The World's Most Carcinogenic Toxin Was Discovered Via Turkey Plague

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It was May of 1960 when turkeys in England started dying of a mysterious disease. By August, over 100,000 were dead — in some places, the mortality rate was 100%. Although pheasants and ducklings were also susceptible, turkey populations seemed most vulnerable, and so the plague got the name Turkey X Disease.

The turkeys seemed to be in good condition up until right before their death, when they showed signs of nervous conditions and fell into a coma. When officials opened them up, they discovered necrotic tissue in the liver, indicating they had been exposed to some kind of poison. When they traced the food supplied to each of the affected farms, and found peanut meal that had come off a certain ship from South America. When the meal was exposed to UV light, it glowed. That wasn’t a good sign.


The meal was contaminated with a fungus called Aspergillus flavus, and the glowing material was what came to be known as aflatoxin. In high quantities, this mycotoxin takes out the liver by causing extreme bleeding, cirrhosis, and killing off tissue. Even if the toxin isn’t sufficient to kill an animal outright, it is one of the most carcinogenic agents known to science. It causes liver cancer, but it also takes out the p53 gene. This gene prevents a cell from multiplying if it has mutated. So aflatoxins cause cancer, and take out our body’s defense against cancer.

Turkeys are more susceptible to these toxins than other animals, but all animals, including humans, are affected by them. And the fungus that causes them is everywhere. All A. flavus needs to grow in stored food is a high moisture content and a hot room. The aflatoxin makes its way into nearly everything. It has been found in the milk of lactating animals, and researchers studying an outbreak of contamination in Nepal found it in human umbilical blood.


Aflatoxin is nearly impossible to get rid of completely, but food regulatory agencies limit the amount of aflatoxin that can be fed to animals, to lactating animals, and to humans. Provided that food is properly stored, and monitored, there’s little danger of aflatoxin.

[Via The Histopathology of Turkey X Disease In Great Britain, Aflatoxin: A 50-Year Odyssey]


Image: Scott Bauer, USDA. Second Image: NIH.