Africa: Cannabis Use Among Male African Pygmies Linked To Decreased Risk Of Infection
By Steve Elliott
Could using cannabis help protect against parasitic infection? A study from Africa seems to show that it does.
In a population of Congo Basin foragers called the Aka, 67 percent of men—but just 6 percent of women—use cannabis, and the practice seems to protect against infection with parasitic worms.
The large sex difference, which is also seen in tobacco use, might be a consequence, in part, of women's avoidance of smoking during childbearing years.
The results highlight the need for more research on the high rate of cannabis use in Aka men.
“Recreational drug use is rarely studied in hunter gatherers,” said Dr. Edward Hagen, senior author of the American Journal of Human Biology study. "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, reports Science Daily.
“We’re intrigued by the possible link between cannabis use and parasitic worms, which resembles the self-medication behavior seen in numerous species.
"We need to be cautious, though, in generalizing from one study in a unique population to other populations,” Dr. Hagen, a Washington State University anthropologist, said.
The Aka, as one of the world's last group's of hunter-gatherers, offer anthropologists a unique window into a way of life covering some 99 percent of human history; they might also offer an alternative hypothesis explaining human drug use.
"So we thought, 'Why would so many people around the world be using plant toxins in this very 'recreational' way?" Dr. Hagen said. "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 researchers noted that cannabis might not be the only recreational drug that protects against parasites. “Our previous research showed that tobacco use also seems to protect against parasitic infection, and many other recreational drugs contain anti-parasitic compounds,” said first author Dr. Casey Roulette.
Reference: Roulette, C. J., Kazanji, M., Breurec, S. and Hagen, E. H. (2015), "High prevalence of cannabis use among Aka foragers of the Congo Basin and its possible relationship to helminthiasis." Am. J. Hum. Biol.. doi: 10.1002/ajhb.22740
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