Marijuana use doubles the risk of stroke, study says

Marijuana may increase the risk of a stroke according to a new study.

Researchers in New Zealand found that smoking pot can double the risk of a stroke in people under 55.

It is considered the strongest evidence thus far that cannabis leads to an increased stroke risk.

However, researchers admit that they it is not necessarily a causal relationship as many of the participants in the study also smoked cigarettes, said Fox News.

The study looked at 160 cases of ischemic stroke in patients between 18 and 55.

Looking at urine sample results the researchers noted that 16 percent tested positive for marijuana versus eight percent of the control patients, reported MyHealthNewsDaily.

More from GlobalPost: Study: More young people suffering strokes

"We believe it is the cannabis and not tobacco," said study author Alan Barber, of the University of Auckland, reported Science Daily.

"This may prove difficult given the risks of bias and ethical strictures of studying the use of an illegal substance. However, the high prevalence of cannabis use in this cohort of younger stroke patients makes this research imperative."

The study will be presented at the American Stroke Association's International Stroke Conference this week.