The review covered foods typically consumed in South East Asia (Singapore, Malaysia, Thailand, Indonesia, Philippines), East Asia (Japan, Korea, China, Taiwan, Hong Kong, India, Sri Lanka), as well as certain parts of the Middle East (UAE, Oman, Saudi, Lebanon).
This is the first GI compendium of non-Western foods. First author Professor Christiani Jeyakumar Henry from the Singapore Institute of Food and Biotechnology Innovation (SIFBI) told FoodNavigator-Asia, “Most international GI tables are based on Western foods such as doughnuts, eclairs and cake, but how many of us really eat these on a daily basis?”
A typical non-Western diet, such as in South Asia, is high in carbohydrates such as polished rice, white flour, finger millet, semolina and wheat.
The principle is that the slower the rate of carbohydrate absorption into the bloodstream, the lower the rise of blood glucose level and the lower the GI value. GI values are categorised into low (≤55), medium (56-69) and high (≥70).
Research has been shown that South Asians elicits postprandial glucose peaks that are two to three times larger than Caucasians for an identical carbohydrate load.
Adding to this is Asia being the epicenter of type two diabetes in the world.
“One of the ways in which we can combat type two diabetes is to select a low GI foods. There is this data set missing so we decided to compile data across the region.”
Research design
For this review, researchers conducted literature search for relevant GI articles published from January 2000 to May 2020 on PubMed and Google Scholar.
Year 2000 was the start point as it marked the exponential growth in GI testing in non-Western countries.
GI misconception
Commenting on the findings, Professor Henry said many people had the misconception about high GI foods, whether it is carbohydrates or fruits.
Professor Henry said most people think rice is high in GI, which is partly true, however the GI of rice was found to have a wide range between 14 (low) to 99 (high).
Choosing low to medium GI rice will allow consumers to still enjoy eating rice every day.
“Foods that are labelled as “bad” or “high GI”, you can actually make good out of it, either by selecting the low GI variety, or by the way in which we eat the food.”
“For instance, eating rice in a particular sequence will lower spike in blood glucose, that is eating vegetables first, soup, meat, finally the rice.”
In addition, not all high GI foods are “bad”, according to Professor Henry.
One example is nasi lemak (Malaysian coconut milk rice). “The coconut milk in nasi lemak reduces glycemic index rise precipitously because it contains lauric and myristic acid that supposedly binds to carbohydrate, so that it is not completely broken down.”
In addition, overall vegetable and fruit intake in people between 20 to 30 is still relatively low, according to Professor Henry.
“In the case of fruits, people still think all fruits are high GI. But there are some medium to low GI fruits, for example, sweeter fruits like mangoes and watermelons are considered low GI.”
In the glossary, watermelon from South Korea has a GI of 53.5, which is considered low GI.
“So, I think they could do more to encourage people to eat more vegetables and fruits.”
Future directions
This study compiled data from different countries around the world, ending up with 950 data points.
It initially consolidated more than 1,400 data points, but had to exclude certain data to meet its standards (recommended GI analysis method, testing equipment, minimum number of subjects).
“The only limitation is that we had to apply some control mechanism to ensure that the data provided can be used by the consumer with some degree of confidence and accuracy,” according to Professor Henry.
This glossary currently covers Asia and the Middle East region.
Professor Henry said these countries were selected for their available market research and GI data.
“We don’t have data from other Middle Eastern countries because there are few researchers working on this particular focus. Data from the Middle East on GI studies are very limited.
“Even in Singapore, just six years ago, there was no footprint on nutrition. And unless, the government invests in research focused on nutrition and GI, there won’t be data generated.”
Source: Nutrition & Diabetes
https://doi.org/10.1038/s41387-020-00145-w
“A glycaemic index compendium of non-western foods”
Authors: Christiani Jeyakumar Henry, Rina Yu Chin Quek, Bhupinder Kaur, et al.