New research demonstrates role of grain legumes in fighting malnutrition

New research led by Washington University, with support from the Feed the Future Legume Innovation Lab administered by Michigan State University, shows the benefits of grain legumes for improved child growth and gut health.

A child having their arm measured during a clinical trial in Malawi.

EAST LANSING, MICH. – New research led by Washington University (WU), with support from the Feed the Future Legume Innovation Lab (LIL) administered by Michigan State University (MSU), shows the benefits of grain legumes for improved child growth and gut health.

Stunting is a persistent problem that reduces the physical and mental growth of children caused by poor nutrition, repeated infection, and inadequate psychosocial stimulation. Its impacts are so detrimental that it has been selected as part of the United Nations Sustainable Development Goals and the World Health Organization Global Nutrition Targets 2025.

Led by Mark Manary, the Helene B. Robertson Professor of Pediatrics at WU, and Kenneth Maleta, Professor of Public Health at the University of Malawi School of Medicine, this study shows a simple dietary intervention can help address the problem. Complementary feeding with cowpea, also known as black-eyed pea, or common bean was found to have positive effects on gut health, nutrient absorption and linear growth during early childhood.

Funded by the United States Agency for International Development through the LIL, the research addressed stunting specifically in young rural African children. Primarily attributed to inadequate dietary intake and chronic inflammation of the small bowel (environmental enteric dysfunction) during early childhood, an estimated 35 percent of children in rural sub-Saharan Africa experience stunting, which has deleterious consequences over an individual’s lifetime including reduced cognitive and physical performance and 22 percent lower lifetime income.

In African children, stunting tends to occur during the critical ages of 6 to 15 months, when complementary foods are first introduced in addition to breastfeeding and the child is exposed to a large variety of microbes in the maturing gastrointestinal tract.

Two long-term clinical trials were conducted in Malawi involving approximately 800 children to determine if the regular consumption of small amounts of cowpea or common bean (4.6-5.2 grams of protein and 4-5 grams of indigestible carbohydrate each day) as a flour supplement to a hot cereal porridge would improve growth, gut inflammation or alter the ecology of the intestinal microbiome.

Three landmark publications by the research team present exciting key results. The addition of cowpea to complementary feeding of Malawian infants between 6 and 12 months old resulted in significantly less stunting, with lower linear growth faltering by 0.13 in height-by-age Z-scores, the most widely used statistical descriptor of malnutrition. In addition, common “navy” bean supplements to the diets of children between 12 and 36 months of age led to reduced inflammation and an improvement in gut health.

These important findings further demonstrate the known nutritional benefits of grain legumes, or pulses, on nutrition and health: pulses are one of the most important sources of plant-based protein for people around the globe. Beans, cowpea, peas, lentils and chickpeas have a positive impact on non-communicable diseases such as diabetes and coronary conditions.

“No known highly effective interventions have so far been available to reduce stunting in the context of rural Africa,” Manary said. “We now have high hopes that our new findings may provide an affordable and accessible solution to the 60 million children under the age of 5 who suffer from stunted growth in Africa.”

Irvin Widders, MSU professor, served as director of LIL.

“The Legume Innovation Lab believes that grain legume supplements in diets could be game changers for addressing stunting and gut health in undernourished young children in developing countries,” Widders said.

For the publications, see:

  • Stephenson KB, Agapova SE, Divala O, Kaimila Y, Maleta KM, Thakwalakwa C, Ordiz MI, Trehan I, Manary MJ. Complementary feeding with cowpea reduces growth faltering in rural Malawian infants: a blind, randomized, controlled clinical trial. Am J Clin Nutr. 2017;106(6):1500-1507.  doi:10.3945/ajcn.117.160986
  • Agapova SE, Stephenson KB, Divala O, Kaimila Y, Maleta KM, Thakwalakwa C, Ordiz MI, Trehan I, Manary MJ. Additional common bean in the diet of Malawian children does not affect linear growth, but reduces intestinal permeability. J Nutr. 2018;148: 267-274. doi:10.1093/jn/nxx013
  • Ordiz MI; Stephenson K; Agapova S; Wylie KM; Maleta K; Martin J; Trehan I; Tarr PI; Manary MJ. Environmental Enteric Dysfunction and the Fecal Microbiota in Malawian Children. Am J Trop Med Hyg.  2017; 96(2):473-476. doi:10.4269/ajtmh.16-0617

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