One Serving of White Rice a Day Increases Diabetes Risk by 10 Percent
Frequent consumption of white rice increases the risk of type II diabetes, especially for Asian populations, according to researchers analyzing past studies of the condition.
The findings show that with each serving per day of white rice, a person’s diabetes risk rises by about 10 percent, and people who ate the greatest amounts of the grain had a 27 percent greater risk of developing the disease compared to those who ate the least, according to Dr. Qi Sun from Harvard School of Public Health.
"We found that higher white rice consumption was associated with a significantly elevated risk of Type 2 diabetes. This association seems to be stronger for Asians than for Western populations," the study authors wrote.
Investigators compared diabetes studies from two Asian countries, China and Japan, and two Western countries, U.S. and Australia, to see whether white rice consumption was linked to risk of developing the disease. The authors said that the average white rice consumption in the Asian countries studied was about three to four servings a day, whereas in Western countries it was about one to two serving per week.
None of the participants in all of the studies researchers looked at had diabetes at the beginning of the study, and researchers reported a total of 13,284 incident cases of type II diabetes were ascertained among 352,384 participants with follow-up periods ranging from four to 22 years.
While the study was not designed to show how white rice may increase the risk for diabetes, researchers believes that white rice, which ranks high on the glycemic index and low in diabetes risk lowering fiber and magnesium, can cause a sudden spike in blood sugar levels which can lead to diabetes.
"Although rice has been a staple food in Asian populations for thousands of years, this transition [to more sedentary lifestyles and greater availability of food] may render Asian populations more susceptible to the adverse effects of high intakes of white rice, as well as other sources of refined carbohydrates, such as pastries, white bread, and sugar sweetened beverages," they wrote.
They said that while Asian countries generally had a significantly higher level of white rice consumption compared to other countries the dose-response relationship may indicate that, "even for Western populations with typically low intake levels, relatively high white rice consumption may still modestly increase risk of diabetes”.
In an accompanying editorial, Dr. Bruce Neal of the University of Sydney in Australia, warned that because the latest study was limited by the observational nature of the previous studies which relied on food frequency questionnaires to determine dietary intake, the "interpretation of the observed association, and, in particular, determination of the likelihood of causality, are problematic”.
Neal wrote that the highest and lowest levels of rice intake varied greatly between studies, and that a "more sophisticated analysis based on primary rather than summary data,” is required before the findings can be substantial.
"Public health nutrition awaits the discovery of the model that will secure the investment needed to answer questions about the role of nutrition in health using large randomized studies," Neal wrote. "Until then, the effect of the consumption of white rice on the development of type II diabetes will remain unclear."
The findings are published in the journal BMJ.
However past studies have suggested that 60 percent of all cases of type II diabetes are likely to occur in Asia, and that those affected in Asian are younger and less likely to be overweight compared to those affected in Western countries, according to an analysis published in the Journal of the American Medicine Association in 2009 that was based on hundreds of articles, data and studies published between January 1980 and March 2009.
Although diabetes in the West is usually seen as a consequence of diet, age and obesity with the average age of patients being 60 to 79 years old compared to Asian countries where the age range was 20 to 59 years old, according to researchers from the 2009 study.
The findings in that study also suggested that because Asian women appeared to be two to three times more likely to have gestational diabetes as their white counterparts Asian populations are born with lower birth weight, which can also increase the risk of diabetes when paralleled with over-nutrition in later life.
Researchers of that study said that while Asian obesity rates are relatively low, changing diets and sedentary lifestyles linked to rapid economic development may be taking a toll on the population’s health.
They predicted that India will see its diabetes rate grow from 40 million to nearly 70 million, China from 39 million to 59 million, Bangladesh from 3.8 million to 7.4 million, and dramatic rising rates in other counties like Indonesia, the Philippines, Malaysia and Vietnam.