REVIEW OF ANCIENT HUMAN BRAINS REVEALS THEY PRESERVE NATURALLY FOR THOUSANDS OF YEARS, LASTING LONGER THAN OTHER ORGANS

Researchers have discovered that archaeologically recorded preserved human brains are not as extremely rare as has previously been believed.

Researchers compiled the records of more than 4,000 preserved human brains from more than 200 sources across six continents, excluding Antarctica, Knewz.com has learned.

A new study conducted by researchers at the University of Oxford, UK, led by postgraduate researcher Alexandra Morton-Hayward in the department of Earth Sciences, highlights that nervous tissues actually persist in greater abundance in ancient human brains than traditionally thought.

“I worked for years with the dead. My own experience is that the brain is pretty quick to liquefy (postmortem). So it was a real shock when I came across a (scientific) paper referencing a 2,500-year-old brain," said Morton-Hayward.

Their research drew on source material in more than 10 languages and represents the largest, most complete study to-date. It uses more than 20-fold the number of brains previously compiled. Many of the brains were up to 12,000 years old and were found in records dating back to the mid-17th century.

The scientists published their work on March 20 in a paper titled “Human brains preserve in diverse environments for at least 12 000 years,” in the Proceedings of the Royal Society B. In studying the literature and speaking with historians across the world, the scientists discovered ancient human brains in far flung places from the shores of a lakebed in Stone Age Sweden, the depths of an Iranian salt mine around 500 BC, and the summit of Andean volcanoes at the height of the Incan Empire.

The brains themselves belonged to everyone from Egyptian and Korean royalty to British and Danish monks, Arctic explorers, and those killed in various wars.

Each brain in the database was matched with historic climate data from the same area, and analysis revealed patterns connected to environmental conditions associated with different modes of preservation through time. Those methods included everything from dehydration and freezing to saponification (the transformation of fats to "grave wax") and tanning (usually with peat, to form bog bodies).

“This record of ancient brains highlights the array of environments in which they can be preserved from the high arctic to arid deserts,” said co-author Erin Saupe in a statement.

According to the researchers, more than 1,300 of the human brains were the only soft tissues preserved, prompting questions as to why the brain may persist when other organs perish. These particular brains, the scientists noted, represent the oldest in the archive, with several dating to the last Ice Age.

“In the forensic field, it’s well-known that the brain is one of the first organs to decompose after death – yet this huge archive clearly demonstrates that there are certain circumstances in which it survives. Whether those circumstances are environmental, or related to the brain’s unique biochemistry, is the focus of our ongoing and future work," said Morton-Hayward. "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.”

To date, less than 1% of preserved brains have been investigated for ancient biomolecules. Their untapped archive of 4,400 human brains could “provide a significant opportunity for unique insights into the early evolution of our species, such as the roles of ancient diseases,” said co-author Ross Anderson.

2024-03-26T00:31:52Z dg43tfdfdgfd