Marijuana doesn’t harm lung function, study found
By LINDSEY TANNER
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.
Colorado Seeks Federal Reclassification Of Marijuana To Facilitate Doctor Prescriptions As Medical Treatment
First Posted: 12/28/11 07:27 PM ET Updated: 12/28/11 07:40 PM ET
By KRISTEN WYATT, Associated Press
DENVER — Colorado has become the third state to ask the U.S. Drug Enforcement Administration to reclassify marijuana in way that allows doctors to prescribe it as a medical treatment.
The head of Colorado’s Department of Revenue, which oversees the state’s booming medical marijuana business, made the request in a letter sent Dec. 22. It wasn’t released to the public until Wednesday because of the Christmas holiday.
The letter says the discrepancy between state law and federal drug law, which does not permit medicinal uses of marijuana, is problematic.
Last month, the governors of Washington and Rhode Island also asked that the government list marijuana as a Schedule 2 drug, like morphine and oxycodone.
Federal Government Rules Marijuana Has No Accepted Medical Purpose
First Posted: 7/9/11 03:03 PM ET Updated: 7/9/11 06:06 PM ET HUFFINGTON POST
The decision comes nearly nine years after marijuana supporters asked the government to reclassify the drug to take into account the growing body of research conducted across the globe that proves it’s effective in treating certain diseases, reports The Los Angeles Times.
The paper spoke to advocates who criticized the ruling but are pleased that the government has finally responded, which allows them to appeal to the federal courts.
Joe Elford, chief counsel for Americans for Safe Access told the Times, he was not surprised by the decision, which came shortly after the Obama administration announced it would not tolerate large-scale commercial marijuana growing operations.
It is clearly motivated by a political decision that is anti-marijuana,” he said. He noted that studies demonstrate pot has beneficial effects, including appetite stimulation for people undergoing chemotherapy. “One of the things people say about marijuana is that it gives you the munchies and the truth is that it does, and for some people that’s a very positive thing.
The Times also noted, this is the third time that petitions to reclassify marijuana have been denied. The first was filed in 1972 and denied 17 years later. The second was filed in 1995 and denied in 2001. Both decisions were appealed, but the courts sided with the federal government.
California and many other states have legalized marijuana for medicinal reasons and a push to legalize it in general is expected to appear on the 2012 ballot in California as Proposition 19, writes LAist.