CHICAGO (AP) — Smoking a joint once a week or a bit more apparently doesn't harm the lungs, suggests a 20-year study that bolsters evidence that marijuana doesn't do the kind of damage tobacco does.
The results, from one of the largest and longest studies on the health effects of marijuana, are hazier for heavy users — those who smoke two or more joints daily for several years. The data suggest that using marijuana that often might cause a decline in lung function, but there weren't enough heavy users among the 5,000 young adults in the study to draw firm conclusions.
Still, the authors recommended "caution and moderation when marijuana use is considered."
Marijuana is an illegal drug under federal law although some states allow its use for medical purposes.
The study by researchers at the University of California, San Francisco, and the University of Alabama at Birmingham was released Tuesday by the Journal of the American Medical Association.
The findings echo results in some smaller studies that showed while marijuana contains some of the same toxic chemicals as tobacco, it does not carry the same risks for lung disease. It's not clear why that is so, but it's possible that the main active ingredient in marijuana, a chemical known as THC, makes the difference. THC causes the "high" that users feel. It also helps fight inflammation and may counteract the effects of more irritating chemicals in the drug, said Dr. Donald Tashkin, a marijuana researcher and an emeritus professor of medicine at the University of California, Los Angeles. Tashkin was not involved in the new study.
Study co-author Dr. Stefan Kertesz said there are other aspects of marijuana that may help explain the results.
Unlike cigarette smokers, marijuana users tend to breathe in deeply when they inhale a joint, which some researchers think might strengthen lung tissue. But the common lung function tests used in the study require the same kind of deep breathing that marijuana smokers are used to, so their good test results might partly reflect lots of practice, said Kertesz, a drug abuse researcher and preventive medicine specialist at the Alabama university.
The study authors analyzed data from participants in a 20-year federally funded health study in young adults that began in 1985. Their analysis was funded by the National Institute on Drug Abuse.
The study randomly enrolled 5,115 men and women aged 18 through 30 in four cities: Birmingham, Chicago, Oakland, Calif., and Minneapolis. Roughly equal numbers of blacks and whites took part, but no other minorities. Participants were periodically asked about recent marijuana or cigarette use and had several lung function tests during the study.
Overall, about 37 percent reported at least occasional marijuana use, and most users also reported having smoked cigarettes; 17 percent of participants said they'd smoked cigarettes but not marijuana. Those results are similar to national estimates.
On average, cigarette users smoked about 9 cigarettes daily, while average marijuana use was only a joint or two a few times a month — typical for U.S. marijuana users, Kertesz said.
The authors calculated the effects of tobacco and marijuana separately, both in people who used only one or the other, and in people who used both. They also considered other factors that could influence lung function, including air pollution in cities studied.
The analyses showed pot didn't appear to harm lung function, but cigarettes did. Cigarette smokers' test scores worsened steadily during the study. Smoking marijuana as often as one joint daily for seven years, or one joint weekly for 20 years was not linked with worse scores. Very few study participants smoked more often than that.
Like cigarette smokers, marijuana users can develop throat irritation and coughs, but the study didn't focus on those. It also didn't examine lung cancer, but other studies haven't found any definitive link between marijuana use and cancer.
20 year study involving 5k+ (mostly)casual(1-2 joints per week) pot smokers focused solely on lung function found no degradation in lung function associated to marijuana. The study had some people that smoked pot AND cigarettes and people that smoked only pot.
The problem is that people don't smoke a joint once a week, it's more like several joints a day. They also are usually unfiltered and people hold the smoke longer and deeper into their lungs. Blow the smoke from a joint through a hankerchief and compare it to the smoke from a cigarette doing the same. I bet you see a big stain from both. If it stains the hankerchief, imagine what it does to your lungs.
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08:58 PM
Doug85GT Member
Posts: 10034 From: Sacramento CA USA Registered: May 2003
The problem is that people don't smoke a joint once a week, it's more like several joints a day. They also are usually unfiltered and people hold the smoke longer and deeper into their lungs. Blow the smoke from a joint through a hankerchief and compare it to the smoke from a cigarette doing the same. I bet you see a big stain from both. If it stains the hankerchief, imagine what it does to your lungs.
My pothead friends must be in the minority as they only smoke on the weekends.
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09:02 PM
Rallaster Member
Posts: 9105 From: Indy southside, IN Registered: Jul 2009
As a past HEAVY smoker of cannibus, and now the couple times a year kind, I just don't see the majority smoking only a couple of joints a week. As a matter of fact, I haven't seen someone roll one since Detroit. Bowls and bongs up here.
Dentists love potheads.. my hygienest told me that someone who regularly smokes has slight resin deposits protecting their teeth, and it slides off easy when cleaning.
Get high to protect your teeth!
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10:25 PM
Raydar Member
Posts: 41474 From: Carrollton GA. Out in the... country. Registered: Oct 1999
If a person only smoked one or two cigarettes a week then I'll bet they would find it doesn't harm lung function either.
True story. Years ago, my father's cardiologist told him that 2-3 cigarettes a day would make no difference. He also told him that he would smoke herb if it were legal.
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10:55 PM
PFF
System Bot
Wichita Member
Posts: 20709 From: Wichita, Kansas Registered: Jun 2002
True story. Years ago, my father's cardiologist told him that 2-3 cigarettes a day would make no difference. He also told him that he would smoke herb if it were legal.
In a normal person, they say the threshold is 4 cigarettes a day will not cause problems. It is the same why so many dudes back in the day never got lung cancer from smoking a pipe after dinner.
What kills and destroys the lungs is excessive packs a day smoking compounded by many years of it.
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10:59 PM
Formula88 Member
Posts: 53788 From: Raleigh NC Registered: Jan 2001
Dentists love potheads.. my hygienest told me that someone who regularly smokes has slight resin deposits protecting their teeth, and it slides off easy when cleaning.
Get high to protect your teeth!
My first thought was what does the resin do to your lungs? It's not like you can scrape it off, unless coughing gets rid of it that easily.
quote
The analyses showed pot didn't appear to harm lung function,... It also didn't examine lung cancer,
Um, last time I checked, lung cancer did affect lung function. I know other studies haven't linked it to cancer, but that makes it sound like the study was very narrowly structured to only look at the results they wanted to get.
[This message has been edited by Formula88 (edited 01-10-2012).]
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11:36 PM
Jan 11th, 2012
WhiteDevil88 Member
Posts: 8518 From: Coastal California Registered: Mar 2007
The problem is that people don't smoke a joint once a week, it's more like several joints a day. They also are usually unfiltered and people hold the smoke longer and deeper into their lungs. Blow the smoke from a joint through a hankerchief and compare it to the smoke from a cigarette doing the same. I bet you see a big stain from both. If it stains the hankerchief, imagine what it does to your lungs.
Several joints per day? Yikes. A decent joint is about 1 gram of dried flower. A gram of decent weed can go for $8-$15, making that a $75 a day weed habit, and a very stoned person.
As far as staining a handkerchief, I am sure you are right. But what is the stain? In tobacco it is tar and chemicals. On Gods herb, it's resin. Pure essence of the plant.
Anyhow, as a legal consumer, I have far superior ways of consuming my THC that are smoke free and far more efficient then burning. I just enjoy an occasional toke during the day because of years of cigarette smoking got me to enjoy the sensation of smoking. Otherwise, I take a capsule.
well, luckily - this is all moot now that you can "Vape".
the THC in weed is heat activated - around 200-300*. you can heat weed, and release the activated THC WITHOUT setting fire to it. and, if you are a capitalist, you may then sell the dimished product to someone else.
tho, I admit - "vaping" is somewhat cumbersome.....
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10:31 AM
jaskispyder Member
Posts: 21510 From: Northern MI Registered: Jun 2002
It is the same why so many dudes back in the day never got lung cancer from smoking a pipe after dinner.
Pipe smokers do not inhale the smoke ... at least not intentionally. That's why pipe smokers tend to develop lip, mouth, tongue, throat, and esophageal cancers rather than lung cancers.
Clean out a smokers pot pipe and you will see what is going into your lungs!
The study sounds bogus to me.
Yes sir. Plant or not, (it may surprise some people to find out that tobacco is also a plant) burning it leave residue in everything the smoke touches. And even (gasp) tar. Call it resin, or whatever cool catchphrase it gets these days, but it is what it is.
I am not a scientist, but as a non-stoned common sense guy I call BS on this study.
As a past HEAVY smoker of cannibus, and now the couple times a year kind, I just don't see the majority smoking only a couple of joints a week. As a matter of fact, I haven't seen someone roll one since Detroit. Bowls and bongs up here.
Tony
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06:30 AM
Khw Member
Posts: 11139 From: South Weber, UT. U.S.A. Registered: Jun 2008
My pothead friends must be in the minority as they only smoke on the weekends.
I wouldn't consider someone like that a pothead, rather a casual user. I've known people I would label pothead, and they were either already high whenever I saw them, in the process of getting high or just waiting for their other buddy to show up to get high. Time of day or day of week did not matter.
Um, last time I checked, lung cancer did affect lung function. I know other studies haven't linked it to cancer, but that makes it sound like the study was very narrowly structured to only look at the results they wanted to get.
