DENVER (CBS4)– A new study on marijuana is raising health concerns among users. It shows marijuana may increase heart complications in young and middle-aged adults.

The research in the Journal of the American Heart Association found 35 cases of cardiovascular complications after marijuana use including 20 heart attacks and nine deaths.

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David from Wisconsin said he’s been a recreational pot smoker for 40 years. The study doesn’t seem to deter him.

“I feel worse about walking across the street than smoking a joint,” said David.

Doctors believe the results of this new study should give pot smokers a reason to pause.

“As more and more marijuana is being used there have been more identified cases of cardiovascular complications,” said Dr. Robert Kloner, Heart Institute Director of Research at Good Samaritan Hospital.

Kloner also points to a newly-released French study that examined about 2,000 health complications following pot use. Researchers found 35 heart-related cases. Most of those were male with an average age of 34.

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“This included 20 heart attacks, some patients had decreased blood flow to the brain, some patients had decreased blood flow to their limbs. The concern was that about a quarter of these patients died,” said Kloner.

Dave Weaver is a recreational pot smoker and said the study results don’t bother him.

“No, it doesn’t worry me. It’s no worse than cigarettes people are smoking all day every day,” said Weaver.

“Food, drink, anything you do, driving a car, everything has complications,” said David.

Kloner said he wants better tracking of heart problems in pot smokers. He’s calling for more research, stating that marijuana may not be as safe as previously thought.

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