OUTRAGEOUS ANTI-POT LIES: MEDIA USES DISGRACEFUL CANCER SCARE TACTICS

On Tuesday, January 29 -- three days prior to the publication of a
forthcoming study assessing marijuana use and cancer -- Reuters News
Wire published a story under the headline: "Cannabis Bigger Cancer
Risk Than Tobacco." Mainstream media outlets across the globe
immediately followed suit. "Smoking One Joint is Equivalent to 20
Cigarettes, Study Says," Fox News declared, while Australia's ABC
broadcast network pronounced, "Experts Warn of Cannabis Cancer 'Epidemic.'

If those headlines weren't attention-grabbing enough, one only had to
scan the stories' inflammatory copy -- much of which was lifted
directly from press statements provided by the study's lead author in
advance of its publication.

"While our study covers a relatively small group, it shows clearly
that long-term cannabis smoking increases lung-cancer risk," chief
investigator Richard Beasley declared. Beasley went on to speculate
that pot "could already be responsible for one in 20 lung cancers
diagnosed in New Zealand" before warning: "In the near future we may
see an 'epidemic' of lung cancers connected with this new
carcinogen."

The mainstream press, always on the look out for a good pot scare
story, ran blindly with Beasley's remarks. Apparently not a scribe
among them felt any need to confirm whether Beasley's study -- which
remained embargoed at the same time it was making worldwide headlines
- -- actually said what was claimed.

It didn't.

For those who actually bothered to read the study's full text, which
appeared in the European Respiratory Journal days after the global
feeding frenzy had ended, they would have learned the following. Among
the 79 lung cancer subjects who participated in the trial, 70 of them
smoked tobacco. These individuals, not surprisingly, experienced a
seven-times greater risk of being diagnosed with lung cancer compared
to tobacco-free controls. As for the subjects in the study who
reported having used cannabis, they -- on average -- experienced no
statistically significant increased cancer risk compared to non-using
controls.

So how'd the press get the story so wrong? There are several reasons.
First, beat writers based their stories on a press release rather than
the study itself. Unfortunately, this is a common practice used by the
mainstream media when writing about cannabis-related science. More
often than not, media outlets strive to publish their reports prior to
a study's publication -- a desire that all but forces reporters to
write about data they have never seen. (Likewise, as a marijuana law
reform advocate I'm also frequently asked by the press to comment on
studies that are not yet public, though I typically choose not to.)

Second, the media chose to selectively highlight data implicating
cannabis's dangers while ignoring data implicating its relative
safety. In this case, the study's authors (and, by default, the
worldwide press) chose only to emphasize one small subgroup of
marijuana smokers (those who reported smoking at least one joint per
day for more than ten years). These subjects did in fact, experience
an elevated risk of lung cancer compared to non-using controls.
(Although contrary to what the press reported, even the study's
heaviest pot smokers never experienced an elevated comparable to those
subjects who reported having "ever used" tobacco.) By contrast,
cannabis consumers in the study who reported light or moderate pot use
actually experienced a decreased cancer risk compared to non-using
controls. (Bottom line, the sample size in all three subgroups is far
too small to draw any sound conclusions.)

Finally, the mainstream media failed to employ its own institutional
memory. For example, some 18 months earlier The Washington Post and
other newspapers around the world reported, "The largest study of its
kind has unexpectedly concluded that smoking marijuana, even regularly
and heavily, does not lead to lung cancer." That study, performed by
researchers at UCLA, assessed the potential association between
marijuana smoking and cancer in over 2,200 subjects (versus only 324
in the New Zealand study), and determined that pot 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.

Prior large-scale population studies have reached similar conclusions.
For instance, a NIDA (US National Institute on Drug Abuse) sponsored
study of 164 oral cancer patients and 526 controls determined, "The
balance of the evidence does not favor the idea that marijuana as
commonly used in the community is a causal factor for head, neck or
lung cancer in adults" and a 1997 Kaiser Permanente retrospective
cohort study of 65,171 men and women in California found that cannabis
use was not associated with increased risks of developing tobacco-use
related cancers -- including lung cancer, breast cancer, prostate
cancer, colorectal cancer, or melanoma. In fact, even the prestigious
National Academy of Sciences, Institute of Medicine says definitively,
"There is no conclusive evidence that marijuana causes cancer in
humans, including cancers usually related to tobacco use." (Tellingly,
when I referred various reporters to these prior studies, I was
consistently told that this information was irrelevant because they
were assigned to write "only about this study.")

In short, had the mainstream media even taken the time to consult
their own prior marijuana coverage, they would have immediately begun
asking the sort of probing questions that the public normally expects
them to. Of course, such hard and steadfast rules governing
professional journalism seldom apply to the media' coverage of pot --
where political ideology typically trumps accuracy and where slipshod
reporting hardly ever even warrants a public retraction. Writing in
the journal Science nearly 40 years ago, New York state university
sociologist Erich Goode aptly observed: "[T]ests and experiments
purporting to demonstrate the ravages of marijuana consumption receive
enormous attention from the media, and their findings become accepted
as fact by the public. But when careful refutations of such research
are published, or when latter findings contradict the original
pathological findings, they tend to be ignored or dismissed."

How little has changed.