On Fri, 25 Sep 1998, Amadeus Schmidt wrote:

> On Fri, 25 Sep 1998 07:03:50 -0400, Todd Moody <[log in to unmask]> wrote:
> >I'm not sure what you are saying here, Amadeus.  W-3 fats are
> >needed by adults, not just for growing brains.
> Hello Todd,
> my impression from recent posts was, that there is a theory that
> humans need so much of these w-3-fats because our brain is so big
> (3 times bigger as apes').
> And that eating brains was necessary (or making possible)
> that our brains could *grow* so big.

No, this is a distortion.  It is true that the developing brain
needs EPA and DHA, but these will be found in mother's milk, as
long as the mother is not w-3 deficient.  Eating brains is a good
way to avoid such a deficiency, but not the only way.

> Something else is the daily *consumption* of the bigger brain.
> Is somebody supposing a bigger w-3 fat consumption of
>  a bigger brain?

You are assuming that the brain is the *only* tissue with a
significant need for w-3 fats.  This is false.  Many, many other
cells in the body use these fats are precursors to the series 3
eicosanoids, which are essential to health.

> We do know that a bigger brain has a bigger *vitamin-b1* consumption.
> (Did anybody read what I worte about it in my first post at this thread?
>  It was below a citation block)

Yes, we know that.  But we also know that even that bigger B1
need is easily satisfied, by modest amounts of meat and/or
vegetables.  1.1 mg of B1 is achieved by a mere 150g of cooked
beef, for example.

> Wouldn't you agree that evolving humans did
> get their APA/EPA supply from plants  *at least* up to
> 2 million years back from today?
> (hominds are counted from 4 million years back from today).

I'm not sure that I do agree.  Specifically, what hominids are
you referring to.  EPA is hard to get from plants.  I'm not sure
if there are *any* plant sources, but there might be.  ALA is
converted to EPA in the bodies of animals, for the most part.

> The later hominids seem to have had both possibilities:
> w3-fats from plants (purslane... and other "weed"
> :-) )
> or from mammal brains.
> Since many humans of today never eat brain or fish, and stay
> (reasonable) healthy, it appears as if we were not dependent on
> brain or fish as a supply.

Brains and fish are not the only sources of EPA and DHA.  They
are also found in game meats, but not in feedlot meats.  I don't
question that adequate ALA can be gotten entirely from plants.  I
do question whether signficant EPA can be gotten from plants.  A
vegetarian diet is one in which the w-3 fats will be almost
exclusively in the form of ALA.  There are theoretical reasons to
suppose that this is not the best, and some experimental evidence
as well, but there is still a lot we don't know.  I think it is
at best premature to say that dietary EPA is of no significance.

For example, I have found several studies that show that many of
the beneficial effects of w-3 fats depend on the presence of
adequate amounts of saturated fat.  Many vegetarian diets would
not provide this saturated fat.

Todd Moody
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