This blog is about the intersection between evolutionary biology and food. But also about practical applications, sustainable agriculture, and general tasty things.
How hard it is to read a scientific study? Should you bother to learn? I recently commented on a blog post on that subject.
Reading a study to figure out what to tell other people what to do is hard. Almost all the people who plant a pubmed reference in front of you to tell you to eat magic macronutrient XYZ or to avoid food X forever lest you perish from cancer are unqualified to pontificate on the subject. That includes many people with fancy titles. The people really qualified to talk about these things are not going to be pontificating. Nutrition science is too young for such surety.
But there is a much lower bar to be able to look up a reference and say whether or not it actually even possibly supports what the author who reference it was saying. That's fairly easy a lot of the time, since apparently many news outlets don't seem to care to fact check. I took a science journalism class in college and was taught a very meticulous and accurate way of writing that I don't see very often. A perfect and wonderfully topical example cropped up recently. The headline reads "Uh-Oh, Paleo: Cavemen Ate Less Meat Than Previously Thought." Surprisingly, the Fox News title, while stupid, is not completely inaccurate: "Secrets of the Caveman Diet." I get the feeling they are more interested in the SEO value of the paleo diet than ancient diets.
It took me more time than I would have liked to find the actual paper because they don't even link to the abstract. It turns out this paper is open-access, so anyone can read it, and that makes not linking to it even more suspicious. Well, I understand why. Just do a ctrl-f for "paleolithic." Don't bother with "caveman" because that's not even a technical or meaningful term. When I did that my computer made that annoying noise that I keep forgetting to disable that means it didn't find that word at all. Well, let's just try "paleo." Aha, something...but it's in the references...it's a paper in the journal " Biogeochemical approaches to paleodietary analysis." I could Google "paleodietary" and realize that the term encompasses all archeologically-studied diets from any time period, but without even reading anything, I've gained a lot of skepticism for the conclusions of news articles. The Fox News article is crafty and does say "first farmers" but makes a tenuous connection to the paleolithic.
I can then read the abstract and the discussion, the least science-y parts of the paper, which have several standouts anyone who is reading this blog post can probably pick up. Oh look at this sentence "This larger value goes some way to resolving the conundrum of interpretations of very high animal protein intake in isotopic studies of prehistoric farmers." Wait, so this whole thing was comparing to prehistoric farmers and not hunter-gatherers? Another minus point to the news articles. If you are a good reader, you can also figure out that the reason they did this study is that stable isotope analyses was based on animal data and they wanted some human data to compare that to.
If you want, you can delve further by reading a bit about that method. Considering how many of my readers are procrastinating computer coders with the next tab over open to their GitHub account or some API, I think a lot of them can handle this. The Fox News article, just like my science journalism teacher taught, describes this method.
To see how much meat ancient people ate, archeologists rely on the fact that protein is the only macronutrient that contains nitrogen. Different foods have different ratios of heavy and light nitrogen isotopes, or atoms of the same element with a different number of neutrons. So in a given ecosystem, scientists can reconstruct ancient diets by measuring the fraction of heavy-to-light nitrogen isotopes in fossilized bones.
But the body also preferentially stores heavier isotopes of nitrogen, so scientists calculate an offset to adjust for that tendency when determining what a person actually ate. Historically, the offset was derived from studies in which animals were fed diets with different protein amounts. [7 Perfect Survival Foods]
Using that offset, many studies estimate that between 60 and 80 percent of the prehistoric human diet came from proteins, with most of that from animal sources.
I'll just Google "isotopes diet." If you've taken a basic college level class in geology or archeology you probably know to Google "stable isotopes diet." The first results are a free and fairly readable paper and a blog post by a physical anthropology professor, John Hawks. Neither of these is easy to read, but if you can read .php or .ru files or are just a good reader, you can probably figure out the basics of the method. Fox News starts to get it right. But that last sentence is flat-out wrong. Isotope analysis is a way to determine trophic level of the protein in the diet, so where the protein might have come from in the local ecosystem. It is simply not capable of telling you what percentage of the total diet was protein.
There are more complexities to the method I could go into, such as potential inaccuracies of the method, but that's the overall gist of it. I'd note that I've also seen this method butchered in books popular with paleo dieters, claiming that because some skeletons from the paleolithic indicate they got most of their protein on the same trophic level as arctic foxes that their diet was like that of an arctic fox. That's the kind of thing this study is relevant to- whether or not we can extrapolate animal data to humans accurately in stable isotope analysis of diet. That's probably not as good for sexy headlines or SEO though, is it? The reality is that if we applied this we'd find paleolithic humans ate many different diets, with plant protein increasing with sedentism and with certain local ecologies. But in the wild plant proteins are not easy to come by. Most of them are not digestible by humans and many that are, such as certain wild legumes, are seasonal. And in the end, both of those articles fail to make the issue relevant in any comprehensible way, the blisstree taking nonsensical potshots at the paleo diet:
Many contemporary paleo diet gurus advocate a diet that’s 50 percent or more animal products (though contrary to what some people think, this doesn’t just mean chowing down on bacon and burgers — paleo dieters stress the importance of eating lean meat, fish and eggs that come from grass-fed livestock). This is based on the conventional wisdom that paleolithic humans ate a diet of between 60% and 80% protein, mostly from animal sources.
First, I don't know where I can get grass-fed fish but it sounds cool and if you know any sources, email me. Second of all, since when are animal products just protein? The ones I eat have plenty of fat. Maybe there is a parallel universe where I eat a 60% protein diet and have already wasted away from rabbit starvation, but in this universe I don't know anyone who eats an 80% protein paleo diet. Most people naturally gravitate away from absurd protein intakes because it's unappetizing and makes you feel bad, though lately I've found many people persist on diets that are exactly that for years and even decades. I don't like feeling bad or eating bad food, so I've never had that long-term problem.
We don't know what percentage of a paleolithic hunter-gatherer's diet was protein, we don't know that for "caveman" or for early farmers. It's just not knowable right now and probably never will be. We do know that for modern humans, there seems to be a physiology ceiling for protein intake which John Speth addresses quite readably in his excellent, though bizarrely expensive (worth getting on interlibrary loan) book, which requires humans not eat like an arctic fox, but be innovative and seek out either fat or carbohydrate in order to avoid potential costs of high protein intake. But that ceiling is controversial.
So there, those two news articles are essentially debunked and we didn't even have to discuss various nitrogen isotopes or anything really truly technical. In the end, we realize that the study in question doesn't tell us how those in the past really ate or what we should eat now. It's just a little piece of a large completely unsolvable puzzle. To even be able to realize that gives you immense power not to be deceived.
I want to explore the evolution of the evolutionary nutrition concept and how evolution was lost from it.
An early variant, The Stone Age Diet, by Walter L. Voegtlin, shows up in the record in 1975, but whether this carnivorous book is an ancestor of later variants is questionable, so it's hard to consider it an ancestor. A more likely candidate would be the paper written in 1985 by Dr. Boyd Eaton and Dr. Melvin Konner, Paleolithic nutrition. A consideration of its nature and current implications. While elements of the paper seem dated today, it was a pioneering collaboration between a medical doctor and a medical anthropologist.
This paper explored how evolutionary concepts could shed light on modern health problems. It was not just a paper about eating well, it was about eating well in the context of human beings having a long evolutionary history, one shared by many other species. And that the selection pressures faced during the long evolution of primitive species to humans could tell us things about diseases, particularly chronic degenerative diseases, humans face today. It was unapologetically a Darwinian paper. It has been cited 964 times.
Around this same time, in 1980, Paul Ewald, a zoologist, published Evolutionary biology and the treatment of signs and symptoms of infectious disease, which explored the implications of host-pathogen adaptations and the "potential importance of determining whether signs and symptoms are adaptations of the host, of the disease organism, both, or neither." The main focus was on acute disease. This paper is considered one of the first in Evolutionary Medicine.
Around this time, the Konner/Eaton team turned their work into a book for layman. Adding Konner's wife Marjorie Shostak to the slate of authors, in 1989 they published The Paleolithic Prescription: A Program of Diet & Exercise and a Design for Living. The book drew extensively from the fossil record of hominid evolution, as well as Konner and Shostak's own fieldwork with the !Kung, one of the last foraging societies that exists today (Shostak's books on this fieldwork are also a great read). It mentioned the word evolution 40 times. They also published a commentary together in 1989 Stone agers in the fast lane: chronic degenerative diseases in evolutionary perspective (PDF).
In 1991, evolutionary biologist George C. Williams and psychiatrist Randolph M. Nesse published a paper titled The Dawn of Darwinian Medicine, another pioneering work in Evolutionary Medicine that outlined methods for applying evolutionary biology to modern medicine, such as understanding "iron deficiency" as one of many potentially costly adaptations to a war between ancestral vertebrates and pathogens that has gone on for millions of years.
Many people seem to think that an adaptationist approach is based on the assumption that organisms are perfect. This is a misconception. It is true that the adaptionist holds the power of selection in high regard and is skeptical of explanations that take quick refuge in proposed defects in the organism. Paradoxically, however, the adaptationist is also particularly able to appreciate the adaptive compromises that are responsible for much disease. Walking upright has a price in back problems. The capacity for tissue repair has a price of cancer. The immune response has a price of immune disorders. The price of anxiety is panic disorder. In each case, natural selection has done the best it can, weighing benefits against costs. Wherever the balance point, however, there will be disease. The adaptationist does not view the body as a perfect creation, but as a bundle of compromises. By understanding them, we will better understand disease
The Eaton/Shostak/Konner team continued to refine their approach over time. The last paper they wrote together was An evolutionary perspective enhances understanding of human nutritional requirements in 1996, published after Shostak's death, along with her book recounting her last journey to visit the !Kung, Return to Nisa. 1996 also saw the publication of Nesse and Williams' book for layman about Evolutionary Medicine, Why We Get Sick (mentions evolution ~78 times).
Eaton and Konner started collaborating with exercise physiologist Loren Cordain and medical doctor Staffan Lindeberg. Cordain became particularly prolific on the subject, publishing a wide variety of academic papers and inspiring a Ray Audette's Neanderthin in 1998, which mentioned the word evolution 14 times. His own diet book, The Paleo Diet, was published in 2001 and mentions the word evolution roughly 11 times. Around this time you start to see intersection between the work originating from the Eaton/Konner paper and Evolutionary Medicine, with the original 1999 compilation Evolutionary Medicine edited by Wenda Trevathan containing Paleolithic nutrition Revisited by Konner, Eaton, and Boyd Eaton's son S. Boyd Eaton III. Nutrition was always part of both approaches and bringing them together influenced many later books and papers on the subject of evolutionary nutrition.
As you can see, the whole foundation of this was always Darwinian Evolution, the idea that humans share a common ancestor with all life forms.
Unfortunately, many Americans reject this. A recent survey found that only 39% of Americans accept evolution as fact. One of the reasons for this is in America, evolution has become politicized due to forms of powerful Evangelical Christianity that started promoting a reactionary anti-science form of Biblical Literalist Creationism (when I refer to Creationism, I refer to this) in the 1920s. Welding significant political power, they have managed to suppress the teaching of Darwinian evolution in public schools.
I have pointed out that Creationism and Creationists are harmful and incompatible with evolutionary nutrition. On Paleohacks, Karen from Paleo Periodical referred to this when she said: "I'm seeing the accusation that someone doesn't "believe" in evolution more and more, which strikes me as intolerably elitist (I say "believe" because I don't think evolution cares what you think about it)."
It's only elitist because Creationists have succeeding in making sure that most Americans are ignorant of evolution. There is no "believing" in evolution, there is accepting scientific evidence. And while you don't need to accept evolution to eat real food, evolution is the foundation of the paleolithic diet concept. So it is disturbing to see Creationists like Jimmy Moore framing debates within the paleo diet community. Over the past few years, he has moderated panels on paleolithic diet debates, published "state of the paleosphere" articles, and generally positioned himself as a person with clout in the "paleosphere." At some point he stopped just putting out podcasts with various paleo voices and instead stepped over a line into shepherding the paleo movement, which alienated many science-based paleo writers like Dr. Kurt Harris and many others, some who simply stopped describing themselves as "paleo" in lieu of a being part of a movement gutted of all meaning.
I do get hatemail for saying this and expect to get more. The latest letter said "Who cares if Jimmy Moore doesn’t believe in evolution? Truth is, there is not much to this Paleo “thing”. Exercise, eat like a caveman and reap incredible benefits." If you need a story about cavemen to tell you not to eat crap and that sprints are good exercise, I think we have a problem. There is already a "real food" movement among Christians. Go to Wise Traditions and you'll meet many of them, though a paleo dieter might have trouble convincing them of their common quasi-religious precept that grains are the devil. I think it's great when people start to eat real, whole foods. And there are many reasons to do so that have nothing to do with human evolution (even if a lot of the science behind them is based on evolutionary models).
But I also think that evolutionary models are important in biology and are the future of understanding what makes our bodies tick. It is more than about eating meat, fruit, and vegetables, it's can help us develop sophisticated treatment protocols for all kinds of diseases. It is sad for me to see that suppressed and stifled for marketing purposes. As Staffan Lindeberg said:
Why does the same thing happen to a piece of food after it has been swallowed by humans of different ethnicity? Why is the anatomy and physiology of the gut virtually identical in a Chinese and an African? Why do all human have the same endocrine system and metabolism? You know the answer: because we share an ancestor from way back when. The experts estimate that our latest shared ancestors lived around 200,000 years ago in Africa.
Before that, during millions of years of evolution, the digestion and metabolism of our primate ancestors had been fine-tuning how it uses the available food substances in the most beneficial manner possible. Nobody would doubt that the best food for the human species would be the kind of food that was available in those days, rather than those that were introduced long after the construction of our physiology. Funny that nutrition authorities never say it loud.
Our primate ancestors have been consuming fruit, vegetables, nuts and insects for 50 million years or more. Meat was successively added, with a probable increase around 2 million years ago. Underground storage organs (roots, tubers, bulbs, corms) possibly become staple foods 1-2 million years ago. The variability was large: single plant foods were rarely available in excess, which reduced the risk of adverse reactions to bioactive substances in plant foods.
I think loss of this is one of the reasons why more and more books are published on paleo that either contain nothing about evolution at all or have evolutionary narratives that seem pulled out of thin air. If the caveman stories are just stories, I suppose it doesn't matter to people much whether or not they resemble the Flintstones more than they do science. Paleo Diet guided by those who don't care about evolution is low-carb dressed up in a sexy leopard skin coat. By far, it's not Creationists who are wholly responsible for this, there is also a secular anti-intellectual slant that overemphasizes self-experimentation and scoffs at reading about science or at those who point out certain "facts" about evolution peddled by gurus are not based on anything but fiction.
The loss is ours, as the difference between caveman stories that tell us not to eat garbage and the adaptationist evolutionary approach is enormous. The former does rely on reenactment of some golden age in which humans lived according to our design. Is it any coincidence that this resembles the story of Adam and Eve? In contrast, the adaptationist approach is one in which species are constantly under pressure and must adapt. Some of these adaptations are imperfect and even costly. It is possible we can do even better by thwarting some of these adaptations through modern technology. Evolutionary medicine isn't just about eating like your ancestors, it's possibly about outrunning some of the adaptations that cause things like aging through pharmaceutical or even cybernetic augmentation. It's not regressive like some calls by various authors like Lierre Keith to give up our technology and return to the Stone Age, it's cutting edge, even daringly post-human.
We have the opportunity to be on the front lines to show that evolution is important to humans now, that evolution, by enhancing our understanding of ourselves, can improve the way we live.
Some have also accused me of discriminating against Christians. As far as I'm concerned, Jimmy is welcome to learn more about biology and join the millions of Christians who are not anti-science. I made that journey myself, having been educated in Creationism as a child, with such anti-science absurd books like It Couldn't Just Happen. I was reading the reviews for that book on Amazon and it's interesting how many other people grew up with that book, but later learned more about evolutionary biology. Some became disillusioned atheists, others realized you don't have to be a Creationist to be Christian. Christians have been fighting Creationism for a long time. A notable example is Orthodox Christian Theodosius Dobzhansky, who wrote the essay Nothing in Biology Makes Sense Except in the Light of Evolution in 1973 response to anti-evolution Creationists:
Does the evolutionary doctrine clash with religious faith? It does not. It is a blunder to mistake the Holy Scriptures for elementary textbooks of astronomy, geology, biology, and anthropology. Only if symbols are construed to mean what they are not intended to mean can there arise imaginary, insoluble conflicts. ...the blunder leads to blasphemy: the Creator is accused of systematic deceitfulness.
It's funny awhile back someone recommended that I just attend some less extreme churches than the ones I grew up in, just to see what it's like to go to a church that doesn't spend time preaching against homosexuality or evolution. Because at that point, that was really the only Christianity I knew. I really enjoyed going to those churches and met a lot of wonderful people, people who generally do not take Genesis literally, people who do not reject evolutionary biology and in fact some who work as evolutionary biologists! I also have learned much about the history of Early Christianity through attending Orthodox churches and it was stunning to me to realize how divorced modern Evangelical Christianity is from those roots or understanding how the Bible was put together by humans. I also came to question many things "paleo" dieters accept almost religiously as facts. Did you know that the monks on Mount Athos live long lives free from modern disease thanks on a diet that is pretty much vegan and high in grains? It is possibly partially due to ancient Christian fasting traditions.
I think American Creationists (and people who think Christianity requires such nonsense) could use some history lessons on their religion, the Bible, and on life itself. As priest Pierre Teilhard de Chardin said "Is evolution a theory, a system, or a hypothesis? It is much more it is a general postulate to which all theories, all hypotheses, all systems much henceforward bow and which they must satisfy in order to be thinkable and true. Evolution is a light which illuminates all facts, a trajectory which all lines of though must follow this is what evolution is."
If you are interested in learning more about how human evolutionary origins shape us today, some great books for anyone to read are Your Inner Fish, Written in Stone, Why Evolution is True, Why We Get Sick, or Before the Dawn, especially if like me, you did not learn much about evolution in grade school. Talk Origins is also a good resource.
In academia, Evolutionary Medicine continues to thrive. It has a society and many different conferences. It is also too bad that so many interesting and relevant evolutionary medicine/nutrition resources are so expensive. Many books on the subject cost upwards of $100 each. Two extensive papers were just published on the subject. One is $45, thank goodness the other is free, which is very unusual. But why aren't these folks publishing writings for laymen like the original pioneers of evolutionary medicine and nutrition did? As we discover more and more about how humans evolved, books become outdated quickly, so perhaps they should consider blogging rather than books.
I'd love to see more writings for laymen by them and more writings not afraid to mention evolution and even to educate readers about it. I think such interactions would not only be beneficial for us, but for them, since I feel the online community in particular can generate hypotheses faster than in academic publishing. You can see some academic researchers, like anthropologist Miki Ben Dor, drawing on hypotheses that have primarily been pushed by the online community like the idea that larger amounts of fat might have been more important in hominid evolution than previously thought.
Edit: here is a great editorial written by Randolph Nesse and Detlev Ganten recently:
The human body is a living archive of evolution, written in our genes, cells, and organs. The line is continuous to the beginning of life on this planet, so nature is inherently conservative. Sequences that are ancient parts of our genomic heritage tend to persist. Those important for survival and reproduction change less over the eons, so genes important for basic functions are generally “old” genes. The basic mechanisms that regulate cellular metabolism, cell division, and gene duplication are fundamentally the same as those occurring in unicellular organisms at the beginning of life on earth 3.5 billion years ago. Likewise, the molecules, cellular functions, organs, complex organization of muscles, bones, sensory organs, and nerves in vertebrates derive in an unbroken line from ancestors millions of years ago. Much of modern man's biology dates back to the origins of life; a complete understanding of this biology can only be appreciated with an evolutionary perspective .
We are not "designed", we are "adapted," and adaptations can be incomplete and imperfect. It matters less what our ancestors ate, than what selective forces were at play and how we adapted to them. Such a paradigm can help us see the costs and benefits of something like getting large amounts of calories from meat, which humans are definitely not perfectly adapted to, which is possibly responsible for such diseases as hemochromotosis.
Edit: Also worth reading is evolutionary biologist Michael Rose's 55 Theses on using evolutionary biology to improve your health, particularly in understanding (and possibly beating) aging.
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?
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.
So modern-day omnivores can rejoice in the fact that a simple hamburger is a beautifully engineered energy delivery system. But they should also remember that those little Harvard mice grew plump dining on tiny gourmet burgers from Julia Childs's butcher. "The mice were eating meat from Savenor's," Carmody says, "while I was eating meat from the local bodega."
So the mice grew plump on an all-meat diet? Hmm, let's pull up the study, evilly paywalled by PNASty even though they are supposed to be open access since it's an "early edition":
Maybe I'm reading this wrong, but considering that all the mean changes to body mass are in the minus zone, I'm not seeing any plump mice here. The researchers say:
Effects of Food Processing on Meat Diets. To assess the energetic impact of food processing, it was necessary to maintain mice on a 100% meat diet for a measurable period. Mice of this species (M. musculus) readily consume meat, and in some ecological contexts, they have been observed to inflict intensive predation pressure on vertebrate populations (16). Nevertheless, pure meat diets are not expected to be beneficial for omnivorous species. In humans, lean meat diets that derive a majority proportion of their calories from protein lead to rabbit starvation, a condition of negative energy balance resulting from the high costs of protein digestion and the limited capacity of the liver for urea synthesis (25, 26). We, therefore, expected mice to lose body mass on all experimental meat diets, with relative loss of body mass indicating the relative values of the underlying diets.
Although mice lost weight on all diets, we observed that cooking but not pounding had a positive effect on energy gain (2 × 2 RM ANOVA; cooking: P < 0.001, pounding: P = 0.138) (Fig. 3)
Hmm, NPR are you biased or what?
I'm pretty sure that feeding the mice this evolutionarily inappropriate diet based on pretty lean meat would have resulted in their deaths had the experiments continued.
The study is somewhat interesting even though it is limited by the use of mice rather than people, because it underscores the fact that cooked food is more caloric than raw food. Sometimes I see people put "ground meat (raw)" in their fitday even though they made cooked hamburgers, which leads to an inaccurate caloric count. Evolutionarily the researchers conclude:
First, the adoption of cooking would have helped ancestral humans thrive. Meat and tubers have been exploited by humans for at least 2 million y, and the energetic resources of these foods are believed to have provided critical support for the evolution of costly increases in activity, birth rate, body size, and brain size (34). Meat would have been a preferred food, but its pursuit would require a large energetic investment with low rates of success (35). Tubers, by contrast, were less preferred but more consistently available, and this consistency would have made investments in the high-risk pursuit of meat possible (36). The proportions of animal and plant foods consumed by ancestral humans are unknown, but the parallel effects of cooking that we found suggest that the adoption of cooking would have led to energetic gains whether meat or tubers predominated. Moreover, because we found the effects of cooking to be incremental to the effects of pounding for both foods, the adoption of cooking was likely advantageous even if pounding methods were already in widespread use.
Some questionable stuff even here. The low rates of success for hunting is based on studies on modern hunter-gatherers. There is some evidence that game was much richer in the Early and Middle paleolithic.
I was poking around papers citing this paper that showed an association between soy intake and low sperm concentrations. Two reviews popped out. One is by Mark Messina, titled Soybean isoflavone exposure does not have feminizing effects on men: a critical examination of the clinical evidence. It basically says that worries about soy affecting masculinity are nonsense. I looked and looked for the conflict of interest statement that is standard on papers these days, but could not find any. It's no wonder, as Mark, an animal-rights vegan, has received funding from the soy industry. His name appears as the author on many industry publications. Another paper from roughly the same time is a little more skeptical. Soy, phyto-oestrogens and male reproductive function: a review says:
Exposure to endocrine disruptors (e.g. BPA or dioxins) during critical periods of reproductive development increases the incidence of reproductive disorders. Given the popularity of soy-based formula, isoflavone supplements and soy-derived products, a better understanding of the influence of phyto-oestrogens on male development is needed. To date, there has been a lack of consistency in human and animal studies examining the effects of soy and phyto-oestrogens on reproductive parameters. These discrepancies certainly reflect the variety of experimental designs, the differences between the specific endpoints measured but also inadequate descriptions or insufficient sample size to permit confidence in the observed results. In humans for example, it would be important to investigate adult male reproductive and endocrine functions of healthy full-term infant fed soy-based formula compared with breast-fed or cow milk formula-fed infants. These studies should investigate pubertal development and reproductive endpoints such as adult testicular function (testicular volume, spermiogram) and endocrine parameters (testosterone, DHT, oestradiol, LH, FSH, IGF1, INSL3, etc). The cohorts should be large enough to ensure statistical power to detect meaningful differences. Concerning animal studies, the choice of the animal model and nutritional differences in animal diets need to be considered carefully when designing experiment. It would be relevant to assess dose response relationships, mutigenerational studies and evaluation of both reproductive and post-natal endpoints. Finally, most studies are designed to investigate the effects of a single endocrine disrupting chemical. Although straightforward in term of scientific design, this approach fails to appreciate the chemical soup that is more typical of the human or animal environment. Thus further investigation is needed to evaluate the consequences of simultaneous exposure to phyto-oestrogens and other EDCs on fertility and testicular function.
Indeed. So they are two ideas at war: the idea that nutritionists are gods that can pronounce with good faith on the health effects on industrial foods. And then the more precautionary idea that we really need to look deeper and at the long-term effects. You know what camp I'm on. Unfortunately the money is behind the other camp and people like Mark get paid to blog and write for the layman.
Honestly, I'm not really against soy per-se. I enjoy tamari and miso soup every so often. These are delicious traditional whole foods. I'm much more concerned with soy in infant formulas and industrial soy products that are engineered for high-levels of consumption. Cutting soy milk out of my diet was one of the best decisions I've ever made and cured me from several digestive ailments and some menstrual irregularities. I was drinking it with every meal because I thought it was a healthy whole food...
In the next few months I hope to write a couple of posts on irritable bowel syndrome. It's interesting because so many (including myself) get relief from IBS by following a low-carb low-fiber grain-free fructose-free diet with probiotic supplementation. There are many reasons this works, but in the long term people following it might want to wean away from probiotic dependence, since probiotics in pills cannot become part of the permanant microbiome of most adult guts. In addition, there are real benefits from short chain fatty acids produced in the colon by fermentation. It's unfortunate so much fiber research has been done on grains, but more and more is being done on the type of fiber that horticulturalists and foragers consume. Here we are getting into self-experimentation since the research is so thin right now. My own goal has been to establish a gut bacterial population that is an asset (har har) rather than a nuisance. I've been trying to do this by feeding my bacterial population appropriately in a way that encourages good bacteria, but does not allow overgrowth.
On Paleohacks someone said something like "the kind of food you eat cannot affect constipation, just the mechanics of the food, IE, how much fiber and fat." That is the OLD view. The reality is that different gut bacteria react differently to different foods. I've been reading a lot of articles by Dr. Kok-Ann Gwee, who studies IBS in Singapore. His article Fiber, FODMAPs, flora, flatulence, and the functional bowel disorders is a really good one and should be essential reading for all doctors. I'd estimate the majority of primary care physicians are still recommending things like bran to treat IBS when there are mountains of scientific evidence against it.
The issue was in the 70s some papers came out that said, "huh, looks like this African farmers don't have stomach problems. Must be all the fiber in their diet!" Nevermind their methods for measuring fiber were bad and that certainly wasn't the only difference in their diets. Then some poorly-designed studies were done on bran, which the cereals industry picked up in order to promote BRAN FOR EVERYONE1111!!!!! Dr. Kok-Ann says:
In fact, a number of contrarian studies, which had been largely ignored, had suggested that favorite sources of dietary fiber such as bran and other cereals, and vegetables and fruits, might actually aggravate symptoms in IBS. The symptoms that appeared to be aggravated were flatulence, bloating and abdominal pain.
Yikes, that certainly was my experience. The more I ate the high-fiber stuff my doctor told me to eat, the worst I felt.
I didn't have Celiac, so that meant wheat was AOK right? Nope, gluten is not the only bad thing in wheat, the fiber in wheat can be quite bad for people with IBS as well.
Based on the use of an exclusion diet, Nanda et al. from Oxford reported that dairy, grains, in particular wheat and rye, and onions were the major foods implicated by IBS patients, and that patients responding to dietary manipulation were likely to have presented with flatulence as an initial symptom.3 They had also observed that intolerance to either wheat or rye was specifically associated with abdominal distension. Whorwell and Prior from Manchester recorded that 55% of their patients felt worse and only 10% felt better on bran.4 John Hunter's group from Cambridge used a whole-body calorimeter to measure the 24-h excretion of hydrogen and methane in both the flatus and the breath.5,6 They compared the gas production of IBS patients and healthy controls on a standard diet with regular fiber intake, an exclusion diet, and a fiber-free diet. They found that IBS patients had a significantly faster rate of gas production on a fiber-rich diet, which reduced significantly on the exclusion and the fiber-free diet, and this appeared to be associated with an improvement in symptoms. Others have also suggested that malabsorption of fructose and sorbitol, of which fruits are rich sources, may give rise to symptoms in IBS patients.7
So fiber not only doesn't help, it makes you gassy and bloated. This paragraph highlights the foods I found triggered my symptoms through trial and error: onions, grains (esp wheat), and a lot of dairy. These are foods I now know are rich in FODMAPS (Fermentable Oligo-, Di- and Mono-saccharides, and Polyols). Interestingly I've found not all FODMAPs trigger my symptoms.
In [the Cambridge study], total gas, as well as breath hydrogen production, was similarly reduced with metronidazole (an antibiotic with activity against intestinal anaerobic organisms) treatment despite a fiber-rich diet. This observation brings us back to our recent appreciation that the flora of intestinal microbes is a key player in the development of IBS.10 Even Segal and Walker, two of the early proponents for the high-fiber diet, have recently acknowledged that reduced dietary fiber intake has not resulted in increased colonic diseases in Africans.11 In fact they have now recognized the importance of the “quality of the intestinal bacteria”, and the impact that this has on the fermentation of malabsorbed carbohydrates.12 In their recent paper they have assembled measurements for various classes of immunoglobulins, and other markers of immune activation, that support a high level of exposure to gastrointestinal infections in childhood.11 Their new hypothesis is that it is this early priming that gives the African a more robust gut microflora, better able to withstand the insults in adult life. The corollary is also that if we expect fiber and oligosaccharides that are promoted as prebiotics to enhance the proliferation of ‘good bacteria’, we have to start feeding these substrates to our gut in the early years of life. In the meantime, it appears that eating a ‘healthy Western breakfast’ of milk with high-fiber cereals, whole grain bread with honey, washed down with apple juice, is perhaps the worst way to start off the day for an adult IBS patient!
What about those of us who didn't get that advantage? Is there hope to normalize? In his other article he points to several factors anyone with IBS should think about:
Then there are some more factors to think about from Irritable bowel syndrome: towards biomarker identification:
Some of my readers might be interested in The Atlantic's debate on "alternative medicine." Reading it, what amused me is that opponents of alternative medicine accuse it of not being "evidence-based." Unfortunately our "normal medicine" isn't really evidence-based either. What doctors and hospitals do often seems more about the status quo than science. That explains why my sister (a biologist) and I are not exactly our doctor's favorite patients. We don't accept treatments based on outdated science, particularly when they have harmful side effects.
For example, the idea that GERD is a disease of acid burning the esophagus is several years outdated, but doctors continue to hand out medicine based on that theory (proton-pump inhibitors) like it's Halloween candy, despite a growing body of evidence that it causes immune dysfunction and bacterial overgrowth!
The list really could go on and on, from unwillingness to adopt life-saving safety practices to the handing out of antibiotics to children for every little thing (even illnesses obviously caused by viruses!) to the use of questionable materials for hip-replacements just because they are "new."
Another example showed up in my RSS reader today: Keeping Mother and Baby Together – It’s Best for Mother, Baby, and Breastfeeding. I suggest you read that post, as it has great information. Basically, in our species, the time immediately after birth is critical. Direct skin to skin contact between mother and baby is important for establishing breast feeding, bonding, and regulating the baby's physical health. That's how our species evolved, it's the infant's natural ecology. This isn't about just doing what our ancestors did; science has confirmed that these practices have important functions. Despite that, hospitals often fight this practice and a woman who wants to simply do what is appropriate for her as a Homo sapians must exert an effort to convince the hospital staff, find a sympathetic birthing center, or arrange for a home birth.
Interestingly, NICU's (new born intensive care units) have been the first to adopt this practice. For babies on the edge, everything counts, but it's something all babies deserve.
Isn't it cute when scientifically ignorant people accuse other people of being scientifically ignorant? You know they are scientifically ignorant because they blather on about "peer reviewed research" while obviously never having read any.
I don't know when or why I subscribed to the mindless platitude drivel blog Zen Habits, but their recent post about soy caught my eye.
It’s one of those things that has spread on the Internet and unbelievably, has become accepted truth to many people: that soy is unhealthy, even dangerous. I mention (to otherwise smart and informed people) that I drink soymilk sometimes, and a look of pity comes over their faces. ‘This guy doesn’t know the dangers of soy, and might get cancer, or worse … man boobs,’ they’re thinking. Just about every fitness expert I read — people I respect and trust — says that soy is bad for you, from Tim Ferriss to the primal/paleo folk. I absolutely respect most of these guys and otherwise think their work on fitness-related matters is great. And yet, when I look for their sources on soy, often they don’t exist, and when they do, I can always trace them back to one place. The Weston A. Price Foundation.
Um, suuuure. So the whole thing is basically setting up a straw man - "only teh evil WAPF sayz soy is baad! WAPF is teh stupid, here are some blag posts from some vegan blogs that sayz they are teh wrong!"
Unfortunately it is true that some WAPF article are pretty questionable. There is an element of woo I can't get behind as a scientist. But there are also articles with scientific references and it would be useful to follow those. But nope, instead the idiot just cites some forum posts and vegan websites.
As for only WAPF having a vendetta, I sincerely doubt Dr. Staffan Lindeberg and Dr. Loren Cordain are associated with WAPF. Maybe you don't know about that because then you might have to go to the library and check out Food and Western Disease instead of Googling crap like the quasi-content farmer you are.
This book has multiple sections about soy.
Soya products cannot be recommended, particularly not for women being treated for breast cancer with tamoxifen, since the tumour-inhibiting effect seems to be counteracted by genistein
447,846,852 . Genistein, the dominant phytoestrogen in soya bean, potentially stimulates the growth of oestrogen-dependent breast cancers by acting as a so-called promoter that accelerates the progress of existing breast cancer 42,321,1464,1622,1803.The idea that soya consumption would explain the relatively low risk of breast cancer in women living in Japan is open for debate 730. There are all sorts of reasons why breast cancer could have been less common in Japan than in Europe and North America. On these grounds, the former enthusiasm for soya has lately turned into caution 447,1445 .
See these little numbers? Those are called references. Real references. Let's compare these references to some references you think are just dandy.
3. FALSE: Soy causes (insert scare claim here: Alzheimer’s, birth defects, etc.). There isn’t any evidence for any of the scare claims that originate from WAPF. I’m not going to argue them all, but I urge you to read these articles from John Robbins, Dr. Neil Barnard, Syd Baumel, and Dr. Joel Fuhrman — they contain many more sources than I could list here, and they’re based on actual evidence.
ACTUAL EVIDENCE? OMG. I am so excited to find out about this actual evidence you speak of.
Do primitive peoples really live longer? No. For example, Innuit Greenlanders, who historically have had limited access to fruits and vegetables, have the worst longevity statistics in North America. Research from the past and present shows that they die on average about 10 years younger and have a higher rate of cancer that the overall Canadian population. 1 Similar statistics are available for the high meat-consuming Maasai in Kenya. They eat a diet high in wild hunted meats and have the worst life expectancy in the modern world. Life expectancy is 45 years for women and 42 years for men. African researchers report that historically Maasai rarely lived beyond age 60. Adult mortality figures on the Kenyan Maasai show that they have a 50% chance of dying before the age of 59.2 We now know that greatly increasing the consumption of vegetables, legumes, fruits, and raw nuts and seeds (and greatly decreasing the consumption of animal products) offers profound increased longevity potential, due in large part to the broad symphony of life-extending phytochemical nutrients that a vegetable-based diet contains. By taking advantage of the year-round availability of high-quality plant foods, we have a unique opportunity to live both healthier and longer than ever before in human history. 1. Iburg KM, Brennum-Hansen H, Bjerregaard P. Health expectancy in Greenland. Scan J Public Health 2001;29(1):5-12 2. http://www.kenya.za.net/maasai-cycles-of-life.html, http://www.who.int/countries/ken/en/
So a defunct website and an article about a modern population in Greenland (I imagine the people of Greenland would be seriously unhappy to be called a "primitive people" since they live a modern lifestyle including books, computers, guns, and modern food and drink and it's just racist to cite the entire country of Kenya when debunking health claims about "primitive people" 0_o ). It's also quite hilarious that Zen Habits cites Dr. Andrew Weil, a potent woo meister himself.
What about the refs in Food and Western Disease?
Duffy, C., Perez, K.&Partridge, A. (2007) Implications of phytoestrogen intake for breast cancer. CA Cancer J Clin 57, 260–77. Power, K.A. & Thompson, L.U. (2007) Can the combination of flaxseed and its lignans with soy and its isoflavones reduce the growth stimulatory effect of soy and its isoflavones on established breast cancer? Mol Nutr Food Res 51, 845–56.
Hmm, these seem different. They almost seem real, as in really relevant and really from real sources or something.
As mentioned earlier, one of the more obvious problems with a vegetarian diet is the development of iron deficiency, which often affects vegetarians, in particular vegans. A high intake of grains and beans contribute to this condition to a considerable degree
488,590,669. Soya beans also contain other substances that impede iron absorption besides phytates 1099.
Enzymatic digestion of the same proteins in the gut should also be supported through a low intake of protease inhibitors from cereals and beans, including soya products. Finally, the intake of plant lectins from grains and beans should be minimised in an attempt to limit the permeability of the intestines and the blood–brain barrier, and prevent potentially damaging proteins and peptides (food-derived or coming from other sources) from entering the body.
Rats who are fed soya beans after weaning have limited growth, partly due to the effect of lectins.
These apprehensions certainly apply to soya beans. Two experts on health effects of soya beans at the US Food and Drug Administration (FDA), Doergeand Sheehan, the former chief of the Oestrogen Base Program, wrote in 1999 a public letter in protest of the FDA’s approval of health claims for soya products (http://www.dcnutrition.com/news/Detail.CFM?RecordNumber=546). The researchers were concerned about the results of animal experiments where flavonoids in soya (genistein and daidzein) were found to have toxic effects on oestrogen-sensitive tissues and on the pancreas
431. Particular caution is needed for children and adolescents children, but this has not prevented the large-scale development and marketing of soya-based infant formulas. Consumption of soya products during pregnancy has been suggested to increase the risk of abnormal development in the nerve system and reproductive organs of the offspring. It has been shown that realistic doses of genistein cause atrophy of the thymus in mice 1983.Ishizuki et al. reported goitre and elevated individual thyroid-stimulating hormone levels, although still within the normal range, in 37 healthy iodine-sufficient adults without known thyroid disease, who were fed 30 g of pickled soya beans per day for as little as 1 month 431 . One study found genistein to disrupt female reproductive function in mice, but the effect in humans has not been examined 27.
On the other hand, it has also been suggested that flavonoids in soya beans have beneficial effects, including inhibiting the growth of cancer, but none of these effects have been proven convincingly
629. With regard to breast cancer prevention, soya can no longer be recommended, as discussed in Section 4.11.
In old Chinese cuisine, soya products were eaten with caution, and the intake of genistein, e.g., is thought to have been well below the intake of ‘health conscious’ Westerners
Whether or not the WAPF is biased, there is a whole lot of bias in the soy industry and a whole lot of funding for people to find uses for soy. When I was an undergrad I participated in soy board research and the food sci department received quite generous stipends for this. I've written about some negative effects of soy and the "soy cartel" in a previous post.
I eat soy sauce and I confess I sometimes indulge in Korean tofu stew (simmered in stock), I just don't use soy as a staple food because I've seen the science and the science says "caution."
And more caution about geting dietary advice from a blog about "zen habits." A hint for future writers from that blog: You can't find studies about why soy might be bad by searching "soy bad." You have to know something about biology and what to look for.
Selected refs, since I'm not spending my entire night copying them.
447. Duffy, C., Perez, K.&Partridge, A. (2007) Implications of phytoestrogen intake for breast cancer. CA Cancer J Clin 57, 260–77.
1445. Power, K.A. & Thompson, L.U. (2007) Can the combination of flaxseed and its lignans with soy and its isoflavones reduce the growth stimulatory effect of soy and its isoflavones on established breast cancer? Mol Nutr Food Res 51, 845–56.
846 . Jones, J.L., Daley, B.J., Enderson, B.L., Zhou, J.R. & Karlstad, M.D. (2002) Genistein inhibits tamoxifen effects on cell proliferation and cell cycle arrest in T47D breast cancer
cells. Am Surg 68, 575–7; discussion 577–8.
852. Ju, Y.H., Doerge, D.R., Allred, K.F., Allred, C.D.&Helferich, W.G. (2002) Dietary genistein negates the inhibitory effect of tamoxifen on growth of estrogen-dependent human breast cancer (MCF-7) cells implanted in athymic mice. Cancer Res 62, 2474–7.
42. Allred, C.D., Allred, K.F., Ju, Y.H., Virant, S.M. & Helferich, W.G. (2001) Soy diets containing varying amounts of genistein stimulate growth of estrogen-dependent (MCF-7) tumors in a dose-dependent manner. Cancer Res 61, 5045–50.
1464. Qin, L.Q., Xu, J.Y., Tezuka, H., Wang, P.Y. & Hoshi, K. (2007) Commercial soy milk enhances the development of 7,12-dimethylbenz(a)anthracene-induced mammary tumors in rats. In Vivo 21, 667–71.
1622. Seo, H.S., DeNardo, D.G., Jacquot, Y., et al. (2006) Stimulatory effect of genistein and apigenin on the growth of breast cancer cells correlates with their ability to activate ER
alpha. Breast Cancer Res Treat 99, 121–34.
1803. Tonetti, D.A., Zhang, Y., Zhao, H., Lim, S.B. & Constantinou, A.I. (2007) The effect of the phytoestrogens genistein, daidzein, and equol on the growth of tamoxifen-resistant T47D/PKC alpha. Nutr Cancer 58, 222–9.
730. Hirose, K., Takezaki, T., Hamajima, N., Miura, S. & Tajima, K. (2003) Dietary factors protective against breast cancer in Japanese premenopausal and postmenopausal women. Int J Cancer 107, 276–82.
488. Ellis, R., Kelsay, J.L., Reynolds, R.D., et al. (1987) Phytate:zinc and phytate X calcium:zinc millimolar ratios in self-selected diets of Americans, Asian Indians, and Nepalese. J Am Diet Assoc 87, 1043–7.
590. Gibson, R.S. (1994) Content and bioavailability of trace elements in vegetarian diets. Am J Clin Nutr 59 (5 Suppl), 1223S–32S.
669. Harland, B.F., Smith, S.A., Howard, M.P., Ellis, R. & Smith, J.J. (1988) Nutritional status and phytate:zinc and phytate × calcium:zinc dietary molar ratios of lacto-ovo vegetarian Trappist monks: 10 years later. J Am Diet Assoc 88, 1562–6.
1099. Lynch, S.R., Dassenko, S.A., Cook, J.D., Juillerat, M.A. & Hurrell, R.F. (1994) Inhibitory effect of a soybean-protein-related moiety on iron absorption in humans. Am J Clin Nutr
431. Doerge, D.R. & Sheehan, D.M. (2002) Goitrogenic and estrogenic activity of soy isoflavones. Environ Health Perspect 110 (Suppl 3), 349–53.
1983. Yellayi, S., Naaz, A., Szewczykowski, M.A., et al. (2002) The phytoestrogen genistein induces thymic and immune changes: a human health concern? Proc Natl Acad Sci USA 99, 7616–21.
27. Akbas, G.E., Fei, X. & Taylor, H.S. (2007) Regulation of HOXA10 expression by phytoestrogens. Am J Physiol Endocrinol Metab 292, E435–42.
Probably the best academic treatment of why modern foods play a role in diseases of civilization.