Scientists explain why humans stopped eating human flesh
Polish and Czech researchers have found that the taboo against cannibalism in human societies may stem not only from morality but also from health risks. The study shows eating human flesh raises the risk of spreading dangerous infections while offering relatively low nutritional value.
For a long time, the taboo against cannibalism in human societies was thought to stem mainly from morality, culture or natural revulsion. A new study by Polish and Czech scientists suggests health risks may have played a significant role as well.
Researchers examined cannibalism from both a cultural and a biological perspective, comparing the energy value of the human body to the potential risks involved. It turns out human flesh is not a particularly efficient food source in terms of calories compared to animals, while the risk of disease is much higher. This is explained by the close physiological similarity between humans, which makes it easier for pathogens to adapt and spread within the same species.
The threat of prion diseases
One of the main dangers comes from prions — unusual protein structures that can cause severe, fatal diseases of the nervous system. Unlike many bacteria or viruses, prions are highly resistant and cannot easily be destroyed through ordinary heat treatment. A well-known example is kuru disease, which once spread among the Fore people of Papua New Guinea, where a tradition existed of eating the body parts of deceased relatives as part of funeral rituals.
Scientists built a mathematical model to assess how cannibalism could have affected ancient human communities. The results showed that when eating human flesh became a regular practice, the risk of disease transmission rose sharply, increasing the chance that such communities would die out.
Possible only in extreme circumstances
Researchers believe that in certain situations, such as during famine, cannibalism could have served as a survival mechanism. However, over the long term, the associated health risks likely outweighed any benefits. This health threat may be one of the reasons such a strong taboo against eating human flesh developed in human societies — scientists note that taboos are sometimes not merely cultural or religious norms, but also a way for societies to protect themselves from dangerous risks over time.
