Maternal fish consumption in the nutrition transition of the Amazon Basin: Growth of exclusively breastfed infants during the first 5 years

Background: Changes in fish-eating habits due to rapid urbanization in Western Amazon was used as model to investigate whether maternal fish-intake rate impacts on children's weight and height during the first 5 years. Aim: The study examined the growth of 82 breastfed children, and maternal fish consumption (hair mercury concentrations, HHg) during pregnancy and lactation. Subjects and methods: Fish consumption in mothers and children was estimated through HHg. The children were measured and weighed at birth and at 6 (exclusive breastfeeding), 36 and 60 months. Results: Fish consumption rate (HHg) had no significant impact on children's growth at the specified ages (p = 0.35). After 6 months of exclusive breastfeeding, children had the highest proportion of Z-scores <-1 SD; however, weaning (with extended breastfeeding) had a substantial impact in moving up the attained growth at 3 years. The duration of breastfeeding was significantly correlated with attained Z-scores for weight-for-age (r = 0.26; p = 0.02) and weight-for-height (r = 0.22; p = 0.04) but not for height-for-age. At 3 years most children had improved Z-scores (>-1 SD) for height-for-age (70/82), weight-for-age (74/82) and weight-for-height (74/82). At 5 years, all but one child attained Z-scores >-1. Conclusion: The apparently good nutritional status of subjects is more likely due to a well balanced diet composition than to only one dietary protein source-fish.