evidence: Moulds that grow naturally on food can produce toxins that have serious effects on health, even causing cancer. Certain moulds — especially those that grow in maize (corn), peanuts and tree nuts such as almonds and pistachios — produce aflatoxin, a carcinogen that is estimated to cause up to 28% of the total worldwide cases of hepatocellular carcinoma (HCC), the most common form of liver cancer1,2. Many people are unaware of the link between naturally occurring food contaminants and cancer. Education, stricter food-quality controls and the cultivation of alternative crops can have a large impact on worldwide rates of liver cancer. Aflatoxin is generated by the fungi Aspergillus flavus and Aspergillus parasiticus and, in addition to liver cancer, it has been associated with acute poisoning, immune-system dysfunction and stunted growth in children. People whose livers are already compromised by infection with hepatitis B virus (HBV) are particularly susceptible to aflatoxin-induced liver cancer3.