New Study Finds Cannabis Users Four Times More Likely to Develop Diabetes

Cannabis Use and Type 2 Diabetes: Unraveling a Surprising Association

When we think of risk factors for type 2 diabetes, the usual suspects come to mind: obesity, sedentary lifestyle, family history, hypertension, dyslipidemia. But a recent large observational analysis presented remarkable findings: people who use cannabis may be nearly four times more likely to develop type 2 diabetes over a five-year period, compared with matched non-users.

This association challenges some prior, more optimistic narratives about cannabis and metabolism. It also forces clinicians and public health professionals to reconsider how we counsel patients and monitor metabolic risk in populations using cannabis.

The Recent Study: What Was Done, What Was Found
Design and scale
Researchers analyzed electronic health records from multiple healthcare organizations across the U.S. and Europe. They identified nearly 100,000 patients aged 18–50 with documented cannabis use between 2010 and 2018. These users were matched with more than four million nonusers of similar age, sex, and baseline health conditions. Both cohorts were followed for five years to detect new diagnoses of type 2 diabetes.

The analysis adjusted for numerous confounders, including obesity, hypertension, cholesterol, cardiovascular disease, alcohol use, and other risk factors.

Key results
Over the five-year period, just over 2% of cannabis users developed type 2 diabetes compared with less than 1% of nonusers. After statistical adjustments, cannabis users were found to have nearly four times the risk of developing type 2 diabetes.

The association remained significant even after adjusting for conventional metabolic risks, suggesting that cannabis may act as an independent factor contributing to diabetes onset.

Strengths and limitations (doctor’s commentary)
Strengths:

• Extremely large cohort sizes provided robust statistical power.
  
  
• Real-world data reflected outcomes beyond the confines of randomized trials.
  
  
• Adjustments for multiple comorbidities improved reliability.
  

Limitations:

• Observational design prevents proof of causality.
  
  
• Cannabis use may be underreported in medical records.
  
  
• Details such as dosage, frequency, and route of administration were missing.
  
  
• Lifestyle factors like diet and physical activity were not fully captured.
  
  
• Biases related to who gets documented in health systems may distort risk estimates.
  

Biological Plausibility: How Might Cannabis Elevate Diabetes Risk?
The Endocannabinoid System and Metabolic Regulation
Cannabis interacts with the endocannabinoid system, especially CB1 receptors, which are found in fat, liver, muscle, pancreas, and the brain. Overactivation of these receptors is known to:

• Increase visceral fat,
  
  
• Promote fat accumulation in the liver,
  
  
• Induce insulin resistance,
  
  
• Trigger inflammatory cytokines,
  
  
• Possibly impair pancreatic beta-cell function.
  

Chronic cannabis use may therefore tip the metabolic balance toward insulin resistance and eventual diabetes.

The “Munchies” and Caloric Overdrive
Cannabis often stimulates intense hunger and cravings for sugary or fatty foods. Repeated episodes of binge-like eating can worsen adiposity and push a person toward insulin resistance, even if overall weight gain is modest.

Low-Grade Inflammation and Oxidative Stress
Cannabis exposure may contribute to systemic inflammation and oxidative stress, both recognized drivers of insulin resistance.

Beta-Cell Stress
As insulin resistance rises, pancreatic beta cells are forced to secrete more insulin. Over time, this stress can exhaust their capacity, reducing secretion and hastening diabetes onset.

Reconciling Prior Contradictory Findings
Earlier studies had suggested that cannabis users might have lower insulin levels or smaller waist circumferences. However, those findings were often cross-sectional, based on self-report, or focused on short-term use. Long-term, heavy, or chronic exposure may reveal a very different picture—one more consistent with the elevated risk seen in this newer large-scale study.

Broader Context: Cannabis, Diabetes, and Complications
Cannabis Use Is Increasing in People With Diabetes
In recent years, more people with diabetes report using cannabis. This trend raises concerns because if cannabis increases metabolic risk, individuals already predisposed to glycemic issues may be further harmed.

Cannabis and Acute Diabetes Complications
In people with type 1 diabetes, cannabis use has been linked with higher risk of diabetic ketoacidosis. Repeated vomiting from cannabis hyperemesis syndrome can also precipitate hyperglycemic crises.

Cardiovascular and Other Complications
Diabetes already amplifies cardiovascular risk. If cannabis use contributes to both diabetes onset and cardiovascular harm, the combined effect may be particularly dangerous.

Implications for Clinical Practice & Public Health
Clinical Practice

1. Ask about cannabis use when taking a metabolic history, especially in younger adults.
   
   
2. Screen earlier and more frequently for diabetes in cannabis users.
   
   
3. Counsel about appetite effects, suggesting healthier snack strategies to manage cravings.
   
   
4. Monitor weight and waist circumference carefully over time.
   
   
5. Offer behavioral support or referrals for patients with heavy cannabis use.
   
   
6. Reconsider medical cannabis prescriptions in high-risk patients.
   
   
7. Educate patients openly about emerging evidence of risks.
   

Public Health

• Create registries to track long-term outcomes in cannabis users.
  
  
• Issue advisories about possible metabolic risks.
  
  
• Design campaigns to counter the “harmless” perception of cannabis.
  
  
• Encourage research funding for prospective studies.
  

Future Research Directions
Unanswered questions include:

• Does risk rise with dose and frequency, or is any use harmful?
  
  
• Do edibles, vaping, and smoking differ in risk profiles?
  
  
• Is risk reversible if use stops?
  
  
• Which populations are most vulnerable?
  
  
• Do specific cannabinoids differ in metabolic impact?
  
  
• How does cannabis interact with obesity, poor sleep, or stress?
  

A Clinical Scenario
Imagine a 28-year-old man, normal weight, with no family history of diabetes. He smokes cannabis socially once or twice a week. His glucose and HbA1c are currently normal. Based on traditional risk factors, his chance of diabetes seems low. But considering the new evidence, a clinician might:

• Screen him annually instead of every few years,
  
  
• Discuss dietary strategies for post-cannabis appetite surges,
  
  
• Advise reducing cannabis frequency,
  
  
• Monitor weight and metabolic markers closely.
  

Such vigilance could detect prediabetes earlier, giving time to intervene before progression.

Final Considerations
The association between cannabis and type 2 diabetes is strong, biologically plausible, and supported by large-scale data. While causation is not proven, prudence dictates caution. Physicians should treat cannabis use as a potential metabolic risk factor, educate patients, and integrate it into preventive care strategies. Public health systems should not ignore the growing evidence that cannabis may carry hidden costs for long-term metabolic health.