As more states move toward legalizing marijuana, new research suggests serious cardiovascular risks are associated with the drug.

Marijuana users are three times more likely to die from hypertension according to a study published Aug. 9 in the European Journal of Preventative Cardiology.

Researchers designed a retrospective follow-up study of 1,213 people age 20 or older using 2005-06 National Health and Nutrition Examination Survey data.

Participants were asked if they had ever used marijuana and at what age they first tried it, which was subtracted from their current age to calculate the duration of use.

Compared to non-users, marijuana users had a 3.42-times higher risk of death from hypertension and a 1.04 greater risk for each year of use. There was no association between marijuana use and death from heart disease or cerebrovascular disease.

“We found higher estimated cardiovascular risks associated with marijuana use than cigarette smoking,” lead author Barbara Yankey, a PhD student in the school of public health at Georgia State University, said in a statement. “This indicates that marijuana use may carry even heavier consequences on the cardiovascular system than that already established for cigarette smoking. However, the number of smokers in our study was small and this needs to be examined in a larger study.”

Another limitation of the research is it assumed continuous use from respondents who had tried marijuana. Still, Yankey said the study should serve as a warning to lawmakers.

“With the impending increase in recreational marijuana use it is important to establish whether any health benefits outweigh the potential health, social and economic risks,” she said. “If marijuana use is implicated in cardiovascular diseases and deaths, then it rests on the health community and policy makers to protect the public.”