Original Research Article
High prevalence of cannabis use among Aka foragers of the Congo Basin and its possible relationship to helminthiasis
Version of Record online: 29 MAY 2015
© 2015 Wiley Periodicals, Inc.
American Journal of Human Biology
Volume 28, Issue 1, pages 5–15, January/February 2016
How to Cite
Roulette, C. J., Kazanji, M., Breurec, S. and Hagen, E. H. (2016), High prevalence of cannabis use among Aka foragers of the Congo Basin and its possible relationship to helminthiasis. Am. J. Hum. Biol., 28: 5–15. doi: 10.1002/ajhb.22740
- Issue online: 4 JAN 2016
- Version of Record online: 29 MAY 2015
- Manuscript Accepted: 6 MAY 2015
- Manuscript Revised: 24 FEB 2015
- Manuscript Received: 26 JAN 2015
- State of Washington Initiative Measure No. 171
Little is known about cannabis use in hunter-gatherers. Therefore, we investigated cannabis use in the Aka, a population of foragers of the Congo Basin. Because cannabis contains anthelminthic compounds, and the Aka have a high prevalence of helminthiasis, we also tested the hypothesis that cannabis use might be an unconscious form of self-medication against helminths.
We collected self- and peer-reports of cannabis use from all adult Aka in the Lobaye district of the Central African Republic (n = 379). Because female cannabis use was low, we restricted sample collection to men. Using an immunoassay for Δ9-tetrahydrocannabinol-11-oic acid (THCA), a urinary biomarker of recent cannabis consumption, we validated cannabis use in men currently residing in camps near a logging road (n = 62). We also collected stool samples to assay worm burden. A longitudinal reinfection study was conducted among a subsample of the male participants (n = 23) who had been treated with a commercial anthelmintic 1 year ago.
The prevalence of self- and peer-reported cannabis use was 70.9% among men and 6.1% among women, for a total prevalence of 38.6%. Using a 50 ng/ml threshold for THCA, 67.7% of men used cannabis. Cannabis users were significantly younger and had less material wealth than the non-cannabis users. There were significant negative associations between THCA levels and worm burden, and reinfection with helminths 1 year after treatment with a commercial anthelmintic.
The prevalence of cannabis use among adult Aka men was high when compared to most global populations. THCA levels were negatively correlated with parasite infection and reinfection, supporting the self-medication hypothesis. Am. J. Hum. Biol. 28:5–15, 2016. © 2015 Wiley Periodicals, Inc.