Cannabis Discovered In 17th-Century Human Bones In Milan Hospital Crypt, First Evidence Of Ancient Weed Use

In a groundbreaking study, traces of cannabis have been discovered in human bones dating back to the 17th century. Researchers working in a hospital crypt in Milan, Italy uncovered the first-ever archaeological evidence of cannabis’s psychoactive components in human bones.

"Molecules of medicinal plants can be detected by toxicological analysis even centuries after the death of an individual," says Gaia Giordano of the Department of Biomedical Science for Health at the University of Milan. "[t]his study reports the first physical evidence of cannabis use in Modern Age in Italy but also in Europe."

Giordano and her team discovered molecules of tetrahydrocannabinol (THC) the psychoactive component of cannabis, and cannabidiol (CBD) in the thigh-bones of a young man and a middle-aged woman who were buried in Milan between 1638 and 1697. Using radiocarbon dating, they extracted bone samples from the remains of nine people who were buried in a crypt at Milan’s Ca’ Granda hospital.

The team performed toxicology analyses by powdering and preparing the bone samples so that individual chemical compounds could be separated and purified within a liquid solution. This enabled them to use mass spectrometry to identify the chemical components, according to the study published in the Journal of Archaeological Science.

Preserved For Centuries
Researchers said the molecules were likely absorbed into the bloodstream and traveled through blood vessels into the bone tissue, where they were preserved for centuries.

Giordano noted that cannabis "was not listed inside the pharmacopeia, suggesting that the plant was not administered as medical treatment at the time in the hospital." She hypothesized that people may have been self-medicating or using cannabis recreationally.

The study is unique in using this toxicology method to analyze human remains at an archaeological site, said Yimin Yang at the University of Chinese Academy of Sciences in Beijing. “I think their study will open a new window for researching cannabis consumption in ancient times,” he said in New Scientist.

Yang's research found chemical traces of cannabis on wooden braziers in tombs dating back 2500 years ago. Cannabis has an even longer history of use by humans, with evidence suggesting that it was used by humans as far back as 12,000 years.

Giordano and her colleagues say they are intending to expand their toxicological search to other substances, such as cocaine, in more modern human remains.

Photo courtesy of University of Milan Laboratory of Forensic Anthropology and Odontology