1.      Steve said:

In his post of 26 May, Loren Cordain stated that
"the reduced carbohydrate content of per-agric. diets would
have improved the portions of the blood lipid profile
(TG, VLDL, HDL, Lp(a)) which are worsened by high carb diets".
He cites a 1995 paper by Reaven.
In their reply to Loren Cordain of June 29, Sally Fallon and
Mary Enig say that "orthodox nutritionists content that high
carb. diets improve blood lipid profiles."
In his reply of Oct. 9, Prof Cordain provides further references
for positive blood lipid changes resulting from reduced
carbohydrate diets.

So, are the orthodox nutritionists wrong?

        What was once outlandish is now orthodox and what was once
orthodox is now outlandish.  Science moves forward, new data is
generated, new hypotheses are generated and tested and new theories are
ultimately developed.   A perfect example of this is vitamin E.   In the
mid to late 60's vitamin E was thought by orthodox nutritionists to have
little or no function - today it's role as an antioxidant is firmly
known and accepted by "orthodox" nutritionists.   The dogma of orthodox
nutritionists regarding macronutrient intake for the past 20-25 years
has been that a high carb, low fat diet was the optimal diet for humans
and benefitted virtually all pathological conditions ranging from heart
disease to cancer.   In the past 10 years, this concept has been
seriously questioned in terms of deleterious changes (elevated TG, and
VLDL and lowered HDL) which occur in blood lipid profiles from such
advice.   Increasingly, influencial scientists (Scott Grundy, Walter
Willett, Gerald Reaven) and institutions (Harvard School of Public
Health) have recognized this shortcoming of high carb, low fat diets and
are now recommending monounsaturated fat in lieu of carbohydrate (1,2).
This message is now being taught to our nutrition students in the
University - when they get out into the real world, this message may
become their dogma and as surely as one generation will replace the
next, new ideas will replace "orthodox" ideas.

                        REFERENCES

1.      Grundy SM.  Comparison of monosaturated fatty acids and
carbohydrates for lowering plasma cholesterol. N Engl J Med
1986;314:745-48.
2.      Mensink RP et al.  Effects of monounsaturated fatty acids versus
complex carbohydrates on high density lipoproteins in healthy men and
women. Lancet 1987;1:122-25.

A second question from Steve is:

"In their reply to Loren Cordain of June 29, Sally Fallon and
Mary Enig state that "fats taken with carbohydrates, esp.
traditional fats such as butter..., lower the glycemic index"
(no reference cited).
I also thought this was the case, due to the role of fat in
increasing the time that the carbs are kept in the stomach.
But in his reply of Oct. 9, Prof. Cordain says "it has been well
established that by mixing fat with carbohydrate, the glycemic
response worsens" (he cites a 1988 paper by Collier et al).
If indeed the latter is correct, could someone kindly explain
why fat would cause this effect."

We need to clarify our terms on this one. The ingestion of fat with
carbohydrate results in lower blood glucose but higher insulin levels
compared to carbohydrate ingestion alone (1,2).   Fat ingestion
stimulates the secretion of glucose dependent insulino-tropic
polypeptide (GIP) and it is thought that the additional rise in insulin
is mediated by the effects of GIP (3).

                                REFERENCES

1.      Collier G, O'Dea K.  The effect of co-ingestion of fat on the
glucose, insulin and gastric inhibitory polypeptide responses to
carbohydrate and protein. Am J Clin Nutr 1983;37:941-45.
2.      Collier G. et al.  Effect of co-ingestion of fat on the
metabolic responses to slowly and rapidly absorbed carbohydrate.
Diabetologia 1984;26:50-56.
3.      Collier G et al.  The acute effect of fat on insulin secretion.
J Clin Endocrinol 1988;66:323-26.

A third point Steve brings up:

In his post of 26 May, Loren Cordain stated that
"pre-agric. eating patterns show that fat and protein
were generally eaten together whereas carbohydrate meals
were eaten separately" (no citation).
In their reply to Loren Cordain of June 29, Sally Fallon and
Mary Enig question this claim.
In his reply of Oct. 9, Prof Cordain again states that
"Hunter gatherers quite often would eat only the animal killed for a
meal without added plant courses.   Thus, protein/fat macronutrient
mixtures were the norm.  Carbohydrates generally were consumed as they
were collected or separate from animal based meals."
Presumably there is considerable data on this issue with respect
to 20th C. hunter-gatherers. I thought that it has been not uncommon
for a main meal to consist of both meat/fish from the hunt and plant
foods that had been gathered that day or before.
Could anyone who is up on the literature comment?
For Paleolithic peoples living in climates with minimal
plant food (or in winter), of course, one would imagine that
the pattern suggested by Prof. Cordain would have been common.
But this situation corresponds to a relatively short part of the ~2
million year evolutionary period of Homo sapiens, does it not?


        Most foraging mammals including primates (1)  consume food as
they encounter it in their day to day travels throughout their range.
Because food sharing occurs infrequently in chimpanzees , man's closest
relative , all individuals in the foraging group, except for nursing
infants, are responsible to obtain their own food (1).This pattern of
foraging almost certainly would have been true for  Australopithecines
(2).   Consequently, organized meals in which multiple foods, collected
from the environment and brought back to a home base to be shared by all
members of the foraging group is quite unlikely until the development of
1), a home base and 2) containers.   The transport and sharing of meat
does not require a container (only a stone tool to dismember the
carcass), whereas the transport of plants back to a home base requires a
container.   It is likely that the scavenging/hunting of animals
preceded the invention of containers (primitive baskets or animal
membrane bags) (2).  So, the concept of a home base likely developed in
conjuction with the transport and sharing of meat only and plant foods
would still have been foraged by each individual in the manner of most
non-human primates (2).   Food sharing by the inclusion of dispersed
vegetable foods would have come later in man's evolution, consequently
early Homo species would have eaten meats separate from vegetable foods.
This pattern of food consumption would have prevailed throughout much of
early man's evolution and the concept of bringing multiple plant and
animal foods together to be shared by all members of a troop for an
organized meal surely only arose much later in man's evolution as
behavioral complexity increased.
        The anthropological literature is full of descriptions of
hunter-gatherers consuming plant foods "on the run", that is as they
move through their environment.  These foods are eaten as they are
encountered by both men and women (without mixing them with animal foods
that may have been killed earlier.    Groups of men who make a kill
while out on a hunt, generally eat portions of the animal immediately
without stopping to gather plant foods to make a "balanced" meal.    I
refer interested readers to (3).

        Steve further comments:

For Paleolithic peoples living in climates with minimal
plant food (or in winter), of course, one would imagine that
the pattern suggested by Prof. Cordain would have been common.
But this situation corresponds to a relatively short part of the ~2
million year evolutionary period of Homo sapiens, does it not?

        Steve's assumption here is incorrect.  Humans left Africa for
more northerly latitudes by at least 1 million years ago and probably
quite earlier (4).   We now have strong evidence that hominids lived in
Spain (>40 degrees North latitude) by at least 750,000 years ago, in
England (>50 degrees North latitude) by at least 500,000 years ago and
in Germany (>50 degrees North latitude) by at least 400,000.   There is
astonishing evidence that early man may have lived as far north as (60
degrees North latitude) by 260,00 years ago (5).   As, Steve has
surmised, the consumption of plant based foods (edible by primates) is
severly seasonally restricted at higher latitudes, so it seems likely
for these populations that plants would have been rarely consumed
simultaneously with animal foods, and this pattern of eating (plants
separate from animals) has been with humans from the very beginings of
the evolution of our species..

                                REFERENCES

1.      Suzuki A.  An ecological study of chimpanzees in a savanna
woodland. Primates 1969;10:103-48.
2.      Isaac G.  The diet of early man: aspects of archaeological
evidence from lower and middle pleistocene sites.
3.      Bicchieri MG.  Hunters and Gatherers Today.  New York, Holt,
Rinehart & Winston Inc, 1972.
4.      Larick R, Ciochon RL.  The african emergence and early
dispersals of the genus Homo. Am Scientist 1996;84:538-51.
5.      Waters MR et al.  Diring Yuriakh: a lower paleolithic site in
central siberia. Science 1997;275:1281-84.

                                Cordially,


                                Loren Cordain, Ph.D.