It’s commonly believed that brown rice has a lower glycemic index (GI) than white rice. But according to the actual scientific data, this is false. Part of the reason for this is that there are over 450,000 varieties of rice (according to Wikipedia at least), and thus not all rice is the same. Last week, I attempted to discuss the overall health benefits of brown rice vs. white rice, and barely touched on the issue of glycemic index. This post is essentially an update on that post that provides some more accurate data I found on this subject.
The values you see in the table I made below come from two studies, referenced at the end of this post. The first is an international table of glycemic index values for hundreds of foods, published in the American Journal of Clinical Nutrition. The second reference provided data on brown basmati rice vs. white basmati rice, and is from “Glycaemic index of some commercially available rice and rice products in Great Britain” (links below this post).
The highlighted values are those at are higher. Thus, for brown rice, two varieties at least have higher glycemic indices than the white, milled, version of the product (doongara and basmati). Calrose rice has approximately the same GI for both white and brown. Brown basmati rice is the most striking; it’s glycemic index was found to be 75, whereas the glycemic index of white basmati rice was 50, making it the only rice product on this list with a low GI (below 55 is low, 56-70 is medium, and above 70 is high).
Now, considering the standard deviations, doongara rice could end up being a low glycemic rice as well. As I wrote in last week’s post, people respond to glucose differently, thus, there is no exact glycemic index for a food. These values represent averages. Considering the varieties of rice available, the GI of rice varies a LOT, and that’s why rice should be used in the plural sense.
Perhaps these results are shocking you. Well, this data is gathered from the studies cited below, and you can verify it yourself, and then compare it to the quality of evidence reported by other health blogs (hint: very bad). From a quick Google search, it is clear that most people are completely confused about brown rice and most importantly, are incorrect (including Wikipedia).
The Fact is This:
Some varieties of brown rice have a lower glycemic index than their white counterpart, but others have a higher GI. Further, brown rice is not a low glycemic index food. It is a medium to a high glycemic index food. In fact, it will vary from low to high but will mostly stay at medium or above, and the same goes for most varieties of white rice.
I haven’t yet found data on brown jasmine rice and other common varieties of rice, but when I do, this post will be updated.
Next week, I’ll talk about why these numbers vary so much. But if you have any guesses, leave a comment below!
- Foster-Powell K, Holt SHA, Brand-Miller JC. International table of glycemic index and glycemic load values: 2002. Am J Clin Nutr. 2002;76(1):5-56.
- Ranawana D V., Henry CJK, Lightowler HJ, Wang D. Glycaemic index of some commercially available rice and rice products in Great Britain. Int J Food Sci Nutr. 2009;60(SUPPL.4):99-110