A new study published in the Canadian Medical Association Journal indicates that adults under age 45 who frequently use marijuana are roughly twice as likely to suffer from a heart attack as adults who do not use marijuana.

Researchers examined health data from more than 33,000 adults ages 18 – 44, of whom more than 4,600 reported using marijuana in the past 30 days.

The study noted that a history of heart attack was more frequent among recent marijuana users than among nonusers, and that a history of heart attack was associated with using marijuana more than four times per month.

The study’s authors even observed that marijuana’s association with heart attack appeared to be similar to tobacco’s, writing, “The association between recent cannabis use and MI [heart attack] was similar in magnitude to associations with MI [heart attack] observed for current tobacco smoking.”

It’s important to point out that this is certainly not the first study to link heart problems with marijuana use.

All of this underscores what we have said for years: Marijuana may be many things, but “harmless” simply is not one of them.