How Might Inflammation Cause Heart Disease?
Mark’s Daily Apple
by Mark Sisson: Are
Your Canned Foods Safe To Eat?: A BPA-Free Buying Guide
obsessive focus on cholesterol
levels as the ultimate arbiter of cardiovascular disease, most of
the medical field agrees that plenty of other factors also contribute:
tobacco usage, psychosocial stress, activity level, and genetic
predispositions. In short, a diverse set of lifestyle and genetic
factors are consistently associated with cardiovascular disease.
This is accepted in the ancestral health community, just as it's
accepted in the mainstream medical community, but the question remains
– why? Why does stress
contribute to heart disease? How does smoking tobacco increase the
risk of heart disease? Why are both the sedentary and the overtrained
at a higher risk for heart disease?
Well, as I'm
(and others are) quite fond of saying, inflammation
is most likely the ultimate cause of heart disease, and all those
factors – even some of the genetic ones – are mediated by inflammation.
When you get down to it, any explanation of the links between smoking
and heart disease, stress and heart disease, exercise and heart
disease, cholesterol and heart disease, and even genetics
and heart disease must include inflammation to be accurate. As I'll
briefly discuss in the following post, each of these lifestyle and
even genetic factors exert much (if not most) of their influence
on heart disease via their effects on inflammation.
the evidence for the inflammatory roots of heart disease and continue
our discussion of inflammation.
The most common
form of tobacco ingestion is smoking – the inhalation of smoked
emitted by the burning of dried tobacco. Now, some would argue that
it's the modern processing of tobacco that makes smoking it so bad
for us, and that unprocessed tobacco is more benign and results
in less heart disease. Or that it's the modern diet that makes smoking
so harmful (see the traditional Kitavans with their moderate smoking
habit and apparent lack of heart disease). That's probably true
on some level, but it's not really within the scope of today's post.
So when I refer to "smoking," I mean the kind of mass market cigarettes
that smokers in the industrialized world use: your Marlboros, your
Camels, your Lucky Strikes. The kind that is linked to heart disease.
Plenty of studies
show that inhaling incredibly hot, burnt tobacco plant material
acutely increases inflammation, quitting immediately
lowers inflammation, and recent review (PDF)
of the literature specifically causally connects smoking-related
inflammation and heart disease. One study
even showed that smoking heaps acute inflammatory stress on atherosclerotic
plaque, thus increasing the chance of a rupture. And when your atherosclerotic
plaque ruptures, or breaks off, the resulting thrombus can lodge
itself in the artery and block the blood flow. That, my friends,
is a garden-variety heart attack caused by inflammation. Does it
get much more cut and dry than that?
It's also worth
noting that smokeless tobacco ingestion, while far from benign,
is associated with lower
inflammatory markers and less heart disease than smoking.
Other Psychosocial Factors
in many guises nowadays. While Grok
had to deal with a few acute, undoubtedly intense psychological
stressors, like facing down an opponent or a large animal bearing
imposing claws and teeth, he probably didn't experience the type
of chronic, persistent psychological stress "enjoyed" by modern
man. We know that psychosocial stress induces
a physiological inflammatory response, and just like chronic
exercise, chronic psychosocial stress can probably lead to chronic
show that folks with higher amounts of psychosocial stress and depression
elevated C-reactive protein and IL-6 levels, both markers of
inflammation. They're also heavier and more likely to be diabetic,
which are absolutely confounding factors, but the inflammation/stress
association holds even when you account for the other variables.
Teasing out cause and effect is probably impossible, but we know
that stress, obesity, heart disease, and inflammation are all linked.
A further clue may be found among people with anxiety disorders
characterized by a heightened inflammatory response to psychosocial
stress; commonly, this population experiences a "pro-inflammatory
state" and hypertension, both of which are predictors
of future cardiovascular disease. Another study found that certain
psychosocial factors, like anger and cynicism, were linked to progression
of cardiovascular disease.
For a further
look at this, check out "The
Great Cholesterol Con" by Malcolm Kendrick, who thinks stress
is the primary cause of heart disease. I wouldn't go that
far, but it, along with the inflammatory response it engenders,
plays a big role. This review paper attempts to explain how psychosocial
stress-induced inflammation might lead to heart disease.
the rest of the article
January 20, 2012
© 2012 Mark's Daily Apple
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