(NaturalNews) New research suggests that watermelon may produce effects in the body similar to that of Viagra, perhaps pointing the way to a natural remedy for men suffering from erectile dysfunction, says Bhimu Patil of Texas A&M University.
Research conducted by Patil and others has recently revealed that the flesh of watermelon contains higher levels of the amino acid citrulline than researchers had thought. Until then, most of the citrulline was believed to reside in the inedible rind of the fruit.
"We have known that watermelon has citrulline," Patil said, "[but] watermelon has more citrulline in the edible part than previously believed."
This is significant because the body converts citrulline into arginine, another amino acid that functions as a precursor to nitric oxide. Nitric oxide, in turn, plays a critical role in the dilation of blood vessels and the process of penile erection.
The drug Viagra functions primarily by targeting the nitric oxide signaling pathway in the penis.
Patil hopes that other researchers will begin to directly study watermelon's effects on erection. But some are skeptical.
Just because nitric oxide is required for an erection, "that doesn't mean eating something that is rich in citrulline will make enough arginine that it will lead to better penile erections," said Irwin Goldstein, editor-in-chief of The Journal of Sexual Medicine and a former consultant for companies that make erectile dysfunction drugs.
"The vast majority of Americans produce enough arginine," he said. "Men with erectile dysfunction are not deficient in arginine."
Patil acknowledges that he doesn't know how much watermelon a man would need to eat to have an effect. Knowing that a four-ounce serving of watermelon contains approximately 150 milligrams of citrulline does not tell researchers what effects that much citrulline will have in the body, he said.
He did note that in a 2007 study, participants were able to increase their arginine levels 11 percent in three weeks by drinking three eight-ounce glasses of watermelon juice per day.