spEEdfrEEk Posted August 27, 2004 Share Posted August 27, 2004 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- 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 Quote Link to comment Share on other sites More sharing options...
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