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there's been a recognition that
cigarette smoking can have a major
effect on bone health on for decades
increasing the lifetime risk of hip
fracture by about half it also appears
to impair bone healing so much so that
surgeons ask if they should be
discriminating against smokers because
the bone and wound healing complication
rates are just so high but what about
smoking marijuana there is accumulating
evidence to suggest that cannabis
compounds play important roles
regulating bone mass and bone loss yeah
but are they friend or foe results from
research on cannabis compounds and bone
mineral density in rodent models have
been inconsistent
some studies show increased bone
formation others show increased bone
loss and others show no association at
all this variation and results may be
due in part to differences in the mouse
strain used but if you can't even
extrapolate from one Mouse to another
how can you extrapolate to human beings
so what if you just measure cannabis use
and bone mineral density in people
thousands of adults were tested and
asked about their cannabis use and there
did not appear to be any link between
the two that's a relief though in this
study heavy cannabis use was defined as
just five days or more of use in the
last month they didn't ask beyond that
so theoretically someone who's just
smoked five joints in their entire life
could be categorized as a heavy user how
about cannabis use on 5000 separate
occasions over a lifetime now that's a
heavy user decades of regular use and in
that case heavy use was associated with
both low bill mineral density and an
increased risk of bone fractures about
double the fracture rate but presumably
due to lower bone density in the hip and
spine though heavy can
users were also skinnier on average and
skinnier people have lighter bones hip
fracture risk goes down as your weight
goes up nearly half of underweight women
have osteoporosis but less than one
percent of obese women do which makes
total sense being obese forces your body
to make your bones stronger to carry
around all that extra weight
that's why weight bearing exercise is so
important to constantly put stress on
your skeleton
it's use-it-or-lose-it that's why
astronauts can lose a percent of their
bone mass every month their bodies
aren't stupid why waste all that energy
making a strong skeleton if you're not
gonna put in any weight on so maybe
that's the only reason heavy cannabis
users have frailer bones because they
tend to be about 15 pounds lighter wait
a second users are slimmer what about
the munchies the lower BMI of heavy
cannabis users may seem counterintuitive
given the appetite stimulation but this
isn't the first time this has been noted
you know pop culture depicts marijuana
users as a sluggish lethargic
unproductive subculture of compulsive
snackers and it's true that marijuana
has been found to increase food intake a
single hit can increase appetite and so
you'd expect obesity rates to rise in
states that legalized it but if anything
the rise in obesity appeared to slow
after medical marijuana laws were passed
where it appeared to just keep rising in
other states the reason pot smokers may
be slimmer is because the effect of
smoked marijuana on metabolism we've
known for nearly 40 years that within 15
minutes of lighting up your metabolic
rate goes up by about 25% and stays
there for at least an hour so that may
be playing a role so is that why heavy
cannabis use is associated with lower
bone mineral density and increased risk
of fractures they're just not as
overweight no even taking BMI into
account
heavy cannabis use appears to be an
independent predictor of weaker bones
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you