The earliest evidence for the use of plants as drugs—possibly for medication or a pick-me-up—may have been found amid human remains in a 15,000-year-old cave burial in North Africa.
According to a study published this month in Scientific Reports, researchers discovered berry-like seed cones from the shrub genus Ephedra in an ancient burial pit at the Grotte des Pigeons (Cave of Pigeons) in northeastern Morocco.
Ephedra cones contain the substance ephedrine, a powerful stimulant that speeds up communication between the brain and body; and the researchers think they were consumed during the burial—suggesting the plant was widely used by the Stone Age people who lived nearby at the time.
The discovery “underscores the important role of plants in Palaeolithic lifeways, long before agriculture or a sedentary lifestyle emerged,” study lead author Jacob Morales, an archaeobotanist at Spain’s University of Las Palmas of Gran Canaria. “Our results emphasize that plants were a significant resource for Palaeolithic communities.”
Today, ephedrine is now known to ease breathing and as a “vasoconstrictor”—a drug that narrows blood vessels and can reduce some types of bleeding.
But the stimulant can also increase blood pressure and heart rate to dangerous levels, and its regular use can cause seizures.
Writings from ancient China show Ephedra shrubs have been used in traditional cold remedies for thousands of years, and they are still sold for that purpose in markets in parts of Africa and Asia; while a less-powerful substance related to ephedrine, called pseudoephedrine, is an ingredient in many cold medicines today.
Drugs at a funeral
The Grotte des Pigeons is also known as Taforalt, from the name of a nearby Amazigh (Berber) village, and contains evidence of human occupation and burials at different times over more than 100,000 years. At the time of this burial, hunter-gathers called the Iberomaurusians lived along the coasts of Northern Africa and likely occupied in the cave.
Morales says the burial “appears to have held special significance,” noting the ancient pit also contained evidence of butchered Barbary sheep and the large birds known great bustards.
“These remains suggest that butchered products were intentionally placed in the burial pit alongside the human body and other valued items,” he says. “It is possible that Ephedra was consumed alongside these special foods during a ritual feast attended by the group, and that all these items were subsequently buried in the pit with the deceased.”
Prehistoric plants
“Ephedra is a powerful plant that can act as a strong stimulant as well as having medicinal properties,” says archaeologist Karen Hardy of the U.K.’s University of Glasgow, who was not involved in the study.
But it is also potentially dangerous, and its use suggests a deep understanding of its effects, she says.
Morales notes that any knowledge of the plant’s physiological effects could only have been gained by consuming it.
Hardy says it is now impossible to know exactly why prehistoric people in Morocco were consuming the plant.
But “no type of use should be discounted, particularly given the context of a purported burial ceremony,” she says. “Its presence in association with the burial… is likely to be significant.”
Archaeologist Anna Maria Mercuri of Italy’s University of Modena and Reggio Emilia, an expert on prehistoric plant use who also wasn’t involved, says the Ephedra cones at the Grotte des Pigeons are evidence of a “competent, sophisticated, and—for us—surprising human behavior.”
“There is no doubt that we humans learnt very early on how to use plants according to their properties, seeking their benefits and help in controlling nature,” she says.
If the Iberomaurusians understood Ephedra’s effects, they may have also used it in other settings. Morales says there is evidence these ancient people were adept at primitive surgeries like extracting teeth and performing trepanations—when a small hole was drilled in the skull, ostensibly to treat disease.
“Given Ephedra’s vasoconstrictive properties, it may have been used to minimize blood loss during these surgeries,” he says. “Its antibacterial and antifungal effects would have further supported healing by lowering the risk of infection.”
Ancient drugs
The new discovery seems to be the earliest evidence of prehistoric people using plants as drugs.
Researchers previously linked pollen from a famous Neanderthal “flower burial” at Shanidar Cave in Iraq to yarrow and chamomile—plants that act as mild sedatives. That particular interment is up to 70,000 years old. But recent research suggests instead that burrowing bees deposited the pollen in modern times.
Ancient writings from China, Egypt, and Mesopotamia—including the Epic of Gilgamesh, a 4,000-year-old Sumerian poem and one of the world’s oldest written texts—describe plants being used as medicines.
Ephedrine also showed up in a recent analysis of 3,000-year-old strands of hair from the Mediterranean island of Menorca, alongside the hallucinogenic plant substances atropine and scopolamine.
Burial rites
Morales didn’t expect to find Ephedracones in his team’s microscopic analysis of the ancient burial.
“Remains of Ephedra fruit are rare in archaeological sites,” he says. “To our knowledge, no such finds have been made in Palaeolithic sites, so discovering them concentrated in one of the oldest cemeteries in Africa was entirely unexpected.”
The study of ancient hair from Menorca suggested the ephedrine had been taken to mitigate the sickness felt from taking hallucinogens, and Morales thinks that may have been a possibility at the Grotte des Pigeons.
But the Ephedra could also have served many other purposes, he says, such as keeping people awake, alleviating pain during ritual events, or reducing tiredness after gathering special foods for a feast at the burial.
It was unlikely, however, to have been used for a simple “trip.”
“We do not believe it was used recreationally, as it often is in modern contexts, since this appears to be a more contemporary practice,” Morales says.
Ethnobotanist Giogio Samorini, an independent researcher who studies the prehistoric use of psychoactive drugs and was not involved in the study, says recent archaeological finds were “finally filling what until now had been an enigmatic gap, regarding the knowledge and use of ephedra in the human past.”
“The exceptionality of the Moroccan discovery undoubtedly lies in its great antiquity, and in being the first on the African continent,” he says.
Many modern archaeologists interpret the use of such drugs as medicinal; but while it isn’t clear why the Iberomaurusians at the Grotte des Pigeons consumed Ephedra cones, the prehistoric use of such plants could be very different than their uses today.
Only one thing is certain, says Samorini: “Even ancient man experienced the intoxicant effects of these plants.”