Estimated effects of white rice consumption and rice variety selection on incidence of type 2 diabetes in Cambodia

Objective: Rice consumption patterns are considered an important risk factor for diabetes in many countries. The present study aimed to model the impact of a shift in consumption of white rice from current to appropriately reduced levels and a shift in rice variety from one with a high glycaemic index to one with a low glycaemic index, on the burden of type 2 diabetes in Cambodia. Design: Prevent Plus software was used to model the impact of selected changes to white rice consumption on the burden of type 2 diabetes. Data used for modelling included: demographic projections, relative risk estimates for white rice consumption and diabetes, diabetes incidence, rice type and quantities consumed. The 10-year projections were based on different scenarios of changes in risk factors. Results: With no intervention, 10-year projections showed that total new diabetes cases will increase from 11 315 (9.1 per 10 000 person-years) for the year 2011 to 14 852 new cases (12.4 per 10 000 person-years) in 2020. However, this increase will be reduced by 27 % (average across 10 years) with a change in rice variety from Phka Rumdual to IR66 and by 26 % (average across 10 years) with a 25 % reduction in quantity from current consumption levels. Conclusions: Changing rice consumption patterns has potential for an important impact on diabetes risk, with a change of rice variety having a similar impact on the burden of diabetes in communities consuming rice with a high glycaemic index as a 25 % reduction in the quantity of rice consumed. Similar effects are likely for other countries with rice as a staple food, diversity in rice varieties and high incidence of diabetes.