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 M 1 (AFM 1 ), a metabolite of aflatoxin B 1 . This study estimated the association between AFM 1 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 1 st , 3 rd and 5 th months of children age. AFM 1 contaminations in the samples were determined using HPLC. Aflatoxin M 1 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 AFM 1 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. AFM 1 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 AFM 1 exposure levels and weight for age Z-score or height for age Z-score. Appropriate strategies should be applied to minimise aflatoxin B 1 exposure in lactating mothers in order to protect infants from AFM 1 exposure.