Indigenous peoples of western South America have been consuming coca leaves for both medicinal and recreational purposes for thousands of years, but it wasn't until Western chemists developed cocaine hydrochloride in the 19th century that the plant became popular across Europe. But thanks to new forensic analysis, at least some people knew about and accepted the benefits of coca 200 years earlier than originally thought.
The evidence is detailed in a study published in the Archaeological Journal by medical and biomedical experts from the University of Milan and the IRCCS Ca' Granda Foundation. According to the team, at least two preserved brains buried in an ossuary near the 17th-century hospital show the presence of cocaine, benzoylecgonine and hygrine – the active ingredients of the coca plant. The presence of these chemicals, especially hygrine, indicates that two local residents from the late Renaissance period had chewed coca leaves or drunk tea with coca shortly before their death and burial at the Maggiore Hospital.
(Related: Shark tests positive for cocaine.)
One of Italy's most famous hospitals at the time, Ospedale Maggiore operated in Milan for almost the entire 17th century. Nearly 100 years of medical activity meant many patient deaths, necessitating the construction and maintenance of an increasingly large ossuary close to the medical facility. As the study authors explain, it eventually became an archaeological treasure trove that is now estimated to contain as many as 2.9 million bones from around 10,000 individuals.
The recovery and study of these remains continues to deepen experts' understanding of the late Renaissance and early modern period. For example, in 2023, mummified brain and bone samples were found to contain traces of poppy seeds and cannabis, indicating opium use, although cannabis was not recorded at the time.
Coca was also thought to be an unknown plant in Italy until the 19th century, when pharmacists first began to synthesize cocaine hydrochloride, but examination of the brains of two mummies buried at Ca' Granda required some revision of that theory.
“Through archaeotoxicological analysis of human remains in the special context of the Ca' Granda Crypt, we provide, to our knowledge, the first solid evidence of coca plant use in Europe, dating coca use in Europe back to the 1600s,” the authors write in their conclusion.
This realization is not entirely sudden. As the researchers point out in their study, historical written evidence indicates that Spanish sailors were at least aware of the benefits of coca after their arrival in South America. At the same time, Europeans soon became increasingly interested in the “exotic plants of the New World” as that knowledge spread across the continent. In the 16th and 17th centuries, maritime trade between South America and Milan, then under Spanish rule, expanded. This, according to the researchers, indicates “a direct link between the Italian city and the continent of the plant's origin.” That “direct link” can now be traced directly to the 17th-century crypt of Ca' Granda, although local pharmacological archives contain no reports of coca or cocaine for another 200 years.
Beyond the chemical signatures, the study authors don't currently know much about how popular coca leaves were at the time, or whether they were used medicinally or recreationally. But based on the location and method of burial, experts believe the bodies were those of poor people. Given this, it's possible that starving indigents turned to coca leaves for their appetite-suppressing side effects. If so, the team hypothesizes that not only was coca leaf present in Milan two centuries earlier than previously thought, it may have also been cheap, popular, and widespread.
