Watermelon Lowers Blood Pressure, Study Finds
By Catherine Donaldson-Evans Oct 14th 2010 11:37AM
Categories: News
Watermelon isn't just a refreshing, warm-weather fruit and a staple of summer picnics. It also has healing benefits when it comes to high blood pressure, a new study shows.
Researchers at Florida State University found that a daily dose of watermelon extract lowered blood pressure and improved the function of the arteries.
The authors attributed the benefits to an amino acid in the fruit called L-citrulline, which converts to another amino acid called L-arginine in the body.
L-arginine is crucial for the formation of nitric oxide, "which relaxes the smooth muscles in the arteries and opens the arteries," study lead author Arturo Figueroa, an assistant professor in the department of nutrition, food and exercise science, told AOL Health. "That decreases the blood pressure."
Watermelon is the richest natural source of L-citrulline that is edible, he said.
Figueroa and his co-author Professor Bahram H. Arjmandi gave nine prehypertensive participants -- five women and four men ages 51 to 57 -- four grams of watermelon extract a day for six weeks. The extract was in the form of a powder that they mixed with water, according to Figueroa.
Prehypertension is the precursor to hypertension, or high blood pressure, which is one of the main risk factors for strokes and heart attacks. About 60 percent of adults in the United States are prehypertensive or hypertensive.
By the end of the study, published in the American Journal of Hypertension, the aortic blood pressure had been reduced in all nine of the subjects and their arterial functions had improved.
"The decreases were significant and were [similar to] the decrease that is found with medication," Figueroa said.
Figueroa said taking L-arginine alone has unpleasant side effects in many who suffer from high blood pressure, including nausea, diarrhea and other gastrointestinal problems. Watermelon, on the other hand, is easily digested.
The juicy, sweet fruit has other health benefits too, because it is packed with fiber; potassium; vitamins A, B6 and C; and lycopene, which is a potent antioxidant.
The downside of the findings, according to Figueroa, is that people would need to consume about four pounds of watermelon a day in order to experience a lowering of their blood pressure -- which he admitted isn't realistic. He advised taking a daily dose of the fruit's extract instead.
"You can eat watermelon in the natural form, but you will not get the dose and not produce these results," he told AOL Health
