CATEGORY: diets/vegetarian
TECHNICAL: **
SUMMARY:
This is part two of one of the most profound documents
I had ever read at the time I found it. It is written by Ward
Nicholson who has done a tremendous amount of research into
human diets based on evolution. As I said in the first part,
Nicholson, initially practiced a type of diet known as the
"hygienic" diet -- which is a strict vegetarian/vegan diet in
which everything is consumed raw and unprocessed. I'm quite
sure that you too will get as much out of this document as I
did. And, after you've had a chance to read through it (and the
remaining parts), I bet you too will find his argument pretty
convincing. And, of course, that arguement is that human beings
could never have evolved the way we did if we had been
vegetarians/vegans or frutarians.
Possibly the most profound statement, and one that I've
repeated, is that most people have forgotten that modern drugs only
masquerade the symptoms of an illness. A real cure can be sought
through reverting back to a natural human-evolution type diet.
The discussion on the use of fire for cooking is pretty interesting
too.

-------------------------------------------------------------
Part 2 of our Visit with Ward Nicholson

Fire And Cooking In Human Evolution,
Rates Of Genetic Adaptation To Change,
Hunter-Gatherers, And Diseases In The Wild

Health & Beyond: Ward, in Part 1 of our interview, you discussed the
extensive evidence showing that primitive human beings as well as almost
all of the primates today have included animal foods such as flesh or
insects in their diets. Why haven't Natural Hygienists and other
vegetarians looked into all this information?

Ward Nicholson: My guess is that: (1) Most aren't aware that
paleoanthropologists have by now assembled a considerable amount of data
about our evolutionary past related to diet. But more importantly, I think
it has to do with psychological barriers, such as: (2) Many Hygienists
assume they don't have to look because the subjective "animal model" for
raw-food naturalism makes it "obvious" what our natural diet is, and
therefore the paleontologists' evidence must therefore be in error, or
biased by present cultural eating practices. Or: (3) They don't want to
look, perhaps because they're afraid of what they might see.

I think in spite of what most Natural Hygienists will tell you, they
are really more wedded to certain specific details of the Hygienic system
that remain prevalent (i.e., raw-food vegetarianism, food-combining, etc.)
than they are truly concerned with whether those details follow logically
from underlying Hygienic principles. The basic principle of Natural
Hygiene is that the body is a self-maintaining, self-regulating,
self-repairing organism that naturally maintains its own health when it is
given food and other living conditions appropriate to its natural
biological adaptation.

In and of itself, this does not tell you what foods to eat. That has
to be determined by a review of the best evidence we have available. So
while the principles of Hygiene as a logical system do not change, our
knowledge of the appropriate details that follow from those principles may
and probably will change from time to time--since science is a process of
systematically elucidating more "known" information from what used to be
unknown. Thus the accuracy of our knowledge is to some extent time-based,
dependent on the accumulation of evidence to provide a more inclusive view
of "truth" which unfortunately is probably never absolute, but--as far as
human beings are concerned--relative to the state of our knowledge.
Science simply tries to bridge the knowledge gap. And a hallmark of
closing the knowledge gap through scientific discovery is openness to
change and refinements based on the accumulation of evidence.
Open-mindedness is really openness to change. Just memorizing details
doesn't mean much in and of itself. It's how that information is
organized, or seen, or interpreted, or related to, that means something.

What's interesting to me is that the evolutionary diet is not so
starkly different from the Hygienic diet. Much of it validates important
elements of the Hygienic view. It is very similar in terms of getting
plenty of fresh fruits and veggies, some nuts and seeds, and so forth,
except for the addition of the smaller role of flesh and other amounts of
animal food (at least compared to the much larger role of plant foods) in
the diet. It's one exception. We have actually done fairly well in
approximating humanity's "natural" or "original" diet, except we have been
in error about this particular item, and gotten exceedingly fundamentalist
about it when there is nothing in the body of Hygienic principles
themselves that would outlaw meat if it's in our evolutionary adaptation.

But for some reason, even though Natural Hygiene is not based on any
"ethical" basis for vegetarianism (officially at least), this particular
item seems to completely freak most Hygienists out. Somehow we have made a
religion out of dietary details that have been the hand-me-downs of past
Hygienists working with limited scientific information. They did the best
they could given the knowledge they had available to them then, and we
should be grateful for their hard work. But today the rank and file of
Natural Hygiene has largely forgotten Herbert Shelton's rallying cry, "Let
us have the truth, though the heavens fall."

Natural Hygiene was alive and vital in Shelton's time because he was
actively keeping abreast of scientific knowledge and aware of the need to
modify his previous views if scientific advances showed them to be
inadequate. But since Shelton retired from the scene, many people in the
mainstream of Hygiene have begun to let their ideas stagnate and become
fossilized. The rest of the dietary world is beginning to pass us by in
terms of scientific knowledge.

As I see it, there remain only two things Natural Hygiene grasps that
the rest of the more progressive camps in the dietary world still don't:
(1) An understanding of the fundamental health principle that outside
measures (drugs, surgery, etc.) never truly "cure" degenerative health
problems. In spite of the grandiose hopes and claims that they do, and the
aura of research breakthroughs, their function is really to serve as
crutches, which can of course be helpful and may truly be needed in some
circumstances. But the only true healing is from within by a body that has
a large capacity, within certain limits, to heal and regenerate itself
when given all of its essential biological requirements--and nothing more
or less which would hamper its homeostatic functioning. The body's
regenerative (homeostatic) abilities are still commonly unrecognized today
(often classed as "unexplained recoveries" or--in people fortunate enough
to recover from cancer--as "spontaneous remission") because the population
at large is so far from eating anything even approaching a natural diet
that would allow their bodies to return to some kind of normal health,
that it is just not seen very often outside limited pockets of people
seriously interested in approximating our natural diet. And the other
thing is: (2) Hygienists are also keenly aware of the power of fasting to
help provide ideal conditions under which such self-healing can occur.

But the newer branch of science called "darwinian medicine" is slowly
beginning (albeit with certain missteps) to grasp the principle of self
healing, or probably more correctly, at least the understanding that
degenerative diseases arise as a result of behavior departing from what
our evolutionary past has adapted us to. They see the negative side of how
departing from our natural diet and environment can result in degenerative
disease, but they do not understand that the reverse--regenerating health
by returning to our pristine diet and lifestyle, without drugs or other
"crutches"--is also possible, again, within certain limits, but those
limits are less than most people believe.

In some ways, though, Hygiene now resembles a religion as much as it
does science, because people seem to want "eternal" truths they can grab
onto with absolute certainly. Unfortunately, however, knowledge does not
work that way. Truth may not change, but our knowledge of it certainly
does as our awareness of it shifts or expands. Once again: The principles
of Hygiene may not change, but the details will always be subject to
refinement.

Speaking of such details subject to refinement, I know you've been
sitting on some very suggestive evidence to add further fuel to the
fire-and-cooking debate now raging between the raw-foodist and
"conservative-cooking" camps within Hygiene. Please bring us up-to-date on
what the evolutionary picture has to say about this. I'd be happy to. But
before we get into the evolutionary viewpoint, I want to back up a bit
first and briefly discuss the strange situation in the Hygienic community
occurring right now over the raw foods vs. cooking-of-some-starch-foods
debate. The thing that fascinates me about this whole brouhaha is the way
the two sides justify their positions, each of which has a strong point,
but also a telling blind spot.

Now since most Natural Hygienists don't have any clear picture of the
evolutionary past based on science for what behavior is natural, the
"naturalistic" model used by many Hygienists to argue for eating all foods
raw does so on a subjective basis--i.e., what I have called "the animal
model for raw-food naturalism." The idea being that we are too blinded
culturally by modern food practices involving cooking, and to be more
objective we should look at the other animals--none of whom cook their
food--so neither should we. Now it's true the "subjective raw-food
naturalists" are being philosophically consistent here, but their blind
spot is they don't have any good scientific evidence from humanity's
primitive past to back up their claim that total raw-foodism is the most
natural behavior for us--that is, using the functional definition based on
evolutionary adaptation I have proposed if we are going to be rigorous and
scientific about this.

Now on the other hand, with the doctors it's just the opposite story.
In recent years, the Natural Hygiene doctors and the ANHS (American
Natural Hygiene Society) have been more and more vocal about what they say
is the need for a modest amount of cooked items in the diet--usually
starches such as potatoes, squashes, legumes, and/or grains. And their
argument is based on the doctors' experience that few people they care for
do as well on raw foods alone as they do with the supplemental addition of
these cooked items. Also, they argue that there are other practical
reasons for eating these foods, such as that they broaden the diet
nutritionally, even if one grants that some of those nutrients may be
degraded to a degree by cooking. (Though they also say the assimilation of
some nutrients is improved by cooking.) They also point out these
starchier foods allow for adequate calories to be eaten while avoiding the
higher levels of fat that would be necessary to obtain those calories if
extra nuts and avocadoes and so forth were eaten to get them.

So we have those with wider practical experience arguing for the
inclusion of certain cooked foods based on pragmatism. But their blind
spot is in ignoring or attempting to finesse the inconsistency their
stance creates with the naturalist philosophy that is the very root of
Hygienic thinking. And again, the total-raw-foodists engage in just the
opposite tactics: being philosophically consistent in arguing for all-raw
foods, but being out of touch with the results most other people in the
real world besides themselves get on a total raw-food diet, and attempting
to finesse that particular inconsistency by nit-picking and fault-finding
other implementations of the raw-food regime than their own. (I might
interject here, though we'll cover this in more depth later, that although
it's not true for everyone, experience of most people in the Natural
Hygiene M2M supports the view that the majority do in fact do better when
they add some cooked foods to their diet.)

Now my tack as both a realist and someone who is also interested in
being philosophically consistent has been: If it is true that most people*
do better with the inclusion of some of these cooked items in their diet
that we've mentioned--and I believe it is, based on everything I have seen
and heard--then there must be some sort of clue in our evolutionary past
why this would be so, and which would show why it might be natural for us.

The question is not simply whether fire and cooking are "natural" by
some subjective definition. It's whether they have been used long enough
and consistently enough by humans during evolutionary time for our bodies
to have adapted genetically to the effects their use in preparing foods
may have on us. Again, this is the definition for "natural" that you have
to adopt if you want a functional justification that defines "natural"
based on scientific validation rather than subjectivity.

So the next question is obvious: How long have fire and cooking been
around, then, and how do we know whether that length of time has been long
enough for us to have adapted sufficiently? Let's take the question one
part at a time. The short answer to the first part of the question is that
fire was first controlled by humans anywhere from about 230,000 years ago
to 1.4 or 1.5 million years ago, depending on which evidence you accept as
definitive.

The earliest evidence for control of fire by humans, in the form of
fires at Swartkrans, South Africa and at Chesowanja, in Kenya, suggests
that it may possibly have been in use there as early as about 1.4 or 1.5
million years ago.[100] However, the interpretation of the physical
evidence at these early sites has been under question in the
archaeological community for some years now, with critics saying these
fires could have been wildfires instead of human-made fires. They suggest
the evidence for human control of fire might be a misreading of other
factors, such as magnesium-staining of soils, which can mimic the results
of fire if not specifically accounted for. For indisputable evidence of
fire intentionally set and controlled by humans, the presence of a hearth
or circle of scorched stones is often demanded as conclusive proof,[101]
and at these early sites, the evidence tying the fires to human control is
based on other factors.

At the other end of the timescale, these same critics who are only
willing to consider the most unequivocal evidence will still admit that at
least by 230,000 years ago[102] there is enough good evidence at at least
one site to establish fire was under control at this time by humans. At
this site, called Terra Amata, an ancient beach location on the French
Riviera, stone hearths are found at the center of what may have been huts;
and more recent sources may put the site's age at possibly 300,000 years
old rather than 230,000.[103]

Somewhat further back--from around 300,000 to 500,000 years ago--more
evidence has been accumulating recently at sites in Spain and France[104]
that looks as if it may force the ultraconservative paleontologists to
concede their 230,000-year-ago date is too stingy, but we'll see.

And then there is Zhoukoudian cave in China, one of the most famous
sites connected with Homo erectus, where claims that fire may have been
used as early as 500,000 to 1.5 million years ago have now largely been
discredited due to the complex and overlapping nature of the evidence left
by not just humans, but hyenas and owls who also inhabited the cave. (Owl
droppings could conceivably have caught fire and caused many of the
fires.) Even after discounting the most extreme claims, however, it does
seems likely that at least by 230,000 to 460,000 years ago humans were
using fire in the cave[105], and given scorching patterns around the teeth
and skulls of some animal remains, it does appear the hominids may have
done this to cook the brains (not an uncommon practice among
hunting-gathering peoples today).[106]

The most recent excavation with evidence for early use of fire has
been within just the last couple of years in France at the Menez-Dregan
site, where a hearth and evidence of fire has been preliminarily dated to
approximately 380,000 to 465,000 years. If early interpretations of the
evidence withstand criticism and further analysis, the fact that a hearth
composed of stone blocks inside a small cave was found with burnt
rhinoceros bones close by has provoked speculation that the rhino may have
been cooked at the site.[107]

Now of course, the crucial question for us isn't just when the
earliest control of fire was, it's at what date fire was being used
consistently--and more specifically for cooking, so that more-constant
genetic selection pressures would have been brought to bear. Given the
evidence available at this time, most of it would probably indicate that
125,000 years ago is the earliest reasonable estimate for widespread
control.*[108] Another good reason it may be safer to base adaptation to
fire and cooking on the figure of 125,000 years ago is that more and more
evidence is indicating modern humans today are descended from a group of
ancestors who were living in Africa 100,000-200,000 years ago, who then
spread out across the globe to replace other human groups.[109] If true,
this would probably mean the fire sites in Europe and China are those of
separate human groups who did not leave descendants that survived to the
present. Given that the African fire sites in Kenya and South Africa from
about 1.5 million years ago are under dispute, then, widespread usage at
125,000 years seems the safest figure for our use here.
/*URHERE*/
One thing we can say about the widespread use of fire probable by
125,000 years ago, however, is that it would almost certainly have
included the use of fire for cooking.* Why can this be assumed? It has to
do with the sequence for the progressive stages of control over fire that
would have had to have taken place prior to fire usage becoming
commonplace. And the most interesting of these is that fire for cooking
would almost inevitably have been one of the first uses it was put to by
humans, rather than some later-stage use.*

The first fires on earth occurred approximately 350 million years
ago--the geological evidence for fire in remains of forest vegetation
being as old as the forests themselves.[110] It is usual to focus only on
fire's immediately destructive effects to plants and wildlife, but there
are also benefits. In response to occasional periodic wildfires, for
example, certain plants and trees have evolved known as "pyrophytes," for
whose existence periodic wildfires are essential. Fire revitalizes them by
destroying their parasites and competitors, and such plants include
grasses eaten by herbivores as well as trees that provide shelter and food
for animals.[111]

Fires also provide other unintended benefits to animals as well. Even
at the time a wildfire is still burning, birds of prey (such as falcons
and kites)--the first types of predators to appear at fires--are attracted
to the flames to hunt fleeing animals and insects. Later, land-animal
predators appear when the ashes are smouldering and dying out to pick out
the burnt victims for consumption. Others, such as deer and bovine animals
appear after that to lick the ashes for their salt content. Notable as
well is that most mammals appear to enjoy the heat radiated at night at
sites of recently burned-out fires.[112]

It would have been inconceivable, therefore, that human beings, being
similarly observant and opportunistic creatures, would not also have
partaken of the dietary windfall provided by wildfires they came across.
And thus, even before humans had learned to control fire purposefully--and
without here getting into the later stages of control over fire--their
early passive exposures to it would have already introduced them, like the
other animals, to the role fire could play in obtaining edible food and
providing warmth.

So if fire has been used on a widespread basis for cooking since
roughly 125,000 years ago, how do we know if that has been enough time for
us to have fully adapted to it? To answer that, we have to be able to
determine the rate at which the genetic changes constituting evolutionary
adaptation take place in organisms as a result of environmental or
behavioral change--which in this case means changes in food intake.

The two sources for estimates of rates at which genetic change takes
place are from students of the fossil record and from population
geneticists. Where the fossil record is concerned, Niles Eldredge, along
with Stephen Jay Gould, two of the most well-known modern evolutionary
theorists, estimated the time span required for "speciation events" (the
time required for a new species to arise in response to evolutionary
selection pressures) to be somewhere within the range of "five to 50,000
years."[113] Since this rough figure is based on the fossil record, it
makes it difficult to be much more precise than that range. Eldredge also
comments that "some evolutionary geneticists have said that the estimate
of five to 50,000 years is, if anything, overly generous."[114] Also
remember that this time span is for changes large enough to result in a
new species classification. Since we are talking here about changes
(digestive changes) that may or may not be large enough to result in a new
species (though changes in diet often are in fact behind the origin of new
species), it's difficult to say from this particular estimate whether we
may be talking about a somewhat shorter or longer time span than that for
adaptation to changes in food.

Fortunately, however, the estimates from the population geneticists
are more precise. There are even mathematical equations to quantify the
rates at which genetic change takes place in a population, given
evolutionary "selection pressures" of a given magnitude that favor
survival of those individuals with a certain genetic trait.[115] The
difficulty lies in how accurately one can numerically quantify the
intensity of real-world selection pressures. However, it turns out there
have been two or three actual examples where it has been possible to do so
at least approximately, and they are interesting enough I'll mention a
couple of them briefly here so people can get a feel for the situation.

The most interesting of these examples relates directly to our
discussion here, and has to do with the gene for lactose tolerance in
adults. Babies are born with the capacity to digest lactose via production
of the digestive enzyme lactase. Otherwise they wouldn't be able to make
use of mother's milk, which contains the milk sugar lactose. But sometime
after weaning, this capacity is normally lost, and there is a gene that is
responsible. Most adults--roughly 70% of the world's population
overall--do not retain the ability to digest lactose into adulthood[116]
and this outcome is known as "lactose intolerance." (Actually this is
something of a misnomer, since adult lactose intolerance would have been
the baseline normal condition for virtually everyone in the human race up
until Neolithic (agricultural) times.[117]) If these people attempt to
drink milk, then the result may be bloating, gas, intestinal distress,
diarrhea, etc.[118]

However--and this is where it gets interesting--those population
groups that do retain the ability to produce lactase and digest milk into
adulthood are those descended from the very people who first began
domesticating animals for milking during the Neolithic periodic several
thousand years ago.[119] (The earliest milking populations in Europe,
Asia, and Africa began the practice probably around 4,000 B.C.[120]) And
even more interestingly, in population groups where cultural changes have
created "selection pressure" for adapting to certain behavior--such as
drinking milk in this case--the rate of genetic adaptation to such changes
significantly increases. In this case, the time span for widespread
prevalence of the gene for lactose tolerance within milking population
groups has been estimated at approximately 1,150 years[121]--a very short
span of time in evolutionary terms.

There is a very close correlation between the 30% of the world's
population who are tolerant to lactose and the earliest human groups who
began milking animals. These individuals are represented most among
modern-day Mediterranean, East African, and Northern European groups, and
emigrants from these groups to other countries. Only about 20% of white
Americans in general are lactose intolerant, but among sub-groups the
rates are higher: 90-100% among Asian-Americans (as well as Asians
worldwide), 75% of African-Americans (most of whom came from West Africa),
and 80% of Native Americans. 50% of Hispanics worldwide are lactose
intolerant.[122]

Now whether it is still completely healthy for the 30% of the world's
population who are lactose tolerant to be drinking animal's milk--which is
a very recent food in our evolutionary history--I can't say. It may well
be there are other factors involved in successfully digesting and making
use of milk without health side-effects other than the ability to produce
lactase--I haven't looked into that particular question yet. But for our
purposes here, the example does powerfully illustrate that genetic
adaptations for digestive changes can take place with much more rapidity
than was perhaps previously thought.*

Another interesting example of the spread of genetic adaptations
since the Neolithic has been two specific genes whose prevalence has been
found to correlate with the amount of time populations in different
geographical regions have been eating the grain-based high-carbohydrate
diets common since the transition from hunting and gathering to Neolithic
agriculture began 10,000 years ago. (These two genes are the gene for
angiotensin-converting enzyme--or ACE--and the one for apolipoprotein B,
which, if the proper forms are not present, may increase one's chances of
getting cardiovascular disease.)[123]

In the Middle East and Europe, rates of these two genes are highest
in populations (such as Greece, Italy, and France) closer to the Middle
Eastern "fertile crescent" where agriculture in this part of the globe
started, and lowest in areas furthest away, where the migrations of early
Neolithic farmers with their grain-based diets took longest to reach
(i.e., Northern Ireland, Scotland, Finland, Siberia). Closely correlating
with both the occurrence of these genes and the historical rate of grain
consumption are corresponding rates of deaths due to coronary heart
disease. Those in Mediterranean countries who have been eating
high-carbohydrate grain-based diets the longest (for example since
approximately 6,000 B.C. in France and Italy) have the lowest rates of
heart disease, while those in areas where dietary changes due to
agriculture were last to take hold, such as Finland (perhaps only since
2,000 B.C.), have the highest rates of death due to heart attack.
Statistics on breast cancer rates in Europe also are higher for countries
who have been practicing agriculture the least amount of time.[124]

Whether grain-based diets eaten by people whose ancestors only began
doing so recently (and therefore lack the appropriate gene) is actually
causing these health problems (and not simply correlated by coincidence)
is at this point a hypothesis under study. (One study with chickens,
however--who in their natural environment eat little grain--has shown much
less atherosclerosis on a high-fat, high-protein diet than on a low-fat,
high-carbohydrate diet.[125]) But again, and importantly, the key point
here is that genetic changes in response to diet can be more rapid than
perhaps once thought. The difference in time since the advent of Neolithic
agriculture between countries with the highest and lowest incidences of
these two genes is something on the order of 3,000-5,000 years,[126]
showing again that genetic changes due to cultural selection pressures for
diet can force more rapid changes than might occur otherwise.

Now we should also look at the other end of the time scale for some
perspective. The Cavalli-Sforza population genetics team that has been one
of the pioneers in tracking the spread of genes around the world due to
migrations and/or interbreeding of populations has also looked into the
genes that control immunoglobulin types (an important component of the
immune system). Their estimate here is that the current variants of these
genes were selected for within the last 50,000-100,000 years, and that
this time span would be more representative for most groups of genes. They
also feel that in general it is unlikely gene frequencies for most groups
of genes would undergo significant changes in time spans of less than
about 11,500 years.[127]

However, the significant exception they mention--and this relates
especially to our discussion here--is where there are cultural pressures
for certain behaviors that affect survival rates.[128] And the two
examples we cited above: the gene for lactose tolerance (milk-drinking)
and those genes associated with high-carbohydrate grain consumption, both
involve cultural selection pressures that came with the change from
hunting and gathering to Neolithic agriculture. Again, cultural selection
pressures for genetic changes operate more rapidly than any other kind.

Nobody yet, at least so far as I can tell, really knows whether or
not the observed genetic changes relating to the spread of milk-drinking
and grain-consumption are enough to confer a reasonable level of
adaptation to these foods among populations who have the genetic changes,
and the picture seems mixed.* Rates of gluten intolerance (gluten is a
protein in certain grains such as wheat, barley, and oats that makes dough
sticky and conducive to bread-baking) are lower than for lactose
intolerance, which one would expect given that milk-drinking has been
around for less than half the time grain-consumption has. Official
estimates of gluten intolerance range from 0.3% to 1% worldwide depending
on population group.[129] Some researchers, however, believe that gluten
intolerance is but the tip of the iceberg of problems due to grain
consumption (or more specifically, wheat). Newer research seems to suggest
that anywhere from 5% to as much as 20-30% of the population with certain
genetic characteristics (resulting in what is called a "permeable
intestine") may absorb incompletely digested peptide fragments from wheat
with adverse effects that could lead to a range of possible diseases.[130]

We have gone a little far afield here getting some kind of grasp on
rates of genetic change, but I think it's been necessary for us to have a
good sense of the time ranges involved. So to bring this back around to
the question of adaptation to cooking, it should probably be clear by this
point that given the time span involved (likely 125,000 years since fire
and cooking became widespread), the chances are very high that we are in
fact adapted to the cooking of whatever foods were consistently cooked.* I
would include in these some of the vegetable foods, particularly the
coarser ones such as starchy root vegetables such as yams, which are long
thought to have been cooked,[131] and perhaps others, as well as meat,
from what we know about the fossil record.

What about the contention by raw-food advocates that cooking foods
results in pyrolytic by-products that are carcinogenic or otherwise toxic
to the body, and should be avoided for that reason?

It's true cooking introduces some toxic byproducts, but it also
neutralizes others.[132] In addition, the number of such toxins created is
dwarfed by the large background level of natural toxins (thousands)[133]
already present in plant foods from nature to begin with, including some
that are similarly carcinogenic in high-enough doses. (Although only a few
dozen have been tested so far,[134] half of the naturally occurring
substances in plants known as "nature's pesticides" that have been tested
have been shown to be carcinogenic in trials with rats and mice.[135])
Nature's pesticides appear to be present in all plants, and though only a
few are found in any one plant, 5-10% of a plant's total dry weight is
made up of them.[136]

[The reason "nature's pesticides" occur throughout the plant kingdom
is because plants have had to evolve low-level defense mechanisms against
animals to deter overpredation. On one level, plants and animals are in a
continual evolutionary "arms race" against each other. Fruiting plants, of
course, have also evolved the separate ability to exploit the fact that
certain animals are attracted to the fruit by enabling its seeds to be
dispersed through the animals' feces.]

We have a liver and kidneys for a reason, which is that there have
always been toxins in natural foods that the body has had to deal with,
and that's one reason why these organs evolved. There are also a number of
other more general defenses the body has against toxins. These types of
defenses make evolutionary sense given the wide range of toxic elements in
foods the body has had to deal with over the eons. [Not clear enough in
the original version of the interview is the point that a wide range of
GENERAL defenses might therefore be reasonably expected to aid in
neutralizing or ejecting toxins even of a type the body hadn't necessarily
seen before, such as those that might be introduced by cooking practices.]
Such mechanisms include the constant shedding of surface-layer cells of
the digestive system, many defenses against oxygen free-radical damage,
and DNA excision repair, among others.[137]

The belief that a natural diet is, or can be, totally toxin-free is
basically an idealistic fantasy--an illusion of black-and-white thinking
not supported by real-world investigations. The real question is not
whether a diet is completely free of toxins, but whether we are adapted to
process what substances are in our foods--in reasonable or customary
amounts such as encountered during evolution--that are not usable by the
body. Again, the black-and-white nature of much Hygienic thinking obscures
here what are questions of degrees rather than absolutes.

Also, and I know raw-foodists generally don't like to hear this, but
there has long been evidence cooking in fact does make foods of certain
types more digestible. For example, trypsin inhibitors (themselves a type
of protease inhibitor) which are widely distributed in the plant kingdom,
particularly in rich sources of protein, inhibit the ability of digestive
enzymes to break down protein. (Probably the best-known plants containing
trypsin inhibitors are legumes and grains.) Research has shown the effect
of most such protease inhibitors on digestion to be reduced by
cooking.[138] And it is this advantage in expanding the range of
utilizable foods in an uncertain environment that was the evolutionary
advantage that helped bring cooking about and enhanced survival.*

I want to make clear that I still believe the largest component of
the diet should be raw (at least 50% if not considerably more), but there
is provision in the evolutionary picture for reasonable amounts of cooked
foods of certain types, such as at the very least, yams, probably some
other root vegetables, the legumes, some meat, and so forth. (With meat,
the likelihood is that it was eaten raw when freshly killed, but what
could not be eaten would likely have been dried or cooked to preserve it
for later consumption, rather than wasting it.) Whether or not some foods
like these can be eaten raw if one has no choice or is determined enough
to do so is not the real question. The question is what was more expedient
or practical to survival and which prevailed over evolutionary time.

A brief look at the Australian Aborigines might be illustrative
here.* What data is available since the aborigines were first encountered
by Europeans shows that inland aborigines in the desert areas were subject
to severe food shortages and prolonged droughts.[139] This of course made
emphasizing the most efficient use of whatever foods could be foraged
paramount. Estimates based on studies of aborigines in northern Australia
are that they processed roughly half of their plant foods, but that no
food was processed unnecessarily, any such preparation being done only to
make a food edible, more digestible, or more palatable.[140] In general
food was eaten as it was collected, according to its availability during
the seasons--except during times of feasts--with wastage being rare, such
a pattern being characteristic of feast-and-famine habitats. Some food,
however, was processed for storage and later retrieval (usually by
drying), including nuts and seeds, but may also have been ground and baked
into cakes instead, before burying in the ground or storing in dry
caches.[141]

Fresh foods such as fruits, bulbs, nectar, gums, flowers, etc., were
eaten raw when collected. Examples of foods that were prepared before
consumption include the cooking of starchy tubers or seeds, grinding and
roasting of seeds, and cooking of meat.[142]

That these practices were necessary to expand the food supply and not
merely induced by frivolous cultural practices like raw-foodists often
tend to theorize can be seen in the fact that after colonization by
Europeans, aborigines were not above coming into missions during droughts
to get food.[143]

But the more interesting and more pressing question, to my mind, is
not whether we are adapted to cooking of certain foods, which seems very
likely,* but how much we have adapted to the dietary changes since the
Neolithic agricultural transition, given the 10,000 years or less it's
been underway. At present, the answer is unclear, although in general, we
can probably say there just hasn't been enough time for full adaptation
yet. Or if so, only for people descended from certain ancestral groups
with the longest involvement with agriculture. My guess (and it is just a
guess) would be that we are still mostly adapted to a Paleolithic diet,
but for any particular individual with a given ancestral background,
certain Neolithic foods such as grains, perhaps even modest amounts of
certain cultured milk products such as cheese or yogurt (ones more easily
digested than straight milk) for even fewer people, might be not only
tolerated, but helpful. Especially where people are avoiding flesh
products which is our primary animal food adaptation, these animal
byproducts may be helpful,* which Stanley Bass's work with mice and his
mentor Dr. Gian-Cursio's work with Hygienic patients seems to show, as Dr.
Bass has discussed previously here in H&B (in the April and June 1994
issues).

How are we to determine an optimum diet for ourselves, then, given
that some genetic changes may be more or less complete or incomplete in
different population groups?

I think what all of this points to is the need to be careful in
making absolute black-or-white pronouncements about invariant food rules
that apply equally to all. It is not as simple as saying that if we aren't
sure we are fully adapted to something to just eliminate it from the diet
to be safe. Because adaptation to a food does not necessarily mean just
tolerance for that food, it also means that if we are in fact adapted to
it, we would be expected to thrive better with some amount of that food in
our diet. Genetic adaptation cuts both ways.

This is why I believe it is important for people to experiment
individually. Today, because of the Neolithic transition and the rates at
which genetic changes are being discovered to take place, it is apparent
humanity is a species in evolutionary transition. Due to the unequal flow
and dissemination of genes through a population during times like these,
it is unlikely we will find uniform adaptation across the population, as
we probably would have during earlier times. This means it is going to be
more likely right now in this particular historical time period that
individuals will be somewhat different in their responses to diet. And as
we saw above (with the two genes ACE and apolipoprotein-B) these genetic
differences may even confound attempts to replicate epidemiological
dietary studies from one population to another unless these factors are
taken into account.*

So while it is important to look for convergences among different
lines of evidence (evolutionary studies, biochemical nutritional studies,
epidemiological studies and clinical trials, comparative anatomy from
primate studies, and so forth), it is well to consider how often the
epidemiological studies, perhaps even some of the biochemical studies,
reverse themselves or come back with conflicting data. It usually takes
many years--even decades--for their import to become clear based on the
lengthy scientific process of peer review and replication of experiments
for confirmation or refutation.

So my advice is: don't be afraid to experiment. Unless you have
specific allergies or strong food intolerances and whatnot, the body is
flexible enough by evolution to handle short-term variations in diet from
whatever an optimal diet might be anyway. If you start within the general
parameters we've outlined here and allow yourself to experiment, you have
a much better chance of finding the particular balance among these factors
that will work you. If you already have something that works well for you,
that's great. If, however, you are looking for improvements, given the
uncertainties above we've talked about, it's important to look at any
rigid assumptions you may have about the "ideal" diet, and be willing to
challenge them through experimentation. In the long-run, you only have
yourself to benefit by doing so.

Ward, despite the evolutionary picture you've presented here, there
are still objections that people have about meat from a biochemical or
epidemiological standpoint. What about T. Colin Campbell's China Study for
example?

Good point. Campbell's famous study, to my mind, brings up one of the
most unremarked-upon recent conflicts in epidemiological data that has
arisen. In his lecture at the 1991 ANHS annual conference, reported on in
the national ANHS publication Health Science, Campbell claimed that the
China Study data pointed to not just high fat intake, but to the protein
in animal food, as increasing cholesterol levels. (High cholesterol levels
in the blood are now widely thought by many to be the biggest single
factor responsible for increased rates of atherosclerosis--clogged blood
vessels--and coronary heart disease.) According to him, the lower the
level of animal protein in the diet (not just the lower the level of fat)
the lower the cholesterol level in the blood. He believes that animal food
is itself the biggest culprit, above and beyond just fat levels in
food.[144]

Yet as rigorous as the study is proclaimed to be, I have to tell you
that Campbell's claim that animal protein by itself is the biggest culprit
in raising blood cholesterol is contradicted by studies of modern-day
hunter-gatherers eating considerable amounts of wild game in their diet
who have very low cholesterol levels comparable to those of the China
study. One review of different tribes studied showed low cholesterol
levels for the Hadza of 110 mg/dl (eating 20% animal food), San Bushmen
120 (20-37% animal), Aborigines 139 (10-75% animal), and Pygmies at 106,
considerably lower than the now-recommended safe level of below 150.[145]
Clearly there are unaccounted-for factors at work here yet to be studied
sufficiently.

One of them might be the difference in composition between the levels
of fat in domesticated meat vs. wild game: on average five times as much
for the former than the latter. On top of that, the proportion of
saturated fat in domesticated meat compared to wild game is also five
times higher.[146]

Other differences between these two meat sources are that significant
amounts of EPA (an omega-3 fatty acid thought to perhaps help prevent
atherosclerosis) are found in wild game (approx. 4% of total fat), while
domestic beef for example contains almost none.[147] This is important
because the higher levels of EPA and other omega-3 fatty acids in wild
game help promote a low overall dietary ratio of omega-6 vs. omega-3 fatty
acids for hunter-gatherers--ranging from 1:1 to 4:1--compared to the high
11:1 ratio observed in Western nations. Since omega-6 fatty acids may have
a cancer-promoting effect, some investigators are recommending lower
ratios of omega-6 to omega-3 in the diet which would, coincidentally, be
much closer to the evolutionary norm.[148]

Differences like these may go some way toward explaining the similar
blood cholesterol levels and low rates of disease in both the rural
Chinese eating a very-low-fat, low-animal-protein diet, and in
hunter-gatherers eating a low-fat, high-animal-protein diet. Rural Chinese
eat a diet of only 15% fat and 10% protein, with the result that saturated
fats only contribute a low 4% of total calories. On the other hand, those
hunter-gatherer groups approximating the Paleolithic norm eat diets
containing 20-25% fat and 30% protein, yet the contribution of saturated
fat to total caloric intake is nevertheless a similarly low 6% of total
calories.[149]

What about the contention that high-protein diets promote calcium
loss in bone and therefore contribute to osteoporosis? The picture here is
complex and modern studies have been contradictory. In experimental
settings, purified, isolated protein extracts do significantly increase
calcium excretion, but the effect of increased protein in natural foods
such as meat is smaller or nonexistent.[150] Studies of Eskimos have shown
high rates of osteoporosis eating an almost all-meat diet[151] (less than
10% plant intake[152]) but theirs is a recent historical aberration not
typical of the evolutionary Paleolithic diet thought to have averaged 65%
plant foods and 35% flesh.* Analyses of numerous skeletons from our
Paleolithic ancestors have shown development of high peak bone mass and
low rates of bone loss in elderly specimens compared to their Neolithic
agricultural successors whose rates of bone loss increased considerably
even though they ate much lower-protein diets.[153] Why, nobody knows for
sure, though it is thought that the levels of phosphorus in meat reduce
excretion of calcium, and people in Paleolithic times also ate large
amounts of fruits and vegetables[154] with an extremely high calcium
intake (perhaps 1,800 mg/day compared to an average of 500-800 for
Americans today[155]) and led extremely rigorous physical lives, all of
which would have encouraged increased bone mass.[156]

Okay, let's move on to the hunter-gatherers you mentioned earlier.
I've heard that while some tribes may have low rates of chronic
degenerative disease, others don't, and may also suffer higher rates of
infection than we do in the West. This is true. Not all "hunter-gatherer"
tribes of modern times eat diets in line with Paleolithic norms. Aspects
of their diets and/or lifestyle can be harmful just as modern-day
industrial diets can be. When using these people as comparative models,
it's important to remember they are not carbon copies of Paleolithic-era
hunter-gatherers.[157] They can be suggestive (the best living examples we
have), but they are a mixed bag as "models" for behavior, and it is up to
us to keep our thinking caps on.

We've already mentioned the Eskimos above as less-than-exemplary
models. Another example is the Masai tribe of Africa who are really more
pastoralists (animal herders) than hunter-gatherers. They have low
cholesterol levels ranging from 115 to 145,[158] yet autopsies have shown
considerable atherosclerosis.[159] Why? Maybe because they deviate from
the Paleolithic norm of 20-25% fat intake due to their pastoralist
lifestyle by eating a 73% fat diet that includes large amounts of milk
from animals in addition to meat and blood.*[160] Our bodies do have
certain limits.

But after accounting for tribes like these, why do we see higher
rates of mortality from infectious disease among other hunter-gatherers
who are eating a better diet and show little incidence of degenerative
disease?

There are two major reasons I know of. First, most modern-day tribes
have been pushed onto marginal habitats by encroaching civilization.[161]
This means they may at times experience nutritional stress resulting from
seasonal fluctuations in the food supply (like the aborigines noted above)
during which relatively large amounts of weight are lost while they remain
active. The study of "paleopathology" (the study of illnesses in past
populations from signs left in the fossil record) shows that similar
nutritional stress experienced by some hunter-gatherers of the past was
not unknown either, and at times was great enough to have stunted their
growth, resulting in "growth arrest lines" in human bone that can be seen
under conditions of nutritional deprivation. Such nutritional stress is
most likely for hunter-gatherers in environments where either the number
of food sources is low (exposing them to the risk of undependable supply),
or where food is abundant only seasonally.[162]

Going without food--or fasting while under conditions of total rest
as hygienists do as a regenerative/recuperative measure--is one thing, but
nutritional stress or deprivation while under continued physical stress is
unhealthy and leaves one more susceptible to pathologies including
infection.[163]

The second potential cause of higher rates of infection are the less
artificially controlled sanitary conditions (one of the areas where modern
civilization is conducive rather than destructive to health)--due to less
control over the environment by hunter-gatherers than by modern
civilizations. Creatures in the wild are in frequent contact with feces
and other breeding grounds for microorganisms such as rotting fruit and/or
carcasses, to which they are exposed by skin breaks and injuries, and so
forth.[164] Contrary to popular Hygienic myth, animals in the wild eating
natural diets in a natural environment are not disease-free, and large
infectious viral and bacterial plagues in the past and present among wild
animal populations are known to have occurred. (To cite one example,
rinderpest plagues in the African Serengeti occurred in the 1890s and
again around 1930, 1960, and 1982 among buffalo, kudu, eland, and
wildebeest.[165])

It becomes obvious when you look into studies of wild animals that
natural diet combined with living in natural conditions is no guarantee of
freedom from disease and/or infection. Chimpanzees, our closest living
animal relatives, for instance, can and do suffer bouts in the wild from a
spectrum of ailments very similar to those observed in human beings:
including pneumonia and other respiratory infections (which occur more
often during the cold and rainy season), polio, abscesses, rashes,
parasites, diarrhea, even hemorrhoids on occasion.[166] Signs of
infectious disease in the fossil record have also been detected in remains
as far back as the dinosaur-age, as have signs of immune system mechanisms
to combat them.[167]

One of the conclusions to be drawn from this is that artificial
modern conditions are not all bad where health is concerned. Such
conditions as "sanitation" due to hygienic measures, shelter and
protection from harsh climatic extremes and physical trauma, professional
emergency care after potentially disabling or life-threatening accidents,
elimination of the stresses of nomadism, plus protection from seasonal
nutritional deprivation due to the modern food system that Westerners like
ourselves enjoy today all play larger roles in health and longevity than
we realize.[168]

Also, I would hope that the chimp examples above might persuade
hygienists not to feel so guilty or inevitably blame themselves when they
occasionally fall prey to acute illness. We read of examples in the
Natural Hygiene M2M which sometimes seem to elicit an almost palpable
sense of relief among others when the conspiracy of silence is broken and
they find they aren't the only ones. I think we should resist the tendency
to always assume we flubbed the dietary details. In my opinion it is a
mistake to believe that enervation need always be seen as simply the
instigator of "toxemia" which is then held to always be the incipient
cause of any illness. It seems to me you can easily have "enervation"
(lowered energy and resistance) without toxemia, and that that in and of
itself can be quite enough to upset the body's normal homeostasis
("health") and bring on illness. (Indeed I have personally become ill once
or twice during the rebuilding period after lengthy fasts when overworked,
a situation in which it would be difficult to blame toxemia as the cause.)
The examples of modern-day hunter-gatherers as well as those of chimps
should show us that you can eat a healthy natural diet and still suffer
from health problems, including infectious disease, due to excessive
stresses--what we would call "enervation" in Natural Hygiene.

Ward, we still have some space here to wrap up Part 2. Given the
research you've done, how has it changed your own diet and health
lifestyle? What are you doing these days, and why?

I would say my diet right now* is somewhere in the neighborhood of
about 85% plant and 15% animal, and overall about 60% raw and 40% cooked
by volume. A breakdown from a different angle would be that by volume it
is, very roughly, about 1/4 fruit, 1/4 starches (grains/potatoes, etc.),
1/4 veggies, and the remaining quarter divided between nuts/seeds and
animal products, with more of the latter than the former. Of the animal
foods, I would say at least half is flesh (mostly fish, but with
occasional fowl or relatively lean red meat thrown in, eaten about 3-5
meals per week), the rest composed of varying amounts of eggs, goat
cheese, and yogurt.

Although I have to admit I am unsure about the inclusion of dairy
products on an evolutionary basis given their late introduction in our
history, nevertheless, I do find that the more heavily I am exercising,
the more I find myself tending to eat them. To play it safe, what dairy I
do eat is low- or no-lactose cultured forms like goat cheese and yogurt.*

Where the grains are concerned, so far I do not experience the kind
of sustained energy I like to have for distance running without them, even
though I am running less mileage than I used to (20 miles/week now as
opposed to 35-40 a few years ago). The other starches such as potatoes,
squash, etc., alone just don't seem to provide the energy punch I need.
Again, however, I try to be judicious by eating non-gluten-containing
grains such as millet, quinoa, or rice, or else use sprouted forms of
grains, or breads made from them, that eliminate the gluten otherwise
present in wheat, barley, oats, and so forth.*

In general, while I do take the evolutionary picture heavily into
account, I also believe it is important to listen to our own bodies and
experiment, given the uncertainties that remain.

Also, I have to say that I find exercise, rest, and stress management
as important as diet in staying energetic, healthy, and avoiding acute
episodes of ill-health. Frankly, my experience is that once you reach a
certain reasonable level of health improvement based on your dietary
disciplines, and things start to level out--but maybe you still aren't
where you want to be--most further gains are going to come from paying
attention to these other factors, especially today when so many of us are
overworked, over-busy, and stressed-out. I think too many people focus too
exclusively on diet and then wonder why they aren't getting any further
improvements.

Diet only gets you so far. I usually sleep about 8-10 hours a night,
and I very much enjoy vigorous exercise, which I find is necessary to help
control my blood-sugar levels, which are still a weak spot for me. The
optimum amount is important, though. A few years ago I was running every
day, totaling 35-40 miles/week and concentrating on hard training for
age-group competition, and more prone to respiratory problems like colds,
etc. (not an infrequent complaint of runners). In the last couple of
years, I've cut back to every-other-day running totaling roughly 20 miles
per week. I still exercise fairly hard, but a bit less intensely than
before, I give myself a day of rest in between, and the frequency of colds
and so forth is now much lower.

I am sure people will be curious here, Ward: What were some of the
improvements you noticed after adding flesh foods to your diet?

Well, although I expected it might take several months to really
notice much of anything, one of the first things was that within about 2
to 3 weeks I noticed better recovery after exercise--as a distance runner
I was able to run my hard workouts more frequently with fewer rest days or
easy workouts in between. I also began sleeping better fairly early on,
was not hungry all the time anymore, and maintained weight more easily on
lesser volumes of food. Over time, my stools became a bit more well
formed, my sex drive increased somewhat (usually accompanies better energy
levels for me), my nervous system was more stable and not so prone to
hyperreactive panic-attack-like instability like before, and in general I
found I didn't feel so puny or wilt under stress so easily as before.
Unexpectedly, I also began to notice that my moods had improved and I was
more "buoyant." Individually, none of these changes was dramatic, but as a
cumulative whole they have made the difference for me. Most of these
changes had leveled off after about 4-6 months, I would say.

Something else I ought to mention here, too, was the effect of this
dietary change on a visual disturbance I had been having for some years
prior to the time I embarked on a disciplined Hygienic program, and which
continued unchanged during the two or three years I was on the traditional
vegetarian diet of either all-raw or 80% raw/20% cooked. During that time
I had been having regular episodes of "spots" in my visual field every
week or so, where "snow" (like on a t.v. set) would gradually build up to
the point it would almost completely obscure my vision in one eye or the
other for a period of about 5 minutes, then gradually fade away after
another 5 minutes. As soon as I began including flesh in my diet several
times per week, these started decreasing in frequency and over the 3 years
since have almost completely disappeared.

What problems are you still working on?

I still have an ongoing tussle with sugar-sensitivity due to the huge
amounts of soft drinks I used to consume, and have to eat fruits
conservatively. I also notice that I still do not hold up under stress and
the occasional long hours of work as well as