The finding has come from scientists based at Washington State University. Data indicates that the more often the hunter-gatherers smoke marijuana, then the less they are infected by intestinal worms. The Aka people are not taking the psychoactive substance for this purpose; the effect is an unintended consequence.
The Aka people are a Mbenga pygmy people, located in southwestern Central African Republic and the Brazzaville region of the Republic of the Congo. The people are nomads and they have a very varied diet, including over sixty plants, various species of game and many insects.
Part of the research was to see if people have traditionally orientated towards the cannabis plant because some component within it helps to keep people healthy, in relation to different regions of the world. The argument is that the brain has in-built sensors that signal if something tastes ‘good’ or ‘bad’ and this might be related to physiological function. The Aka people, when interviewed, did not think of cannabis as medicine. This was unlike tea from a local bush called motunga, where the people believed that drinking the tea had medicinal properties.
A similar finding relates to the use of tobacco; where those among the Aka who smoke the tobacco plant leaves also had lower incidences of parasitic worms in their intestines. The presence of helminth worms was examined through fecal samples. Helminths are worm-like organisms living in and feeding on living hosts.
It should be noted, however, that such results are based on lose correlations and the sample size was quite small (400 people based around the Lobaye River in the Central African Republic.) There is supporting data that both nicotine and marijuana, at certain concentrations, can kill worms under laboratory conditions. However, there is no direct evidence about the effect in people.
The research has been published in the American Journal of Human Biology. The paper is headed “High prevalence of cannabis use among Aka foragers of the Congo Basin and its possible relationship to helminthiasis.”