Recent research led by Alexandra Morton-Hayward, a forensic anthropologist from the University of Oxford, challenges long-held beliefs about the decomposition of human brains after death.

Fragments of a brain from an individual buried in a waterlogged Victorian workhouse cemetery in the UK, some 200 years ago. Credit: Alexandra L. Morton-Hayward

Contrary to long-held beliefs that the brain swiftly decomposes following demise, this study, published in the Proceedings of the Royal Society B, demonstrates that human brains can endure for millennia under certain conditions.

The study, тιтled “Human brains preserve in diverse environments for at least 12,000 years,” represents the culmination of extensive global research conducted by Morton-Hayward and her team. The collaborative effort involved scouring archaeological records from various sources, amᴀssing data from over 4,400 preserved human brains spanning approximately 12,000 years of history.

Traditionally, soft tissue preservation in the archaeological record has been viewed as a rarity, with the brain’s survival considered even more exceptional, especially in the absence of other soft tissues. However, this research reveals that nervous tissues persist far more abundantly than previously acknowledged, facilitated by conditions that impede decay.

The archive compiled by Morton-Hayward and her colleagues showcases a diverse array of brain preservation environments, ranging from the icy expanses of the Arctic to the arid deserts of Ancient Egypt. Surprisingly, over 1,300 of the preserved brains were found as the sole surviving soft tissue in otherwise skeletonized remains, highlighting the remarkable resilience of this organ.

Morton-Hayward emphasized the potential of these ancient brains as a treasure trove of information about our past. She remarked, “We’re finding amazing numbers and types of ancient biomolecules preserved in these archaeological brains, and it’s exciting to explore all that they can tell us about life and death in our ancestors.”

The mechanisms behind the enduring preservation of these ancient brains remain enigmatic. While factors such as freezing, dehydration, and tanning have been implicated in short-term preservation, the persistence of brains over millennia suggests the existence of unknown preservation mechanisms specific to the central nervous system. Proposed mechanisms include molecular crosslinking and metal complexation, although further research is required to elucidate these processes fully.

Co-author Professor Erin Saupe from the Department of Earth Sciences at the University of Oxford highlighted the geographic and climatic diversity of brain preservation environments uncovered by the study. She noted, “This record of ancient brains highlights the array of environments in which they can be preserved from the high Arctic to arid deserts.”

The implications of this research extend beyond archaeology. Morton-Hayward emphasized the potential relevance of these findings to contemporary neurological conditions, stating, “The research could even provide insights into neurodegenerative conditions that affect people today, such as Alzheimer’s and other forms of dementia.”

More information: Morton-Hayward, A. L., Anderson, R. P., Saupe, E. E., Larson, G., & Cosmidis, J. G. (2024). Human brains preserve in diverse environments for at least 12 000 years. Proceedings of the Royal Society B: Biological Sciences, 291(2019), 20232606. doi:10.1098/rspb.2023.2606