This summer, anthropologists at Washington State University published new research about medical-marijuana use in the Congo Basin. According to their report, the hunter-gatherer Aka people “are characterized by a preference for forest life, polyphonic music… and are generally peaceful and egalitarian with marked gender equity.”
They also smoke. A lot.
The research, led by Casey Roulette, Edward Hagen, and others found that roughly 95 percent of Aka men smoke tobacco (compared to around 17 percent in sub-Saharan Africa and 31 percent around the globe) and 68 percent smoke cannabis—both of which, the anthropologists found, are correlated with lower rates of helminths, or parasitic worms. (Fun fact from an earlier report about Aka tobacco use by Roulette, Hagen, et al.: "In an interesting use of plant toxins among urban sparrows and finches, cigarette butts containing residual nicotine are placed in nests to defend against nest-dwelling ectoparasites such as mites.")
Aka women smoked far less, Hagen wrote by e-mail, because they live in “a natural fertility population—no modern birth control—so women are pregnant or nursing most of their adult lives. They avoid tobacco to avoid harming their fetuses and nursing infants.”
Researchers found that both Aka men and women over-reported how much they smoke—perhaps because they live in such a smoke-positive culture. "Fewer than 15 percent of Aka women self-reported smoking tobacco," the anthropologists wrote, "and only 5 percent were smokers according to their levels of cotinine, a nicotine metabolite."
The Aka did not tell researchers they smoke to prevent helminths, but to “increase their courage on a hunt, dance better, increase their vital force, or to increase their work capacity when working for Europeans or village people.” The Aka say cannabis is especially helpful when hunting elephants and that women prefer husbands who smoke—which could account for such high rates of male smoking.
Foragers in the Congo Basin, the report says, tend to be "heavily parasitized" with helminths, which "is associated with anemia, growth stunting, protein-calorie under nutrition, fatigue, and poor cognitive development."
The anthropologists noted competing theories about when cannabis came to Africa—some, using linguistic and archaeological evidence, argue it arrived "via Moslem sea traders from the Indian subcontinent around the 1st century AD" and spread with caravan traders. Others say that even if marijuana had been growing in Africa for centuries, it wasn't popular for smoking until the arrival of European colonizers.
"Ethnographically, elephant hunting specialists have been described as the heaviest users of cannabis," the anthropologists wrote, "which might indicate that it was adopted at the height of the ivory trade in the 19th century."
Edward Hagen, one of the researchers, says their earlier report on tobacco use among the Aka, as a kind of "chemotherapy" against helminths, was an even better study—but that their work on "'medical' tobacco" has been "downplayed" by the press.