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Don and Rachel Matesz <[log in to unmask]>
Next Generation Nutrition. (419) 476-2967

Wrt the article on cooked vegetables "Early humans got smart by cooking
veggies, study says":  This idea that we got smart by cooking vegetables,
not by hunting and meat eating, may be politically correct, but it is
illogical and biochemically incredible.  Here are my reasons:

1)   Cooking is a highly sophisticated behavior that requires intelligence
not had by any other primate.   No non-human primate cooks.  Our closest
primate relatives, the chimps, do hunt.  Therefore, hunting definitely
preceded cooking.  The "advance" from eating everything raw to using fire
for cooking had to wait for improvements in brain capacity, hand eye
coordination, manual dexterity, etc.  In other words, cooking could not have
become common activity for man until after his nervous system had developed
beyond that of the chimps.   Hence, cooking must have come after man became
"smart"--in other words, man did not become "smart" by cooking, he started
cooking after becoming "smart".

2)  Further, there is not enough of essential fatty acids in cooked
vegetables to support
development of a more sophisticated nervous system or brain.  The omega-6
EFA arachidonic acid (AA) and the omega-3 EFA docosahexaenoic acid (DHA) are
of prime importance as structural materials of the brain.

To the best of my knowledge, there are no vegetable sources of AA (Whitney
and Rolfes, Understanding Nutrition, West Publishing Co, 1993, pp. 140-142),
but land animal meats are rich in this fat.  Land vegetables do not provide
significant amounts of DHA.  Most have no DHA, but Simopoulos  et al suggest
that buttercrunch lettuce and mustard greens supply .001 mg DHA per g, and
red leaf lettuce supplies .002 mg DHA per g (Simopoulos AP, w-3 Fatty acids
in Growth and Development and in Health and Disease, Part I, Nutrition
Today, March/April 1988).   This is compared to salmon, for example, which
contains 6 mg DHA per g, and land animal brains, which are approximately 60%
fat, approx 40% of that fat being DHA.

It is generally accepted that although humans can produce some AA from
linoleic acid found in vegetables (mostly seeds), and some EPA or DHA from
linolenic acid found in vegetable sources, HOWEVER "The converson process is
slow, so the most effective way to sustain body stores of arachidonic acid,
EPA, and DHA is to obtain them directly from foods."  (Whitney and Rolfes,
Understanding Nutrition, West Publishing Co, 1993, pp. 141)

Greens do provide alpha-linolenic acid (ALA), which some animals can convert
to DHA, but various studies have shown that  modern humans have little or no
ability to achieve this conversion.  For example, I have been informed (I
have not yet read the entire study myself) that a study recently published
in the Am J Clin Nutr (1999; 69: 872-82) compared the biological value
vegetable source ALA and fish source EPA and DHA and concluded:  "Because
such small amounts of EPA and other long chain Omega-3 PUFAs are produced
after ALA-rich diets, it is clear that the 2 main sources of Omega-3 PUFAs
(plants and fish) do not have equivalent biological effects in humans."

This research supports previous studies (cited by professor Michael Schmidt,
Smart Fats, North Atlantic Books 1997, pp. 48-49) that have shown that long
term vegetarians have low blood levels of DHA compared to omnivores (Agren
JJ et al. Fatty acid composition of erythrocyte, platelet, and serum lipids
in strict vegetarians, Lipids 1995; 30 (4): 365-69), that infants born of
vegetarian mothers have lower blood levels of DHA compared to infants born
of omnivores (Reddy S et al, The influence of maternal vegetarian diet on
essential fatty acid status of the newborn, Eur J Clin Nutr 1994; 48:
358-68), and that the DHA levels of breast-fed infants of vegetarian mothers
are only about one-third of the levels found in breast-fed infants of
mothers who consumed meat and vegetables (Sanders TAB, Reddy S, The
influence of a vegetarian diet on the fatty acid composition of milk and the
esential fatty acid status of the infant, J Pedeatr 1992; 120: s71-77).

Other primates are incapable of producing much DHA from ALA.  Monkeys
require DHA as proven by the fact that monkey infants deprived of DHA lose
visual acuity. (Crawford and Marsh, Nutrition and Evolution, Keats 1995, p.
128)

In fact, there is no known mammal that is capable of making enough AA from
LA or DHA from ALA to produce a large brain.  Thus, in their book Nutrition
and Evolution (Keats 1995) professors Crawford and Marsh observe "it is
consistently true over the whole range of species that carnivores are
cleverer than their prey" (p. 129) and "The paleontological evidence tells
us that throughout evolution the brains of the carnivores have consistently
been in advance of the corresponding herbivores." (p. 130)  This is in spite
of the fact that herbivores consume large amounts of green leaves rich in
ALA and perhaps containing tiny amounts of DHA.

I suggest to all reading the excellent examples Crawford and Marsh provide
showing the vast difference between herbivore and carnivore anatomy,
physiology and behavioral capacities, and relating those differences to
differences in EFA intake.  The general rule, to which there are no known
exceptions:  All animals having large brains, sophisticated nervous and
vascular systems, and a capacity for complex intelligent  behavior are
carnivores or omnivores, and must be in order to obtain sufficient EFAs for
building their large brains, sophisticated nervous and vascular systems.

So there is no reason to believe that early man had any ability to make
large
amounts of DHA out of the alpha-linolenic acid (ALA) found in green leaves.
Furthermore, it has been estimated that even in the best of ALA converters,
it takes 10 grams of ALA to produce just one gram of DHA.   The absolute
amount of ALA in green leaves is very small, on average less than one half
gram per 100 gram portion, so literally enormous amounts of green leaves
would have to be eaten to get significant amounts of DHA.  Mankind simply
does not have the kind of gut needed to process that amount of greens.
Finally, both ALA and DHA are heat-labile, so cooking greens would have
destroyed much of
the value of any omega-3 fats.

3)  The authors of this "research" say "We don't see meat as a high energy
food source.  It has to be (a) high energy food source to explain this
doubling of body size."  If they don't see meat as a high-energy food source
and think that cooked vegetables are high-energy foods, I suggest that they
try living on nothing but cooked vegetables for a few weeks.  Here are some
facts:

Energy value for one cup portions (one cup of raw meat is approximately 8 -
9 ounces):

Food                                            Calories

Cabbage, cooked                                32
Kale, cooked                                     40
Broccoli, cooked                               50
Pumpkin, cooked                                50
Onions, cooked                                 60
Carrots, cooked                                70
Winter squash, cooked                      110
Sweet potato, boiled and mashed        364

Nuts, raw                                       933

Eggs, eight medium raw                     640

Wild game, raw, lean only                  232    (Average, taken from
Eaton, et al Paleolithic Prescription)

Beef brains, raw                              392


Animal fat, raw                               1840    (This would represent
marrow,  storage fat, etc.)

From these figures it is hard to understand how the authors of the "study"
in question could conclude that cooking vegetables gave early man access to
"high energy" foods.  My guess is that the authors have not looked at energy
density in terms of volume, i.e. calories per cup, but have been misled by
looking only at calories per gram.   If you look at calories per cup, the
only vegetable that on a cup for cup basis comes near to the energy value of
wild game lean meat is the tuber sweet potato.  A hunter gatherer would have
to eat two cups of cooked winter squash, over three cups of cooked carrots,
nearly four cups of cooked onions, or nearly six cups of cooked green leafy
vegetables to equal just one cup of raw lean meat.

Brains are higher in fat, so they are almost twice as energy dense as lean
meat; the fat content
of brains is not affected by feeding practices--the brains of wild game are
just as rich in fat as are the brains of domesticated cattle.   Further, the
EFA profiles of brains of all species so far studied are identical (Crawford
and Marsh, Nutrition and Evolution, p. 125)

Eggs also are much more energy dense than vegetables--and wild bird's eggs
are also rich in both AA and DHA compared to vegetables (they are in there
as the building blocks for the nervous system of the bird).  Further, it is
known that not only aboriginal people but also chimpanzees eat raw brains
and eggs when they can
get them.   So we don't have to guess that maybe early man ate those
things--it would be odd if he didn't.

Now take a look at nuts--which are mostly fat-- and animal fat--THERE IS THE
ENERGY DENSITY REQUIRED!  Again, it is known that both chimps and aboriginal
people eat marrow and kidney fat.  But "primitive" people eat more meat and
more fat than chimps.

The idea that cooking vegetables was the key to a high energy density diet
is absurd.  The easiest way for a land locked primate to get a high energy
density diet
is to EAT BRAINS AND MARROW FAT.  These foods are also the best for
increasing intake of linoleic acid, EPA, DHA, and other fats needed for
development and maintenance of sophisticated eyes, brain, nervous and
vascular systems.

If you discard the preconception that our ancestors were land-locked, there
are other sources of the required fats.  At the shoreline,  a primate can
get a high energy density diet by eating SEA MAMMALS AND/OR FATTY FISH.
Professors Crawford and Marsh make a good case (in Nutrition and Evolution)
for the theory that early man was a consumer of sea foods rich in fats,
along with land animal fats (brains and marrow).

But eating brains and marrow fat is politically incorrect these days.  With
all the popular hysteria about the dangers of eating organ meats and fat,
who is going to publish a head-line stating that "EARLY MAN DEVELOPED A BIG
BRAIN BY EATING BRAINS AND FAT, STUDY SAYS"?

This is one of the worst examples of junk reporting and junk science we've
seen in a while.  By presenting this half-baked politically correct
supposition to the public before the scientific community has an opportunity
to comment upon it, the authors of this supposed research will be patted on
the back, and their "conclusions" will be by many laymen accepted as
"fact"--after all, it is very unlikely that Reuters will in a few days
publish with bold headlines all of the logical and biochemical objections I
or any one else will have to their mistake.

Don Matesz