Medical marijuana: Modern hunter-gatherers may use cannabis to treat intestinal infections

It has been found that the more cannabis that modern foraging tribes smoke, the less they are infected with parasitic intestinal worms. Scientists are trying to determine if ancient-hunter gatherers were aware of this connection. Early peoples did, as many do now, use plants medicinally—but was this deliberate, or was cannabis used ‘unconsciously’ by ancient societies?

Anthropologists have been studying the marijuana use of a modern hunter-gatherer culture in Central Africa order to shed light on human history, and the purposes behind ancient drug use.

Cannabis and other psychoactive plants have played a role in human civilization throughout history and around the globe; it was used to treat symptoms of illness and wounds, as a part of recreation and ritual, and as a pain killer. However, little is known about drug use in hunter-gatherer societies.

The marijuana habits of a modern foraging society are continuing the eons-old tradition, and are providing insight to scientists into why humans might have taken up the practice in the first place, and have continued it to this day.

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Washington State University anthropologists have published a study in which they examined cannabis use among one of the few remaining hunter-gatherer groups of the modern world, the Aka foragers of tropical Central Africa. The research team was working with the possibility that ancient hunter-gatherer tribes “might have used cannabis as a way to unconsciously stave off intestinal worms,” reports Medical Daily.

The study poses alternative hypotheses explaining human drug use. The current understanding is that recreational drugs target pleasure centers in the brain and make people feel good and well, and this was the case then as now. But a reaction to the toxicity of the drugs can also occur, making many feel ill. So the question remains: why did humans continue consuming such plants when they caused strong effects?

 “In the same way we have a taste for salt, we might have a taste for psychoactive plant toxins,” said study author Ed Hagen, an anthropologist at Washington University Vancouver in a press release.

“So we thought, ‘Why would so many people around the world be using plant toxins in this very recreational way?’ If you look at non-human animals, they do the same thing, and what a lot of biologists think is they’re doing it to kill parasites,” he continued.

A family from a Ba Aka pygmy village, Democratic Republic of the Congo. The Aka are one of the few remaining hunter-gatherer groups of the modern world. Public Domain

A sampling of 400 Aka adults were analyzed in the study. The Aka are a “pygmy” people from the Congo basin, and their society offers “a window into a way of life accounting for some 99 percent of human history,” the press release notes.

A survey found that approximately 70 percent of men and 6 percent of women used cannabis for various reasons, not, however, to treat intestinal infections or parasites. Instead, the Aka drink tea made from the local motunga plant to fight these infections, and do not consider cannabis to be a medicine.

Collected stool samples revealed that roughly 95 percent of men suffered from an intestinal helminth infection—but surprisingly those who smoked cannabis had a significantly lower infection rate than those who didn’t.

Helminth eggs of different helminth (parasitic worm) species. In the body they impede nutrient absorption, and cause weakness and disease. Wikimedia Commons

This suggested to the anthropologists that the Aka might be using cannabis “unconsciously” to combat infection.

The deliberate use of drugs can be found through archaeological findings and historical record, such as chemical residues from psychoactive plants in dwellings from various eras and in artifacts and human remains from thousands of years ago.

Ancient relief carving depicting drug use (Michael Bradley)

Golden Scythian artifacts have been found with traces of cannabis and opiates, leading researchers to conclude that ancient rituals were performed involving drugs.

Scientific research on the Siberian Ice Maiden mummy shows that the young woman died from breast cancer, and suffered numerous other ailments. Cannabis may have been used to cope with the symptoms of her illnesses.

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Regarding the study on the Aka people, Medical Daily writes, “It’s important to note that this study was conducted by anthropologists acting on assumption. There’s no evidence yet to suggest that the Aka foragers used the drug because of its medicinal benefits, or if it was simply a correlation. In addition, researchers still aren’t sure whether cannabis can treat parasites and worms. In a previous study, author Ed Hagen and a team of researchers found that cannabis can kill worms in a petri dish, but it hasn’t been proven to work in humans yet.”

However, the research into cannabis use and intestinal parasites is important. Hagen and colleagues note that intestinal infection and substance abuse are “two of the developing world's great health problems.”

Study findings have been published in the American Journal of Human Biology.

Featured Image: Do hunter gatherers smoke marijuana “unconsciously” to combat intestinal parasites? Cannabis sativa plant (Wikimedia Commons)

By Liz Leafloor