Occurrence and dietary factors associated with the presence of aflatoxin B-1 and M-1 in breast milk of nursing mothers in Iran

Abstract

Breast milk is recommended as the sole source of nutrition for the first 6 months of life and its purity is essential for the beginning of human life. Aflatoxins, a group of highly toxic metabolites, can be accumulated in breast milk as a result of maternal dietary exposure. Therefore, the objective of this study was to determine the occurrence, levels and dietary factors associated with the presence of aflatoxin B-1 and aflatoxin M-1 in breast milk samples collected from Kurdish lactating women in Iran. A total of 88 breast milk samples obtained from urban and rural areas were analyzed for the presence of aflatoxin B-1 and M-1 using Enzyme linked-immunosorbent assay method (ELISA). A Semi-Quantitative Food Frequency Questionnaire was used to determine the daily intake of foods, focused on more probable AFs contaminated foodstuffs. Aflatoxin B-1 and aflatoxin M-1 were detected in 93.2% and 100% of samples in the range of 10-80 and 0.1-13.6 ng/L respectively. There were no significant differences in the occurrence and levels of aflatoxins in breast milk samples between urban and rural regions (p > 0.05). The presence of aflatoxin B-1 was significantly associated to consumption of bread and egg (p < 0.05) and the presence of aflatoxin M-1 was associated to consumption of wheat flour and traditional Doogh (p < 0.05). The mean daily intake of aflatoxin B-1 by mothers and infant was 0.61 and 3 ng/kg b.w./day, respectively which suggested, for the first time, that breast-fed infants in Kurdish areas in West Azarbaijan province, Iran, are exposed to significant levels of this toxin through mother's breast milk. However, the mean daily intake of aflatoxin M-1 by infants (0.33 ng/kg b.w./day) was close to the calculated tolerable daily intake of 0.2 ng/kg b.w./day of AFM(1). These findings highlight the high risk of infants' exposure to aflatoxins and the necessity for developing strategies to reduce exposure to aflatoxins especially aflatoxin B-1, involving interventions targeted at decreasing contamination of consumed foods. (C) 2017 Elsevier Ltd. All rights reserved.