Third-World Toddlers Reach New Heights With Breastfeeding

Abstract

Source: Simondon KB, Simondon F, Costes R, et al. Breast-feeding is associated with improved growth in length, but not weight, in rural Senegalese toddlers. Am J Clin Nutr. 2001;73:959–967.The authors report a study of breastfeeding and growth in 443 children born in the Niakhar area in central Senegal between January and October 1995. This area has been under continuous demographic surveillance since 1983 when a central database was established. The study was undertaken because of many reports that breastfed children have poorer nutrition and growth than weaned children. It has been suggested that breastfeeding beyond 12 months depresses growth and that malnourished children should be weaned by 12 months. In this study, children were recruited at 2 months of age and followed from 1.5 to 3 years of age by home visits every 6 months. The objectives were to analyze growth in toddlers by duration of breastfeeding, season, and economic level and to compare height-for-age at 3 years with duration of breastfeeding, while taking into account height-for-age during infancy.Nine hundred and fifteen infants were born in the study areas, but 472 were not included in the analysis because of failure to attend vaccination sessions (176), missing length measurements at 2 months (128), death (82), or migration out of the study area (42). The children not included in the analysis had younger mothers, more working mothers, and an earlier birth order than those studied, but were not different with respect to sex ratio, education of parents, or duration of breast-feeding. The cohort of 443 children with complete data was characterized by a high prevalence of malnutrition during the second year of life, especially during the rainy season. The prevalence of stunting decreased slowly with age, mainly from the first to the second home visit, and the prevalence of wasting decreased dramatically across the 4 home visits. The mean age of weaning was 24.1 months. For children of similar age, the mean number of daily meals was 3.3 for the weaned children compared with 2.6 for those who were breastfed. The staple food was cereal-based (millet and rice); fish was consumed at least once during the preceding week by 91.7% of 3 year olds, animal milk by 20% and meat by 13%.At age 3 years mean height for age was negatively related to age at weaning. This negative association remained significant in a multiple linear regression analysis adjusting for sex, maternal age, housing, and education. Increments in length, weight, arm circumference, and triceps skinfold thickness were all significantly lower during the rainy season than during the dry season. The longer the children were breastfed, the faster they grew during both the second and third years. Duration of breastfeeding was not associated with weight gain, arm circumference, or growth in triceps skinfold thickness. Duration of breastfeeding was not associated with the quality of maternal housing or with growth in length, weight, arm circumference, or triceps skinfold thickness. The study found no evidence, as has been suggested in the past, that slow growth leads to weaning.Many articles about children in Sudan, Guinea-Bissau, southern Brazil, and Nepal have suggested that prolonged breastfeeding is associated with impaired growth and/or malnutrition.1 This carefully done study is reassuring because it documents improved growth in length during the second and third years of life in children breastfed for longer periods. Growth in weight did not differ significantly with duration of breastfeeding. The authors attribute this either to the possibility that: 1) prolonged breastmilk consumption improves the children’s intake of particular nutrients and micronutrients more than their overall energy intake; or 2) growth in weight is more strongly affected by illness. In other words, healthy children are more likely to be weaned than sick children so that the preferential breastfeeding of ill children obscures the effect of breastfeeding on weight. This article reminds us of the ongoing major problem of malnutrition during the period of life when the brains of young children should be developing most rapidly and are most vulnerable to injury. Many of the children in this study were malnourished in spite of breast-feeding. Dietary analysis indicates that they received relatively little protein during the weaning and post-weaning periods. They also manifested poorer growth during the rainy season, a finding that has been reported many times. Malaria became a higher risk as the rainy seasons progressed and there was lower food availability.