Cannabis users are nearly four times more likely to develop type 2 diabetes than non-users, according to a major new study that analysed data from more than 4 million healthcare users across Europe and America.
The research led by Dr. Ibrahim Kamel and others from the Boston Medical Center, Massachusetts, analysed records of 96,795 cannabis users from 54 healthcare organisations across the US and Europe. The group was 52% female, aged 18-50, and included patients diagnosed with cannabis use disorders, intoxication and withdrawal.
Researchers then compared this group with 4,160,998 individuals who had no previous record of cannabis or other drug use and had no underlying illnesses at the beginning of the study.
Both groups were followed for five years. After adjusting for variable factors such as HDL and LDL cholesterol, uncontrolled high blood pressure, atherosclerotic cardiovascular disease, cocaine use, alcohol use and several other lifestyle risk aspects, researchers found that new diagnoses of type 2 diabetes were 4 times more likely to occur in the cannabis using group than the large, non-cannabis using control group.
“As cannabis becomes more widely available and socially accepted and legalized in various jurisdictions, it is essential to understand its potential health risks,” said lead author Dr. Kamel.
Dr Kamel added that the results of this study highlight the importance for doctors and professionals to talk to their patients about how cannabis and other drug use can affect diabetes care.
She also noted that while it is still unclear exactly how cannabis use could lead to more people developing type 2 diabetes, unhealthy eating practices (having the munchies) and insulin resistance could be the drivers.
Cannabis use around the world is increasing, and the research team felt it was important to study what effect cannabis has on diabetes. Previous studies have produced mixed results, with some claiming cannabis to have anti-inflammatory qualities that can help diabetics, and others focusing on factors such as insulin resistance and glucose metabolism, both of which could be negative side effects of cannabis use.
“These new sights from reliable real-world evidence highlight the importance of integrating diabetes risk awareness into substance use disorder treatment and counseling, as well as the need for health care professionals to routinely talk to patients about cannabis use so that they can understand their overall diabetes risk and potential need for metabolic monitoring.”
The findings contradict previous research, which has shown that cannabis could have a positive effect on people with diabetes.
A 2016 pilot study examined the effects of CBD and THCV (tetrahydrocannabivarin) on patients with untreated type 2 diabetes, finding that both cannabinoids could have therapeutic properties and be used as an alternative to conventional treatment.
“THCV improved glycaemic control and therefore warrants further investigation in this therapeutic area,” the authors of the 2016 study said. “CBD failed to show any detectable metabolic effects despite producing desirable changes in some adipokines and gut hormone concentrations.”
In a separate Swedish study, nearly 18,000 people from Sweden aged between 18 and 84 years, were followed over a period of 11 years. Researchers found no elevated risk of developing type 2 diabetes in cannabis users compared to non-cannabis users.
“To conclude, our results indicate no association between cannabis use and subsequent type 2 diabetes,” the authors of the Swedish study said, recommending that “more robust conclusions, longitudinal studies with longer follow-up and more detailed information about cannabis use are needed.”
The authors of the latest study acknowledged that more research is needed to fully explain the association between cannabis and diabetes, as the data were gathered retrospectively. As a result, the findings do not prove that cannabis use causes diabetes, and the authors added that they could not rule out the possibility that other unmeasured factors may have influenced the results despite efforts to reduce confounding bias.
