SciDev.Net

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[COLOMBO] Sri Lanka's traditional brown rice varieties are rich in a group of chemicals that could aid diabetes control, new research shows.

Scientists have found that bran — the outer covering of brown rice grains — contains chemicals that inhibit the enzyme responsible for the breakdown of complex sugars into glucose, and thus reduces the amount of sugar available to the body.

The scientists, from the Industrial Technology Institute (ITI) of Sri Lanka, Colombo, studied 23 traditional rice varieties between March 2008 and May 2009.

They found that brown rice inhibited the enzyme more than white rice. Brown varieties inhibited the enzyme from around 47 to 92 per cent, while white rice inhibited it by 14 to 32 per cent.

An additional benefit of brown rice, say the researchers, is that it reduces the frequency of a process called 'protein glycation' in which sugar molecules randomly attach themselves to proteins.

The process can cause side effects in diabetics such as retina damage — which eventually leads to blindness — and kidney disease, says Sirimal Premakumara, a senior scientist at ITI who co-ordinated the research. These occur in up to 80 per cent of patients who have had diabetes for ten years or more.

Kanchana Abeysekera, a PhD student at ITI who conducted the studies, told SciDev.Net that traditional rice varieties are being neglected in commercial rice cultivation because of their low yield.

Premakumara says the team now plans to study the potential nutritional value and health benefits of such rice.

Sagarika Ekanayake, a biochemist at the University of Sri Jayewardenepura, says that scientists need to conduct more studies to find a way to tap the benefits of brown rice — such as breeding rice crops with the useful traits or using rice bran as a food additive.

The findings are reported in the September 2009 issue of Chemistry in Ceylon and were presented at an annual meeting of the Colombo-based Institute of Biology last month (25 September).