Elizabeth Miller wrote:

>Tom,
>
>Do you know the mechanism responsible for saturated fat downregulating LDL
>receptors or have a good descriptive reference.
>
>

It's Todd, actually.

I don't have anything right at hand.  There are lots of references to
this on the web, but I'm looking for something like a primary source.
 I'll have to get back to you.  I haven't had a lot of time lately.

>It sounds like you were what in the literature is called a responder --
>although this designation is slippery - people who raise their cholesterol in
>response to short term dietary changes don't necessarily respond like that
>again. The lower carb approach may have produced results over a longer time
>period.
>

That's true.  And I have tracked my cholesterol in the past few years.
 Lutz did a lot of research on this and found that carb reduction and
fat increase would often cause an increase in LDL for a few months, and
then a decline.  In younger patients, the decline would be to below
pre-diet levels; in older patients, it would just return to about the
same as pre-diet level.

>Was reading a medical physiology book from 1965 and the authors claimed then
>that to lower one's cholesterol one could either lower fat intake or
>carbohydrate intake -- they talked about evidence that more benefits from
>lowering carb intake. The role carbohydrates play in cholesterol synthesis
>is not played up in recent physiology texts.  Suppose it's not politcally
>correct.
>
>

Right.  And yet there's no doubt of the insulin-mediated effect.
 Personally, I think that total caloric balance plays a role as well.
 Groups such as the Masai and Samburu, who were noted for their high-fat
diets and very low cholesterol levels, also had rather low caloric intake.

>Do you think your diet is responsible for  your cholesterol drift down in the
>case of TC and up in the case of HDL. Or perhaps your diet has fostered
>greater health (less inflammation, etc.) that means whatever need your body
>had for cholesterol has lessened. Less need -- less production and more
>clearance.
>
>

I do think my increase in HDL is the result of greater saturated fat
intake.  Probably the LDL too, but the other thing is that there are
plenty of non-dietary factors, such as stress, that can cause insulin
levels to be elevated.

Todd Moody
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