Reader Sarah wrote in to ask, “If you eat a person who has an infectious disease, will you get the disease too? A morbid question I thought of while sitting in a doctor’s office and was too shy to ask.”
Most human illnesses aren’t going to pose a problem for a potential Hannibal Lecter. Cancer isn’t contagious, and one person’s cancer cells generally aren’t able to live inside anyone else because a healthy immune system will wipe them out. (There have, however, been a few instances where people “caught” cancer from an organ transplant, because they had to take drugs to suppress their immune systems so their bodies wouldn’t reject the new organs). HIV and most other nasty microorganisms, meanwhile, can be "cooked out," or destroyed by heat.
This isn’t to say that you should whip out the fava beans and Chianti just yet.
There are still a few risks that go along with cannibalism. Malaria parasites can spread among mice through cannibalism and blood-drinking, and scientists think that the simian immunodeficiency virus and hepatitis spread among chimpanzees the same way. (However, none of this has been shown in humans, and such a study probably wouldn’t pass an ethics board anyway.) It’s also possible that people could pick up tapeworms through cannibalism.
However, the biggest health threat tied to cannibalism is prion diseases, a group of neurodegenerative disorders that are spread by eating contaminated meat. Prions are misfolded proteins that wreak havoc in healthy bodies by causing healthy proteins to change shape and convert even more proteins into prions. You wind up with a cascade of misshapen proteins that cause tissue damage and cell death, and eventually brain deterioration, loss of motor control and death. It's nasty stuff, and the human brain, bone marrow, spinal cord and small intestine can all harbor prions, which aren’t easily killed denatured by cooking.
You Probably Shouldn't Read This Part While Eating
You’ve heard of at least one prion disease, mad cow disease, but the one more relevant to human cannibalism is kuru. In the 1950s and '60s, the Fore people of Papua New Guinea experienced an outbreak of a strange, unidentified and incurable illness. Villagers in the Eastern Highlands area, predominantly women and children, fell ill with muscle tremors, uncontrollable fits of laughter, slurred speech and loss of motor control. Almost every single one of them died, often in a few months or less. Scientists went to the villages to treat the victims and study the disease, and soon discovered that the sickness had a grisly origin.
The Fore were known for their tradition of “mortuary feasts,” where the death of a family member was commemorated with the ritual consumption of their body, including the organs. The scientists figured out that the disease was being spread through prions contained in the funerary meal. Women and children got sick more often because they usually got stuck eating the brains and viscera, while the men of the family got the “better” meat from the muscles.
At the height of the epidemic the government banned mortuary feasts, and although a few might still have happened in secret afterwards, the last known case of kuru ended with the death of the patient in 2005.