"Effects of Smoking Marijuana on the Lungs"
There is unequivocal evidence that
habitual or regular marijuana smoking
is not harmless and causes respiratory
symptoms and airway inflammation.
If you take biopsies from the airways
of those that smoke crack, cannabis,
or tobacco, compared to nonsmokers,
there is significantly more damage
in the lungs of crack smokers,
marijuana smokers,
and tobacco smokers.
And, the levels of damage
seems comparable, especially
between the marijuana smokers and
tobacco smokers, which is remarkable,
since the tobacco smokers were smoking
about a pack a day,
whereas the marijuana smokers were
only smoking about 20 joints a week,
rather than 25 cigarettes a day,
and those smoking crack were just
doing a gram or two a week.
So, to see similar rates of damage
between marijuana smokers
and cigarette smokers
suggests each joint is way
worse than each cigarette.
And indeed, we’ve known for 30 years
that smoking 3 or 4 joints
is the equivalent of smoking
a pack a day of cigarettes,
in terms of bronchitis symptoms
and acute lung damage.
How is that possible?
Well, it may be the way they’re smoked.
Pot smokers inhale more deeply,
and then hold the smoke in
four times longer,
resulting in more tar deposition in the lungs.
And, joints are more loosely
packed and unfiltered,
resulting in both hotter smoke
and smokier smoke.
So, even though in many ways
smoke is smoke, the different method
of smoking may explain how
a few joints a day appear to cause
as much inflammation as an
entire pack a day of cigarettes.
The visual evidence of airway injury
was at times striking.
This is what your airways
are supposed to look like,
the tubes inside your lungs.
This is your lung;
this, is your lung on tobacco.
See how your airways get all inflamed?
And this is your lung on pot.
You get the same kind of inflammation,
and what’s crazy is that’s just
5 joints a day,
compared to 26 cigarettes a day
in the tobacco smokers.
If you compare the respiratory symptoms
associated with marijuana
versus tobacco,
compared to nonsmokers,
both marijuana smokers and tobacco smokers
have elevated rates of chronic cough
and excess sputum production
acute episodes of
bronchitis and wheezing.
Now, when you quit tobacco,
these respiratory symptoms
eventually go away.
Does the same thing happen
with marijuana?
What are the effects of quitting
cannabis on respiratory symptoms?
About 30 to 40% of regular cannabis
users suffer from cough,
excess sputum,
wheezing,
and shortness of breath.
A thousand young adults
were followed for years,
and in those who kept smoking,
their respiratory symptoms got worse
or remained the same.
But, those that quit
tended to get better.
If we don’t quit, what are the
long-term lung consequences?
What about COPD
(Chronic Obstructive Pulmonary Diseases),
like emphysema?
Even if smoking a single joint
compromises lung function
as much as up to 5 cigarettes,
you’re still smoking 15 times less overall,
and so, should end up with less
long-term lung damage, right?
That's indeed what’s been found.
Even long-term pot smokers
don’t appear to suffer
lasting lung damage.
Follow people for 20 years,
and an occasional joint appears
to have no discernable effect
on long-term lung function,
though may be some
accelerated decline in function
among those smoking joints
every day for decades, and so
“marijuana moderation” is suggested.
In other words, a caution against regular,
heavy marijuana usage is prudent,
but even regular, heavy use
of marijuana is nothing compared
with the grave pulmonary consequences
of tobacco.
Any toxicity of marijuana pales
when compared with the greatest
legalized killer in the world today.
In fact, the greatest risk to our lungs
from marijuana may be that it
could be a gateway drug to cigarettes.