On Thu, 5 Jun 1997, Dean Esmay wrote:

> You're probably correct inasmuch as we may eat more AA than historically.

A recent posting on the Zone list included the assertion
(undocumented, however) that free-range eggs have more EPA than
"regular" eggs.  And Eaton states that the fat of wild meat is 4%
EPA whereas the fat of feedlot animals is devoid of it.

The GJ Nelson work recently posted by Gary Jackson supports what
Andrew has been saying, namely that dietary AA, even in
substantial amounts (1.5g/day above the normal 200mg, or about 23
egg yolks' worth) has no measurable impact on health, at least
not during a 50-day trial).  In fact, it seems that in the
presence of a liberal amount of AA and a small amount of EPA, the
D5D enyzme is switched off and the body produces no additional AA
at all.

This suggests (to me) that the endogenous AA system is an
emergency backup system, to get us through times when meat is
scarce.  My speculation is that the health problems are the
result of the backup system being chronically and inappropriately
activated by insulin, which indeed upregulates D5D.

I was intrigued by the comment in one of the Nelson studies to
the effect that AA took the place of LA in the cells.  If I am
not mistaken, LA is far more oxidation-prone than AA, so the
presence of AA would tend to reduce the probability of oxidation
of LDL, etc.

> Recent posts from Loren Cordain on the Paleodiet Symposium also suggest the
> possibility that trying to get more monosaturated fats may be a more
> natural paleolithic pattern after all, because bone marrow is (a) popular
> among hunter/gatherers, and (b) largely monosaturated.  I'm not interested
> in sucking bones and eating brains too much so I begin to feel that olive
> oil looks even more attractive than it has been.

I suppose one could utilize those monounsaturated fats by using
bones to make soup stock, if sucking the marrow out of them seems
too tedious.

Todd Moody
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