Pot Impacts Heart, Study Shows
WebMD News Archive
Mittleman did note some interesting differences between the users and
nonusers of marijuana. Those who had smoked marijuana prior to having a heart
attack were much younger, with an average age of 44 compared to 62 in the
nonsmokers. Also, the marijuana users were less likely to have other risk
factors for heart disease, such as high blood pressure and diabetes, and were
less likely to have had a history of chest pain prior to the heart attack, says
The study also shows that frequent marijuana use was certainly not a
requirement to be at risk of having a heart attack. Of the marijuana users, 32
used it a few times a month and 40 used marijuana less than once a month,
The Marijuana Policy Project (MPP), a Washington-based group that lobbies
for laws to decriminalize marijuana use and supports the use of medical
marijuana, immediately issued a press release warning that the study could be
misinterpreted. MPP spokesperson Chuck Thomas tells WebMD, "Our concern is
that some legislator is going to say that marijuana causes heart attacks.
That's not what this study says." Six states have decriminalized marijuana
use and several others are considering similar laws. Thomas says the risk of
adverse events with marijuana use is "comparable to [the] risk associated
with legal drugs."
At a press conference, several reporters asked about the timing of the
study. Mittleman says that his team decided to do the study in response to last
year's report on marijuana from the Institute of Medicine (IOM). That report
concluded that there was no significant risk of heart disease due to marijuana
in young marijuana users but urged a study of its effect in older populations.
"We just decided to take IOM up on that suggestion."
- New research reports that during the first hour after smoking marijuana,
one's risk of heart attack jumps nearly five times. By comparison, a sedentary
person shoveling snow increases heart attack risk 100 times. Having sexual
intercourse would raise heart attack risk in the same person 2.5 times.
- Observers say the apparent risk of heart attack should be considered even
in cases where the drug is used medically, such as in cancer patients.
Marijuana legalization advocates say they fear legislators will interpret this
study as a warning that marijuana causes heart attacks.
- Experts add that researchers still need to figure out what marijuana does
to the body and why those changes may increase heart attack risk. Scientists
also do not know if the drug itself triggers heart problems or if a component
in the smoke is to blame, such as carbon monoxide