Share on PinterestCannabis use is linked to a four times higher diabetes risk, a new study finds. Image credit: Mal de Ojo Studio/Stocksy
- People who use cannabis are four times more likely to develop type 2 diabetes than people who do not use it, according to a new analysis.
- The analysis compared medical data from well over 4 million people to arrive at its observation.
- While the association between cannabis use and type 2 diabetes seems robust, identifying a causal connection between them was beyond the scope of this analysis.
- The two most likely candidates for the connection are changes in insulin sensitivity and overeating as well as poor eating as a result of cannabis use.
Researchers report a striking association between cannabis use and an elevated risk of developing type 2 diabetes.
People who use cannabis are four times as likely to develop type 2 diabetes as people who do not use cannabis, according to a new study presented at the Annual Meeting of The European Association for the Study of Diabetes (EASD) 2025, held in Vienna, Austria, between 15-19 September.
This research is yet to appear in a peer-reviewed journal.
While the research presents evidence regarding a correspondence between cannabis use and type 2 diabetes, it is beyond the scope of a retrospective study such as this to establish direct causation. It merely describes an association between the two things, although it appears to be a strong one.
Higher incidence of diabetes in cannabis users
The World Health Organization (WHO) estimates about 147 million people, or 2.5% of people globally, use cannabis, and its use is increasing more rapidly than other recreational substances. Popular cannabis-based products include — in addition to smokable cannabis in various forms — edibles, oils, and tinctures.
Globally, about 589 million adults between the ages of 20 and 79 have diabetes, and 90% of diabetes cases are type 2 diabetes. While type 2 diabetes can be genetic, it is often a byproduct of preventable risk factors.
In their analysis, researchers from Boston Medical Center in Massachusetts, led by Ibrahim Kamel, MD, MHA, identified 96,795 cannabis-using patients from 54 healthcare organizations in the United States and Europe.
They were matched with 4,160,998 people who had no record of cannabis use, and both groups were followed for five years. Comparing the incidence of type 2 diabetes between the two groups, the association became apparent.
The analysis revealed that diabetes incidence in cannabis users was of 2.2%, compared to 0.6% in nonusers.
The researchers accounted for uncontrolled high blood pressure, cocaine and alcohol use, other lifestyle risk factors, and atherosclerotic cardiac disease.
The two most likely means by which cannabis use might lead to type 2 diabetes are an increase in insulin resistance and poor diet linked to snacking urges resulting from cannabis use, the researchers suspect.
“The association was surprising, as we are still not sure of the mechanism, and it isn’t that obvious,” Kamel told Medical News Today.
Jason Ng, MD, BA, a clinical associate professor of medicine specialized in endocrinology and metabolism, from the Department of Medicine at the University of Pittsburgh, who was not involved in this research, told MNT that:
“Studies regarding cannabis use and diabetes are limited, with some studies suggesting benefits and others showing worsening of sugar control. So this association is not necessarily surprising, given the lack of data across the board.”
Cannabis may be linked to insulin resistance
“Cannabis may contribute to type 2 diabetes through endocannabinoid system overstimulation, particularly CB1 receptor activation,” explained Kamel. “[This] promotes visceral adiposity, hepatic fat accumulation, and insulin resistance.”
Insulin resistance is a key characteristic of type 2 diabetes.
Kamel also cited “low-grade inflammation, oxidative stress, and potential beta-cell dysfunction, all of which impair glucose homeostasis. Lifestyle factors such as reduced physical activity and co-use of alcohol or nicotine may further increase risk.”
Even so, said Ng, “there is mixed literature currently, with some studies even showing a stable weight to weight loss and increased insulin sensitivity [with cannabis use], which is paradoxical to this study’s findings. [This illustrates] how the interactions are likely complex and not understood completely between cannabis and development of [type 2 diabetes].”
How cannabis use may lead to poor eating
There is also the likelihood that cannabis use could lead to unhealthy eating habits, which may increase the risk of diabetes.
“Experimental and epidemiologic data suggest that cannabis use can increase both the quantity and type of food consumed,” noted Kamel, a phenomenon “consistent with the well-known ‘munchies’.”
“The mechanistic evidence is that CB1 receptor activation heightens the reward value of palatable foods,” he said. “Such dietary shifts could plausibly promote type 2 diabetes risk through excess caloric load, central adiposity, and glycemic stress.”
Cannabis legalization and type 2 diabetes risk
The association presented in this research emerges in a context of increasing legalization for cannabis and cannabis products. As of this writing, 24 U.S. states have legalized to one degree or another the recreational use of cannabis.
While cannabis has not been legalized on a federal level, according to the Centers For Disease Control and Prevention, it is the most commonly used federally illegal drug in the U.S. The CDC says that roughly 52.5 million people, about 19% of U.S. residents, have used it at least once since 2021.
In the U.S., type 2 diabetes affects 38.4 million people of all ages, or 11.6% of the nation’s population. Every year, 1.2 million people in the U.S. are newly diagnosed with diabetes.
Where does research such as this fit into a landscape of relaxing restrictions and attitudes on the use of cannabis?
Kamel suggests that, “while more evidence is growing regarding the use of cannabis (largely due to legalization), I personally do not think it will be reversed, as many other substances with established risks still remain accessible.”
“The purpose of this study is to help physicians risk-stratify patients and provide the best support for them,” he said.
“I think, of course, with any intervention we review the benefits and side effects,” Ng also added. “So if this association is confirmed and a causative relationship found, this would be part of the public discussion on the pros and cons of cannabis use and may given some people in the public pause before pursuing [the use of cannabis] depending upon their specific circumstances.”
