Eating brown rice instead of white may reduce Type 2 diabetes risk
MedWire News: Results from three large cohort studies suggest that eating two or more servings of brown rice per week may significantly reduce a person’s risk for developing Type 2 diabetes.
In contrast, eating five or more servings of white rice per week may actually increase the risk for developing Type 2 diabetes.
“Rice consumption in the US has dramatically increased in recent decades. We believe replacing white rice and other refined grains with whole grains, including brown rice, would help lower the risk of Type 2 diabetes,” said lead author Qi Sun (Harvard School of Public Health, Boston, Massachusetts, USA).
Writing in the Archives of Internal Medicine, Sun and colleagues report the results of a prospective analysis of brown and white rice consumption in 39,765 men and 157,463 women, aged 26–87 years, from the Health Professionals Follow-up Study and the Nurses’ Health Study I and II.
Rice consumption was assessed using results from a food frequency questionnaire filled out at baseline between 1984 and 1991. The participants were then followed up for incident Type 2 diabetes until 2005–2006.
Sun and team found that following adjustment for age, lifestyle, and other dietary risk factors, participants who consumed two or more servings of brown rice per week, compared with less than one serving per month, had a significant 11% reduction in relative risk for incident Type 2 diabetes.
In contrast, those who consumed five or more servings of white rice per week, compared with less than one per month, had a significant 17% increase in relative risk for developing Type 2 diabetes.
The authors estimated that replacing 50 g/day of uncooked white rice with an equivalent amount of brown rice would reduce the risk for Type 2 diabetes by 16%. They also suggest that a similar substitution with whole grains as a group would reduce the risk for Type 2 diabetes by 36%.
“The high glycemic index of white rice consumption is likely the consequence of disrupting the physical and botanical structure of rice grains during the refining process, in which almost all the bran and some of the germ are removed,” say the authors.
“The other consequence of the refining process includes loss of fiber, vitamins, magnesium and other minerals, lignans, phytoestrogens, and phytic acid, many of which may be protective factors for diabetes risk."
Sun et al conclude: “From a public health point of view, replacing refined grains such as white rice by whole grains, including brown rice, should be recommended to facilitate the prevention of Type 2 diabetes.”
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By Helen Albert