Medicinal marijuana has its many champions, and the drug’s potential therapeutic benefits have paved the way to full legalization in some regions of the United States. But the science isn’t always so positive. A growing body of evidence suggests that using cannabis may put people at risk of a host of medical issues — and it may even put younger users at risk of a life-threatening condition.

A new analysis done in 43,000 adults suggests using marijuana over a sustained period of time is associated with higher odds of a stroke. People who consumed cannabis, and who did not use tobacco products, for more than 10 days a month were approximately 2.5 times more likely to have a stroke compared to non-users, the analysis found.

This risk increased among individuals who also smoked cigarettes or used e-cigarettes: This population was three times more likely to have a stroke compared to non-users.

The preliminary findings are set to be presented this month at the American Heart Association’s Scientific Sessions in Philadelphia, and are expected to be published in the journal Stroke.

Smoking marijuana could put young people at an increased risk of stroke. PeakPx

First author Dr. Tarang Parekh, a research assistant at George Mason University, and co-author Dr. Rupak Desai, a research fellow at the Atlanta VA Medical Center, tell Inverse that while the study does not establish a cause-effect relationship, the findings do suggests that young people who frequently use marijuana may be at a higher risk of stroke compared to those who don’t use marijuana.

“We believe this study was a crucial step towards this important subject of stroke risk in young cannabis users amidst legalization and decriminalization in the United States,” they say. “Frequent cannabis users could have a higher risk of stroke compared to non-users.”

Future studies are needed to validate and expand on the findings. The study did not account for how people consumed cannabis, for example, nor how much they consumed, the exact age that individuals experienced a stroke, or whether they used the drug more frequently than 10 days a month.

"“Frequent cannabis users could have a higher risk of stroke compared to non-users.”

The risk of early on-set stroke persisted in the marijuana-users group after the researchers took various confounding factors, like co-occurring conditions, into account.

The science behind a stroke. NIH

Strokes occur when one of the blood vessels that carry oxygen and nutrients to the brain are either blocked by a clot or burst. This sudden and sometimes fatal interruption of blood supply to the brain can happen at any time, but the risk does increase with age. According to the CDC, in 2009 about 34 percent of people hospitalized for stroke were less than 65-years old.

This new research jibes with previous studies which suggest using marijuana may put young people at risk of a stroke.

It also adds to a growing pile of evidence that using marijuana may adversely affect people’s health. At the same conference, another team of researchers plan to present preliminary findings linking cannabis use disorder diagnoses and being hospitalized for heart arrhythmia — an irregular heart beat.

How marijuana affects the cardiovascular system is unclear, but it’s hypothesized that it may have something to do with how different cannabinoids, the chemicals in cannabis, interact with the brain and its blood vessels. Only more research will answer this and the myriad other questions scientists still have about cannabis’ affect on our bodies.