Different studies over the years have come to different conclusions on whether cannabis can increase the risk of a stroke.
Now, a new study has joined the ranks of research that found no association between the drug and the serious medical condition.
Published in Neurology, the study compared the urine tests of cannabis consumers with their medical history.
As the research was observational – and not experimental – it can’t definitively claim that cannabis doesn’t contribute to the risk of having a stroke. But it found that the marijuana-consuming participants were no more likely to have a stroke than those who didn’t use the drug.
The number 1 factor
To reach their conclusions, the researchers sifted through data of 9,350 patients who were admitted to the University of Mississippi Medical Center from the beginning of 2015 to the end of 2017.
All participants had been submitted to a urine drug test on arrival at the hospital, which detailed which drugs, if any, they had recently used. A total of 1,643 patients (18 percent) tested positive for marijuana. People who tested positive for other drugs were excluded from the study.
Of those who tested positive for cannabis, 8 percent had experienced an ischemic stroke – a type of stroke caused by a blockage in a blood vessel, such as a blood clot.
Of those who tested negative, 16 percent had experienced an ischemic stroke – double the rate of those who consumed cannabis.
But after the researchers adjusted for other factors that affect stroke risk, such as high blood pressure, high cholesterol, age, obesity, and diabetes, they found no link between recent cannabis use and the chance of having a stroke.
“Our observational study looked specifically at recent cannabis use by reviewing drug testing data for people admitted to the hospital,” Carmela V San Luis, a neurology researcher at the University of Mississippi in Jackson, said in a statement.
“While more research is needed with larger numbers of people, our study lends support to the studies showing that cannabis use does not increase the risk of stroke,” she added.
While informative, the study has its caveats. The researchers didn’t account for how often the patients used cannabis, or their levels of physical activity and BMI, which could affect their chances of having a stroke.
So, to better conclude whether there is a relationship between cannabis use and stroke risk, the researchers hope that future studies will investigate dose-related effects and use larger sample sizes.
“Our research adds to the list of studies with conflicting results, so it is important to continue to investigate stroke risk and cannabis use,” said San Luis.
“Future studies are now needed in larger groups of people that not only include data from drug screenings but also dosing amounts as well as a person’s history of cannabis use.”