Marijuana legalization linked to cardiovascular hospital admissions, new study suggests

New research that involved the analysis of more than 50 million patient discharge records from 2012 to 2018 has concluded that legalization of recreational cannabis in the US is associated with a rise in hospital admissions for cardiovascular disease.

Medical marijuana is legal in 41 states across America, but only 24 have legalized it for recreational use.

Researchers focused their attention on 13 states in Western region of the US, those being: Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming.

These were homed in on because the Western region of the US started legalizing recreational cannabis back in 2014, long before other regions.

"Admissions for atrial fibrillation (abnormal heart rhythm), heart failure, and heart attack all rose faster after the law was enacted in the Western region of the US with the policy than in states without, the analysis shows," BMJ Group – where the study has been published – said in a news release.

Nevada is one US state to have legalized marijuana that was included in the study (Marli Miller/UCG/Universal Images Group via Getty Images)

Patients hospitalized for these conditions in these states had an average age of 51, compared with 55 in other regions.

It adds: "Legalization policies have been associated with more widespread use of cannabis products, particularly among older people who are already at heightened risk of cardiovascular problems."

Before its legalization in states like California, Illinois, Maryland, and Nevada, hospital discharge rates for the conditions studied were lower in the Western region that didn't allow recreational use of marijuana.

"The estimated change in admission rates for each year of legal cannabis sales was statistically significant for atrial fibrillation (just over 2 percent higher), heart failure (nearly 4 percent higher), and heart attack (just over 3 percent higher), after adjusting for potentially influential factors," BMJ Group states.

Nearly 44 million Americans are said to regularly use marijuana (Getty Stock)

But researchers noted that there are various limitations to their findings. One was the inability to separate out individual states, and another was that they couldn't look at the method of cannabis use (whether it was smoked or not).

Nevertheless, they point out: "While several studies have examined the association of recreational cannabis legalization on psychiatric conditions, substance use, emergency visits, and traffic accidents, ours is the first study to examine the association with [cardiovascular] hospitalizations."

"While an observational study cannot prove causality, our findings point to potential adverse effects of recreation legalization on population health," they added.

"Globally, our findings support a cautious approach to legalization laws accompanied by data collection on [cardiovascular] outcomes."