Aflatoxins are toxins (mycotoxins) produced by some species of Aspergillus molds (fungi). Many foods such as peanuts, corn (maize), and other grains are frequently contaminated with aflatoxins.
Aflatoxin contamination is especially common in foods improperly stored in damp or wet conditions, and is especially common in hot and humid climates such as those found in many parts of Africa.
Aflatoxins are toxic to the immune system and are potent carcinogens (ie. cancer causing compounds). Recent research has reported that high levels of aflatoxin exposure are associated with high viral loads in HIV+ people. Aflatoxins in foodstuffs are estimated to cause 105,000 to 142,000 annual liver cancer cases worldwide.
The US Centers for Disease Control estimates that 4.5 billion people in the developing world are exposed to significant levels of aflatoxins in foods. Reducing levels of aflatoxins are critical in many parts of the world. The most important method to control aflatoxin contamination involves water control of harvested crops. Grains and peanuts should be harvested under dry conditions if possible, and the grains/peanuts should be quickly dried to less than 17% water (using mechanical drying such as fans and heaters if available) and then stored under clean and dry conditions. Contaminated foods should be discarded. Research is currently being conducted to develop corn and wheat strains resistant to aflatoxin producing Aspergillus species. Another method being tried involves the use of inoculating crop fields with bacteria or non-aflatoxin producing molds to prevent growth of aflatoxin producing Aspergillus. Innoculating corn and peanuts with non-aflatoxin producing Aspergillus flavus can reduce aflatoxin contamination of corn and peanuts by as much as 90%. Much more research is needed to reduce aflatoxin production in crops and stored food.