"Does Marijuana Cause Health Problems"
“The popular notion seems to be that
marijuana is a harmless pleasure,”
but what are the potential
adverse effects of marijuana use?
That’s not an easy question to answer.
Most studies to date have been cross-sectional
or rely on self-reported health.
Cross-sectional means a snapshot in time;
and so, you don’t know which came first.
Are people sick because they’re smoking marijuana,
or are they smoking marijuana
because they’re sick?
And, if you just ask people how they are,
pot smokers may be like: “I feel great!”,
even if they’re actually suffering
from some health problem.
Few longitudinal studies have been done,
meaning studies done over time,
using objective measures of health, until…
now.
More than a thousand individuals followed up
from birth to age 38,
testing associations between cannabis use over decades
and multiple domains of physical health.
They looked at 12 health outcomes,
and tobacco use was associated
with worse health for 8 of 12,
from impaired lung function to systemic inflammation,
and metabolic derangements.
And, cannabis use was associated with…
just gum disease.
That’s it?
“Cannabis use was unrelated to other physical health problems.”
Now, periodontal disease can lead to tooth loss,
and there may be other dental health problems
associated with smoking marijuana,
but when cannabis is described as nefarious,
the first thing to come to mind
is probably not gingivitis.
Is it possible that cannabis users
are just living healthier- than-average lifestyles
to counteract the effects of the drug?
Like eating more fruits and vegetables
or maybe drinking less alcohol?
No.
Neither are pot smokers exercising anymore;
and so, the absence of associations
between cannabis use and poor physical midlife health
could not be attributed to any of these other things;
so, maybe marijuana is just not that bad.
Heroin may increase your risk of dying,
cocaine use may increase your risk of dying,
but no association was found
between mortality and marijuana.
Now, they did just follow these folks until age 38.
To find out what happens after that,
we need to turn to Sweden,
where they recently published the longest study ever
on cannabis and mortality:
50,000 men followed up to around age sixty.
About 30 years ago, when they first reported on this cohort,
no significant excess mortality was found among cannabis users,
or abusers as they called them.
But, back then, these men were in their 30s,
like in that other study.
What happens when you follow them past middle age,
when perhaps the health- related detrimental effects
might begin to emerge?
Those with a history of heavy cannabis use
did end up having a significantly higher risk of death,
a 40% higher risk of dying prematurely.
But, wait a second...
I thought cannabis didn’t kill.
Cocaine kills thousands of Americans every year,
alcohol kills tens of thousands,
and tobacco breaks the graph,
wiping out hundreds of thousands
of people in the U.S. every year.
But, marijuana doesn't even make it onto the graph.
But, what they’re referring to is
that “no deaths have been directly attributed
to the acute physical toxicity of cannabis.”
So, when some 19-year-old eats a cannabis cookie
and then jumps off the fourth floor balcony,
the direct cause of death was the fall,
but that doesn’t mean cannabis didn’t contribute.
It’s true that people don’t directly OD on cannabis
like you can with opiates,
which can shut down your breathing.
Unlike many pharmaceuticals, for which a harmful dose
may just be a few times larger than the prescribed dose,
the therapeutic index for cannabis
is like 40,000 to 1.
Does that mean you could smoke
like 40,000 joints without OD-ing?
No.
You may be able to smoke 2 million joints
before a lethal overdose.
Cannabis use contributes more to disease than death
in part because people aren’t injecting it,
but the health-related harms of cannabis
had never been quantified on a global scale, until…
2013.
Every year, cannabis is estimated
to result in 2 million years of healthy life lost
due to disability.
Now, this is tiny compared to 100 million
or so years attributed to alcohol or tobacco,
but still results in a lot of pain and suffering.
But, what about our gum disease study?
I thought the only physical health problems
were dental in nature.
Well, they were just looking
at a specific set of health problems;
they emphasize that the periodontal problems
are in addition to all the other potential issues,
like increased risk of accidents and injuries,
bronchitis, heart attacks and strokes,
possibly infectious diseases, and cancer,
as well as the mental health concerns.
But, in terms of a more direct cause of death,
marijuana may be suspected in maybe hundreds of deaths
over an 8 year period,
whereas a single pharmaceutical drug—Viagra—
was involved in thousands.