Posted by Jim Whitaker

In Reply to: What causes arteries to constrict? posted by Rick

This doesn't make any sense to me at all. It is so outlandish of an
assertion that it made me question my memory enough to go back and
dig through my old medical school textbooks. I would really like
to know what your sources are to look this up, because this is
the best conclusions I can come to with the information availiable
to me:

Lets assume for the moment that magnesium was necessary for the artery
muscles walls to relax. I'm not sure about this, and I don't see it
here anywhere in _Circulatory Physiology -- the essentials_ 3rd ed,
Smith and Kampine, 1990. It does say something about the exact
mechanisms of constriction and dialation not being known as of the date
the book was written. My other sources are pretty much in compliance
with this. Frankly, I have never heard of it and apparently neither
have the authors of these books here. But lets give you this point
just to see where it leads as a viable cause of any form of
hypertension that a person is likely to have.

Muscle cells are VERY picky about the upper limits on calcium and
magnesium they will pick out of the blood, no matter what the blood
levels of these are. They have to regulate their internal pH, among
other things. It is the muscle cells in the artery walls that
constrict in emergency conditions. This sets an absolute limit on the
calcium levels that the arterial muscle cells have to work with at a
"normal" level. What you are really saying here is that hypertension
can be caused by a magnesium deficiency. I have never heard of it
actually being demonstrated. Magnesium deficency isn't exactly
symptomless. Long before your blood pressure could go up from
magnesium deficiency, you would be carted off to a hospital in an
ambulance with dramatic symptoms: nerve disorders, severe kidney pains,
and a host of relatively easily identifiable symptoms and this would
show up in a blood workup. Magnesium is also very prevalent in many
foods, almost impossible to avoid. You have to be an improperly
medicated diabetic constantly losing body fluids, a raging alcoholic,
have chronic vomiting, suffer chronic dysentary, have severe protein
malnutrition, or be in the throngs of kidney failure to develop a
magnesium deficiency of a magnatude to cause chronic artery wall muscle
cramping, that is assuming that magnesium deficiency can even do this.
Not exactly a silent killer, that magensium deficiency. The
calcium/magnesium ratio problems that I remember are all related to
laying down mineral in the bone.

Something else to keep in mind -- if your blood serum magnesium is
too low -- your bones automatically cough some up to set things right.
Your arteries muscle cells will immediately pull the magnesium
out of the blood made availiable to it from the bones. Your bones
would have to be in a terrible state of osteoperosis before a
magnesium deficiency would deprive the blood magnesium level down
to deficiency levels.

Now, Consider that there must be over a 75% occlusion of the artery to
produce a significant rise in blood pressure. You would be suffering
from a procession of major muscle cramps and and other problems long
before arteries would be forced to hold a pose that would be unable to
relax to at least 25% of the original cross sectional area for 24 hours
a day. Not only that, a twitch caused by an errant nerve could be
fatal in that it could shut off the blood supply through that artery
that could never un-cramp without "sufficient" magnesium to balance the
cells internal calcium levels. Remember now, magnesium deficiency
causes motor nerves to get kind of twitchy and unstable...

A typical diet contains about 120 mg/1000 dietary calories.
You have to work HARD to avoid magnesium. The USRDA for adult
males is 350mg. And so, OK, probably 80% of the population of
adult males fall short of this. That isn't low enough to cause
muscle cramping in artery walls even if the association between
hypertension and magnesium were correct.

I simply don't think this is possible. Please send me some references.
I am very interested. Or was this some kind of an MD's idea of a way
to find out if I knew what I was talking about?

Follow Ups:

• The concept of mineral imbalance as a major contributor to cardiovascular disease has been elucidated in epidemiological, animal, and human (clinical) studies Anthony Brea D.C.
  • Atherosclerotic plaque is actually composed of different layers Rick
    • The first stage is a fatty streak, not calcification. Martin Banschbach, Ph.D.
    • I've got to correct your conception of atherogenesis. The first phase of atherosclerosis is the fatty streak, which is composed of foam cells Cindy J. Fuller, Ph.D., R.D.

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