Aflatoxin M1 in milk and dairy products: The state of the evidence for child growth impairment.

Aflatoxin M1 (AFM1) is a metabolite of the more toxic aflatoxin B1 (AFB1) a mycotoxin produced by the fungi Aspergillus flavus and A. parasiticus; which contaminates maize, peanuts, tree nuts, and oilseeds, among other crops in warm regions of the world. When mammals consume AFB1 in these foods, they secrete AFM1 in milk. A recent analysis indicated negligible cancer risk associated with AFM1 exposure, but whether AFM1 impairs children's growth is important to understand because children consume relatively more milk than adults worldwide. Our paper reviews the evidence on the link between AFM1 exposure and child growth impairment. We find that the existing studies are contradictory and necessitates further studies on this question; in particular, those that control for potentially confounding factors such as household socioeconomic status, children's overall diets, hygienic factors, and agroecological zone. Though many nations have policies for maximum AFM1 limits in dairy foods, they are not based on an explicit health risk analysis of AFM1 but on conversion rates of AFB1 levels to AFM1 in dairy products. Future studies on AFM1's potential harmful effects on child growth will help to better inform policies on maximum allowable AFM1 in milk and other dairy products.