Paleo Phil wrote:
> These seem to be the best of the anti-saturated-fat studies (there are
> others that contradict these, such as the Stanford Atkins-Ornish study and
> the Framingham study). I was hoping that Todd or someone might have good
> counterarguments to or criticisms of these, as I couldn't find any online.

I have a hypothesis.  It is this: if a human eats saturated fat but not a
lot of carbs, especially highly glycemic carbs AND his total caloric 
intake does not exceed his daily needs, then most of his energy will
come from the fat, and the fat consumed will be burned fairly completely.
In this case he will NOT suffer the supposed negative effects of saturated 
fat consumption (and consequent risk of heart disease).

If on the other hand a human eats a diet high in carbohydrates PLUS a lot
of saturated fat, OR he regularly eats lots of saturated fat and his total
caloric intake exceeds his daily needs, then he will incompletely process
some of these SFAs (saturated fats) and consequently experience elevated 
cholersterol, arterial plaque, inflammation, and eventual death from CHD.

Or, in short, if you're lean and paleo, then saturated fat is good, and if 
you're fat and eat "civilized", then saturated fat is bad.

This just occurred to me yesterday while thinking about the controversy
over SFAs, but probably many on this list were already thinking along 
those lines because it just makes intuitive sense.  We just have to define
it clearly as a hypothesis so we can see if it fits the evidence... and
looking at just the descriptions of these studies, so far it does seem to:

> [SF is a strong predictor of CHD mortality in middle aged American Indians.]

Are these Indians by any chance overweight and drinking too much?  Sorry
about the stereotype, but alcohol is a high-glycemic carbohydrate, and 
middle aged American Indians are known to consume a lot of it on average.

> [SFAs were found to be positively associated with the inflammatory markers
> C-reactive protein and circulating interleukin [IL]-6 in overweight men, but
> not lean men]

What I said!

> [Beef Fat Increased LDL; subjects were restricted to nonfat dairy to avoid
> confounding data with SF from dairy foods; cited by Loren Cordain, Ph.D.]
> Am J Clin Nutr. 1990 Sep;52(3):491-4. 
> Cholesterol-lowering effect of a low-fat diet containing lean beef is
> reversed by the addition of beef fat.

Ok, here we just need to know a bit more about this "low-fat diet"... but
it's a good guess that it's a classic high-carb diet and not a Cordain-style
low-fat paleo diet.  If so, it still fits the hypothesis.

What could invalidate this hypothesis?  High incidence of heart disease 
amongst traditional peoples living on a mostly or completely carnivorous diet, 
for example.  Any studies for or against?

:j