Healthy rice made easy

Key points

• Obesity increases the risk of many other “lifestyle” diseases including diabetes, one of the leading causes of death worldwide.
• Dietary intervention can be an important strategy to reduce the incidence these diseases and eating foods with a low GI can help prevent and manage diabetes.
• Australian researchers have developed a rapid method for ranking the genetic properties in rice that convert starch to sugar during digestion allowing them to identify what drives glycemic index (GI).
• This screening tool will be used to assist in the development of new low GI varieties of rice that will give consumers access to a healthier product.
• New low GI rice varieties will not only deliver health benefits to consumers but also provide Australian rice growers with a high value product.
• The research was a joint project by Charles Sturt University and the NSW Department of Primary Industries (DPI), supported by AgriFutures Rice Program.

Not all carbohydrates are equal: Making rice healthier

Half of the world is overweight and here in Australia, that percentage is even higher, 65%, and 30% of us are categorised as obese. And it is not just about carrying some extra weight, obesity increases the risk of many other “lifestyle” diseases including diabetes, one of the leading causes of death worldwide.

Dietary intervention can be an important strategy to reduce the incidence these diseases and eating foods with a low GI can help prevent and manage diabetes. GI is a relative ranking of carbohydrates according to how they affect blood glucose levels. Carbohydrates with a low GI value are more slowly digested and absorbed providing sustained energy. Foods with a low GI are thought to be associated with health benefits that include better weight management and lower levels of diabetes.

Unfortunately, many commercial rice varieties are digested quickly and have a high GI, which makes them unsuitable for consumers who want (and/or need to) to better manage their glycaemic load. If rice with a lower GI is widely adopted, there may be an associated decrease in ‘lifestyle’ diseases.

Professor Chris Blanchard, Director of the Australian Research Council Industrial Transformation Training Centre for Functional Grains (Functional Grains Centre) at Charles Sturt University led a research project to develop a rapid screening method to identify genotypes that produce rice with lower digestibility rates. He said that for the Australian rice industry to thrive it needs high value, health-promoting rice varieties.

“We wanted to develop a tool that could efficiently test the health properties of rice. Local and international markets are demanding healthier options for a range of foods – including rice. We needed a tool to identify these properties, quickly and efficiently, so that rice breeders can select for these properties when developing new varieties.”

Professor Blanchard said, “Market intelligence tells us that while incidence of diabetes around the world is increasing, consumers still want to eat what they’ve always eaten. So, if we improve the health benefits of rice then that’s a win-win.”

Delivering value to Australian ricegrowers

Professor Blanchard said, “Now we have a tool to measure the contribution to health that our new rice varieties can have. It gives us the ability to work out the other drivers of GI and change the GI of rice, driving up the value of the product.

“Value is really important to the Australian rice industry so while undertaking this research we were also thinking about maximising efficiency for growers in terms of dollars per megalitre [of water].”

Professor Blanchard explained, “Traditionally when we develop rice varieties in Australia there has been a big focus on high yielding, disease resistant varieties. Now we are paying more attention to the quality of the rice variety, its health properties and its potential profitability.”

Change driven by consumer demand

Lucinda Staley, Manager, Research at AgriFutures Australia said consumer demand for heathier products is driving change in food choices worldwide and this trend is only expected to accelerate.

“We’ve now got the opportunity to change rice, an established and popular staple food product around the world, to make it even healthier.”

“The new screening tool opens up the opportunity for Australia to develop healthy rice varieties that are lower GI and high value, providing our rice growers with greater returns and giving consumers around the world greater health benefits.”

The research report, Next-generation healthy rice, describes how the automated rapid screening method was developed and has been validated by screening more than 200 diverse genetic characteristics in rice for their digestibility. In addition, extensive training with NSW DPI and the Australian Rice Partnership, has ensured the method is ready for adoption when assessing and developing new rice varieties.

Lowering the GI of existing rice varieties

Recommendations from the research include the urgent implementation of the newly developed digestibility screening tool in the Australian rice breeding program. Research is now underway to lower the GI of existing rice varieties using the tool.

This research was funded by AgriFutures Australia’s Rice Program which aims to improve the profitability and sustainability of the Australian rice industry with a key focus on water use efficiency and varieties that deliver increased yield and improved eating quality. The project also demonstrated the benefit of funding collaborative projects between Charles Sturt University and NSW DPI. The complementary skills of these two organisations contributed to the success of the project. The project also interacted with several other Australian Research Council (ARC)-funded Functional Grains projects, which resulted in enhanced outcomes for all projects.

View the final report and register to receive updates from the AgriFutures Rice Program at agrifutures.com.au/rice.