By Paul Armentano, NORML Deputy Director
Adults with a history of marijuana use have a lower prevalence of type 2 diabetes and possess a lower risk of contracting the disease than those with no history of cannabis consumption, according to clinical trial data published in the British Medical Journal.
Investigators at the University of California, Los Angeles assessed the association between diabetes mellitus (DM) and marijuana use among adults aged 20 to 59 in a nationally representative sample of the US population of 10,896 adults. The study included four groups: non-marijuana users (61.0%), past marijuana users (30.7%), light (one to four times/month) (5.0%) and heavy (more than five times/month) current marijuana users (3.3%). Diabetes was defined based on self-report or abnormal glycaemic parameters.
Researchers hypothesized that the prevalence of type 2 diabetes would be reduced in marijuana users because of the presence of various cannabinoids that possess immunomodulatory and anti-inflammatory properties.
Investigators reported that past and present cannabis consumers possessed a lower prevalence of adult onset diabetes, even after authors adjusted for social variables (ethnicity, level of physical activity, etc.), despite all groups possessing a similar family history of DM. Researchers did not find an association between cannabis use and other chronic diseases, including hypertension, stroke, myocradial infarction, or heart failure compared to nonusers.
Past and current cannabis users did report engaging in more frequent physical activity than nonusers, but also possessed higher overall levels of total cholesterol and triglycerides. By contrast, the highest prevalence of marijuana consumers were found among those with the lowest glucose levels.
Investigators concluded, "Our analysis of adults aged 20-59 years ... Showed that participants who used marijuana had a lower prevalence of DM and lower odds of DM relative to non-marijuana users." They caution, however: "Prospective studies in rodents and humans are needed to determine a potential causal relationship between cannabinoid receptor activation and DM. Until those studies are performed, we do not advocate the use of marijuana in patients at risk for DM."
Previous studies in animals have indicated that certain cannabinoids possess anti-diabetic properties. In particular, a preclinical trial published in the journal Autoimmunity reported that injections of 5 mg per day of the non-psychoactive cannabinoid CBD significantly reduced the incidence of diabetes in micecompared to placebo. Investigators reported that control mice all developed adult onset diabetes at a median of 17 weeks (range 15-20 weeks), while a majority (60 percent) of CBD-treated mice remained diabetes-free at 26 weeks.
Full text of the study, "Decreased prevalence of diabetes in marijuana users: cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) III," appears online here.