Dean Esmay writes:

>I had my preconceptions rocked this week.  Which is always a healthy thing,
>but I'm still reeling from it.
>
>My assumption has long been that most cereal grains and beans are foreign
>to the human digestive tract because they can only be rendered edible by
>technology--i.e. extended cooking.  Earliest evidence for use of fire for
>cooking among humans seems to be 25,000 years (I have no reference for that
>handy, let me know if that's in dispute), which would indicate the
>potential for some adaptation to cooked foods.

From what I know from having combed through the research I have been able
to find myself, the evidence for earliest use of fire itself goes back much
further than 25,000 years, although it is very difficult to say with any
certainty just when cooking practices began as a result of previous
familiarity with fire. About controlled use of fire itself, however, even
someone as skeptical as Steven James, in a review article of the evidence
for early fire use, concedes that by at least 230,000 years ago, at the
Terra Amata site in Spain, one finds clear evidence. [James S, 1989,
"Hominid use of fire in the lower and middle Pleistocene. A review of the
evidence." Current Anthropology, v.30:1-26] (Newer dating techniques may
have pushed the date for this site back to 300,000 years, but I am not
sure.)

However, since this review-of-the-evidence article, there is now other
recent evidence at, I believe, another 2 or perhaps 3 sites in Spain and/or
France, including one in France (Menez-Dragan) that would push the
controlled-fire-use date back to around 380,000 to 465,000 years if the
claims stand up to testing. Also of significance is that burnt rhinocerous
bones were found close to a hearth inside a cave at this site, leading the
researchers to tentatively conclude cooking had occurred, as it seemed
unlikely to them the rhinocerous bones could have gotten inside the cave
otherwise. [reported by journalist Patel T 1995, "Burnt stones and rhino
bones hint at earliest fire." New Scientist, June 17, 1995, p.5]

I also believe (and would like to hear informed comment from those here
better acquainted with the evidence than I) that while some of the very
earliest claims for control of fire by humans (approx. 1.5 million years
ago) at Zhoukoudian Cave in China have now been disputed or discredited,
more recent analysis of the ash layers in the cave dated to 230,000 to
460,000 years ago, in which animal skulls have been found, show burn
patterns around the teeth and skulls that would indicate cooking of the
brains [Rowley-Conwy, Peter 1993, "What do the Zhoukoudian finds tell us?"
In: Burenhult, Goran (ed.) The First Humans: Human Origins and History to
10,000 B.C. New York: Harper-Collins, p.65. This is a compendium put out by
the American Museum of Natural History, and not peer-reviewed, but
Rowley-Conwy is a well-known authority in the field, I believe.]

One thing I have heard only one writer discussing fire address is what can
be  inferred about cooking just from the evidence for control of fire
itself. Somehow the question of fire use seems to catch the researchers'
attention, but the advent of cooking--which seems to be just as much or
more interesting a question to me--does not. But if one were going to
suppose, doesn't it seem logical to infer--when you consider why hominids
would have been interested in controlling fire in the first place (why were
they doing it at all?)--that it would have been for either warmth or
cooking food, or both? I wonder what others think about that supposition,
given that fire does not leave many useful traces behind, at least,
according to what I have heard stated in the literature. As is often said,
"Absence of evidence is not evidence of absence."

Dutch writer Johan Goudsblom, in his 1992 book "Fire and Civilization"
[Penguin Books: London; New York] notes that animals in the wild, like
birds of prey such as kites, quickly gather around burned-out wildfires to
eat the burnt victims, and other animals can be seen gathered round the
wildfire-sites later at night, apparently attracted by the warmth. The
implication of this leads to the supposition, which I believe was
Goudsblom's point in bringing it up, that if other animals take advantage
of fire in this way, then it would seem unlikely that observant hominids
would not also have followed suit with regard to its use for warmth and
possible processing of food fairly early on after first controlled use.
(Ann Brower Stahl, however--commenting in the follow-up section to James'
Current Anthropology article--believes that fire's use for warmth would
have predated its use for cooking.)

The most relevant question, though, it seems to me, where Paleodiet is
concerned, is when the use of fire for cooking became *widespread* enough
that it would have begun to constitute a serious evolutionary selective
pressure. On this point, Steven James notes that consistent evidence for
fire use itself in a number of different archeological locations is not
seen until at least the late Paleolithic, which he defines as roughly (if I
am remembering correctly) 125,000 years ago and more recently.

However, if it is true that ancient fires would not leave many traces
behind archaeologically in most cases, it may be we are faced with a paucity
of evidence by the very nature of the question, which leaves us in a
dilemma. I don't know, though, what do others think?

Where hard evidence is concerned, though (as opposed to inference), there
does not seem to be much indication that *widespread* use of fire for
cooking goes back more than about 40,000-60,000 years or so, but I would
like to hear more input from others more well-versed than I, since I have
had trouble even finding much interest, let alone data, in the
fire-and-adaptation-to-cooking question in what Paleodiet literature I have
been able to unearth myself.

>Yet it would seem that the fact that grains and beans are inedible without
>>things like cooking pots and mortar and pestle ought to make us look with
>>suspicion to those foods, since that all by itself would tend to indicate
>that >humans would never have eaten them in any appreciable quantity until
>around the >time of agriculture.
>
>Enter the members of the raw food community who I recently encountered
>online.  These people eat absolutely everything raw, on the belief that the
>molecular changes wrought by cooking foods are unnatural, addicting, and
>carcinogenic.  I am mildly skeptical of this belief system, although there
>is some rational argument for it; humans ARE the only animals who cook food
>and most of the evidence I've seen suggests that we haven't been doing it
>for very long.

I am still reserving judgment myself on the question of whether or to what
degree cooking foods may render them "unnatural," addicting, or
carcinogenic. (Cooking creates some carcinogens, but neutralizes others;
and most plant foods contain a certain level of "nature's pesticides" in
the first place as a self-defense tactic to discourage animals from eating
them; so the question is not a cut-and-dried one. [See Ames, B 1983,
"Dietary carcinogens and anticarcinogens." Science, v.221 (Sept. 23, 1983),
pp. 1256-1264])

However, one thing about the raw-foods community that I think should be
strongly emphasized, which I point out here based on my own first-hand
experience as a former member of the raw-foods community myself, is that
the walk does not match up completely to the talk. You will hear lots of
claims that someone is eating 100% all-raw foods, but when you get them in
private, or cross-examine them in public, most will admit they can't or
don't sustain the full regimen. This is not to say that there are not some
very notable examples of people who do, because there definitely are (and I
know one or two of them on this listgroup).

But most avowed "raw-foodists" are actually eating more like 70% to 80%,
perhaps 90%, raw foods. Still a lot of raw food, of course, but it seems
to me very significant that for the vast majority who try (and most who
become convinced it is the ultimate way to eat get pretty motivated about
it and try hard) there seems to be some sort of barrier preventing them
from taking it all the way. (Also, it is important to note in saying this
that most raw-foodists are vegetarians as well, and the lack of animal-food
intake could be affecting their ability to otherwise successfully sustain a
raw-food regime.)

I recently resigned the editorship of a small many-to-many newsletter on
health and vegetarian raw foods that I ran for 4 years, due to growing
disillusionment with what I saw regarding preaching vs. practice, as well
as becoming increasingly familiar with the evolutionary Paleodiet
literature. (Many-to-manys work just like on-line listgroups as far as
comment-and-response discussions, except they are distributed through
snailmail.) Many of the participants were, or claimed to be, or had tried
to make a go of, eating all-raw foods.

But when their actual practices were flushed out through cross-examination,
as near as I could tell, not more than about 10-15% of them were actually
successful at walking their talk over the long-term in good health. And of
those who had tried to eat all-raw foods but could not sustain it, most
gave it up either because of strong cravings they could not satisfy on the
all-raw regimen, or because of health problems, or both. There are no
scientific studies or surveys of raw-foodists that I know of myself, but I
wrote an article last year from the "former insider" perspective about
raw-foodists who follow the Natural Hygiene philosophy of natural diet,
which strongly emphasizes raw foods, and the problems many of them
experience. (If anyone is interested, I can snailmail a xerox of it for $2
(to cover my time and copying/mailing expense) to anyone interested. (The
article runs 12,000 words.) Or I might see if I can't get it translated to
ASCII here soon instead to email to those who have an interest.

>But what really rocked me is that these people (and I've seen messages from
>more than one of them) eat whole cereal grains and beans raw.  They most
>commonly will use overnight soaking methods, either in pots or jars or even
>just wrapping the stuff in moist rags.  However they will also apparently
>eat them even without this, eating them completely raw without even any
>soaking.  Their claim is that if you haven't been eating this way all your
>life it might take a week or two for your digestive tract to adjust, but
>that they otherwise have no trouble at all living this way.

As a former insider, this is true--at least for those 10-15% who succeed on
the type of raw-foodist dietary program that may include such practices
(though not necessarily for the other 85-90% who don't succeed too well).
It should also be specifically noted in connection with this practice that
most people who attempt a raw-food vegetarian diet and fail are usually
only able to later succeed on their dietary program by modifying it to
include some sort of concentrated starch or protein food. (Most end up
including something like steamed or cooked squash, potatoes, legumes, or
grains.)

However, as Dean says, those who are really serious about continuing to eat
only raw foods--but who resort to eating grains or legumes to round out the
diet to succeed--will soak or sprout them (for a day or two or less) to be
able to ingest them raw. And then there are a very few who, as Dean
mentions, will also eat the grains raw without even soaking them. (They may
grind them first, of course.) Whether and how much of the grain they are
actually digesting when eaten this way is an open question. (Cooking helps
neutralize the trypsin inhibitors commonly found in legumes and grains that
otherwise interfere with digestion, so it is questionable how much raw
grain eaters actually digest and assimilate of it, even if they can
tolerate it fine. [I don't know what a trypsin inhibitor is, but Ann Brower
Stahl briefly discusses the situation in her 1984 paper, "Hominid dietary
selection before fire," Current Anthropology, April 1984, v.25, no.2,
pp.151-168.]) But I agree with Dean's inference that Paleodiet researchers
really ought to look into this and see what is going on here
physiologically with these folks.

Regarding the many failures of those attempting a raw-food diet, I have
also had conversations with a person well-acquainted with the "instincto"
segment of the raw foods community from the inside who I believe is on this
list. (Instinctos are raw-foodists who do not limit themselves to
vegetarianism and freely include raw meat in their diet.) This individual
can comment here themselves if they like, but they have told me that in
their estimation the success rate for raw-food instinctos is no better than
for the raw-food vegetarian crowd (i.e., 10-15% or less, they thought, from
widespread acquaintance).

In bringing all this up with a Paleodiet researcher (and again, if they are
on this list, I'm sure they will speak up for themselves) who believes
humans are not yet genetically much-adapted to cooked foods, it seemed
their opinion was the raw-food failures were due to two things. First,
since hominid diets have evolved over the eons to include not only much
more animal foods than our primate cousins--and these animal foods are in
general more concentrated, less fibrous, and more efficiently assimilated
foods than plant foods--vegetarian raw-foodists will have a hard time
getting a concentrated enough stream of nutrients without including
concentrated vegetarian starch foods like grains or cooked tubers, etc.
I.e., since every organ system comes at a metabolic cost, and it takes a
large gut to digest a diet high in fiber; and since humans have smaller
guts than their primate cousins, for which we have compensated by eating
more concentrated, more nutrient-rich, less-fibrous animal foods that
allowed us to evolve a large metabolically costly brain, many people who
attempt a vegetarian diet are going to find they have to eat more food than
they can realistically handle-volume wise unless they include more
concentrated foods like grains, legumes, and tubers by way of cooking them
to make them edible. (And this supposition seems to agree very well with
the actual results and practices I have seen in the raw-foods community
myself.)

Second, the reason the instincto raw-foodists (who include meat) may be
having a hard time succeeding, is that it seems from observations of modern
hunter/gatherers eating meat that they go for the organ meats first which
they value most highly, also even the bone marrow. Muscle meats are eaten
last and least valued, yet those of us in the modern age have access to
mostly only these muscle meats. So it appears that even most raw-foodists
who include animal foods have trouble because they do not eat the best
portion of the animal, and may be shorting themselves nutritionally.

My question in all this is: If hominids evolved eating nothing but raw
foods, and we are not yet adapted to the cooking practices begun relatively
late in our evolution (though considerably more ancient than agriculture),
why then do so many people fail on raw-food diets, even the ones who eat
plenty of meat? Do the above reasons just given make sense to those of you
who are researchers? I don't get the feeling from my perusal of the
literature that very many Paleodiet researchers have even thought to
address the cooking vs. raw-foods survival question, and whether homo is
now adapted to a certain amount of cooked foods (or to certain ones
customarily cooked during evolution) or not, but I would be interested to
hear comments. To me, this consideration also bear on the question of how
we might compensate these days for the fact that we cannot obtain organ
meats and bone marrow, and whether cooking of certain foods may be a
necessary evil to help make up the difference somehow.

>At first I was tempted to dismiss this as a bizarre cultish sort of thing.
>But if these people apparear to be happy eating this way.

Actually, as I've said, most people who try to 100% raw-foods do not
succeed at it over the long-term--though they will rave about it during the
short-term and be most vocal before they start having problems--and a lot
them are not very happy about that fact, or disguise it. However, as you
also say...

>The very fact
>that it's POSSIBLE for them to do this should, at minimum, throw back open
>to question whether or not humans have been eating cereal grains since
>before the advent of agriculture after all.  Although it's hard to imagine
>them making up the majority of the diet, if people can comfortably eat wild
>grains without technology then there's not much reason to think they
>wouldn't, is there?

Great question. It *is* possible to eat grains without technology, and some
individuals that try it--mostly vegetarians--are able to succeed healthwise
at it. However, there is also the well-known fact that apparent success or
not, phytates in grains greatly impair mineral absorption which seems to
indicate we are not yet very well adapted to them, even if it is possible
to eat them.

--Ward Nicholson <[log in to unmask]> Wichita, KS