Investigators at the University of California, San Francisco analyzed the association between marijuana exposure and pulmonary function over a 20 year period in a cohort of 5,115 men and women in four US cities.

Predictably, researchers “confirmed the expected reductions in FEV1 (forced expiratory volume in the first second of expiration) and FVC (forced vital capacity)” in tobacco smokers. By contrast, “Marijuana use was associated with higher FEV1 and FVC at the low levels of exposure typical for most marijuana users. With up to 7 joint-years of lifetime exposure (eg, 1 joint/d for 7 years or 1 joint/wk for 49 years), we found no evidence that increasing exposure to marijuana adversely affects pulmonary function.”

The study concludes, “Our findings suggest that occasional use of marijuana … may not be associated with adverse consequences on pulmonary function.”

To those familiar with the science of cannabis, JAMA’s findings should come as no great surprise. They are consistent with previous findings reporting no significant decrease in pulmonary function associated with moderate cannabis smoke exposure. For instance, according to a 2007 literature review conducted by researchers at the Yale University School of Medicine and published in the Archives of Internal Medicine (and summarized by NORML here), cannabis smoke exposure is not associated airflow obstruction (emphysema), as measured by airway hyperreactivity, forced expiratory volume, or other measures.

Further, in 2006, the results of the largest case-controlled study ever to investigate the respiratory effects of marijuana smoking reported that cannabis use was not associated with lung-related cancers, even among subjects who reported smoking more than 22,000 joints over their lifetime. (Read NORML’s summary of this study here.)

“We hypothesized that there would be a positive association between marijuana use and lung cancer, and that the association would be more positive with heavier use,” the study’s lead researcher, Dr. Donald Tashkin of the University of California at Los Angeles stated. “What we found instead was no association at all, and even a suggestion of some protective effect” among marijuana smokers who had lower incidences of cancer compared to non-users.

A previous 1997 retrospective cohort study consisting of 64,855 examinees in the Kaiser Permanente multiphasic health checkup in San Francisco and Oakland also reported, “[E]ver- and current use of marijuana were not associated with increased risk of cancer … of the following sites: colorectal, lung, melanoma, prostate, breast, cervix.”

Separate studies of cannabis smoke and pulmonary function have indicated that chronic exposure may be associated with an increased risk of certain respiratory complications, including cough, bronchitis, phlegm. However, the ingestion of cannabis via alternative methods such as edibles, liquid tinctures, or via vaporization — a process whereby the plant’s cannabinoids are heated to the point of vaporization but below the point of combustion –- virtually eliminates consumers’ exposure to such unwanted risk factors and has been determined to be a ‘safe and effective’ method of ingestion in clinical trial settings.

Riggs asked the Czar some tough questions, including this one specific to medical cannabis: “You’ve said before that you don’t see medical benefits to smoked marijuana and also that the jury is still out on medical marijuana. What sort of scientific consensus does the ONDCP require? How many studies have to come out arguing for medical benefits? What do you need to see?”

The Czar’s reply? “[Y]ou know there are over 100 groups doing marijuana research, and they’re getting their marijuana from the University of Mississippi. There are several things in clinical trials right now. So we’ll just have to wait for those.”

To which I reply ‘Bulls–t!’

As I write today on Alternet.org, a review of the U.S. National Institutes of Health website clinicaltrials.gov shows that there are presently only six FDA-approved trials taking place anywhere in the world involving subjects’ use of actual cannabis. Of these, two are completed, one is assessing the plant’s pharmacokinetics, and one is assessing pot’s alleged harms.

Memo to the Drug Czar: That leaves a grand total of — not “over 100″ — but rather just two ongoing clinical trials to assess the medical efficacy of cannabis. You sir, are a liar (but then again, I suppose we all knew that already).

Pot May Be Instrumental in Combating Cancer, MS and Other Diseases But the Gov’t Refuses to Fund the Necessary Research

via Alternet

[excerpt] A review of the U.S. National Institutes of Health website clinicaltrials.gov shows that NIDA’s kibosh on medical marijuana trials continues unabated. Though a search of ongoing FDA-approved clinical trials using the keyword ‘cannabinoids’ (the active components in marijuana) yields 65 worldwide hits, only six involve subjects’ use of actual cannabis. (The others involve the use of synthetic cannabinoid agonists like dronabinol or nabilone, the commercially marketed marijuana extract Sativex, or the cannabinoid receptor blocking agent Rimonabant.)

Of the six, two of the studies are already completed: ‘Opioid and Cannabinoid Pharmacokinetic Interactions‘ and ‘Vaporization as a Smokeless Cannabis Delivery System,’ both of which were spearheaded by researchers (primarily Dr. Donald Abrams) at the University of California at San Francisco.

The four remaining studies are still in the ‘recruitment’ phase. Of these, only two pertain to the potential medical use of cannabis: ‘Cannabis for Spasticity of Multiple Sclerosis,’ which is taking place at the University of California at Davis and is likely the final clinical trial associated with the soon-to-be-defunct/defunded California Center for Medicinal Cannabis Research, and ‘Cannabis for Inflammatory Bowel Disease,’ led by researchers at the Meir Medical Center in Israel.

Of the remaining studies, one focuses on the detection of cannabinoids and their metabolites on drug screens, while the other, entitled ‘Effects of Smoked Marijuana on Risk Taking and Decision Making Tasks,’ seeks to establish pot-related harms — hypothesizing that subjects “demonstrate poorer decision-making abilities and increased risk-taking behaviors” after smoking marijuana.

You can read the full text of my Alternet.org story here.

You can read the full interview with Drug Czar Kerlikowske here.

The ‘news’ story, which several other mainstream media outlets are also promoting, is based on a new British study assessing the effects of, ahem, “calf thymus DNA treated in vitro (in a Petri dish) … with the smoke generated from 1, 5, and 10 cannabis cigarettes.”

Yes, really.

So how did Fox “We report, you decide” News summarize this non-story? Let’s take a look.

What Fox News reported: “Smoking marijuana not only gets you high, but it also alters your DNA.”

What the study actually said: “[T]hese results provide evidence for the DNA damaging potential of cannabis smoke, implying that the consumption of cannabis cigarettes may be detrimental to human health with the possibility to initiate cancer development.”

What Fox News reported: “There have been many studies on the toxicity of tobacco smoke,” researcher Rajinder Singh said in a news release. “Cannabis in contrast has not been so well studied.”

What Fox News didn’t report: From the March 2009 issue of the scientific journal Medicinal Research Reviews, “Research on the chemistry and pharmacology of cannabinoids and endocannabinoids has reached enormous proportions. … [A]pproximately 15,000 articles on Cannabis sativa L. and cannabinoids and over 2,000 articles on endocannabinoids (are available in the scientific literature).”

What Fox News reported: “Singh said cannabis smoke contains 400 compounds including 60 cannabinoids. It also contains 50 percent more carcinogenic polycyclic aromatic hydrocarbons including naphthalene, benzanthracene, and benzopyrene, than tobacco smoke, Singh added.”

What Fox News didn’t report: From the November 2007 issue of the scientific journal Clinical Pharmacology & Therapeutics, “Vaporization of marijuana does not result in exposure to combustion gases, … and [was] preferred by most subjects compared to marijuana cigarettes. … The Volcano [vaporizer] device is an effective and apparently safe vehicle for THC delivery, and warrants further investigation in clinical trials of cannabis for medical purposes.”

What Fox News reported: “‘The smoking of 3-4 cannabis cigarettes a day is associated with the same degree of damage to bronchial mucus membranes as 20 or more tobacco cigarettes a day,’ the team wrote in the journal.”

Except for the fact that it isn’t. In fact, here’s what Donald Tashkin of the UCLA David Geffen School of Medicine, Division of Pulmonary and Critical Care Medicine, had to say about the subject earlier this month in an interview with the McClatchy newspaper chain. (**Note: Dr. Tashkin has performed US-government sponsored studies of marijuana and lung function for over 30 years and is considered to be the United States’ — if not the world’s — foremost expert on the subject.)

“What we found instead was no association (between marijuana smoking and cancer) and even a suggestion of some protective (anti-cancer) effect. … Early on, when our research appeared as if there would be a negative impact on lung health, I was opposed to legalization because I thought it would lead to increased use and that would lead to increased health effects. But at this point, I’d be in favor of legalization (of marijuana). I wouldn’t encourage anybody to smoke any substances. But I don’t think it should be stigmatized as an illegal substance. Tobacco smoking causes far more harm. And in terms of an intoxicant, alcohol causes far more harm.”

Just for the record, in 2006, Tashkin led the largest population case-control study (yes, Dr. Tashkin actually performed research on humans, not ‘calf thymus DNA’) ever to assess the use of marijuana and lung cancer risk. The study, which included more than 2,200 subjects (1,212 cases and 1,040 controls), reported that marijuana smoking was not positively associated with cancers of the lung or upper aerodigestive tract – even among individuals who reported smoking more than 22,000 joints during their lifetime.

Let the folks at Fox put that in their pipe and smoke it.