If cannabis is part of your routine, you may have wondered what it means for long-term health. New data suggest a notable link to metabolic risk. A large analysis of electronic health records from the United States and Europe found adults with documented cannabis use were roughly four times more likely to develop type 2 diabetes within five years than similar adults who did not use substances. About 2.2% of cannabis users were diagnosed with type 2 diabetes over that period compared with 0.6% of non-users. The research, presented at the European Association for the Study of Diabetes meeting in Vienna, raises timely questions as cannabis consumption climbs globally.
The findings draw attention because of scale and real-world relevance. Researchers at Boston Medical Center used the TriNetX Research Network to examine records from 54 healthcare organizations that reflect routine clinical practice. The analysis included nearly 97,000 adults aged 18 to 50 with cannabis-related diagnoses and more than 4 million comparable adults without recorded substance use or major chronic conditions. After matching individuals on conventional diabetes risk factors and controlling for variables such as lipid levels, blood pressure, cardiovascular disease, and use of other substances, the higher risk persisted. While absolute risk remained modest, the relative difference was substantial and could translate into thousands of additional cases at the population level.
How the study worked
The team reviewed records from 2010 through 2018 and tracked outcomes for five years. Cannabis exposure included a wide spectrum, from occasional use to dependence, intoxication, and withdrawal, as captured by diagnostic codes. The comparison group was constructed to be similar in age, sex, and comorbidities, using propensity matching and survival analyses to evaluate who remained diabetes-free over time. Because the dataset spanned dozens of U.S. and European systems, the results may generalize to everyday care settings.
It is important to note that these results have not yet been peer reviewed. Observational studies can reveal associations but cannot prove cause and effect. Even with extensive adjustment, unmeasured factors such as diet quality, sleep, mental health, socioeconomic status, and detailed patterns of substance use can confound results. Still, the size and diversity of the sample strengthen confidence that the signal is not a fluke.
Why cannabis might affect metabolism
Biology offers several plausible pathways. Overactivation of the endocannabinoid system, particularly CB1 receptors, has been linked to increases in abdominal and liver fat, reduced insulin sensitivity, and impaired glucose control. Low-grade inflammation and oxidative stress may further disrupt how muscles and the liver handle glucose. Some laboratory studies suggest potential effects on pancreatic beta cells, which could interfere with insulin production.
Behavior and lifestyle may add to the risk. Many users experience post-use cravings for calorie-dense foods, a pattern that can raise daily energy intake over time and worsen metabolic markers. Reduced physical activity after use, combined with co-use of alcohol or nicotine, could amplify insulin resistance. Although the study controlled for other substances, real-world behaviors are complex and often intertwined. These overlapping influences make the association biologically and behaviorally credible.
What this means for you
Even in adults without classic risk factors, cannabis use was associated with greater diabetes risk, which suggests potential vulnerability in otherwise healthy people. If you choose to use cannabis, prudence is warranted while the science evolves. Paying attention to central adiposity is a practical starting point. A waist circumference around or above 40 inches for many men and 35 inches for many women often signals insulin resistance even when body mass index looks normal.
Simple daily habits can support better glucose control without demanding a full lifestyle overhaul. Replacing late-night snacks with a protein-forward dinner of roughly 25 grams may help stabilize overnight blood sugar and reduce cravings. A brisk 20-minute walk can boost muscle glucose uptake and improve insulin sensitivity. Gradual reduction in use and mindful eating around sessions can also limit excess calorie intake. As always, personal risk factors and preferences should guide decisions, ideally in partnership with a clinician.
Caveats and unanswered questions
Key uncertainties remain. The analysis does not clarify whether frequency, dose, or duration of use changes risk, and it cannot disentangle effects by product type, potency, THC to CBD ratio, or route of administration. Because diagnostic codes likely miss some use, exposure could be underestimated, and patterns such as edibles versus vaping are unknown. The study focused on adults ages 18 to 50, so findings may not extend to older adults or reflect risks beyond five years. Until peer review provides full methodology and sensitivity analyses, conclusions should be considered preliminary.
The bigger picture and next steps
As hundreds of millions worldwide report using cannabis, even small absolute increases in diabetes incidence can have large public health consequences. Clinicians may wish to screen cannabis users for metabolic risk, including waist measurements, blood pressure, lipids, and fasting glucose, while offering counseling on diet and physical activity. Research priorities include confirming these results in peer-reviewed publications, exploring dose-response relationships, and assessing how age of initiation shapes risk. Future studies should also examine product characteristics, modes of consumption, co-use with alcohol or nicotine, and interactions with obesity, sleep, mental health, and social determinants.
For now, the headline is clear. In a very large, multi-country analysis, cannabis use was linked with an approximately fourfold higher likelihood of developing type 2 diabetes over five years. Until more definitive data arrive, smart preventive habits and informed conversations can help users enjoy autonomy while reducing potential metabolic downsides.