http://www.redflagsweekly.com/kendrick/2003_nov06.html
November 6, 2003
LIQUID DRANO-LIKE SYNTHETIC "GOOD CHOLESTEROL" PLAQUE BUSTER! IT'S
SCIENCE, BUT NOT AS WE KNOW IT
By RFD Columnist Malcolm Kendrick MbChB, MRCGP (email -
[email hidden] )
Synthetic 'Good' Cholesterol Helps Clear Arteries
Small Study Indicates the Possibility That Drug Therapy Could Reverse
Heart Disease. Rob Stein Nov 5th 2003
‘A synthetic form of "good" cholesterol has been shown to quickly
shrink blockages clogging coronary arteries, offering for the first
time the possibility of a drug that could actually rapidly reverse
heart disease, researchers reported yesterday….'
I'm writing a book at the moment called Cholesterolmania. That plus a
job, plus children and home, an attempt at a social life and columns
at redflagsdaily.com. That's a tad busy, and I thought I'd take a
short break from column writing, but…I couldn't let the above story
from the Washington Post go without comment.
Here is my immediate response. Aaaaaarrrrrrggggghhhhh! Thud.
It's almost impossible to know where to start without ranting.
Firstly, just to clear something up, HDL is not cholesterol ‘good' or
otherwise. HDL, stands for High Density Lipoprotein. It is a
lipoprotein that is manufactured in the guts and the liver, and it
contains a small amount of cholesterol.
HDL appears to have two basic functions in the body. Firstly, it
transfers proteins, known as apolipoproteins, to VLDL, allowing the
VLDL to be recognised by receptors around the body. Secondly, it
removes cholesterol that is floating about and takes it back to the
liver.
When cells do break down in body, which is happening all the time, the
cholesterol from cell walls is released into the surrounding extra
cellular fluid. The HDL lurking in the vicinity ‘mops up' this excess
cholesterol and transfers it back to the liver. This scavanged
cholesterol is then used in the manufacture of Very Low Density
Lipoproteins VLDLs. VLDLs contain two basic ingredients, fats (in the
form of triglyderides) and cholesterol.
VLDLs are then sent back out into the bloodstream. As VLDLs lose
triglycerides they shrink in size, becoming Low Density Lipoproteins
LDLs (otherwise known as ‘bad' cholesterol – for some stupid reason).
LDLs are then absorbed by cells that need cholesterol, and the
cholesterol is unpacked and used to build various structures within
the cell, including the cell wall.
Which means that HDLs are part of a re-cycling mechanism for
cholesterol. At the risk of repeating myself, the liver manufactures
cholesterol and sends it out within VLDLs. As VLDLs lose triglyceride
– which provides energy for cells around the body - they shrink into
LDLs, and LDLs are then absorbed into cells where the cholesterol is
unpacked.
When a cell then dies, it releases cholesterol, which is mopped up by
HDL and transferred back to the liver. This is not immensely complex,
but for some reason, mainstream researchers have decided that HDL can,
in some way, protect against the build up of atherosclerosis.
There are two reasons for this, I think. Firstly, because a low HDL
level seems to be an important risk factor for CHD, even more so than
a raised LDL level (So surely it must be doing something…Duh!)
Secondly, because it has been noted that, as HDL does indeed transfer
cholesterol from around cells and back to the liver, it is thought
that this reverse cholesterol transport might, in some way, be able to
suck cholesterol out of atherosclerotic plaques.
In answer to the first piece of stupidity. If VLDL levels go up HDL
automatically goes down, it's all to do with the transfer of
apolipoproteins from HDL to VLDL. The raised VLDL itself is caused by
underlying insulin resistance – one of the basic causes of heart
disease. So a low HDL is merely a ‘marker' for raised VLDL, which
itself is a marker for insulin resistance. A low HDL by itself causes
nothing and prevents nothing.
With regard to the reverse cholesterol transport nonsense. HDL cannot,
I repeat cannot, remove cholesterol from atherosclerotic plaques. It
is impossible for this to happen. The cholesterol in a plaque is not
‘floating free' in the extra cellular fluid. It is trapped in a solid
atherosclerotic lump. HDL is completely and utterly incapable of
getting at it, and even if it could, it could not separate it out from
the surrounding plaque structure. HDL is a passive inanimate chemical.
It cannot carry out complex tasks.
The concept that HDL could remove cholesterol from a plaque is such a
stupid idea that I cannot believe it still exists. Once you understand
the science, the whole thing is patently ridiculous.
If synthetic HDL can reduce the size of plaques then I will eat my
hat. What these researchers are seeing, probably, is what all
researchers see. Most plaques, if left alone, do gradually reduce in
size – a bit. Alternatively, they have been looking at their findings
with eyes of faith. Let's just see if anyone else can verify these
results.
P.S. In the Heart Protection Study (HPS), a major study in which the
rate of deaths was reduced in patients taking a statin (simvastatin),
at post-mortem, the people who had been taking the statin had bigger
and more complex plaques than those who had not. In reality, the size
of the plaque does not actually have anything to do with how dangerous
it is.