Watermelon helps lower blood pressure

Eating watermelon may help to stave off high blood pressure, research suggests.

Amino acids found in watermelon extract were found to lower blood pressure in nine patients with hypertension, who were given the extract daily for six weeks.

People with prehypertension have raised blood pressure and have a higher risk of high blood pressure.

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 in the healthy regulation of blood pressure.

The patients, aged 51-57, were given six grams of L-citrulline extracted from watermelons.

Once in the body, the L-citrulline is converted into L-arginine. Many people with high blood pressure have problems taking L-arginine supplements because they can cause nausea, stomach upset and diarrhoea, said study leader Dr Arturo Figueroa, of Florida State University.

But, according to preliminary results, watermelon appears to be well tolerated. None of the patients experienced any side-effects.

As an added bonus, watermelon is also rich vitamin A, B6, C, fibre, potassium and lycopene, a powerful antioxidant.

The researchers also said taking L-citrulline supplements might reduce the amount of blood pressure drugs necessary to control the condition.

"Even better, it may prevent the progression from prehypertension to hypertension in the first place," Dr Figueroa said.

"These findings suggest that this 'functional food' has a vasodilatory effect, and one that may prevent prehypertension from progressing to full-blown hypertension, a major risk factor for heart attacks and strokes.

"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," he added.

The findings are published in the American Journal of Hypertension

This article was published on Fri 15 October 2010