Traces of cannabis in human bones suggest 17th-century Italians were recreational pot users

People have been consuming weed for a very long time.

Ancient Greek historian Herodotus wrote about flowers with psychotropic effects in 440 BC, and medical records from the Middle Ages in Europe show cannabis was widely administered to treat everything from gout, urinary infections and birthing pains to weight loss, as well as being used as an anesthetic.

But in 1484, Pope Innocent VIII passed a bull, or decree, labelling cannabis an "unholy sacrament" and banning its use among the faithful. During the time of the Inquisition, medicinal and hallucinogenic herbs were associated with magic and witchcraft.

For the centuries that followed, there has been no hard evidence of its use — that is, until now, with the discovery by a team of forensic scientists in Milan, Italy, of traces of cannabis in the remains of two skeletons from the 17th century.

"We know that cannabis has been used in the past, but this is the first study ever to find traces of it in human bones," said biologist and doctoral student Gaia Giordano at the University of Milan's Laboratory of Forensic Anthropology and Odontology (LABANOF) and Laboratory of Toxicological Investigation.

"This is an important finding, because there are very few laboratories that can examine bones to find traces of drugs."

The study was published in the December issue of the peer-reviewed Journal of Archaeological Science.

In it, the team of scientists examined nine femoral bone samples from people who lived in 1600s Milan and who were buried in the Ca' Granda Crypt, under a church annexed to the Ospedale Maggiore, the city's most important hospital for the poor at the time.

The goal of the study was to find traces of plants used for medical or recreational purposes in the general population. (It follows an earlier study by Giordano that found traces of opium in cranial bones and well-preserved brain tissue.)

In the study, two of the bones — one belonging to a woman around age 50 and another to a teenage boy — showed the presence of two kinds of cannabinoids: Delta-9-tetrahydrocannabinol and cannabidiol, commonly referred to today as DTC and CBD.

The researchers say the finding not only suggests cannabis was consumed by all ages and genders, but that it was used recreationally, most likely prepared in cakes and infusions, says Giordano.

The team scanned the medical records of Ospedale Maggiore and found no mention of cannabis in its detailed records of the healing plants, remedies and potions administered to patients in all hospitals in Milan in the 1600s.

Its absence in the list of pharmacopeia led researchers to surmise cannabis found in the two individuals was likely used for the same reasons it is today — to relax, zone out or self-medicate.

"Life was especially tough in Milan in the 17th century," archaeotoxicologist Domenico di Candia, who led the study, told the newspaper Corriere della Sera. "Famine, disease, poverty and almost nonexistent hygiene were widespread."