Soybeans, legume, kidney, pinto—so many beans, so many benefits.
The classic burrito may be due for a face-lift. If nutritional scientists have their way, the beans and peppers of the future may be grown and harvested to maximize their potential as functional foods, allowing more people to enjoy their health benefits.
Soybeans and similar dried legumes are currently the best-known nutraceuticals, or “functional foods.” Beans are inexpensive, tasty, provide more protein than most plant foods, and their phytochemicals are thought to prevent cancer. Yet consumption of legumes in both Western and developing countries is surprisingly low. We all know why: Beans are notorious for causing flatulence and take a long time to prepare. Canned beans can be a viable alternative (although not as nutritious), but they may not be available to those living in developing countries.
Legume flatulence is caused by the body’s inability to break down several sugars found in beans: raffinose, stachyose, and verbascose. If these sugars can’t be broken down, they can’t be absorbed, and thus will pass into our intestinal tract where bacteria ferment them, producing carbon dioxide, hydrogen, and methane gas.
Researchers for the Spanish National Agricultural Department studied twenty-seven varieties of dried common beans (Phaseolus vulgaris) grown in two localities in Spain. (Common North American bean varieties such as green, bush, navy, kidney, and pinto are all varieties of P. vulgaris; the Spanish study used a similar set of varieties with Spanish names.)
The amount of total indigestible sugars in the beans ranged from 18.6 (var. Morada Larga) to 33.2 (var. Cardeno) g/kg indicating that choosing the variety with a lower sugar content could reduce flatulence by nearly half.
Consumers should try to pick the variety lowest in the troublesome phytochemicals. Although this information isn’t yet available to the general public, the new research may lead to more consumer choices down the road. For now, it is best to let your body be the judge—if you’ve found a certain variety of beans that seems to agree with you, your body may be telling you that variety’s indigestible sugar content is low.
Burbano, C., et al. “Evaluation of antinutritional factors of selected varieties of Phaseolus vulgaris.” Journal of the Science of Food and Agriculture 1999, 79:1468–1472.
Furr, H. C., and R. M. Clark “Intestinal absorption and tissue distribution of carotenoids.” Journal of Nutritional Biochemistry 1997, 8:364–377.