Occurrence and dietary factors associated with the presence of aflatoxin B1 and M1 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 B1 and aflatoxin M1 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 B1 and M1 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 B1 and aflatoxin M1 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 B1 was significantly associated to consumption of bread and egg (p < 0.05) and the presence of aflatoxin M1 was associated to consumption of wheat flour and traditional Doogh (p < 0.05). The mean daily intake of aflatoxin B1 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 M1 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 AFM1.These findings highlight the high risk of infants’ exposure to aflatoxins and the necessity for developing strategies to reduce exposure to aflatoxins especially aflatoxin B1, involving interventions targeted at decreasing contamination of consumed foods.