U.S. study sees no marijuana link to lung cancer

Baby-boomer research results surprise doctors expecting to find connection

Updated: 10:10 p.m. ET May 23, 2006

LOS ANGELES - Marijuana smoking does not increase a person's risk of developing lung cancer, according to the findings of a new study at the University of California Los Angeles that surprised even the researchers.

They had expected to find that a history of heavy marijuana use, like cigarette smoking, would increase the risk of cancer.

Instead, the study, which compared the lifestyles of 611 Los Angeles County lung cancer patients and 601 patients with head and neck cancers with those of 1,040 people without cancer, found no elevated cancer risk for even the heaviest pot smokers. It did find a 20-fold increased risk of lung cancer in people who smoked two or more packs of cigarettes a day.
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The study results were presented in San Diego on Tuesday at a meeting of the American Thoracic Society.

The study was confined to people under age 60 since baby boomers were the most likely age group to have long-term exposure to marijuana, said Dr. Donald Tashkin, senior researcher and professor at the UCLA School of Medicine.

The results should not be taken as a blank check to smoke pot, which has been associated with problems like cognitive impairment and chronic bronchitis, said Dr. John Hansen-Flaschen, chief of pulmonary and critical care at the University of Pennsylvania Health System in Philadelphia. He was not involved in the study.

Previous studies showed marijuana tar contained about 50 percent more of the chemicals linked to lung cancer, compared with tobacco tar, Tashkin said. In addition, smoking a marijuana joint deposits four times more tar in the lungs than smoking an equivalent amount of tobacco.

"Marijuana is packed more loosely than tobacco, so there's less filtration through the rod of the cigarette, so more particles will be inhaled," Tashkin said in a statement. "And marijuana smokers typically smoke differently than tobacco smokers — they hold their breath about four times longer, allowing more time for extra fine particles to deposit in the lung."

He theorized that tetrahydrocannabinol, or THC, a chemical in marijuana smoke that produces its psychotropic effect, may encourage aging, damaged cells to die off before they become cancerous.

Hansen-Flaschen also cautioned a cancer-marijuana link could emerge as baby boomers age and there may be smaller population groups, based on genetics or other factors, still at risk for marijuana-related cancers.
Copyright 2006 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content is expressly prohibited without the prior written consent of Reuters.

Interesting.

I wonder why no comment was made about oral/throat cancers? The article said they compared marijuana smokers against lung cancer patients and head/neck cancer patients, but they only make a conclusion about lung cancer and marijuana.

why no mention of the other nasties?

"marijuana users hold their breath for four times as long"

fuck, when i smoke a cig i hold it for 2 seconds tops...with pot i take a hit and it's for as long as i can hold my breath (at least a minute)

uh...... okay.

You must be short on supply? Trying to make every last particle count?

I don't buy it. I'm quite sure there'll be another study in a few years (possibly months) that debunks this one....seems to always happen this way.

Yeah, just wait until DARE comes out with their study in July. Because, there's two sides to every story, don't ya know?

I named my bong Ted Nugent.

I'd always been told that holding it in longer than 8 seconds is pretty much worthless.

Yeah, I think I remember that 90% of the THC is absorbed in the first second, 99% by the end of two seconds, or something like that. However, if you're going for how much resin you can get to stick to your alveoli, then hold your breath as long as you can!

I'm probably the winner in that category then.

I have smoked both cigarettes and pot.

Guess what, NEITHER is good to put in your lungs...IT IS SMOKE

Meh. I don't care whether it's harmful any more than I care that you think it makes The Wall sound "amazing." It shouldn't be illegal, but once or twice a year is plenty for me, thanks. It's cool and all, but I can't figure why either side of this argument is so passionate about it.

Instead of worrying about pot smokers, we should be grumping about pregnant women who chain smoke...what the fuck, is this some kind of fad, now?

It's about personal freedom, and the fact that we put thousands of people in jail for weed, where they then learn how to rob, murder, and make/sell other drugs. Decriminalization would be an excellent thing for this nation.

fuckin A right

Bingo!