Association between aflatoxin M1 exposure through breast milk and growth impairment in infants from Northern Tanzania

Abstract

Infants breastfeeding from mothers consuming aflatoxin contaminated foods may be exposed to aflatoxin M1 (AFM1), a metabolite of aflatoxin B1. This study estimated the association between AFM1 exposure levels and growth indicators, for infants under six months of age in the Rombo district in Northern Tanzania. A total of 143 infants and their mothers were involved. Breast-milk samples, infants' anthropometric data and 24 h dietary recall for mothers were taken at the 1st, 3rd and 5th months of children age. AFM1 contaminations in the samples were determined using HPLC. Aflatoxin M1 exposure by an infant was estimated by multiplying contamination in the breast milk consumed by him/her with the breast milk intake recorded by the United States Environmental Protection Agency for infants of his/her age divided by the infant's body weight. All the breast-milk samples were contaminated by AFM1 at levels ranging from 0.01 to 0.55 ng/ml. Above 90% of samples exceeded the EU limit of 0.025 ng/ml for infants' foods while over 76% exceeded the EU limit of 0.05 ng/ml for dairy milk and milk products. Only 1% of the samples exceeded the limit of 0.5 ng/ml set for dairy milk in the United States and several countries in Asia. AFM1 Exposures ranged from 1.13-66.79 ng/kg body weight per day. A small but significant (P<0.05) inverse association was observed between AFM1 exposure levels and weight for age Z-score or height for age Z-score. Appropriate strategies should be applied to minimise aflatoxin B1 exposure in lactating mothers in order to protect infants from AFM1 exposure.