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. Also, the fruit's concentrations of citrulline and arginine are good for your heart. Arginine can help improve blood flow and may help reduce the accumulation of excess fat. A study published in the American Journal of Hypertension found that watermelon extracts helped reduce hypertension and lower blood pressure in obese adults.
2. 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.
"Watermelons are the perfect example of a food that can help you stay hydrated," said Jarzabkowski. Their water content can help keep you hydrated, and their juice is full of good electrolytes. This can even help prevent heat stroke.
The watermelon contains fiber, which encourages a healthy digestive tract and helps keep you regular.
5. Skin and hair benefits
Vitamin A is stellar for your skin, and just a cup of watermelon contains nearly one-quarter of your daily recommended 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.
6. Muscle soreness
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.
7. Cancer prevention
Like other fruits and vegetables, watermelons may be helpful in reducing the risk of cancer through their antioxidant properties. Lycopene in particular has been linked to reducing prostate cancer cell proliferation, according to the National Cancer Institute.
8. 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.
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."