Researchers see link between hunter-gatherer cannabis use, fewer parasites


Washington State University researchers have found that the more hunter-gatherers smoke cannabis, the less they are infected by intestinal worms. The link suggests that they may unconsciously be, in effect, smoking medical marijuana.

Ed Hagen, a WSU Vancouver anthropologist, explored cannabis use among the Aka foragers to see if people away from the cultural and media influences of Western civilization might use plant toxins medicinally.

"In the same way we have a taste for salt, we might have a taste for psychoactive plant toxins, because these things kill parasites," he said.

In an earlier study, Hagen found that the heavier tobacco smokers among the Aka also had fewer helminths, parasitic .

He cautions, however, that the studies have their limits. While nicotine has been seen killing worms in livestock, that hasn't been directly demonstrated in humans. Cannabis kills worms in a petri dish, but researchers have not shown it killing worms in animals, Hagen said.

The Aka are a "pygmy" people of the Congo basin. As one of the world's last groups of hunter-gatherers, they offer anthropologists a window into a way of life accounting for some 99 percent of human history. They might also offer an alternative hypothesis to explain human drug use.

The prevailing explanation is that recreational drugs "hijack the pleasure centers of the brain," making people feel good. But they also trigger mechanisms that tell us we're consuming something toxic, tasting bitter and making us feel sick.

"So we thought, 'Why would so many people around the world be using plant toxins in this very 'recreational' way?" said Hagen. "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."

The issue is significant on at least two fronts, write Hagen and his colleagues, with substance abuse and intestinal helminth infection being "two of the developing world's great health problems." Their study appears in the American Journal of Human Biology.

Researchers are unsure when the Aka might have first smoked cannabis or when it arrived on the continent. It may have come with traders from the Indian subcontinent around the first century A.D., but Hagen and his colleagues say it might not have been smoked until European colonization in the 17th Century.

Hagen surveyed almost all of the nearly 400 adult Aka along the Lobaye River in the Central African Republic and found roughly 70 percent of the men and 6 percent of the women used cannabis. The polling was supported by bioassays of the men that found high enough levels of THCA, a metabolic byproduct of cannabis's active ingredient, to indicate that 68 percent of them had recently smoked.

Stool samples collected from the men to gauge their worm burden found some 95 percent of them were infected with helminths. But those who consumed cannabis had a significantly lower rate of infection. A year after being treated with a commercial antihelmintic, the were reinfected with fewer worms.

While the Aka deliberately consume a tea of a local plant, motunga, to fight parasitic infections, they do not think of cannabis or tobacco as medicine, Hagen said. This suggests they are unconsciously using to ward off parasites, he said.

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More information: High prevalence of cannabis use among Aka foragers of the Congo Basin and its possible relationship to helminthiasis, American Journal of Human Biology, DOI: 10.1002/ajhb.22740
Citation: Researchers see link between hunter-gatherer cannabis use, fewer parasites (2015, June 1) retrieved 21 September 2019 from
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Jun 01, 2015
they were stoned :D

Jun 01, 2015
My belief for a long time has been that many, perhaps most, people who smoke pot "recreationally" are prompted to do so by the needs of their bodies; they only think they're smoking to get "high."

We have subjected to arrest and in some cases imprisonment millions of completely blameless people whose crime was they were self-medicating.

Jun 01, 2015
There is evidence that some helminths are beneficial and a requirement for a healthy immune system.

-I think that the desire to self-medicate stems in part from the fact that we are over-evolved due to forced competition in an overcrowded world. Our brains are too large and begin to deterioriate soon after adolescence. Our immune systems are over-developed in response to over-exposure to all sorts of human and animal diseases. And we must constantly deny our animal proclivities in order to live within the often irrational social confines of the tribe.

I think these conditions cause us constant subliminal pain and anxiety, and we seek out meds to help us cope. Eden is the abstract representation of a world where we can live without the constrictions of society, and of the domestication which has distorted us. Like the poor little dachshund.

Jun 08, 2015
Symbiotic plants are to be expected. Prohibition is myopic. The inhabitants of the fairest cape of storms were reported by the mariners to be chewing the leaves of the Dagga plant.

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