These recent papers cite studies on this topic that have been conducted in Africa:
Prado EL, Dewey KG. Nutrition and brain development in early life. Nutrition Reviews 2014;72(4):267-84. doi: 10.1111/nure.12102.
Sudfeld CR, McCoy DC, Danaei G, Fink G, Ezzati M, Andrews KG, Fawzi WW. Linear growth and child development in low- and middle-income countries: a meta-analysis. Pediatrics 2015;135(5):e1266-75. doi: 10.1542/peds.2014-3111.
A large team of researchers led by Kay Dewey at UC Davis has recently completed four randomized trials providing lipid-based nutrient supplements to pregnant women and infants in Malawi, Ghana, and Burkina Faso. The studies showed mixed results on 18-month motor, language, socio-emotional, and executive function, with positive effects of the intervention in Burkina Faso, but not Malawi or Ghana.
Two of the papers reporting the developmental outcomes have been published, and two are in press.
Prado, E. L., Phuka, J., Maleta, K., Ashorn, P., Ashorn, U., Vosti, S. A., & Dewey, K. G. (In Press). Provision of lipid-based nutrient supplements from age 6 to 18 months does not affect infant development scores in a randomized trial in Malawi. Maternal & Child Health.
Prado, E. L., Adu-Afarwuah S., Lartey A., Ocansey M., Ashorn P., Vosti S. A., & Dewey, K. G. (In Press). Effects of pre- and post-natal lipid-based nutrient supplements on infant development in Ghana. Early Hum Dev.
Prado, E. L., Abbeddou, S., Yakes Jimenez, E., Somé, J. W., Ouédraogo, Z. P., Vosti, S. A., et al. (2016). Lipid-based nutrient supplements plus malaria and diarrhea treatment increase infant development scores in a cluster-randomized trial in Burkina Faso. Journal of Nutrition. (Epub ahead of print)
Prado, E. L., Maleta, K., Ashorn, P., Ashorn, U., Vosti, S. A., Sadalaki, J., & Dewey, K. G. (2016). Effects of maternal and child lipid-based nutrient supplements on infant development: a randomized trial in Malawi. Am J Clin Nutr, 103(3), 784-793.