HealthPop
By

Ryan Jaslow /

CBS News/ January 10, 2012, 4:48 PM

Is smoking marijuana bad for your lungs?

Is smoking marijuana bad for your lungs? What study says istockphoto

(CBS) - Is smoking marijuana bad for your health? The question is often debated when it comes to medical marijuana, but a new study suggests if smoking pot is bad for your body, your lungs aren't bearing the brunt of the damage.

PICTURES: 17 stoner states: Where's marijuana use highest?

The study found occasional marijuana smoking did not negatively impact a person's lung function.

For the study, researchers performed routine pulmonary function tests on 5,115 young adults who were part 20-year study on coronary artery disease risk. The researchers wanted to test lung function against a person's "joint years" of life-time marijuana exposure. For example, if a person smoked one joint or pipe's worth of marijuana per week for 49 years, or if a person smoked one joint or pipe's worth per day for seven years, both people would be identified as having "7-joint-years" of marijuana exposure.

That might sound like a lot, but most of the marijuana smokers in this study were not heavy users, according to study co-author Dr. Stefan Kertesz, an associate professor of preventive medicine at the University of Alabama at Birgmingham.

"This is not a study focused on the kinds of individuals you would see in treatment programs for chemical dependence or in the latest 'Harold and Kumar' movie," Kertesz told CBS News in an email. Kertesz said the median marijuana smokers in the study used roughly two to three joints per month, which may include some people who would smoke frequently but then stop for a long period of time.

What the researchers find?

"With up to 7 joint-years of life-time exposure, we found no evidence that increasing exposure to marijuana adversely affects pulmonary function," the researchers wrote in study, published in the Jan. 10 issue of the Journal of the American Medical Association. In fact, the researchers found a slight increase in occasional marijuana smokers' lung function. That increase may be indicative of marijuana smokers taking deep breaths and holding the smoke in, the researchers said.

At more than 10 joint-years of marijuana exposure, the researchers saw a slight decline in lung function, but the researchers said that finding was not statistically significant, so could be due to chance. Cigarette smokers, who smoked a median of eight to nine cigarettes per day, saw a significant drop in lung function over the twenty year study.

"Marijuana may have beneficial effects on pain control, appetite, mood, and management of other chronic symptoms," the researchers wrote. "Our findings suggest that occasional use of marijuana for these or other purposes may not be associated with adverse consequences on pulmonary function."

The researchers said it's more difficult to determine if long-term, heavy marijuana use is worse for lungs - because that pattern of smoking was "relatively rare" among the study participants - but they said there was a need for caution and moderation when marijuana use is considered.

Is smoking marijuana easier on the lungs than smoking cigarettes?

Kertesz told CBS News that low doses of marijuana among users who aren't addicted, "seems to pose lower risk to lungs than the typical usage patterns of cigarette smoking."

But that doesn't mean it's good for your lungs. Kertesz said smoking marijuana irritates the airways, triggers cough and phlegm production, and could be especially dangerous for asthmatics. Also, since the participants were originally enrolled in a heart study, the researchers couldn't determine how many got lung cancer.

"So don't assume that there is 'no' risk no matter who you are," Kertesz said.

Dr. Robert Glatter, an emergency medicine physician at Lenox Hill Hospital in New York City, told CBS News in an email, "while casual marijuana use may not reflect an immediate decrease in lung function, marijuana smoke contains high levels of tar, which is bad for your health."

Glatter said smoking marijuana could lead to chronic coughing, wheezing and potentially chronic obstructive pulmonary disease (COPD).

"Casual or recreational marijuana use is not a safe alternative to tobacco smoking."

Marijuana smoke not as damaging to lungs as cigarette smoke from uabnews on Vimeo.

© 2012 CBS Interactive Inc. All Rights Reserved.
44 Comments Add a Comment
linkicon reporticon emailicon
malcolmkyle says:
1) Tobacco is cancer causing largely because it delivers specific carcinogens such as NNK and NNAL that are not present in cannabis. Not all "tar" is created equal, and tobacco has some of the most carcinogenic types of tar known to science, whereas cannabis does not.

http://jnci.oxfordjournals.org/cgi/content/full/91/14/1194

2) Cannabis (marijuana) use is associated with a DECREASE in several types of cancer... potentially even providing a protective effect against tobacco and alcohol related cancer development.

Donald Tashkin, a UCLA researcher whose work is funded by NIDA, did a case-control study comparing 1,200 patients with lung, head and neck cancers to a matched group with no cancer. Even the heaviest marijuana smokers had no increased risk of cancer, and had somewhat lower cancer risk than non-smokers (tobacco smokers had a 20-fold increased lung cancer risk). Tashkin D. Marijuana Use and Lung Cancer: Results of a Case-Control Study. American Thoracic Society International Conference. May 23, 2006.

Researchers at the Kaiser-Permanente HMO, funded by NIDA, followed 65,000 patients for nearly a decade, comparing cancer rates among non-smokers, tobacco smokers, and marijuana smokers. Tobacco smokers had massively higher rates of lung cancer and other cancers. Marijuana smokers who didn't also use tobacco had no increase in risk of tobacco-related cancers or of cancer risk overall. In fact their rates of lung and most other cancers were slightly lower than non-smokers, though the difference did not reach statistical significance. Sidney, S. et al. Marijuana Use and Cancer Incidence (California, United States). Cancer Causes and Control. Vol. 8. Sept. 1997, p. 722-728.
reply
linkicon reporticon emailicon
Zann-Zel says:
Funny in the same news day - "red wines not as good as we thought"
and
"Pot isn't as bad as we thought!"

LOL! Someones trying to make money somewhere!
reply
linkicon reporticon emailicon
you_MAY_be_right says:
"Kertesz said the median marijuana smokers in the study used roughly two to three joints per month, which may include some people who would smoke frequently but then stop for a long period of time."

----------------------


So, esentially, this whole study is worthless, and a waste of money, since many/most pot smokers smoke more than 2 or 3 joints a day.
reply
democracy8 replies:
linkicon reporticon emailicon
Not true at all.
linkicon reporticon emailicon
Zann-Zel says:
testing..
reply
linkicon reporticon emailicon
Zann-Zel says:
If you read the comments after one of these articles, you notice 99% of us seem to agree! So what's stopping our government from legalizing it?

Could it be they wouldn't have so quick an excuse to throw people in jail and use them for slave labor for the corporations?
reply
hsinco-2009 replies:
linkicon reporticon emailicon
Or big Pharma is holding us back from real progress on the issue.
Zann-Zel replies:
linkicon reporticon emailicon
Yeah they would probably lose a lot of money!
linkicon reporticon emailicon
MargaretYork says:
I cannot believe people are defending this crap. Let me guess--make pot "socially" (and of course medicinally) acceptable, and then the government has another source of tax income, and lo and behold, an entire cannabis industry can take root (and weed) and flourish. Disgusting. Like the United States needs more brain dead zombies. Lung cancer or not, pot is very physically and exceptionally harmful mentally. Anyone who uses pot "to relax" is, to my mind, a loser. And spare me the tripe about alcohol. It is dangerous when abused. I have never been drunk in my life, and drink a glass of wine every day--which is quite healthy in fact. Now the next problem in line for the States: doped out car accidents, doped out kids in schools, doped out morons having hallucinations on city streets, doped out kiddies stumbling their way into insanity. A jackass country getting more idiotic by the day. I am voting for Paul, but I strongly dislike his views on this.
reply
antoniof123 replies:
linkicon reporticon emailicon
And you are an idiot now every day more and more evidence is coming that pot is not as bad not that it is good remember but smoking (which is legal) is a million times worst.

So read the story instead of spouting nonsense.
MCM1009 replies:
linkicon reporticon emailicon
Seriously? There are many people out there, including CEOs, Presidents, doctors, lawyers, etc. that smoke pot occasionally. Just as you go home after work and down a glass of wine, there are folks that like to go home and smoke pot. What's the difference? These folks are not going to work stoned, they don't head out to lunch and smoke a joint. They simply go home after work .... JUST LIKE YOU ... and want to enjoy the drug of their choice. The only difference is that one is legal and one is not. And that has absolutely nothing to do with the effects of each drug, but instead due to the fact that long ago our government decided to reap the financial benefits of alcohol sales (not to mention that fact that it seems most of our Senate and Congress are overpaid alcoholics ... but that's another story). So, MargartYork, I could go on comparing alcohol to weed, but you wouldn't like the statistics. So it's OK for you to use a glass of wine to relax but not for others to use another drug to relax. HYPOCRITE!!!!!!
See all 12 Replies
linkicon reporticon emailicon
ReckonedTruth says:
What? Not black or hispanic kid in the picture?
But anyway all exploitation aside..

I'm not a pot smoker and I stuggles with taking prescription drugs..I perfer holistic healing..

..can POT be deemed as holistic? California says so..

.. for medcine.. I say make it federally legal.. or bounce to the 10th amendment on the subject by state legality and tax the pot users with a host of state guidelines for the medical user and outside of medical use..
reply
linkicon reporticon emailicon
Jhihmoac says:
Great fer ya head though, man! *_*
reply
linkicon reporticon emailicon
RickCain4150 says:
Smoking ANYTHING is bad for your lungs.
reply
sawolf replies:
linkicon reporticon emailicon
Volcano Vaporizer
linkicon reporticon emailicon
rwsmith29456 says:
Tobacco causes lung disease and alcohol causes cirrhosis and addiction problems. I'm not personally for marijuana use but I consider it to be comparatively benign.
reply
See all 44 Comments