One of last week’s big nutrition news items was about a method to reduce the calories in white rice. Researchers from Sri Lanka found that when you add a small amount of fat to white rice during the cooking process, and then refrigerate the cooked rice for at least 12 hours, the result is a higher content of resistant starch.
Resistant starch is starch that is poorly digested in the small intestine, and there is lots to like about it. Since it isn’t well digested and absorbed, this type of starch provides fewer calories than other carbohydrates. It also stimulates growth of good bacteria in the colon and production of short chain fatty acids. These fats may lower the pH of the intestines which inhibits growth of harmful bacteria. Consumption of resistant starch has been associated with improved intestinal health and better insulin sensitivity (1-5).
The potential benefits of boosting the resistant starch content of rice are likely to be greatest for people in Asia who have chronic diseases like diabetes and metabolic syndrome and whose diets include large amounts of white rice. Asians are at high risk for diabetes compared to people of European ancestry. There is evidence that Asians have a much greater blood glucose response to rice compared to people of other ethnicities (6-10). Among Asian populations, overreliance on white rice and other refined starches like noodles is linked to higher risk for chronic disease (11-14).
It’s certainly possible that shifting the starch content of white rice toward resistant starch could have benefits in these populations. And the fact that cooks can do this easily at home is a plus. Replacing some refined starch with good fats isn’t a bad idea either. (So far, these researchers have used only coconut oil, but they plan to test healthier fats.)
But what does it mean for the average vegan? I would say probably not much. Hopefully, you are not eating all that much white rice. Although I might have it occasionally at a restaurant, I doubt that I eat white rice more than three or four times a year. Instead, like most vegans, my diet is built around foods that are rich in resistant starches and in fiber. Beans are especially good sources of resistant starch as are bananas, uncooked oats, and barley.
So while there may be public health benefits of these findings for some population groups, I wouldn’t change any of my cooking practices based on them. If you eat a diet based mostly on whole plant foods, you don’t need to worry about whether the occasional cup of white rice in your meals has a lot or a little bit of resistant starch.
References:
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Higgins JA, Brown IL. Resistant starch: a promising dietary agent for the prevention/treatment of inflammatory bowel disease and bowel cancer. Curr Opin in Gastroenterol 2013; 29:190-194.
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Grabitske HA & Slavin JL. Gastrointestinal effects of low-digestible carbohydrates. Crit Rev Food Sci Nutr 2009; 49:327-360.
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Maki KC, Phillips AK. Dietary substitutions for refined carbohydrate that show promise for reducing risk of type 2 diabetes in men and women. J Nutr 2015;145:159S-163S
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Yamada Y, Hosoya S, Nishimura S, Tanaka T, Kajimoto Y, Nishimura A, Kajimoto O. Effect of bread containing resistant starch on postprandial blood glucose levels in humans. Biosci Biotechnol Biochem.2005;69:559-566.
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Noakes M, Clifton PM, Nestel PJ, Le Leu R, McIntosh G. Effect of high-amylose starch and oat bran on metabolic variables and bowel function in subjects with hypertriglyceridemia. Am J Clin Nutr. 1996; 64:944-61.
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Chan JC, Malik V, Jia W,et al. Diabetes in Asia: epidemiology, risk factors, and pathophysiology. JAMA 2009; 301:2129–2140.
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Dickinson S, Colagiuri S, Faramus E, et al. Post-prandial hyperglycemia and insulin sensitivity differ among lean young adults of different ethnicities. J Nutr 2002; 132: 2574–2579.
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Henry CJ, Lightowler HJ, Newens K, et al.Glycaemic index of common foods tested in the UK and India. Br J Nutr 2008; 99: 840–845.
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Venn BS, Williams SM & Mann JI Comparison of post- prandial glycaemia in Asians and Caucasians. Diabet Med 2010; 27:1205–1208.
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Kataoka M, Venn BJ, Williams SM, et al.(2013) Glycaemic responses to glucose and rice in people of Chinese and European ethnicity. Diabet Med 2013; 30: e101–e107.
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Song S, Young Paik H, Song WO, Song Y. Metabolic syndrome risk factors are associated with white rice intake in Korean adolescent girls and boys. Br J Nutr 2015;113:479-87.
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Song S, Lee JE, Song WO, Paik HY, Song Y. Carbohydrate intake and refined-grain consumption are associated with metabolic syndrome in the Korean adult population. J Acad Nutr Diet 2014;114:54-62.
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Zuniga YL, Rebello SA, Oi PL, Zheng H, Lee J, Tai ES, Van Dam RM. Rice and noodle consumption is associated with insulin resistance and hyperglycaemia in an Asian population. Br J Nutr 2014;111:1118-28.
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Hu EA, Pan A, Malik V, Sun Q. White rice consumption and risk of type 2 diabetes: meta-analysis and systematic review. Bmj 2012;344:e1454.
I think this is interesting for those who have someone in the house that is resistant to healthier brown rice. I prefer the mouthfeel of white rice with certain foods (Chinese) but chose brown rice because I know I should. This gives me an option and I won’t feel as guilty about it. While it isn’t as nutritious, it would at least not spike blood sugar as much?
Tanya, how much it affects blood sugar really depends on so many factors. It’s not just brown versus white but short grain versus long grain. (Long grain is better.) And what else you include in the meal. I think if you have plenty of fiber in your meals and are including protein-rich foods and some healthy fats, then it shouldn’t matter too much. And I’m like you–I really like white rice with Chinese food, but otherwise choose brown rice most of the time because it’s better for me.
I sway back and forth on white vs brown rice. I like both, but worry about arsenic content. So depending on the dish, I will choose one or the other. Do you have a link on how to prepare white rice rich in resistant starch?
Linda, these researchers added 1 teaspoon of fat for every 1/2 cup of dry rice. And I believe they cooked it for a half hour or so. Then they cooled it in the refrigerator for 12 hours before eating. So that is sort of the recipe for doing this. But, I believe that how much resistant starch it produces depends on the type of white rice. Here is one method that I found: http://www.popsugar.com/fitness/How-Make-Healthier-Rice-37167924 Just keep in mind that results may vary!
Is it not true that diabetes was nearly unheard of in Asian communities until they started to adopt western eating habits (meat and cheese)? I find it highly unlikely that rice is the culprit.
Jennifer, I didn’t say at all that rice was *the* culprit in rising rates of diabetes among Asians. What I said was that it is not an especially healthy component of Asian diets as the research clearly shows. It’s likely that the overall traditional healthful diet and lifestyle in these countries compensated for high intake of rice. As that lifestyle has changed and body weights have increased, rice may be harmful. This research is aimed at addressing some of that.
While it would be even better for people to return to more traditional habits, the fact is that obesity and diabetes are common in some of these countries and white rice is a traditional food. So the research is aimed at mitigating some of its harmful effects.
Why not just keep it simple and eat brown rice? You get the whole intact rice grain with the naturally occurring fat of the bran and the germ (which are the parts removed to make white rice) instead having to add fat to white rice when cooking and then refrigerating.
I agree–this is the simpler and much healthier solution. But it may not be a realistic one in some parts of the world where cultural diets include large amounts of white rice. If people are unwilling to eat brown rice, then there is probably a need for a different solution.
Thanks for letting us know about resistant starch – I had not heard of it before! Three questions, if I may, Ginny:
1. I had heard that white basmati rice has a slight advantage nutritionally over ordinary white rice – maybe a little more fibre? But when I searched the USDA data base, basmati rice was not listed. Do you know of any such advantage, albeit small?
2. Though sweeteners that pass through the intestine undigested have several benefits, they often cause some intestinal looseness and gas. Is this true for the resistant starches too? (extrapolating that this may be one factor in beans causing gas).
3. Does the presence of resistant starch in, say, beans, mean that, with less of the starch being absorbed, the relative protein absorbed is higher than the percentage in the actual bean? If so, this would has good implications for vegans.
Thanks again for this post. It is extremely interesting and, as you can see, has set me thinking!
Radha, New Zealand
Radha, basmati rice is a long-grain rice so should have a lower glycemic index. I’m not sure whether or not this is due to a higher resistant starch content, but it might be.
And, resistant starch is associated with improvements in bowel function but it’s certainly possible that it might be associated with some increases in gas–which is common when gut bacteria go to work on undigested food. I suspect it’s not as big a concern as the gas produced from beans, though.
It *might* be true that protein as a percent of the calories absorbed is higher–but of course, you still end up with the same amount of protein from a serving of food.
Thanks for your good questions!
This article has sparked my interest in resistant starch. It looks like it’s all the rage in the former paleo crowd. Many of those sites are suggesting you eat 4 tablespoons of Bob’s Mill unmodified potato starch to get in 40 grams of resistant starch a day. I started adding it to my morning muesli and lunchtime lentil soup. It sounds a bit too zoodoo-ish to me, but I notice better digestive health (I hope that isn’t TMI). I have also purchased something called Hi-Maize 260 resistant starch from a company called Honeyville. It supposedly adds fiber and resistant starch without adding heaviness to baked goods. We’ll see. BTW, I also eat a fair amount of beans, whole grains and fruits and veggies, normally eating 35 – 50 grams of fiber a day. Here’s an article I found on resistant starch which I found provided a helpful review on the subject:
http://onlinelibrary.wiley.com/doi/10.1111/j.1541-4337.2006.tb00076.x/epdf