On Wed, 28 May 1997, Andrew S. Bonci, BA, DC, DAAPM wrote:

> True AA serves as the basis for series 2
> eicosanoids however it is vital to our biological survival.  I firmly
> believe that there is an evolutionary basis (however, I'm not an expert
> in evolution and feel funny about what I'm going to say).  I believe our
> organism needs and expects AA from its dietary sources.  These dietary
> sources are organ meats, skeletal muscle and eggs.  AA is so necessary
> that provisions have been made biochemically to allow the body to
> manufacture large quantities of AA if they are not provided directly by
> the diet.

I agree, and in fact it's not difficult to surmise the
evolutionary basis for this.  The series 2 eicosanoids govern
such processes as inflammation and clotting.  For most of our
evolutionary history, some of the main threats to human life have
been infection and trauma, and inflammation and clotting are
essential to surviving these.

In the age that we now live in, however, infection and trauma are
*not* the primary threats to human life; the degenerative
diseases are.  This means that AA, while still important, is not
as important as it used to be.

> AA is not a villan.  It helps to clot your blood which is useful if you
> plan on not bleeding to death.  And not bleeding to death is a good
> evolutionary mechanism we shouldn't ignore <BIG SMILE>.  Thanks for
> being the midwife to this post!

But it is a villain if it is present in sufficient quantities to
cause clotting in coronary arteries, etc.

We need to ask ourselves whether this aspect of the paleodiet is
in fact optimizing our bodies for survival in an environment
quite different from the one that we actually live in.  And if
our modern food sources are even higher in AA than those to which
we are biologically adapted, this only magnifies the problem.

In the "Paleolithic Nutrition" article (NEJM 312:5), Eaton and
Konner point out that "the fat of wild animals contains an
appreciable amount (approximately 4 percent) of eicosapentaenoic
acid (C20:5) ... Domestic beef contains almost undetectable
amounts of this nutrient."  This means that while our ancestors
probably ate adequate amounts of dietary EPA, we don't, unless we
eat a fair amount of oily fish.  Thus, even though it might not
be "natural" to take fish oil supplements, it might nevertheless
be a good idea, given that our ancestors adapted to an intake of
this substance that most of us are not getting.  And dietary EPA,
as you know, can reduce AA levels in the body.

So the situation seems to be this:  We probably need less AA than
our paleolithic ancestors needed.  On a contemporary paleodiet,
we are probably getting more than they got.  We are also probably
getting less EPA than they got, which makes the situation further
unbalanced.  This implies that we might be best served by
limiting our intake of dietary AA somewhat and supplementing our
intake of EPA, in order to approximate the levels to which our
bodies are best adapted.

Todd Moody
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www.sju.edu/~tmoody/