Study: Marijuana legalization linked to increase in heart-related hospitalizations 

Hospital stays for serious heart problems rose faster in western states after they began allowing recreational marijuana sales, a new study found.

Researchers linked each year of legal sales to higher hospital admission rates for heart failure and heart attacks. They also saw an increase in atrial fibrillation, which causes an irregular heartbeat.

The team reviewed more than 50 million hospital discharge records from 2012 to 2018. BMJ Open published the study last week.

After accounting for other factors, researchers found admission rates were 3.7% higher for heart failure, 3.1% higher for heart attacks and 2.3% higher for atrial fibrillation for each year of legal sales, compared with states where sales were not legal.

Those figures reflect hospital admissions and do not measure individual marijuana users’ odds of developing heart disease.

Researchers chose the West because states such as Colorado, Washington and Oregon were among the first to legalize recreational marijuana sales.

By 2018, more than 98% of people in the western United States lived in or next to a state with legal marijuana sales.

The team compared hospital trends before and after legal sales began with trends elsewhere. Researchers also examined many other conditions, such as strokes, but those results did not meet the study’s threshold for a clear statistical link.

The findings cannot prove legalization caused the increases. Researchers could not separate the results by state or determine whether people smoked marijuana or used it another way. They also could not account for changes in illegal marijuana use.

“While an observational study cannot prove causality, our findings point to potential adverse effects of recreation legalisation on population health,” the researchers wrote in BMJ’s release.

Researchers have previously voiced concerns about marijuana’s impact on heart health.

A 2025 review of 12 studies found that current cannabis users had a 50% higher risk of a heart attack than people who did not use it, according to the American College of Cardiology.

Similarly, the American Heart Association has warned that THC – the chemical in marijuana that produces a high – can raise heart rate and increase the heart’s need for oxygen.

“Many consumers and health care professionals don’t realize that cannabis smoke contains components similar to tobacco smoke,” Robert Page said in the association’s 2020 release.

Heart problems aren’t the only health concern.

An August story published in Heartlander News covered rising emergency room visits for cannabis hyperemesis syndrome. Frequent marijuana use can cause the condition, which includes repeated bouts of severe vomiting.

Massachusetts to vote on repealing recreational marijuana 

The debate over marijuana’s health risks has also arisen in Massachusetts.

Bay State voters will decide Question 8 next week. The measure would end recreational retail sales while keeping medical marijuana legal.

“Question 8 would keep personal possession of marijuana legal, keep medical marijuana legal, and stop commercial marijuana stores,” the Coalition for a Healthy Massachusetts says in the state’s voter guide.

Adults 21 and older could still possess up to 1 ounce, including no more than 5 grams of concentrate. Possession of 1 to 2 ounces would carry a $100 civil fine.

Existing recreational businesses could seek medical marijuana licenses through a faster application process.

Supporters cite health harms, including risks to young people. Opponents argue that closing licensed stores would push sales into the illegal market and remove product-testing safeguards.

The state legalized marijuana in 2016, with the first dispensaries opening in 2018.

The state estimates that recreational marijuana taxes brought in about $280 million for state government and $50 million for municipal governments in fiscal 2025.

A yes vote would repeal legal recreational sales. The repeal would take effect at the start of 2028. A no vote would keep the current law.

However, the repeal appears highly unlikely. A University of Massachusetts poll released earlier this month found 31% of Bay Staters support the repeal effort, while 61% oppose it.