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Don Matesz <[log in to unmask]>

Amadeus Schmidt <[log in to unmask]> wrote:
>
>But I *don't* think that brain eating or DHA eating was essential
>to having large and functional brains, IMO not.
>Otherwise we would have lost the metabolic capability
>to build it up ourselves from precursors, just like cats lost it.

Well the evidence is that we do not have the ability to produce DHA ourselves AT THE RATE
REQUIRED FOR PROPER DEVELOPMENT AND MAINTENANCE OF THE BRAIN.  The point is that an animal
may have the ability to produce some DHA but not enough to meet all needs or achieve
proper development or health.

It is estimated that under the best circumstances humans require at least 100 molecules of
ALA to make one molecule of DHA (see Smart Fats by Michael Schmidt, Ph.D.).

And it has been shown repeatedly that vegetarians have much lower DHA levels than is
optimal.  "In a study of the blood levels of long chain fatty acids of vegetarians,
doctorsw found that DHA levels were very low, especially in long-term vegetarians.  When
studying the effects of mothers' vegetarian diet on the fatty acid levels of newborns
researchers foudn there  to be less DHA in the blood of infants.  Thsiw sould also suggest
that the mother's DHa levels might be low.  Another groups of researchers foudn the DHA
levels of breast-fed infants of vegetarian mothers to be only about one-third the level of
breast -fed infants of mothers who consumed meat and vegetables."   That is from page 49
of Smart Fats by Michael Schmidt, Ph.D., the references are: Argen JJ, et al.  Fatty acid
composition of erythrocyte, platelet, and serum lipids in strict vegetarians.  Lipids
1995; 30(4): 365-69; Reddy S, Sanders TAB, Obeid O.  The influence of maternal vegetarian
diet on essential fatty acid status of the newborn.  Eur J Clin Nutr 1994; 48: 358-68;
Sanders TAB, Reddy S.  The influence of a vegetarian diet on the fatty acid composition of
milk and the essential fatty acid status of the infant.  J Pediatr 1992; 120: S71-77.
>
>The Omega Plan describes disorders by insufficient w-3 fat supply,
>which may be precursors or DHA itself.
>IMO this is indeed a very justified observation since the common
>western diet (including heavy meat and many vegetarian diets)
>come short in supplying the essential w-3 and even w-6 fats
>(in addition to a seemingly odd ratio).
>
>Cereals and cows muscle *only* lack it.

Actually cow muscle fat does contain omega 3 fats, and more if the animal is grass fed.
Beef suet is about 10% PUFAs.
>
>Neolithic trading was on long ranges with flintstone for example.
>But fish go bad (this means poisonous) in a matter of a few hours.
>Drying isn't such easy, especially polyunsaturated fats easily go
>rancid. Rancid means danger for the liver.

Take a trip to Asia, or even an Asian foods store.  You can purchase dried fish in large
amounts.   I've eaten such fish with no ill effects.   Drying fish is not that hard, and
it is widely practiced all over the world.   As for rancidity, this is not an issue if the
fish are dried whole, there are plenty of anti-oxidants in the tissues to protect the
fats.   Plus we know that primitive diets have included "rotten" fish, that is what
fermented fish sauces are, found in many areas of the world, including Worcestershire
sauce.   Such sauces are used extensively in Asia.

>Humans are capable to synthesise EFAs from the proper precursors.

This is true only to an extent, as noted above.  The amount we can synthesize is shown
most probably far short of what is needed.
>
>But I wouldn't build a whole theory
>of encephalization and human origin on this topic.
>Homo erectus, Homo habilis, Australipethines, Neanderthals.
>they all would have had problems to *catch* much fish other than mussles.
>Nets and fishooks are a recent invention only about 40kyears old.

Your point is mute.  None of those hominids had brains like modern man, and that may be
because they did not eat much fish.  That is Crawford's theory.  We don't need nets and
fish hooks to catch fish, and certainly not to get shellfish, fish roe, tiny new fish,
etc.  I recall Hans reporting he caught a fish with his hands and ate it alive not too
long ago.

I'm not trying to build a theory of encephalization, I'm just reporting parts of
Crawford's theory.  I think this is THE topic on which to build any theory of human
orgins, such a theory MUST be focused on accounting for nervous system development because
this is the specialization of the human body.

Don