Link between polished rice intake and diabetes found

Published in The Hindu on August 20, 2009

Rice is a major source of dietary carbohydrates. But the link between diet, rice in particular, and diabetes has not been studied in great detail till now. A paper published recently in the British Journal of Nutrition shows a clear link between the consumption of white, polished (refined) rice and the prevalence of diabetes.

Every tenth participant of the 2001-02 Phase I CURES (Chennai Urban Rural Epidemiology Study) conducted by Dr. V. Mohan of the Dr. Mohan’s Diabetes Specialities Centre in Chennai was chosen for the current study to see for a link between dietary carbohydrate and diabetes. 1,843 people who did not know their diabetes status were selected for the study.

The chosen participants were then tested for diabetes and their food habits were recorded. The risk factors for diabetes such as sedentary lifestyle, age, BMI (body mass index), etc., were adjusted before trying to find a link between the kind/quantity of food consumed and diabetes.

When the food habits of the chosen participants were studied, it became clear that those who consumed more rice (polished and refined) were more likely to have diabetes.

For instance, the study participants were split into four quartiles based on the amount of various food consumed. It was found that people in the lowest quartile consumed about 320 grams per day of rice compared with 516 grams per day by those in the highest quartile.

“What we found was, as the amount of rice consumption increased, the consumption of other food items, like fruits and vegetables, legumes and dairy products became less,” said Dr. Mohan. “We found a link not just between carbohydrate consumption and diabetes but the kind of carbohydrate consumed and its effect,” said Dr. Mohan.

The carbohydrate derived from polished white rice is 66 per cent of the total carbohydrate intake.

“Another interesting finding was that as the increased intake of rice was at the cost of other other food items,” he said. For instance, in the lowest quartile that consumed less rice, the intake of fruits was about 300 grams per day, while fruit consumption in the highest quartile was 233 grams per day. The same trend was observed in the case of other food items.

But the biggest positive link was found in the case of dairy products. Those having the least quantity of dairy products were more likely to have diabetes; those who consumed the most had less chances of having diabetes.

Polished rice

“It is not that our eating habits have changed in the recent past. Our fathers and grandfathers had also consumed rice. But the kind of rice they consumed and what we consume today are totally different,” he said.

The rice that we get today is the highly refined and polished variety. “The more polished the rice, the more glycaemic index (GI) it would have,” he said. The GI indicates the glucose-raising effect of a food.

Polishing removes the bran and the germ. While the bran contains fibre, protein and vitamin B-complex; polished rice has only starch, which is nothing but carbohydrate.

According to Dr. Mohan, rice used to be 2 per cent polished earlier; now it is polished to 8 per cent -10 per cent.

The only good news is that increased consumer awareness of the ill-effects of various food items has made many companies produce healthier food products. Rice that is relatively less polished is now available in the market. Similarly, many products made from whole-wheat are available.