption reduced the risk of aggressive cancer by 44% in men and the risk of prostate cancer by 25%.6
In another study, breast cancer cells were treated with watermelon juice. Next, they were incubated in 5% carbon dioxide at 37 degrees C for six days. Other samples were similarly treated with pure lycopene and extracted lycopene. The juice samples were found to be most effective in inhibiting the growth of cancer cells.7
2. Improved Heart Health
When the body generates more oxidant compounds than our antioxidant defense mechanism can handle, tissue damage called oxidative stress occurs. Unfortunately, elevated oxidative stress is the primary cause of ailments like diabetes and cardiovascular diseases. This is where watermelons fit in. Because of its antioxidant properties, lycopene extract from watermelons can significantly reduce oxidative stress and blood glucose levels. And since patients with hyperglycemia or high blood sugar are extremely prone to heart disease, watermelons may provide protection against heart disease, too.8
A study conducted on 14 obese patients (around 58 years old) with hypertension and pre-hypertension symptoms showed that a six-week intake of watermelon extract noticeably reduced ankle blood pressure levels. This could be a possible reflection of improved arterial flow. In this case, the amino acids L-citrulline and L-arginine were the main highlights.9
3. Immune System Boost
It’s not uncommon to reach for an orange when you have the sniffles. But if you’re looking for a change, you’re in luck. Two cups of watermelon provide 30% of your daily vitamin C recommendation, giving you a reason to reach for those watermelon slices, too.10
Vitamin B6, another nutritional component of watermelons, can also enhance your immune system. It boosts the production of lymphocytes (white blood cells).11Lymphocytes produce antibodies that attack invading viruses, bacteria, and toxins.12
4. Excellent Skin And Hair
Vitamins C and A in watermelon double as healthy fuel for hair and skin. Specifically, vitamin C plays a key role in collagen production.13This protein prevents wrinkles and protects your skin from sun damage. Furthermore, it acts as a tonic for your hair’s growth and volume. As for vitamin A? It can keep your skin supple by preventing dryness and scaling. It doesn’t hurt that vitamin A is imperative for good eye health, too.
5. Relief For Sore Muscles
The citrulline in watermelon can relieve sore muscles by relaxing blood vessels and improving circulation. In a study that tested the potential of watermelon juice as a health drink, seven athletes were given natural watermelon juice, enriched watermelon juice, and a placebo before exercise. Both watermelon juices reduced muscle soreness and recovery heart rate the very next day.14
6. Natural Viagra
Citrulline doesn’t just improve blood flow to your heart. It can also treat (and prevent) erectile dysfunction. No wonder watermelon is sometimes referred to as a “natural Viagra.” The citrulline–arginine–nitric oxide path promotes relaxation of the blood vessel muscles, increasing blood flow. This happens to be the same basic principle of Viagra. And while impotence is caused by many physiological and psychological factors, the higher amounts of nitric oxide could also improve blood flow without side effects.15Not convinced? In an Italian study, oral supplementation of L-citrulline was found to be effective in treating mild cases of erectile dysfunction. Hopefully, further research will continue to provide more concrete proof.16
Eat With Care
The benefits of eating watermelons cannot be denied. However, as with all good things, you can’t afford to overdo it. People with kidney disease and diabetics should exercise extra caution. As a diuretic, watermelon can interfere with water retention in those with kidney diseases.17
Additionally, when the kidneys aren’t functioning properly, potassium from food tends to accumulate. This can lead to a condition known as hyperkalemia. And since high potassium levels can be detrimental, this is definitely something to watch out for. Undesirable symptoms include irregular heart beats, reduced muscle control, and a complete collapse of the heart.18
Watermelon also has a high glycemic index, making it easily digestible. Unfortunately, this can cause glucose levels to quickly shoot up. Yet, limited consumption in a diabetic diet earns a thumbs up from the American Diabetes Association.19
It’s vital to keep in mind that lycopene in excess can also lead to gastrointestinal trouble. Consuming too much can cause bloating, nausea, vomiting, and diarrhea. How much is too much? Well, there is no authoritative study or source that firmly states a safe daily dose of lycopene. However, it is widely accepted that 30 mg per day of lycopene is a safe quantity. A cup and a half of watermelon has about 9 to 13 mg of lycopene. Consequently, two to three cups of watermelon per day is a safe bet.20At the end of the day, you must remember – moderation is everything.