Potential Risks and Benefits: Canadian and US Perspectives
Health and safety risks vary with each of the different ways of using cannabis for individuals with and without diabetes, depending on a host of patient- and product-specific factors.
In a recent article proposing a “THC unit” for Canada’s legal cannabis market, researchers reported that consumers lack familiarity with THC levels, don’t know what constitutes a “low” or “high” THC amount, have trouble dosing, overconsume, and commonly experience adverse health events from cannabis use.
A recent study suggested that most clinicians are similarly uninformed, with “a lack of knowledge of beneficial effects, adverse effects, and of how to advise patients,” even for medical cannabis.
Diabetes Canada takes a stab at summarizing what’s known with respect to cannabis and diabetes, stating that:
“Research on recreational cannabis use suggests it may negatively impact diabetes metabolic factors and self-management behaviors. The safety of recreational cannabis use has not been demonstrated, whereas regular cannabis use is associated with worsening glycemic control, more diabetes-related complications, and poorer self-care behaviors, such as adequate glucose monitoring, adherence to medications, and compliance with dietary and physical activity recommendations for people living with both type 1 and type 2 diabetes.”
The American Diabetes Association’s information on cannabis consists of a patient-oriented article on CBD oil. The article stated:
“There’s a lot of hype surrounding CBD oil and diabetes. There is no noticeable effect on blood glucose (blood sugar) or insulin levels in people with type 2 diabetes. Researchers continue to study the effects of CBD on diabetes in animal studies.”
It concludes that:
“Although many claims continue to be made about CBD oil, there is little evidence of any benefit. It’s certainly not an alternative to traditional diabetes management. The safety of CBD is also unknown — it may have dangerous side effects that we won’t know about unless further research is done.”
A Roundup of Recent Studies
A smattering of recent studies have touched on various aspects of cannabis consumption and diabetes.
Angela Bryan, PhD, professor and co-director of CUChange at the University of Colorado Boulder, has been evaluating cannabis use in young adults (ages 21-40 years) in the SONIC study. Dr. Bryan reported at the American Diabetes Association (ADA) 84th Scientific Sessions that cannabis users were more likely to have a lower body mass index and less likely to develop T2D. Furthermore, chronic cannabis users were less likely to have measures of inflammation and no loss of insulin sensitivity.
Another study by Dr. Bryan’s group found that CBD-dominant forms of cannabis were associated with acute tension reduction, which might lead to longer-term reductions in anxiety. Bryan said the findings could be relevant in the context of diabetes distress.
Similarly positive results were found in a 15-week, double-blind, randomized, placebo-controlled, parallel-group study of THC/CBD spray for neuropathic pain among treatment-resistant patients. The investigators reported that “clinically important improvements” were seen in pain, sleep quality, and subjective impressions of pain. Another small study of inhaled cannabis in treatment-refractory patients found a dose-dependent reduction in diabetic peripheral neuropathy pain.
Findings from a 9-year longitudinal study of approximately 18,000 Swedish men and women suggested no association between cannabis and subsequent T2D development after controlling for age, although these authors also called for longer follow-up and more detailed information about cannabis use to make “more robust” conclusions.
On the other side of the spectrum, a “rapid” review of recreational cannabis use in people with T1D and T2D found that recreational cannabis use may negatively impact diabetes metabolic factors and self-management behaviors and may increase risks for peripheral arterial occlusion, myocardial infarction, and renal disease. However, the authors cautioned that more robust research is needed to confirm the potential impact of cannabis on diabetes.