Scientists have found that the glycemic index (GI) of rice varies a lot from one type of rice to another, with most varieties scoring a low to medium GI.
And they have revealed that rice varieties such as India’s most widely grown rice variety, Swarna, have a low GI.
The findings of the research, which analyzed 235 types of rice from around the world, is good news because it not only means rice can be part of a healthy diet for the average consumer, but it also means people with diabetes, or at risk of diabetes, can select the right rice to help maintain a healthy, low-GI diet.
The study found that the GI of rice ranges from a low of 48 to a high of 92, with an average of 64.
The research team from the International Rice Research Institute (IRRI) and Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) Food Futures Flagship also identified the key gene that determines the GI of rice, an important achievement that offers rice breeders the opportunity to develop varieties with different GI levels to meet consumer needs.
Future development of low-GI rice would also enable food manufacturers to develop new, low-GI food products based on rice.
Dr. Melissa Fitzgerald, who led the IRRI team, said that GI is a measure of the relative ability of carbohydrates in foods to raise blood sugar levels after eating.
“Understanding that different types of rice have different GI values allows rice consumers to make informed choices about the sort of rice they want to eat,” she said.
“Rice varieties such as India’s most widely grown rice variety, Swarna, have a low GI and varieties such as Doongara from Australia and Basmati have a medium GI,” Dr. Fitzgerald noted.
Dr. Tony Bird, CSIRO Food Futures Flagship researcher, said that low-GI diets offer a range of health benefits: “Low-GI diets can reduce the likelihood of developing type 2 diabetes, and are also useful for helping diabetics better manage their condition.
“This is good news for diabetics and people at risk of diabetes who are trying to control their condition through diet, as it means they can select the right rice to help maintain a healthy, low-GI diet,” he added.
Low-GI foods are those measured 55 and less, medium-GI foods are those measured between 56 and 69, while high-GI foods measure 70 and above.
When food is measured to have a high GI, it means it is easily digested and absorbed by the body, which often results in fluctuations in blood sugar levels that can increase the chances of getting diabetes, and make management of type 2 diabetes difficult.
Conversely, foods with low GI are those that have slow digestion and absorption rates in the body, causing a gradual and sustained release of sugar into the blood, which has been proven beneficial to health, including reducing the chances of developing diabetes.
Eating rice with other foods can help reduce the overall GI of a meal and, when combined with regular exercise, can reduce the chances of getting diabetes. In addition, people who exercise need more carbohydrates in their diet and can take advantage of low-GI foods for sustained activity.
Rice plays a strong role in global food security. Being the staple for about 3.5 billion people, it is important to maximize the nutritional value of rice. Low-GI rice will have a particularly important role in the diets of people who derive the bulk of their calories from rice and who cannot afford to eat rice with other foods to help keep the GI of their diet low. Low-GI rice could help to keep diabetes at bay in these communities.
This is the first of several studies the group plans to carry out based on investigating the role of rice in mitigating chronic diseases such as type 2 diabetes.