This blog is about the intersection between evolutionary biology and food. But also about practical applications, sustainable agriculture, and general tasty things. I originally started eating this way to heal from chronic health problems and...it worked!
Melissa McEwen
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04/07/2012 - 16:01
In my last post, I wrote about how it's impossible for epigenetic changes from very cold environments 3-4 billion years ago to have been conserved. Somehow people thought I was accusing Dr. Kruse of making up cold-adapted monkey ancestors or something.
No, I realize he doesn't mention cold-adapted monkeys, but he also doesn't stick to bacteria living in sad cold slurries either. He also mentions ancient mammals. Dr. Kruse also has an interesting belief that all mammals “evolved in the polar environments on earth.”
I can't find any evidence that early eutherian mammals evolved in such an environment or even a later candidate for a polar eutherian that could be a possible ancestor. They discovered the earliest known (so far) eutherian fossil last year in China, Juramaia sinensis, in a Late Jurassic formation. The climate in the area at the time was relatively warm and dry. Juramaia sinensis' teeth suggests it was an insectivore. Many other early mammal fossils have been found in Asia, but as we know, mammals went on to colonize a variety of environments and climates.
Dr. Kruse says "mammals were ideally adapted for hibernation too, until they got too smart for their own genes sake.” It is indeed true that Juramaia sinensis and other early eutherians did hibernate. Mevolutionary biologists now consider the origin of biological changes distinct to hibernation behaviors to have originated even before the evolution of class mammalia and are displayed even in reptiles who live in very warm environments.
Why did most mammals stop hibernating then? As the excellent paper The Evolution of Endothermy and Its Diversity in Mammals and Birds says “ energy-optimization-related selection pressures, often dictated by the energetic costs of reproduction, apparently favored abandonment of the capacity for short- or long-term torpors." In most primates, it seems this abandonment was characterized by a species with a large brain and increased adaptability to a variety of foods and climates.
That's too bad, because hibernation (or even torpor, a less extreme form) would be very useful for things like organ transplantations, surgery recoveries, or long space flights. In the future, if we figure out how to do it, being able to trigger hibernation would be incredibly useful. Unforunately, the exact way to trigger hibernation is not currently known, though there are many promising candidates. Dr. Kruse however believes that the stimuli is already known: “the stimulus for hibernation in eutherian mammals and their descendants are tied to high dietary carbohydrate intake (proven fact already in science and not controversial).” If only it were that easy. A search of the scientific literature found no papers that posited that carbohydrate consumption triggers hibernation, though it is established that carbohydrate metabolism undergoes changes before and after hibernation. Scientists who propose triggering hibernation believe it would probably involve injection of chemicals produced by hibernating animals. This would be possible because many of the genes related to hibernation are still present in primates, not because we hibernate, but because they have other functions. We'd also have to figure out how to prevent brain damage, which has been a major challenge to such research since humans appear to suffer memory loss from brain changes normal to hibernating mammals.
Evolution is efficient and while genes that had interesting past uses (wouldn't it be cool if we could "reawaken" gills or the ability to lay eggs??) are often conserved in our genome, they are often expressed in radically different ways. It seems the areas that once encoded for gills, for example, are now related to the bones in the ear. As for those that don't seem to be in use now, as geneticist Paul Szauter says:
If genes are not expressed in the human genome, they do not survive intact over evolutionary time, because they accumulate mutations in the absence of selection. If there were squid genes in the human genome that could be "activated," it is likely that the accumulated mutations would result in a truncated gene product (3 of the 64 codons are "stop") with many changes in its sequence.
Dr. Kruse believes that humans, like all mammals, are optimized for hibernation and that remnants of mammalian hibernation are activated in humans based on certain times of the day: "It appears 12-3 AM are the critical hours at night are where the remnants of mammalian hibernation lies for our species". This is a far cry from the current state on literature related to hibernation. The idea that remnants of hibernation occur in humans at night also goes against the definition of hibernation. An excellent paper authored by another McEwen, Dr. Bruce McEwen, has a great concise definition "Hibernation is a highly regulated physiological response to adverse environmental conditions characterized by hypothermia and drastic reductions of metabolic rate"
Re-definition and special unique definitions of terms is another of Melia’s characteristics of bad books: “ The texts of these books all continue in the same excited first-person voice. They often introduce vague, undefined or invented terms.” A good example of this is in Dr. Kruse’s PaleoFX talk, where he references “ geothermal circadian cycles.” It sounds scientific, but there are no known circadian cycles that are tied to Earth’s internal heat* and it appears Dr. Kruse invented the concept since it is found nowhere else. It is a particularly deceptive practice, made easier by the fact that many of the terms that are often mis-used by these authors, such as the species concept or even hibernation, are the subject of some academic contention. But while academics might be arguing about whether or not bears are “true hibernators,” we can be assured that no one is considering that humans are hibernating every night because that doesn’t even fit into the realm of contention or the fringes of what is considered hibernation.
The only known primate that hibernates is Cheirogaleus medius, member of suborder Strepsirrhini, which diverged from the evolutionary line that led to humans over 70 million years ago. They also store a lot of fat beforehand, so I don't know if I'd like to hibernate like them anyway. I don't think I'd look so good and I probably wouldn't get much work done.
Even if it were conserved, Dr. Kruse makes the mistake of tying hibernation to extreme cold: “Cold environments are found as mammals hibernate in normal circadian biology…….this completely reverses IR in mammals and wakes them up when conditions are better for life.” Dr. Kruse’s cold therapy involves exposure to freezing temperatures, because he thinks that is linked to hibernation in humans. Kruses asks his readers if maybe diabetes has “become thought of as a neolithic disease in humans because we we have simultaneously lost the ability to hibernate because we evolved the ability to control our environment completely?” However, there are many animals that hibernate without exposure to very cold temperatures and biologists are still debating whether or not relative cold is even needed to trigger hibernation at all. For example, the only hibernating primate, the aforementioned Cheirogaleus medius, hibernates at 30 degree celsius (86 F). And if humans had lost the ability to hibernate because we control our environment, we would find the ability in related primates who do not control their environments. But we do not. The northernmost living non-human primate, Macaca fuscata, does not show any evidence of hibernation or even torpor, even those that do not visit hot springs. Interestingly, their winter diet does include digging for roots.
Why do so few primates hibernate? Around the equator, where primates evolved, seasons operate quite differently than they do in the arctic and other regions far from the equator. Because the environments and climates of Africa are so diverse, with many micro-climates in certain regions, most primates closely related to humans have evolved to be able to adapt to scarcity regardless of Earth’s axis tilt through the reliance on “fall back foods.” Possibly because of this evolutionary strategy, there is no particular dietary pattern that consistently characterizes the seasons for primates as an order or even within species.
Even in non-primates that live in the north, a very small percentage hibernate. For example, some squirrels hibernate, some don't. Those that don't often will cache food and eat it later. Some humans are known to raid rodent caches for carbohydrates. This contrasts with Dr. Kruse’s idea of seasonal biological changes being triggered by changing to carbohydrates or one season being devoid of carbohydrates: “it appears that dietary carbohydrates, which are only present in long light cycles in the summer in cold places, induce mammals to add PUFA’s to our cells to become fluid so we can function as we hibernate.”
According to Kruse, since carbohydrate consumption is tied to hibernation in cold environments, since we don’t really hibernate now (except sort-of, at night according to Kruse), carbohydrates might not be safe to consume: “Since we no longer hibernate……..maybe you need to consider how you eat carbohydrates within the circadian controls? Maybe what you thought was safe………really is not?” The implication is that carbohydrate consumption is only “safe” for mammals in the context of nature’s “design” for hibernation. In terms of our evolutionary line, that makes little sense. The vast majority of primate species consume diets of mainly carbohydrate, with two main digestive strategies. The evidence is that ancestors of modern hominins relied on a mainly-carbohydrate diet until somewhat recently.
If Dr. Kruse’s line of reasoning is true, most primates are living out of balance with nature and have been for millions of years. Some of his followers have said that this only applies if you live in the north since there are somehow some circadian controls only in the North that are tied to carbohydrates (zero evidence provided), but then the mice and squirrels who are eating stored or underground roots are violating natures law. And the idea that if you put an individual primate in the north that it will change its underlying biology to fit the north's light cycles does not have any evidence behind it (and in fact the fact that individual humans don't adapt particularly well to northern light cycles is perhaps behind the etiology of many modern illnesses).
As I will write in my next post, some human populations (and possibly other hominin lines) have genetic adaptations to more polar light cycles, but these are recent adaptations and are not shared by all humans. And one unique thing is that humans that inhabit cold regions have a raised metabolic rate during the coldest season, not a lowered one characteristic of torpor or hibernation, which suggests adaptations more similar to those found in wolves rather than ground squirrels**. Also, I must also discuss longevity being derived rather than ancestral. But I'll leave that to the next post.
* Geothermal according to the OED is “ 1. Geol. Relating to or resulting from the internal heat of the earth; (of a locality or region) having hot springs, geysers, fumaroles, etc., heated by underlying magma.””
** are non-hibernating squirrels naughty "nature's law" breakers? Particularly if they are eating stored carbohydrates?
03/31/2012 - 09:55
In my last post on the subject of Dr. Jack Kruse, AKA, The Quilt, I briefly touched on the misuse of the ideas of quantum theory. Not long after, the WSJ had an excellent article on the mis-use of that subject.
Actually, it's pretty interesting because I agree that both the mis-use of evolutionary biology and quantum science aren't that bad, because they show that people really are interested in science. They are just suseptible to bad science, which isn't a surprise considering the abysmal state of scientific education in this country. Only about 4 in 10 Americans actually believe that evolution is a real thing.
Well, here is some background for new readers. My original post confused some people who do not post on Paleohacks, where my rivalry with Dr. Kruse has a very long history.
The question of what drives popular interest in such evolutionary fantasies is a difficult one. Frequently, they are bundled in with good advice, further increasing credibility among laymen. They contrast with legitimate evolutionary biology in that they contain simple and often epic “just so” narratives that appeal to people, in contrast with the complexities and fervent debates in the academic study of human evolution.
An example of one such internet popularizer is the aforementioned Dr. Jack Kruse, a Tennessee neurosurgeon and dentist who started plying a “paleo” diet and lifestyle program called the Leptin RX Reset on various popular paleo diet websites (particularly Mark’s Daily Apple, which is ranked 2000 on the Alexa web traffic rating system in the US, and Paleohacks, which is ranked 8000) in 2010. Calling himself “The Quilt,” his posts quickly became some of the most popular on these sites. In June of 2011, he launched his own website, containing a blog and his master “Quilt” manifesto and cracked Alexa’s top 100,000 sites in the US within months, hitting 26,581 in March 2012. He gained a further audience from the online Paleo Summit, where his talk was among the most popular and where many people learned about the next part of his Leptin RX Reset program, the Cold Thermogenesis Protocol (CT). Then he was a keynote speaker at PaleoFX, an Austin paleo conference sponsored by The Ancestral Health Society that drew many of the movement’s most popular speakers. In the fall of 2012, he will be a panelist on a debate about “safe starches” at the Ancestral Health Society’s main conference, the Ancestral Health Symposium.
Evolution is central to Dr. Kruse’s ideas and recommendations. In a comment to reader he explained “ Adapting evolutionary biology to what we learn makes us a better physician not matter what we do.” His writings contain many references to human evolutionary origins and how his readers can use them to improve their health in a modern context. Many of his readers have reported success from using his recommendations, but is the evolutionary basis behind them sound?
During a panel at PaleoFX in Austin Dr. Kruse said
Only humans who fail to listen to evolutions rule book of engagement die. You can eat a banana in the winter and feel fine but Mother Nature says it’s impossible………therefore we ought not to do it. I will follow her lead over a diet book guru or the opinions of a bunch of people who let their thoughts subjugate their genes. Feelings and thoughts do not trump neural biochemistry …
But his writings reveal a more ambivalent view of evolution. On one hand, on one blog post he says that “The speed of evolutionary change has far out stripped the ability of our paleolithic genes to catch up.#” But in his Quilt manifesto he outlines an extremely plastic view “A human is the only animal that can actually change its DNA just by thinking. Moreover, what we really think is just a biologic secretion. No different than any hormone released by the pituitary gland. Thinking is… well it is a meme that hijacks our brain’s chemistry. Any one thought can alter our genetic and biologic purpose in life.#” Therein lies an essential paradox- on one hand our genes are “paleolithic,” but on the other they are malleable simply by thinking differently. Perhaps it is just part of our genes that are “paleolithic.” For example, he refers to our brains being neolithic and able to “subjugate” our paleo genes, with negative consequences: "our neolithic brains allow us to make decisions that subjugate out paleolithic genes all too often.”
The idea that human genetics have not changed since the end of the Paleolithic roughly 10,000 years ago and that they are mismatched to the modern neolithic environment is a common one in paleo diet circles. Unfortunately, its origin can be traced back to academia and it lives on as a popular principle despite the fact that it has been the subject of considerable controversy in evolutionary biology. A common citation in paleo books is to An evolutionary perspective enhances understanding of human nutritional requirements, a paper written by Boyd Eaton, Melvin Konner, and Marjorie Shostak in 1996:
Geneticists believe that the increased human number and mobility associated with civilization have produced more, not less, inertia in the gene pool and that when the humans of 3000-10,000 years ago (depending on locality) began to take up agriculture, they were, in essence, the same biological organisms as humans are today (Neel 1994).
More recent research has come to the opposite conclusion, as newer statistical genetics models have actually found that human evolution has accelerated greatly in the past 40,000 years, certainly not freezing with the advent of agriculture. However, along with many other paleo authors, Dr. Kruse is still of the less dynamic mindset, writing that “Evolutionary pressures are selected for by the environments of our ancestors were exposed to and not for what we face today.”
n academic anthropology, new discoveries in archaeology and rapid advances in genetics have spawned a discipline in which textbooks are outdated as soon as they are published. Human origins are constantly under debate, which means that even if scientific education were adequate in the US, it is fairly hard for anyone to keep up. But even a basic outdated education on the topic would help a layman be critical of several pop-science fringe evolutionary theories that have cropped up, such as the “aquatic ape” theory. Why do such theories become popular? As anthropologist Jim Moore put it:
Even among scientists, as we've seen with Hoyle, there are times when assertions are put forth which are poorly drawn, yet, because they strike a chord, often of wishful thinking, they catch on and are repeated. Yet refuting them can be an exercise in futility. A good scientific review and critique is a lot of work, and takes a lot of time. But it's far easier to pop off with a theory that's poorly researched than it is to accurately go over all the things that the original theorist should've, and to provide a point by point refutation.
In the case of the Aquatic Ape theory, Jim Moore did a major service by creating a website to refute it, since as he elucidates there, there is very little incentive for academics to engage in debates with popular pseudoscientific theories, since they are so focused on doing their own original research for the benefit of their careers.
This is unfortunate, because pseudoscience has great power to shape the public’s consciousness. As anthropologist John Hawks puts it:
Is the Aquatic Ape Theory fairly described as pseudoscience? Every statement of natural causes is potentially scientific. What distinguishes science from pseudoscience is social. Pseudoscience is supported by assertions of authority, by rejection or ignorance of pertinent tests, by supporters who take on the trappings of scientific argument without accepting science's basic rules of refutation and replication. Pseudoscience is driven by charismatic personalities who do not answer direct questions. When held by those in power, like Lysenkoism, it destroys honest scientific inquiry. When held by a minority, it pleads persecution.
In a world where many people are unhappy and unhealthy despite our scientific advances, the idea that conventional science is wrong can be quite appealing. It allows people to buy into fringe pseudoscience for which little evidence exists and not question the lack of evidence.
Dr. Kruse has a new interesting spin on the "paleo" diet, though whether his approach is "paleolithic" is up for debate. His spin on the evolutionary approach lately has emphasized cold. Why?
Considering that 90% of the earth’s current biome lives in extreme conditions on our own planet today still, we might need to consider that what we think is “our normal environment” is not so normal for most of life on our planet or our evolutionary history. Life on Earth evolved in an environment much like we see on Titan today; in a deep ocean frozen solid at its surface with the capability of life buried deep with in it. The only escape was due to ejectants of water vapor from super heated water from underwater volcano’s. All these things are present today on Earth’s crust too. There is one major difference now between the two. We are warmer today than life began. There are others, but when one looks at Titan we see a frozen giant moon with a monsterous ocean beneath it.
This creates an issue of whether or not Dr. Kruse is even promoting a paleo diet or if instead he is promoting a Archean diet. But if he is referring to the Archean, it is mystifying that he emphasizes cold, considering that the Archean was probably warmer than today. Dr. Kruse has "references" on his blog, but I would challenge anyone to tie the meandering list on his blog post with any actual "facts" in his writing, like that cold promotes autophagy or that Neuropeptide Y is downregulated in cold weather.
Either way, debates as to the origin of life on Earth are still happening, with some (but not a consensus!) emphasizing the possibility that colder temperatures were the ideal place for single-celled life forms to originate. Dr. Kruse believes this is important because “life first adapted to extreme environments and then was naturally selected and adapted to a cyclic warming trend on our planets crust over time.” But he seems to believe that this adaptation was somehow incomplete: “Our hominid species may have adapted during this warming trend, but the DNA we inherited came from animals that were cold adapted.” Did DNA not adapt during this warming trend even through our hominin ancestors themselves adapted? It seems strange since Dr. Kruse believes that “One thought might just alter your DNA!”
Instead, he believes that these adaptations were mostly epigenetic, once again appealing to the idea that he knows more than conventional science “We know today that the power of epigenetics dictates a lot more about newer generations adaptations than we even knew ten years ago.” While epigenetics has become an important field, it is clear that a species adaptation to changing environments involves both epigenetic and genetic adaptations. Unfortunately, epigenetic is an appealing buzzword, which has been co-opted to absurdity. Dr. Kruse says that the warm paleoclimate that our primate ancestors were exposed to might not matter as much as we think it does because we might still carry an epigenetic imprint from the cold that engulfed Earth 3-4 billion years ago:
The modern science of epigenetics shows that who we came from and what they faced has a direct biologic effect upon subsequent generations DNA and phenotypes. It is crystal clear today, but the biologic implications remain unexplored in all modern day literature. What is happening on Titan maybe like opening up a blackhole back to a reality that used to be our own. The ability to see Earth at life’s evolutionary beginning.
This is confusing, because while here he blames epigenetic relics, in other writings he blames static genetics: “ The speed of evolutionary change has far out stripped the ability of our paleolithic genes to catch up. This mismatch causes major problems for modern humans.” Dr. Kruse seems to want to have it both ways.
The idea that epigenetic relics from billions of years ago are affecting us today is questionable, since the latest evidence shows that epigenetic changes are not stable enough to carry on from thirty generations and certainly not from 3-4 billion years ago. Evolutionary biologist Jerry Coyne has addressed people who hype up the evolutionary significance of epigenetics: “ There are a handful of examples showing that environmentally-induced changes can be passed from one generation to the next. In nearly all of these examples, the changes disappear after one or two generations, so they couldn’t effect permanent evolutionary change.“ This is in direct opposition to Dr. Kruse’s view of how evolution works:
I think evolution found that epigenetic modifications to be quite effective way to pass on environemental information to succeeding generations. So successful that it became a backbone law of genomic functioning. Evolution follows fractal patterning. So it is also highly conserved in all species. Today that appears to be true too.
While epigenetics has indeed led to important new understandings, it is less of a game-changer than Dr. Kruse presents: “Evolution uses epigenetics to determine adaptation to environments. We have discarded the strict definition of genetic determinism that came from Watson and Crick, as founders of DNA.” As evolutionary biologist Rama S. Singh succinctly put it:
While the new discoveries of the laws of developmental transformations are enriching our knowledge of the intricate relationship between genotype and phenotype, the findings of epigenetic inheritance do not challenge the basic tenets of the neo-Darwinian theory of evolution, as other than producing new variation no new processes of evolutionary change have been added to the ones we already know — mutation, migration, selection, and drift
Unfortunately, Dr. Kruse’s erroneous beliefs on human evolution have wide-ranging consequences holistically on his philosophy and recommendations, since it causes him to believe in conservation of many traits for which there is no evidence of conservation in Hominidae. Daniel F. Melia, professor of Celtic studies, recently wrote an article about characteristics of bad books that promote pseudoscience in his discipline. One of these characteristics is “Confident conclusions are often the result of chains of circumstance and supposition so long that even remembering their origin points while reading the books is difficult.” It’s easy to see that here and it shows how particularly ingenious this characteristic is since it makes anyone who tries to criticize the absurdities wade through the mire, further dis-incentivizing criticism.
A reasoning that Dr. Kruse uses for carbohydrate restriction is that epigenetics has sped up: “epigenetics has sped up and you eat a warm climate diet you by definition increase mitochondrial ROS that slowly kills you” A search of the scientific literature and academic databases found zero papers on epigenetics speeding up in modern humans. His article cites Wikipedia and himself.
The phenomena he blames on an epigenetic speed up also often do not have known epigenetic causes.
This is more fuel or proof that the “metabolic trap door” I found makes all starches less safe when they are eaten outside how our circadian biology accounts for them in our sped up systems. Evolution power laws has sped up too simultaneously to compound the issue. This explains why kids today are huge and bigger than their preceding genrations. It explains also why they reach puberty faster today.
Scientists are not sure what is causing earlier puberty(NYtimes article yesterday). If Dr. Kruse really knows, he should be eligible for a Nobel prize. It’s also interesting because paleo authors are often quick to point out that Paleolithic humans were bigger and stronger than modern humans because of their healthier diets and lifestyles. Yet Dr. Kruse is portraying this phenomenon as a bad thing, which begs the question as to why the paleolithic humans were bigger. Were they eating too many carbs? Why modern humans are catching up to paleolithic humans in terms of height is a matter of debate, but the best theory is it has to do with greater access to calories and less malnutrition stress.
Overall, on the issue of genetics and epigenetics, Dr. Kruse seems willing to rewrite definitions and build a pseudoscientific narrative that has little basis in reality. It shows that new scientific discoveries that become buzzwords in the public consciousness are very easy to manipulate in order to build such narratives. They make them sound scientific and cutting-edge, when in reality they are empty and devoid of factual basis.
I have MUCH more to write on this subject, including more on the evolution of mammals, hibernation, and hominin adaptations to cold. Also, a history of how he did not invent most of the regimens his followers praise so highly, as well as the actual non-pseudoscience evolutionary biology reasons that they work for those people.
02/19/2012 - 19:25
I realized something hilarious today. Dr. Jack Kruse is the What the Bleep Do We Know? of Paleo. You know, that pretentious movie about "quantum physics" that was actually woo dressed up in scienecy language? Here is a fun game, which quotes is from Dr. Jack Kruse and which is from What the Bleep Do We Know?
a "If thoughts will do that to water, imagine what our thoughts can do to us."
b "One thought might just alter your DNA!"
c "Now that quantum mechanics has crashed into modern biologic theory, we have finally found out why we think the way we do with our brain. "
d "Each cell has a consciousness, particularly if we define consciousness as the point of view of an observer."
A and D are What the Bleep Do We Know. B and C are Dr. Kruse. I also find his random references to "quantum" to be quite hilarious and it reminds me of a Richard Feynman quote:
"If you think you understand quantum mechanics, you don't understand quantum mechanics"
It's also self-experimentation gone awry. For example, while self experimentation is great for finding what works for you, I'm not interested in someone beating a dead horse about carbs with anecdotes about how eating some blackberries prevented them from sleeping last night (that's one real robust Paleolithic-style metabolism right?). Self-experimentation works to place yourself on the bell curve, not to place others. It's like, cool data point bro, but maybe I'm on the other side of the curve.
Think a little bit about the fact that Dr. Kruse is a headlining speaker at almost every upcoming "paleo" event. Notice something about these events? Notice the complete lack or very small amount of evolutionary biologists and biological anthropologists? I don't know if they were even invited, but most of the ones I talk to would be too embarrassed to be part of the circus where people are having to debate whether or not 100 grams or starch is SAFE. It's almost like a joke.
More posts from people who have Balls and are willing to call Dr. Kruse out on his bullshit (I'm hoping more prominent bloggers will discover their balls in the future):
Carbsane has also written quite a bit on Dr. Kruse. I have a feeling that self-diagnosed "leptin resistance" is the new "candida."
09/10/2011 - 11:27
Since a diet a raw vegan of only raw fruits, vegetables, and nuts is not an appropriate diet for our species, many people suffer from health problems on such diets. When I get comments from healthy long-term raw vegans here, I take it with a grain of salt since I know that people are so attached to the "purity" of raw vegan that they will engage in denialism before they admit they have a problem.
A questionnaire study of raw vegan diets found that many women on them suffer from amnorrhea, which means they stop having their monthly periods. They concluded that "Since many raw food dieters exhibited underweight and amenorrhea, a very strict raw food diet cannot be recommended on a long-term basis." (note the study did not include raw foodists who include animal products in their diets).
Unfortunately, instead of admitting their diet was deficient, many have written articles about how periods are bad anyway, because it's not something wild animals or our primate relatives have and it's a sign that we have "toxins" on our bodies. Here is one from Debbie Took (who later confessed on Letthemeatmeat that she was considering adding raw dairy into her diet and has since stopped posting on her blog, though I hear she is fruitarian now):
To many feminists, the idea of the menstrual blood as being 'impure' is heresy, but...'The toxicity of menstrual blood has been well substantiated. Mach and Lubin (Journal of Pharmacology and Experimental Therapy 22:413 (1924)) showed that the blood plasma, milk, sweat and saliva of menstruating women contains a substance that is highly toxic to protoplasm of living plants. This toxic substance is not present during the intermenstrual periods.' Even the sweat and saliva! And these toxins are not present when not menstruating. It's as if the body is 'gathering together' toxins in the period preceding menstruation, prior to expulsion at menstruation, to get the body all nice and clean again for possible impregnation the following month. But, sure, the study's old, and if anyone knows whether any subsequent studies have refuted it, let me know.
I thought of this post because Dr. Kate Clancy, a physical anthropologist, just posted about it in her blog:
Dr. Bela Schick, a doctor in the 1920s, was a very popular doctor and received flowers from his patients all the time. One day he received one of his usual bouquets from a patient. The way the story goes, he asked one of his nurses to put the bouquet in some water. The nurse politely declined. Dr. Schick asked the nurse again, and again she refused to handle the flowers. When Dr. Schick questioned his nurse why she would not put the flowers in water, she explained that she had her period. When he asked why that mattered, she confessed that when she menstruated, she made flowers wilt at her touch...Dr. Schick decided there was something nasty in the sweat of menstruating women. Others took up the cause. Soon, people were injecting menstrual blood into rodents, and those rodents were dying (Pickles 1979). Others were growing plants in venous blood from menstruating women to determine phytotoxicity; the sooner the plants died, the higher the quantity of menotoxin assumed in the sample.
It reminds me of elementary school science fairs and of the people who claim vegetables are toxic because of some study that put something ridiculous like purifiedcapsaicin on a cell culture and...no surprise the cells died! As if that is like eating peppers. These experiements were badly done and produced invalid results, the modern scientific understanding of periods is that they don't have to do with toxins:
Thankfully, the most accepted idea is that menstruation did not evolve at all, but is a byproduct of the evolution of terminal differentiation of endometrial cells (Finn 1996; Finn 1998). That is, endometrial cells must proliferate and then differentiate, and once they differentiate, they have an expiration date. Ovulation and endometrial receptivity are fairly tightly timed, to the point that the vast majority of implantations occur within a three-day window (Wilcox et al. 1999). So it’s not that menstruation expels dangerous menotoxins, but rather that menstruation happens because the endometrium needs to start over, and humans in particular have thick enough endometria that we can’t just resorb all that blood and tissue.
Guess what? Plants didn't evolve to grow in menstrual blood, just like we didn't evolved to eat uncooked animal-free food. The essential factors of cooking or eating animal fat is that they are appropriately calorically dense for our small digestive systems and giant hungry brains. Physical anthropologist Dr. Richard Wrangham discusses his book Catching Fire here:
I think we can probably digest them—this is guesswork because we don't really know—but the point is they're very full of indigestible fiber. So the average human diet has, even in the more fibrous hunter-gatherer types, 5 to 10 percent, say, indigestible fiber. With our chimp studies, they eat 32 percent indigestible fiber. So that is something that the human body is not designed to handle. And the reason we can say that is that we have small colons and small stomachs which are adapted to food that has high caloric density. And food the chimps eat has low caloric density.
Anthroologists will continue to argue about which is more important- animal foods or cooking, but either way, a raw vegan diet doesn't fit our anatomy.
This lovely little piece of woo makes the claim that healthy humans eating a "natural" diet don't have periods.
The majority of women in modern cultures however, experience instead a copious disabling monthly bleeding - that neither their wild primate cousins nor humans living close to nature do (2:30; 15:232). Insightful doctors have long been aware that nature did not intend the ovulation cycle to be accompanied by cramping, nervous tension, or any of the long list of symptoms we've come to associate with "having a period" - let alone by the days of bloody flow we now accept as "normal", but which they rightly call a hemorrhage:
That's also nonsense. It's not discussed often enough in ethnographies, but it's clearly there. The biography of Nisa, a !Kung woman, discusses it. And I doubt that if it were unnoticeable and rare that some Melanesian societies would have taboos about it.
That said, if your period is disabling, that might have to do with a modern diet. I've definitely had shorter, lighter, and less painful periods since I started eating whole unprocessed real foods, but I would be very alarmed if I didn't have a period. If you aren't getting one, you do need to see a doctor, and if you are paleo you need ton consider whether or not you are eating enough calorie-dense foods.
If you do not want to eat animal-based foods, consider following Wranghams example and eating some cooked food. I think a lot of vegans initially benefit from raw veganism because so many vegan foods are so horribly processed (and it is an excellent weight-loss diet). Some of them succeed because they are able to eat massive amounts of fruit or tons of calorically dense nut concoctions, though many eventually succumb to nutrient rather than calorie issues (or they are post-menopausal and telling young women that not having a period is normal, which just boggles my mind). When I think of what unhealthy veganism means, I not only think of raw veganism, I think of Foodswings in Williamsburg, which serves up such unhealthy delicacies as breaded fried processed soy-meat. There are plenty of alternatives to both diets, such as steamed root vegetables, soaked or sprouted lentils, or fermented buckwheat.
06/16/2011 - 08:25
Last year I met a girl who was trying the paleo diet and complaining she "felt weird" and her stomach hurt. I asked her what she was eating and it turns out she was eating 5 tablespoons of coconut oil for breakfast! I told her that wasn't food, that it was an ingredient you can use to make foods or a supplement and that maybe she should try eating food. Later she said she felt better.
I guess there is some impression among certain people that because I and others don't think fat is *bad* that you should drown yourself in it. As far as I'm concerned it's a far cry from a certain Paleo cookbook that advocates trimming fat off of GRASS FED meat, throwing away the fat that is leftover from cooking grass-fed meat, and avoiding grass-fed "fatty cuts" like shanks to eating a pound of bacon for breakfast with a side of heavy-cream flavored coconut milk. Let's be honest: I don't eat that way. I cook with tallow that I save from the whole goats and lambs I buy, I certainly don't ever throw away any "fatty" cut, and sometimes I use some ghee, bacon, butter, or coconut milk as ingredients. I go through a pound of bacon a month, mostly because of my boyfriend, and maybe a can of coconut milk every two weeks and a pack of Pasture Butter a month. I never make any "paleo" desserts anymore and I don't eat very much dairy unless it's well-fermented and raw. Heavy cream makes my digestive system into sludge. I do eat some grains: I find my stomach is happiest when I include some rice in my diet every few days or so.
I suspect someone who is more athletic or who doesn't have IBS might tolerate more fat. But this is my personal "sweet spot." I do have experience doing almost-vegan paleo: starches, veggies, fruits, no added fats, and only shellfish as protein. Perhaps it could be perfected, but I found that my keratosis really was itchy and red. I also felt more depressed and had bloating. If I tried it again I would probably use some coconut milk with carrot juice or something in an attempt to get vitamin A, but maybe my body isn't suited for it because of my genetics and health problems. Maybe it's also different for people in different life-stages. I'm a woman of reproductive age, so it's possible my need for certain vitamins is higher.
I also would note that food sensitivities don't care about the paleolithic. It's very possible to be allergic or sensitive to a host of "paleo" foods from types of meat, to nuts, to eggs, to shellfish. I am personally quite sensitive to vegetables like broccoli, onions, and cauliflower. Honestly, they do a number on my stomach worse than any grain. I think people get caught up in the "paleo" paradigm thinking that because we evolved with foods like it, it must be good. But modern food sensitivities don't discriminate. I find that interestingly my stomach feels much better if I get starch from regular potatoes rather than sweet potatoes. The latter is considered "more paleo" though that stems from botanical ignorance.
Either way, I don't really follow an orthodox "paleo" diet either, though I do use what I learn about the paleolithic to think about what I eat. I think there is tons of room for experimentation, particularly as the evidence for starch consumption in the paleolithic becomes stronger and stronger.
I don't think there is much room for combining "paleo" with various religious philosophies and I'm a little dismayed that Chinese medicine has somehow crept in and become tolerated. I think if I blogged about how I use Christianity to tell me what to eat I'd get about a million angry comments. Remember, the mechanisms behind Chinese medicine are scientifically implausible and even if a few tiny studies show that Chinese medicine works, it's not because of supernatural forces like conveniently undetectable "energy fields" operating outside of the forces of biology, chemistry, and physics. I know plenty of people who follow a "paleo" diet that is compatible with their religion, such as kosher or halal folks, but they don't claim that their diet is somehow better because of it or that it explains their diet's success.
There has got to be a scientific explanation or I'm just not buying it...
Addendum:
It seems that some people were upset with the idea that I was attacking alternative medicine in the last post. No, I was attacking scientifically implausible theories of food being integrated by the ancestral food community. It's because people don't want to believe there are both unverifiable supernatural beliefs AND beliefs worth investigating to find out whether or not they have some natural basis or benefit.
Acupuncture, for example, is a system worth investigating because of the possibility that the ancient literature refers to real physiological processes, as Chris Kessler points out, and not energy fields (scientists have looked for these energy fields and NOT found them).
The idea that some Chinese roommates once told me that going to bed with my hair wet would cause demonic possession leading to pneumonia made me wonder if perhaps people in rural China did get sick from chills, but otherwise it is a supernatural belief.
Likewise, I am a huge fan of traditional Chinese foods, but when my waitress at my favorite restaurant in Flushing tells me I eat too much fatty "Yang" food and will get acne and clog my blood (that would be awesome since I have a mild form of hemophilia) I think it's worth investigating, but most of the time Chinese traditional food beliefs have been investigated, they have found to be incorrect or vast simplifications. I'm impressed at the latter, but I won't be basing my food choices on whether or not foods are "Yin" or "Yang." I suspect these beliefs have very little to do with Taoism anyway, as they were probably added on as Taoism blended with local folk religions.
Some of these folk beliefs lead to some absurdly unhealthy behaviors. I know Thai people who believe it's good to wash down beef, which is a "hot" food, with Coke, which is a "cold" food. And Chinese people who follow their fried chicken with heavily sugared red date tea because it's "Yin" and replenishes their "Qi." Since these beliefs are not based on real concepts, they are particularly vulnerable to industrialization.
Religions/folk beliefs and food: worth investigating and important tools for believers, but not always scientific.
04/03/2011 - 19:27
In a recent post I discussed how the death of a vegan baby wasn't caused by veganism, but by a denialist myth that humans are naturally herbivores, so vegans don't need to supplement. I tallied up some of the documented cases of unsupplemented veganism harming or killing children. Now Rhys at Let Them Eat Meat has a great post on whether or not this case is really about veganism.
I wasn't aware until reading Rhys' post that our friend T. Colin Campbell, pseudoscience grandmaster, was a peddler of deadly vegan creationism:
I’ve asked myself why, if the health benefits of a plant-based diet are as comprehensive as contemporary research suggests - meaning that Nature did the packaging for us during our evolution and that a plant-based diet is our natural diet - then why did she leave out this one very important piece of the puzzle? Having paid attention to the research literature and having questioned clinicians who treat vegan patients, I’ve reached the following somewhat unorthodox conclusions and observations:
1. Contrary to the most recent U.S. Dietary Guidelines, B12 can be found in plants.
2. Organically grown plants contain higher levels of B12 than plants grown non-organically with chemical fertilizers.
3. Plant roots are able to absorb certain vitamins produced by soil microorganisms, thus suggesting that plants grown in healthy soil, full of microflora and microfauna, are more nutritious.
4. Vegans - and anyone else - should be able to obtain B12 by consuming organically grown produce.
There is some evidence that produce contaminated with feces contains b12, but NONE that shows that plant sources themselves contain bioavailable b12 (some forms of fungi and mushrooms contain b12 we can't absorb). If y'all want to start a business called Steve's Poo-Covered Natural B12 Potatoes, go ahead, but don't pretend that b12 deficiency isn't a real and serious thing for vegan children.
But vegans Looooove Colin. Imagine how many vegans might read that and chose not to supplement. Guess who suffers?
But Colin, why do you want us to be B12 deficient because of your stupid ideas?
03/30/2011 - 19:41
Most of us know enough anthropology to know that the natural diet of our species in not herbivorous. The evidence for meat consumption goes back millions of years and our closest great ape cousins consume at least small amounts of meat. We also have digestive and other biochemical adaptations to meat consumption.
Unfortunately there are vegans who subscribe to what is really a form of creationism, a fictional evolutionary narrative in which humans are a peaceful herbivorous species. Proponents of this often cite "evidence" that is very poor and completely irrelevant, such as our lack of fangs (plenty of herbivores have fangs and many omnivores do not).
Other vegans recognize their diet as a modern diet for their modern philosophy. These people are willing to follow science and supplement to make up for the animal foods they are not consuming.
These folks need to be very critical of the woo vegans, because frankly woo veganism kills people and makes, This baby that died in France of b12 deficiency died of woo. I would never argue that veganism can ever provide optimal nutrients for childhood development and there is ample and growing body research to support this contention (DHA, Taurine, Carnitine, are known issues, what is unknown is more interesting…also the massive amounts of human variation which is why some children seem to do OK, but who knows how many IQ points have been lost?), but there is no reason to die from veganism. b12 supplements are widely available, though some people don't absorb them very well and may need injections. Vegans might also want to consider that the environmental impact of having children is definitely greater than that of eating a steak every day.
Paleo and real foodists also have to be aware of woo. There are plenty of people parroting ideas that have not only no evidence, but no plausible scientific basis in our side of the internet. I guess the main advantage we have is that we are usually not ideologically attached to our diets the way some vegans are. My doctor tells me my kid needs some corn? OK, we're having grits! My diet is about humans living well, not humans sacrificing themselves.
Remember the movie Independence Day? An awesome piece of campy b-movie sci-fi, but animal rights folks really remind me of the people on the roof of that building in New York with the "Welcome Aliens!" signs that subsequently get blown to smithereens.
In conclusion: I think veganism is suboptimal and anti-humanistic, but there is no reason to also be antiscientific and die for your cause, however foolish it might be. Just admit you are not a cud-chewing herbivore and take some freakin b12 and DHA supplements and stop making yourselves look stupid. Or how about eating just a few brainless oysters a week? Oh, sorry, that's against your religion even though oysters possess no thoughts, feelings, or nerves.
A few other woo victims (strict vegetarianism =vegan):
Nutritional Vitamin B12 Deficiency in a Breast-fed Infant of a Vegan-diet Mother
Vitamin B12 deficiency in a breast fed infant.
Brain damage in infancy and dietary vitamin B12 deficiency.
Severe nutritional vitamin deficiency in a breast-fed infant of a vegan mother
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