Want the Viagra effect without taking a pill? Try eating a watermelon

Eating fresh watermelon could help men pep up their love lives, scientists said yesterday.

The fruit has a similar effect to taking Viagra, the nutritionists claim.

But don't get too excited. You'd have to eat at least six slices to have the same effect as one Viagra tablet, and it's not as 'organ-specific' as the impotence drug.

There's another downside too. 'The problem you have when you eat a lot of watermelon is you tend to run to  the bathroom more," said U.S. Department of Agriculture researcher Penelope  Perkins-Veazie.

Watermelons contain an ingredient called citrulline that can trigger production  of a compound that helps relax the body's blood vessels, similar to what  happens when a man takes Viagra.

Found in the flesh and rind of watermelons, citrulline reacts with the body's enzymes when consumed in large quantities and is changed into arginine, an amino acid that benefits the heart and the circulatory and immune systems.

'Arginine boosts nitric oxide, which relaxes blood vessels, the same basic effect that Viagra has, to treat erectile dysfunction and maybe even prevent  it," said Bhimu Patil,  director of Texas A&M University's Fruit and Vegetable  Improvement Centre.

"Watermelon may not be as organ-specific as Viagra, but it's a great way to relax blood vessels without any drug side effects."

Todd Wehner, who studies watermelon breeding at North Carolina State University, said anyone taking Viagra shouldn't expect the same result from watermelon.

"It sounds like it would be an effect that would be interesting but not a substitute for any medical treatment," he said.

The nitric oxide can also help with angina, high blood pressure and other  cardiovascular problems, according to the Texas study, which was paid for by  the U.S. Department of Agriculture.

More citrulline - about 60 percent - is found in watermelon rind than in the  flesh,
Citrulline is found in all colours of watermelon and is highest in the  yellow-fleshed types.

Apart from the added toilet breaks, another problem is the amount of sugar  eating that much watermelon would spill into the bloodstream - a jolt that  could cause cramping, said Perkins-Veazie.

Patil said he would like to do future studies on how to reduce the sugar content in watermelon.

The relationship between citrulline and arginine might also prove helpful to those who are obese or suffer from type-2 diabetes.

The beneficial effects -  among them the ability to relax blood vessels, much like Viagra does - are just  beginning to be revealed in research.

Citrulline is present in other curcubits, like cucumbers and cantaloupe, at  very low levels, and in the milk protein casein.

The highest concentrations of citrulline are found in walnut seedlings,
"But they're bitter and most people don't want to eat them," said  Perkins-Veazie.