From: Robert J. Bradbury (bradbury@aeiveos.com)
Date: Sun Apr 13 2003 - 13:58:13 MDT
B
On Sun, 13 Apr 2003, Brian Atkins wrote:
[big snip]
> 3) more recent research is
> beginning to show that what actually causes heart disease is an
> inflammation process, which actually has little if any relation to the
> particular fats and cholesterol that most doctors and individuals in the
> USA currently believe is the cause. What causes this inflammation is a
> very interesting topic...
Brian, I'm a little unsure about your points #1 and #2 since I've
never seen any supporting literature on the assertions -- but as
far as #3 goes, I've got a working hypothesis.
Macrophages are designed to kill bacteria, in particular with with an
"oxidative burst" (among other things). This would induce the oxidation
of the lipids in the surrounding environment, esp. the lipids in the
bacteria. So macrophages have a receptor for oxidized LDL's to clean up
the mess they produce. But macrophages are also designed to detect and
migrate into tissues where viruses or bacteria are present (or there are
other immune system cells detecting the presence molecules that serve as
indicators for viruses or bacteria).
I think what happens is that excess oxidized LDL activates the
macrophage program that says "bacteria are present -- migrate into
the tissues", they then get into the arterial walls -- but there
are no further chemoattractants (bacterial or other immune system
cell cytokines) that tell them where to go further within the tissue.
Thus they remain stuck within the arterial walls and end up causing
the plaques that cause the problems we eventually see in athersclerosis.
So the two solutions are to decrease total LDLs -- that is what low
fat diets are all about -- or increase antioxidants to protect the
LDLs from becoming oxidized (which prevents the macrophages from
improperly activating "there be bacteria here" program). I suspect
the H-G/paleolithic diet had some combination of both of these.
If one looks at the modern Chimpanzee diet -- it is mostly, if not
completely fruit/other-vegi-products I believe -- if we evolved from
that base then we presumably would naturally have higher antioxidant
levels and lower saturated fat levels in our diet.
Adapting to more modern levels of less fruit/more meat consumption
are probably incomplete from an evolutionary standpoint. Its probably
only been 3-4 million years. And the selection pressure on the
"elderly" has been very poor from a historic perspective. The aging
Alpha males probably have a very high mortality rate due to fights/
accidents with their upcoming replacements. Pressure to adjust the
genetic program to prevent heart disease probably doesn't have much
of a chance.
Robert
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