On Thu, 24 Sep 1998, Ilya wrote:

> Clearly you know the difference. Though this is the first time I have
> seen linolenic acid referred to as alpha-linoleic. Are you sure this
> is right?

Not really.  I'm sure that I've seen it called that, but I don't
recall where, so it may well be a mistake.

> > According to Eaton, the fat of wild game animals
> > (not just the brains) has about 4% EPA+DHA, while the fat of
> > domestic cattle has none.
> I specifically named brains because that's where much of those fats
> are needed and used. Considering how easily they oxidize I would
> not expect much of them used for plain old fat storage.

The Eaton figure gives us at least a rough idea of what EPA
levels should be on a paleodiet.  This is why I made a point
about EPA deficiency in the recent "all-meat diet" discussion.
If the meat is all from feedlot cattle, one will likely end up
with an w-3 deficiency.  A small amount of oily fish would fix
that, but one would have to make an explicit point of it.  There
is a small amount of ALA in beef fat, but I don't think it would
be enough.

> I never understood why it had to be an either or situation - it's
> either ALA itself or EPA or something down stream. It seems the body
> has uses for all of them, aside from needing one as a substrate for
> another.

So it seems.  From a pure paleo perspective, flax seed oil would
be forbidden, but purslane would be okay.  This again give us
some idea of magnitudes, since you'd have to eat a *lot* of
purslane to get the equivalent ALA of a tablespoon of flax oil.
HGs in temperate climates would be eating ALA-containing greens
and seeds, along with EPA-containing meats.  HGs in colder
climates would need marine sources of w-3 fats along with the
meats.

I believe some wild or free-range eggs also have w-3 fats,
because the birds eat purslane and seeds.

Todd Moody
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