Cannabis consumption is growing worldwide, with an estimated 219 million users in 2021—about 4% of the global adult population. While cannabis is often discussed in terms of pain relief or potential anti-inflammatory benefits, its long-term impact on metabolic health has been less clear.
Previous studies have shown mixed results, with some suggesting cannabis may help with weight control, while others raised concerns about its effects on blood sugar regulation. Now, new research adds weight to the concern side of the debate.
What the study found
Researchers from Boston Medical Center analyzed electronic health records from more than 54 health care organizations across the U.S. and Europe. Their study, presented at the European Association for the Study of Diabetes (EASD) annual meeting, compared nearly 97,000 adults with cannabis-related diagnoses to more than 4.1 million adults without a history of substance use or major chronic disease.
Participants were tracked for five years. After accounting for cholesterol levels, blood pressure, cardiovascular disease, alcohol and cocaine use, and other risk factors, cannabis users were found to have nearly four times the risk of developing type 2 diabetes compared to non-users.
Specifically, 2.2% of cannabis users developed diabetes during the study period, compared with just 0.6% of the comparison group.
Why the link may exist
The exact reason for the increased risk is not yet known. Researchers suggest possible explanations include cannabis-related effects on insulin resistance and dietary habits. They caution, however, that more research is needed to determine whether the risks are tied specifically to smoking cannabis, or if they extend to edibles and other forms of use.
Important caveats
The study has limitations. Because it relied on electronic medical records, cannabis use may have been underreported, particularly in regions where it remains illegal. The study also lacked detailed data on how often or how much cannabis participants used. And while the findings show a strong association, they cannot prove that cannabis directly causes diabetes.
What this means for patients and providers
Despite these limitations, the findings have important public health implications.
“As cannabis becomes more widely available and socially accepted, it’s essential to understand its potential health risks,” said lead author Dr. Ibrahim Kamel. He noted that health care providers should discuss cannabis use with their patients and consider routine monitoring of blood sugar and metabolic health in those who use it.
The study highlights the need for more long-term research on cannabis and endocrine health. For now, experts recommend that patients who use cannabis—particularly those with other diabetes risk factors—speak with their health care provider about monitoring and prevention strategies.
