marijuana and strokes

Heavy Marijuana Use Could Double Stroke Risk for Young People, Study Suggests

For those who used marijuana frequently and also smoked cigarettes or e-cigarettes, the risk was even greater.

Young people who use marijuana frequently are more than twice as likely to have a stroke compared to those who don’t use the drug at all, according to a new study.

The findings, which will be presented next week at the annual American Heart Association (AHA) Scientific Sessions meeting in Philadelphia, add to a growing body of research linking marijuana use to an increased risk of cardiovascular problems. The new study, which will also be published in an upcoming issue of the journal Stroke, is one of the first to specifically focus on the risk of stroke in young cannabis users (under age 45).

The researchers analyzed results from a national survey, called the Behavioral Risk Factor Surveillance System, which had published data on marijuana use and stroke incidence.

The authors compared the frequency of marijuana use to the incidence of stroke in people ages 18 to 44 years old. Among the 43,860 participants, 13.6% had used marijauna in the last 30 days. (The data doesn’t specify the way in which participants used marijuana, though a majority of the survey respondents said they smoked it). Marijuana users tended to also report heavy drinking and use of tobacco cigarettes.

The authors found that frequent marijuana users, or people who used marijuana more than 10 days a month, but who did not use tobacco products were nearly 2.5 times more likely to have a stroke than people who did not use marijuana, according to a statement.

For those who used marijuana frequently and also smoked cigarettes or e-cigarettes, the risk was even greater. These individuals were nearly three times more likely to have a stroke, compared with those who didn’t use either marijuana or cigarettes.

But these findings show only an association and cannot prove that marijuana use causes strokes. The authors noted that other substances, such as alcohol, may also influence the risk of stroke seen in the study, even though the scientists attempted to adjust for additional substance use in their analysis.

What’s more, even if there is a cause-and-effect relationship between marijuana use and stroke, researchers don’t exactly know how the drug might be leading to stroke. Marijuana use has been linked to an increased number of blood clots, which might, in turn, increase the risk of stroke, according to a previous Live Science report.

Cannabis might also trigger “reversible cerebral vasoconstriction,” or a temporary narrowing of the blood vessels in the brain that has been linked with stroke, said lead author Dr. Tarang Parekh, a health policy researcher at George Mason University in Virginia.

“In the current discussion of legalization of marijuana in the United States, we believe this study was a crucial step towards” understanding stroke risk in young marijuana users, Parekh told Live Science. “Even though cannabis is not [as] harmful or addictive as other substances, we cannot ignore its potential health risks.”

A separate study, which will also be presented at the AHA meeting next week, found a link between marijuana use and an increased risk of heart arrhythmia (or rhythm problems) in young adults. The authors found that young people, or those between the ages of 15 and 34, who have cannabis-use disorder had a 47% to 52% increased risk of being hospitalized because of an arrhythmia.

The latter study has not yet been published in a peer-reviewed journal.

Young people who use marijuana frequently are more than twice as likely to have a stroke compared to those who don’t use the drug at all, according to a new study.

Stroke Rates Higher Among Pot Users

By Steven Reinberg

HealthDay Reporter

FRIDAY, Oct. 19, 2018 (HealthDay News) — As the use of marijuana is growing, with Canada legalizing the drug just this week, a new study that ties pot to a raised risk for stroke might give users pause.

The risk for any stroke could increase by 15 percent and it could jump 29 percent for an ischemic stroke — the most common kind, said lead investigator Dr. Krupa Patel. She is a research physician at Avalon University School of Medicine in Willemstad, Curacao.

Patel cautioned that the study can’t prove that using marijuana causes strokes, only that the two are associated.

“We can’t establish causation, but what we can say is that recreational marijuana users are at higher risk in terms of stroke,” she said.

In addition, the researchers don’t know if the risk is tied to smoking marijuana or ingesting it in other ways, and whether it depends on the amount of the drug used or if it is due to other psychoactive ingredients mixed in with the marijuana.

Patel said the risk may be exacerbated by chronic medical conditions of the marijuana users who had strokes, such as diabetes or obesity.

Also, the researchers could not tell from the data whether marijuana users used other drugs like cocaine or smoked tobacco, she said.

Still, more strokes occurred among marijuana users than nonusers, which leaves open the question of what accounts for the increase in risk.

“At this point we can just say there is this increased risk,” Patel said.

The best way to sort out whether marijuana is truly associated with an increase in stroke is in a clinical trial, said Dr. Thalia Field, an assistant professor of neurology at the University of British Columbia in Vancouver.

“It’s too early to say that this is causative,” she said. “It has to be borne out in other studies.”

In the study, Patel and her colleagues found that among more than 2.3 million American recreational marijuana users who were hospitalized, the risk of stroke rose, compared with people who didn’t use the drug.


Between 2010 and 2014, strokes among marijuana users steadily increased, even though the overall stroke rate remained unchanged, Patel said.

Among marijuana users in the study, more than 32,000 had a stroke — including nearly 19,500 who suffered an ischemic stroke. Ischemic strokes occur when a clot blocks blood vessels in the brain.

Over five years, the rate of all types of stroke increased from 1.3 to 1.5 percent among marijuana users, and the rate of ischemic stroke rose from 0.7 to 0.9 percent, the researchers found.

The increase in strokes among marijuana users was across all age groups — for people in their teens to those in their 80s, Patel said. In addition, costs to care for these patients rose between 2010 and 2014, from $71,000 to $92,000, she said.

The findings were to be presented Friday at the World Stroke Congress, in Montreal. Such research is considered preliminary until published in a peer-reviewed journal.

Paul Armentano, deputy director of the marijuana advocacy group NORML, said, “This finding is inconsistent with other population-based studies, which failed to identify cannabis as an independent risk factor for stroke in younger subjects.”

NORML, however, recognizes that the data on this subject is evolving and that cannabis smoke can cause a cardiovascular response, he added.

People with a history of heart disease or stroke may be at an increased risk for adverse side effects from marijuana, particularly smoked cannabis, Armentano acknowledged.

“As with any drug, people should consult their doctor before deciding whether the medical use of cannabis is safe and appropriate,” he said.

A new study says that smoking marijuana could raise the risk for any stroke by 15 percent and 29 percent for an ischemic stroke — the most common kind, ]]>