Rice gene discovery opens doors for low-GI products

By Kacey Culliney

- Last updated on GMT

Researchers analysed 235 global rice grains for GI levels
Researchers analysed 235 global rice grains for GI levels

Related tags: Nutrition, Diabetes mellitus

Research has identified the key gene that determines the glycemic index (GI) of rice, opening up opportunities to develop low-GI rice and rice-based products to reduce the risk of type-2 diabetes, according to the researchers.

The glycemic index is a measure of the effects of carbohydrates in food on blood sugar levels and GI levels can vary from low (55 or less), medium (56-69) and high (70 and above).

Researchers from the International Rice Research Institute (IRRI) and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) identified the Waxy gene (Wx gene) as the major gene associated with GI variations in the rice samples.

GI levels were also found to be associated with amylose content (a starch component) with increasing amylose content leading to decreased values of GI.

The study Identification of a Major Genetic Determinany of Glycaemic Index in Rice ​analysed 235 global rice types to assess the GI levels. Natural and improved rice samples were analysed including indica and tropical and temperate japonica rices.

“Strong correlations between amylose content, the Waxy locus and GI were observed across all samples,”​ the researchers wrote.

“Until recently, the nutritional potential of rice has not been a target of rice improvement programmes, and while various countries would like to develop low-GI rices, the limitation lies in the selecting for the trait.”

“This paper reports the first large-scale phenotyping of this trait,”​ they said.

“Ultimately it provides a mechanism for breeding programmes to select for GI based on amylose content,”​ they continued.

This is “an important achievement that offers rice breeders the opportunity to develop varieties with different GI levels to meet consumer demands”,​ the researchers said.

“Future development of low-GI rice would also enable food manufacturers to develop new, low-GI food products based on rice,”​ they added.

Rice important in curbing chronic disease

The study marks part of a wider research commitment to investigate the role of rice in mitigating chronic diseases such as type-2 diabetes.

Dr Tony Bird, researcher at CSIRO Food Futures Flagship, said: “Low-GI diets can reduce the likelihood of developing type-2 diabetes, and are also useful for helping diabetics better manage their condition.”

The research is “good news”​ for diabetics or those at risk of diabetes looking to control their condition through diet, Bird said.

According to the International Diabetes Federation, incident rates of diabetes will rise from 240m in 2007 to 380m in 2025, with 60% coming from Asia.

Source: Rice
2011 issue, Volume 4, number 2, pages 66-74 
"Identification of a Major Genetic Determinant of Glycaemic Index in Rice"
Authors: M. A. Fitzgerald, S. Rahman, A. P. Resurreccion et al.

Related news

Show more

Related product

Related suppliers

1 comment

Rice

Posted by Amit,

It is good that ToI has brought out such an awareness filled article. It is requested that research study on usefulness/harmfulness of parboiled rice may please be taken up. Parboiled rice might be harmful as it is precooked and then de-husked. Nature never wanted rice to be consumed that way.

Report abuse

Follow us

Products

View more

Webinars

Food & Beverage Trailblazers

F&B Trailblazers Podcast