Researchers Discover Traces of Cocaine in the Brain Tissue of 17th Century Mummies Buried in Milan
Residues of cocaine were found by researchers in two individuals buried in a tomb at Ospedale Maggiore, a “pioneering hospital” in Milan that served the poor, according to a study published in the Journal of Archaeological Science.
Out of approximately 10,000 individuals buried in the tomb, researchers examined brain tissue from nine people who died at the hospital in the 1600s and were naturally mummified. They performed toxicological analysis of the tissue using mass spectrometry, a technique that identifies the chemical composition of samples by measuring the mass of individual molecules. This analysis revealed three main molecules – cocaine, hygrine, and benzoylecgonine – in the brain tissue of two individuals.
Signs of tertiary syphilis, a severe and late-stage pathology, are seen in the X-ray images of one of the 17th-century individuals who tested positive for cocaine. (Photo: Gaia Giordano and collaborators).
The presence of hygrine indicates that the cocaine in their tissues originated from the consumption of coca leaves. The consumption of cocaine salt, a method commonly used in modern times, does not produce hygrine.
Cocaine is extracted from the coca plant (Erythroxylum coca), a shrub native to South America. When the Italian explorer Amerigo Vespucci arrived in Venezuela in 1499, he noted that indigenous people chewed coca leaves with lime and roasted shells, according to the research. Later, Spanish invaders observed that the Inca Empire controlled coca fields and used them for religious, recreational, and medical purposes.
The study indicates that the Inca people regarded the coca plant as a miraculous and magical plant capable of alleviating hunger and thirst, producing an exhilarating effect, serving as medicine (such as antiseptics and pain relievers, aiding digestion, treating asthma, stomach pain, chest pain, wounds, reducing nosebleeds and vomiting), and providing comfort.
Although the Spanish conquerors learned about the medical and recreational properties of coca leaves, they initially kept it a secret while focusing on exporting other resources like gold, silver, sugar, and tobacco. However, chewing coca leaves enabled the Spaniards to work tirelessly in gold and silver mines, as well as on plantations. A few conquerors attempted to send coca leaves back to Europe, but their contraband spoiled during the trans-Atlantic journey, preventing the introduction of the plant to Europe until the 1800s.
However, the study suggests that the plant may have arrived in Europe earlier. Radiocarbon dating of one of the skeletons buried alongside the cocaine-positive individuals indicates they lived approximately 350 years ago.
“The laboratory analyses not only push back the timeline of when Erythroxylum spp. appeared in Europe by nearly two centuries, but also demonstrate that some people in Milan had contact with this New World plant and chewed or made tea from its leaves,” said Gaia Giordano, the lead author of the study and a PhD candidate in archaeology at the University of Milan.
Hospital records at Ospedale Maggiore do not mention cocaine as a treatment method until the 19th century, so it is likely that these two individuals sourced coca leaves themselves, researchers noted. The presence of cocaine in brain tissue indicates use occurred when the user was near death. Interestingly, one of the coca users also lived with tertiary syphilis and was identified as an opiate user in a 2023 study published in Scientific Reports.
Giordano believes these individuals may have used coca leaves for recreational purposes or self-medication. “It could have been used as part of a medicinal remedy by healers not working in the hospital,” she said.
Since Milan was under Spanish rule in the 17th century and was one of the destinations for maritime trade from the Americas, it is possible that some coca plants arrived in Milan unbeknownst to the authorities. In the subsequent centuries, cocaine spread throughout the world, becoming “a widely used addictive substance due to its psychoactive properties, as well as being responsible for 1 in 5 overdose deaths worldwide in the 20th century,” the authors wrote in the study.
