Complementary feeding with cowpea reduces growth faltering in rural Malawian infants: a blind, randomized controlled clinical trial

Background: Growth faltering is common in rural African children and is attributed to inadequate dietary intake and environmental enteric dysfunction (EED). Objective: We tested the hypothesis that complementary feeding with cowpea or common bean flour would reduce growth faltering and EED in 6-mo-old rural Malawians compared with the control group receiving a corn-soy blend. Design: A prospective, double-blind, randomized controlled clinical trial was conducted in which children received daily feeding for 6 mo (200 kcal/d when 6-9 mo old and 300 kcal/d when 10-12 mo old). The primary outcomes were change in length-for-age z score (LAZ) and improvements in EED, as measured by percentage of lactulose Kexcretion (% L). % L <0.2% was considered normal. Anthropometric measurements and % L through urine were compared between each legume group and the control group with Student's t test. Results: Of the 355 infants enrolled, 291 infants completed the trial, and 288 were breastfed throughout the duration of the study. Cowpea and common bean added 4.6-5.2 g protein/d and 4-5 g indigestible carbohydrate/d to the diet. LAZ and weight-for-height z score were reduced in all 3 groups from 6 to 12 mo of age. The changes in LAZ [mean (95% CI)] for the cowpea, common bean, and control groups from 6 to 9 mo were -0.14 (-0.24, -0.04), -0.27 (-0.38, -0.16), and -0.27 (-0.35, -0.19), respectively. LAZ was reduced less in infants receiving cowpea than in those receiving control food from 6 to 9 mo (P = 0.048). The absolute value of % L did not differ between the dietary groups at 9 mo of age (mean +/- SD: 0.30 +/- 0.43, 0.23 +/- 0.21, and 0.26 +/- 0.31 for cowpea, common bean, and control, respectively), nor did the change in % L from 6 to 9 mo. Conclusion: Addition of cowpea to complementary feeding in Malawian infants resulted in less linear growth faltering.