On Wed, 17 Feb 1999, Michele Wiedemer wrote:

> Todd and everyone,
> I just wanted to add my 2 cents' worth (if that) about this
> cholesterol discussion. We are all influenced by the incredible
> simplicity of health information and advice. The cholesterol issue is
> almost certainly a very complex process, and one cannot necessarily
> draw a direct correlation between one factor and another (like diet
> and raised levels)--even though that's exactly what researchers seem
> to try to do.

I agree completely.  I am not at all convinced that cholesterol
or the various ratios are the significant risk factors that they
are sometimes held to be, but that is just my opinion, and I
recognize that the matter is hotly debated.  Clearly there are
things other than diet that affect cholesterol levels.  My only
complaint is with the way this is handled in Neanderthin, where
it is implied that elevated insulin alone causes elevated
cholesterol and therefore the Neanderthin diet will correct it.
This simply isn't so.

> I've recently done some reading on homocysteine and how it fits into
> the cholesterol picture. Studies seem to now be revealing that it's at
> least as important as cholesterol as a risk factor for heart disease,
> if not more important than cholesterol (again, that simplistic
> thinking). However, I understand that what seems to happen is the
> homocysteine does the blood vessel damage  and the cholesterol comes
> in to repair the damage. So it seems logical that if the homocysteine
> levels are raised and causing blood vessel damage, the cholesterol
> levels would raise in response.

Yes, there is pretty good evidence for the role of homocysteine
in athersclerosis.

> It is furthermore logical that on a diet high in animal foods and low
> in b vitamins would contribute to high homocysteine levels.
> Homocysteine is simply an intermediary breakdown of the amino acid
> methionine, which is certainly found in animal foods.

Red meats are especially high in methionine.

> The conversion
> from homocysteine to a less "free-radical" producing substances
> requires an enzymatic process involving folic acid, B12 and B6.
> Perhaps with good absorption one would get enough B12 and B6 from
> animal foods, but I don't know about folic acid.

The B vitamins are known to be easily degraded by heat and time.
Most of us cook our meats, or preserve them by drying.
Measurements of so-called "fresh" produce often show a marked
drop in B vitamin content, just from sitting around in trucks and
on supermarket shelves for days.

> Anyway, it would be interesting to see if those with high cholesterol
> also have high homocysteine, and if by lowering the homocysteine
> (through b vitamin supplementation) the cholesterol levels also go
> down.

I think it doesn't, but the argument from the homocysteine people
is that the high cholesterol is less problematic if homocysteine
is low.  It may be that homocysteine is just one of the agents
that damage artery walls.  Glucose and insulin are also
candidates.  So it's possible that when glucose and insulin are
elevated, they are doing the damage and elevated cholesterol is
just a side-effect.  If this is so, then elevated cholesterol in
the absence of elevated glucose, insulin, and homocysteine would
be an abnormality but not a dangerous one.

But this is all speculation.  I wouldn't want anyone to mistake
it for established fact.

Todd Moody
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