Back in 2017, Prime Minister Lee Hsien Loong urged Singaporeans to start replacing white rice with brown or mixed-grain rice for a healthier diet. White rice, he said, would cause your blood sugar to rise up, implying that eating white rice would increase a person’s risk of developing diabetes – a major health concern in Singapore. He suggested switching to brown rice instead.
In fact, Singapore’s Health Promotion Board in 2016 cited studies by the Harvard School of Public Health in the United States which showed that each plate of white rice eaten daily on a regular basis raises the risk of diabetes by 11 per cent in the overall population.
However, the PM and the SHPB might want to rethink their advice upon reading two new studies that suggest white rice on its own isn’t linked to increased risk of diabetes.
Professor Koh Woon Puay, director of the Centre for Clinician-Scientist Development at Duke-NUS Medical School and co-author of the studies said that the risk of getting diabetes depends on what the rice is substituted with and the overall quality of a person’s diet.
Both studies used data from the ongoing Singapore Chinese Health Study, which was started in 1993 by the National University of Singapore (NUS).
One study, by researchers from NUS and Duke-NUS Medical School, found no link between the quantity of white rice consumed and the risk of Type 2 diabetes when other variables like age, sex, body mass index (BMI), and other food intake were controlled for.
“Even over a relatively wide range of rice intakes, from half a bowl to several bowls a day, we didn’t see much of an increase in the risk of diabetes,” said Professor Rob Martinus van Dam, domain leader of epidemiology at the Saw Swee Hock School of Public Health in NUS and one of the study’s co-authors.
When someone eats less rice, they are likely to eat more of something else to maintain their calorie intake, says Prof van Dam. So researchers found that people who ate different foods in rice were affected differently.
For example, switching to noodle dishes would mean a higher salt and oil in take. Others might eat more meat to feel full.
These can affect their risk of developing diabetes.
The study also found that substituting white rice with whole grains does actually decrease the risk. So PM Lee did get that part right – switching to brown rice, a whole-grain rice, would reduce your risk of developing diabetes.
In the second study, researchers found that whole grains, fruits, vegetables, nuts and a moderate amount of dairy were associated with lower risks of cancer, diabetes, heart disease and stroke. This is in line with other established dietary studies from mostly Western countries.
On the other hand, researchers found that sugar-sweetened drinks, processed meat and red meat – including beef, pork and even the darker portions of poultry like chicken thigh meat – were associated with higher risks of the same diseases.
It is the first such study to examine local food specifically.
Additionally, Prof Koh also noted that the amount of food consumed played a bigger role in the risk of developing diabetes than the absolute intake of calories. Basically, you can eat everything in moderation – yes, even unhealthy foods like red meat and sugar.
These studies also suggest that the top 20% of participants who had ‘higher quality’ diets were 20% less likely to develop diabetes compared to the bottom 20%.
Diet quality was ranked based on how often and how much of a specific food that each participants ate on average. So those who consumed more whole grains, low-fat dairy, nuts, seeds, legumes, fruits and vegetables were ranked higher.
Those who ate more processed and red meats, sugary drinks, and sodium were given lower scores. Foods like fish and refined grains such as white rice were not scored.
Group director of policy, research and surveillance at the Health Promotion Board, Dr Annie Ling said these studies are timely given the findings of the National Nutrition Survey 2018.
The survey showed that there have been gradual improvements in the dietary habits of Singaporeans but there was still room for improvement. Dr Lin said, “While Singaporeans are consuming more whole grains, fruits and vegetables, high sugar and sodium intake remains a cause for concern.”