Cholesterol is in every cell in our body and becomes concentrated
in our brain. Our brain is 60% fat, with over 25% of that being
cholesterol. Most of the cholesterol in the brain is produced in the
hypothalamus itself, establishing cholesterol as an integral part of our brain.
One of the most dramatic difference between young and old
brains is the reduced myelination—fat sheathing—around nerves, which might
explain why aging brains shrink at 1% a year. Myelin is a sheet of lipid, or
fat, with the highest cholesterol content of any brain tissue. Even neurotransmitters,
the chemical words used in the language that the brain communicates in, are
made of cholesterol. George Bartzokis, with UCLA, and his colleagues, found a correlation
between diminishing speed of performing tasks and diminishing level of
myelination. The older we get, the less myelination we have. And in older age
we can destroy this protective layer much faster through excessive alcohol intake
and some non-/prescription drugs.
Myelination seems to be important in how we learn. Although
grey matter—on the outside of the cortex made up of neurons—carry messages and
does the “thinking”—white matter—the myelinated part of the brain—controls the
strength of signals. Myelination is how we learn, strengthening some signals
above others. Myelination also occurs in at different ages. Starting from the
back of the brain as children, and finishing off at the front of the brain in
adulthood. This explains why certain tasks are easier when you are a child then
at older ages (learning to speak without an accent.)
And the role of cholesterol seems crucial to this process of
myelination. In 2008 Rebecca West and her colleagues from Mount Sinai School of
Medicine, New York, unexpectedly found that among normal—no expression of
dementia and not having the genes that predispose you to get dementia—older
adults aged 85 years and older, high total cholesterol and high LDL (bad) cholesterol
were associated with higher memory scores.
Other evidence is mounting. Elizabeth Johnson and Ernst Schaefer
with Tufts University, Boston, MA conjectured that one commercially available
fish oil capsule per week—180 mg dietary DHA/d—might reduce the risk of
dementia by half. On the negative side,
two small trials published in 2000 and 2004 by Matthew Muldoon from the
University of Pittsburgh, suggest that prescription medication we use to lower
cholesterol—statins—might bring about cognitive decline. He reported that
participants taking placebo pills improved on repeated tests of attention and
reaction while those on statins did not. This was further confirmed by anecdotal
evidence published in an article in 2003 in Reviews of Therapeutics which
reported that among 60 statin users who
had reported memory problems to MedWatch, when they stopped taking the medication
more than half reported improved memory.
Science is not truer than religion. Science is being able to
challenge the accepted reality of today. Science is a method rather than a body
of truths. The method is to question beliefs, to test expectations. The problem
with science in large U.S. institutions is that it has become a religion.
© USA Copyrighted 2014 Mario D. Garrett
No comments:
Post a Comment