For anyone who isn’t familiar with the Glycemic Index (GI), it’s basically a measure of the ability of a food to raise your blood sugar. A food with a high GI causes a rapid increase in blood sugar (this is bad), while a food with a low GI increases blood sugar more gradually (this is desirable).
For years, it was assumed that the GI of a food is universal, however, research has shown that this is not the case. A study comparing the glycemic response elicited in Asians versus Caucasians, showed that the GI of a ready-to-eat breakfast cereal was 77 in Asians, while it was only 61 in Caucasians. So basically, the exact same food caused a larger spike in blood sugar in the Asians compared to the Caucasians. Researchers have speculated that this may arise from differences in starch digestion amongst ethnic groups. Nevertheless, regardless of the mechanism, it’s always interesting to see how the exact same food can affect different people in different ways.
I learned about this fact from: Venn BS, Williams SM, Mann JI. Comparison of postprandial glycaemia in Asians and Caucasians. Diabet Med 2010;27:1205-8.