Who doesn’t love a cold, juicy slice of watermelon on a hot summer day?Watermelon has always been a healthy choice for a sweet treat – packed with fiber, electrolytes, nutrients including vitamins A, B6, C, potassium, and lycopene, a powerful antioxidant.
Now there may be even more of a reason to love it – a small pilot study by food scientists at Florida State University suggests that eating watermelon may ward off high blood pressure.
The researchers, led by FSU Assistant Professor Arturo Figueroa and Professor Bahram H. Arjmandi, gave a group of nine middle-aged men and women all suffering from pre-hypertension (meaning they had elevated blood pressure but not yet full blown hypertension) six grams of watermelon extract a day for six weeks. As the researchers described in the American Journal of Hypertension, the watermelon extract not only lowered each one of their subjects’ blood pressure, but it improved the function of their arteries.
“Given the encouraging evidence generated by this preliminary study, we hope to continue the research and include a much larger group of participants in the next round,” Figueroa said.
But why watermelon in particular?
“Watermelon is the richest edible natural source of L-citrulline, which is closely related to L-arginine, the amino acid required for the formation of nitric oxide essential to the regulation of vascular tone and healthy blood pressure,” Figueroa explained. Taking a strict L-arginine dietary supplement isn’t an option for many patients with hypertension because it can cause gastrointestinal problems. The researchers reported there were no adverse side effects in the new study.
“Cardiovascular disease (CVD) continues to be the leading cause of death in the United States,” Arjmandi pointed out. “Generally, Americans have been more concerned about their blood cholesterol levels and dietary cholesterol intakes rather than their overall cardiovascular health risk factors leading to CVD, such as obesity and vascular dysfunction characterized by arterial stiffening and thickness –– issues that functional foods such as watermelon can help to mitigate.”
The downside of the study, however, is that you’d need to consume about four pounds a day — that’s about one and a half watermelons — to gain the benefit, which even Figueroa admits has no bearing on reality. That’s why his subjects took the fruit extract — in a dose about equivalent to a teaspoonful a day.
“Individuals with increased blood pressure and arterial stiffness –– especially those who are older and those with chronic diseases such as type 2 diabetes –– would benefit from L-citrulline in either the synthetic or natural (watermelon) form,” Figueroa said. “The optimal dose appears to be four to six grams a day.”
Approximately sixty percent of American adults are prehypertensive or hypertensive, according to the researchers. So although you may not be ready to replace your apple a day with four pounds of watermelon quite yet, the study shows great promise both as a preventive measure all on its own, as well as for use in combination with hypertension medication, which could allow patients to take smaller doses of their regular medicine.
Photo courtesy of Steven Depolo