If you want to understand how hard the war on drugs is to win, consider how quickly drugs spread despite major obstacles: Analysis of 17th-century corpses has revealed that traces of the drug had made their way into European brain tissue shortly after Europeans first encountered coca in South America, and centuries before anyone isolated cocaine.
There is widespread evidence that chewing the leaves of the Erythroxylum genus, known as coca, has been a popular pastime in South America for centuries. The drug known as cocaine was probably the main attraction, but the amount consumed was likely small because the leaves also contain many other molecules, some of which may have also contributed to the attraction.
The Spanish conquistadors were initially outraged and tried to ban the plant, then used it to consolidate their power. By the mid-19th century, chemists had figured out how to purify the drug, and it became all the rage across the continent, at least among those who could afford it.
While records of cocaine consumption are easily found from the 19th century onwards, it's unclear whether the leaf was used in Europe before then. Researchers from the University of Milan obtained samples from Ospedale Maggiore, a 17th-century hospital that treated Milan's poor, where more than 10,000 patients are buried in the crypt of a nearby church.
Archaeologists have found a treasure trove of bones in the basement, including one where the same team found traces of marijuana last year. Some of the brain tissue was surprisingly intact after the passage of time. When researchers examined nine of the remains, they found that one of them had tertiary syphilis.
Two of the samples contained cocaine itself as well as benzoylecgonine, a molecule that is metabolized from cocaine in the body.
The authors are confident that this is not due to modern contamination, both due to the careful collection of samples and the fact that not all samples gave the same results. Ruling out contamination is important: there are claims that ancient Egyptian mummies contained cocaine, but if this were true it would require contact between Africa and South America, and there is no other evidence. It is more likely that the samples were contaminated.
A third molecule, hygrine, was also present in two samples. The molecule is found in coca leaves, which are chewed and used to make tea, but not in refined cocaine.
This is the oldest evidence of coca in Europe going back more than two centuries.
It is unclear why the two men were chewing coca leaves. South Americans used the leaf for various medicinal purposes; it is possible that the Ospedale Maggiore, ahead of its time in many ways, adopted this; but there is no mention of the hospital's use of coca. Meanwhile, coca must have been taken not long before death to be detectable, so it was likely taken medically, perhaps as a painkiller, rather than recreationally.
Milan was under Spanish control at the time these people died, which helps explain the drug's presence there more than in many other parts of Europe. But it's worth noting that coca leaves seem to have been widely used, and in some places even the poor could have obtained them. It's unlikely that coca was cultivated in Europe, and transporting it across the Atlantic was still very expensive.
The report has been published in open access format in the Journal of Archaeological Science.
