Outrageous Anti-Pot Lies: Media Uses Disgraceful Cancer Scare Tactics

By Paul Armentano, AlterNet
Posted on March 10, 2008, Printed on March 10, 2008
http://www.alternet.org/story/78886/

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.

Paul Armentano is the Deputy Director of NORML and the
NORML Foundation.