This blog is about the intersection between evolutionary biology and food. But also about practical applications, sustainable agriculture, and general tasty things.
What’s the deal with gluten sensitivity? Gluten sensitivity as a proposed disease showed up in the scientific literature in the past few years. The key here is proposed, because there was evidence it might exist, but it remained in a scientific grey area because there was not a known mechanism behind it.
But enough people had already decided or wanted to decide gluten was bad that they took the proposed disease and ran with it, producing and selling a large volume of scientifically dubious diet books featuring “gluten sensitivity”.
A profitable food scare
One of the most popular studies was Gluten causes gastrointestinal symptoms in subjects without celiac disease: a double-blind randomized placebo-controlled trial. Whole Health Source’s Stephan Guyenet covered in in a popular post. It has been cited over a hundred times in the scientific literature and cited as evidence that gluten is bad in many popular diet books.
But the authors knew it had flaws (listen to an excellent podcast with one of them, Dr. Peter Gibson, here). And so they did another study to make sure it was gluten, a protein, that was the problem, and not carbohydrate intolerance.
Their new study, No Effects of Gluten in Patients With Self-Reported Non-Celiac Gluten Sensitivity After Dietary Reduction of Fermentable, Poorly Absorbed, Short-Chain Carbohydrates, was published recently and is available for free online.
They found a source of gluten that was carbohydrate depleted. As Dr. Gibson says in the podcast “We wanted to do a more detailed and intense study to control for other things in the diet to ensure it was only the gluten we were looking at.” It was also cross-over and examined inflammatory markers in detail. Celiac disease, a gluten-related disease with a well-developed mechanism behind it, was ruled out in the subjects. The subjects were people with “IBS” who reported they felt better on a gluten free diet.
The diet they used for carbohydrate intolerance was FODMAPs (Fermentable, Poorly Absorbed,
Short-Chain Carbohydrates), a diet developed in Australia for gastroenterological symptoms. They used it as their background diet and supplied all the food for the participants. The re-challenge trial diet was even more strict, eliminating FODMAPs, dairy, and low in naturally occurring and artificially added food chemicals “salicylates, amines, monosodium glutamate, as well as preservatives benzoates, propionate, sulfites, nitrites, sorbic acid, plus added antioxidants and colors”
Of course these diet books say “just try eliminating gluten and see how you feel.” But their eliminations usually violate basic scientific experimental principles. Most of these diet books have their adherents completely overhauling their diets. For example, Wheat Belly and a new book called Gut Bliss both tell dieters to not only eliminate all gluten from their diet, but to avoid gluten-free grain products. That is not testing the elimination of gluten, but the elimination of gluten AND foods with added sugar, starchy grain-based foods, etc. That’s testing a lot more than gluten intolerance. In the end I meet a lot of people who end up living a grey area, people who believe gluten is bad, but sometimes will eat it as part of their 20%. If they really have celiac this is devastating. If they don’t, they are living in fear for no reason.
Interestingly many of the subjects in the study got better on the diet they used than they had been on their previous gluten-free diets. This was my own experience as well, that I felt better on a FODMAPs diet, even though it contained some foods I once thought were kind of questionable, but in small amounts, than I did on a “paleo” diet. In fact I’d almost dread going to a “paleo” potluck these days, when so many paleo recipes seem along the lines of “let’s turn cauliflower (which is high in certain FODMAPs) into everything from faux rice to faux pizza crust.”
Of course this doesn’t tell us much about whether or not gluten plays a role in other diseases besides celiac, such as skin conditions. There are some hypotheses about that out there. Unfortunately, as “Stabby the Raccoon” said, paleo has become about “about scaring people over hypotheses.” Why? Simply because it’s profitable. Witness the rise of content farms that publish low-quality articles in this genre and manage to get massive amounts of hits and social media shares that can be reaped for ad dollars.
If you believe you might be affected by gluten, I’d recommend you get screened for celiac. If you don’t have celiac, I wouldn’t jump to the conclusion you have gluten “sensitivity” especially given how poorly defined this potential condition is. It seems wise to consider that FODMAPs might be an issue for you, which turned out to be the case for me.
Luckily, FODMAPs intolerance doesn’t have very much in common with celiac disease. Eating a little wheat is not going to cause a cascade of inflammatory reactions in your body. People who have issues with FODMAPs can typically tolerate some of the offending foodstuffs depending on individual differences and the preparation of that food. The re-challenge diet in the study also seems to point to dietary context as being an oft-overlooked consideration. Some people might be sensitive to one food only if another food is causing the initial irritation.
For example, I do not possess lactase persistence genetically, so technically I am lactose (a FODMAP) intolerant. In the real world, that means it might get uncomfortable if I guzzled a lot of fresh milk, but I can tolerate plenty of low-lactose dairy products and small amounts of fresh dairy. I also seem to be intolerant of the fructans in wheat. When I thought it was gluten, I ate a gluten-free diet that contained a lot of FODMAPs and often my symptoms were much worse than before. When I realized it wasn’t the gluten, I am now able to enjoy small amounts of wheat-containing foodstuffs. Same of fructan-containing alliums such as onions. I can’t enjoy them fresh, but when they are cooked down they do not seem to bother me. That means a lot for me since I love to travel and try a lot of foods. It might not be a biological “need,” but it is meaningful to me.
Someone I know who follows a gluten-free diet said that he saw an ad for this product called GlutenCutter, an supplement that claims it helps people digest gluten, on Facebook. I would assume he "likes" many gluten-free/paleo/etc. blogs on Facebook that that is why he saw this ad. I looked at the product out of curiosity and it is a bit worrying, particularly the FAQ:
Q: Is Gluten Cutter intended for those with Celiac Disease?
A: It is recommended that those with Celiac Disease first consult with a doctor prior to using Gluten Cutter.
I would only hope they have a competent doctor who tells them the truth, which is that while some research is being done on using enzymes that would possibly allow a celiac to digest gluten, this is in very preliminary stages. There is currently no safe accepted dose of gluten for a person with celiac disease.
Furthermore with the state of our health care systems, I would worry that people with celiac symptoms would use this product. People who haven't had celiac ruled out. In the US I meet many people like this who cannot afford the diagnostic tests, particularly since the gold standard if it's not ruled out otherwise is biopsy that is performed as a surgical procedure. In places like the UK, it is often hard to obtain these tests as well, as it is not easy to see a specialist.
The supplement industry often thrives by filling in the gaps of the healthcare system, and sometimes in unsafe ways. I would not use this kind of product if it were possible that I might have celiac.
I have used Glutenease in the past, but celiac is ruled out in my own case. Glutenease mainly contains one of the enzymes under study, which is dipeptidyl peptidase IV (DPPIV). It seemed to help me transition out of a gluten-free diet, but I stopped taking it late last year and haven't had any problems. I think if i had continued to need it, it would have indicated the possibility of a more serious problem since low levels of it in the body are tied not just to celiac, but to other diseases that cause mucosal damage.
Compared to Glutenease, Glutencutter contains a host of other supplements which might have unintended side effects. One of the many reasons I think people experimenting with supplements should avoid bundled supplements and just supplement what they need in doses that are adjustable.
It just reminds me that gluten is probably a major public health issue in our time because
Not being gluten-free anymore has significantly broadened my ability to travel, eat-out, and go to social gatherings. And that's kind of a sad fact considering not everyone has that choice.
In developing countries, this problem is magnified:
Wheat and barley are major diet constituents with few acceptable alternatives, rendering the convincing of parents that bread is the cause of diarrhea very hard. Also, convincing patients with atypical CD to adhere to a GFD is difficult. Finally, lack of information about CD manifestations, lack of benefit from a GFD and lack of encouragement to adhere to such a diet may contribute. More than 10% of adults with CD do not adhere strictly to long term GFD and more than 30% who believe they are, are actually consuming grams of gluten daily.
Interestingly, some of the most at-risk populations come from the "Fertile Crescent" where wheat agriculture originated. Rather than poor adaptation to grains, celiac might be more of a legacy of more recent evolutionary trade-offs, an issue explored in Aaron Sam's dissertation (PDF). The crop that these early farmers so successful may also have ended up being a curse on their wide-ranging descendants.
Over the years I've been involved in this community, I've met many many people who have seen their health improve when they eliminated wheat gluten from their diet. But I also see it as part of a worrying trend that relies all too much on self-experimentation and self-diagnosis. Often when I meet these people they are noshing on a burger without a bun at a regular restaurant or ordering a salad a restaurant like Hanna's Bretzel where gluten-free ingredients are laid side by side with non-gluten free ingredients.
If these people actually have celiac disease, this is probably not an acceptable behavior. To be clear, celiac disease, which is an autoimmune disorder, is an extremely serious disease. Any gluten in the diet can contribute to long-term health problems and even cancer.
Scary stuff. Scary enough that celiacs need to seriously consider cross-contamination at places like restaurants. Fries that are fried in the same oil as breaded chicken nuggets, eggs cooked in a pan that was used to cook French toast, salad made from lettuce served with tongs used to pick up croutons, these can introduce damaging gluten into a celiac's system. So it's not acceptable to just go to a regular restaurant and order a burger with a bun and some fries. Doing so might mean subjecting yourself to chronic damage. Senza, which is the gluten-free restaurant I reviewed recently, does not allow any gluten at all in its building ever. That is the level of strictness required to achieve remission of damage in most celiacs.
It's not surprising to find that in our culture where eating out is so common, many celiacs still present with intestinal damage years after initiating a gluten-free diet.
I've asked many of these people who eliminated gluten from their diets and saw an improvement why they do not get tested for celiac. Sometimes it's a financial issue. They feel they cannot afford the tests. Other times they are concerned because a true diagnosis by intestinal biopsy requires that they eat gluten for some time before getting the test. I'd say that a month of feeling sick is worth it in order to avoid years of chronic damage. The alternative would be to commit to a truly strict gluten-free diet and stop eating at the local Irish pub.
Which is think is totally unnecessary and silly for those of us who are not actually celiac. There is growing evidence non-celiac wheat sensitivity exists, but none that show that trace gluten could cause the kind of damage seen in celiac. It is likely it is more similar to lactose intolerance, which is dependent on dose (few lactose intolerants can truly never tolerate any lactose ever), than an autoimmune condition like celiac.
I'm completely against strictness when it is unnecessary. For me it absolutely is. I was able to avoid a biopsy because I did a genetic test that showed I completely lack any of the genes related to celiac. Through the FODMAPs elimination diet, I found out it was the fructans that were causing trouble for me. I do occasionally consume wheat products, primarily fermented wheat and those made with heritage grains. They are not a staple for me because I don't think they are particularly great for you (that doesn't mean they are "bad") and they require quite a bit more effort than just making a meal with fresh meat and vegetables. I will continue to eat whatever I can get away with on special occasions and when traveling unless I see conclusive science that says any gluten ever is bad for anyone.
But if you have the genes, that doesn't mean you have celiac, it just means it's possible for you to have it and you should pursue the matter further. I created this chart once to explain it to a friend:
Yes, it's crappy to have to go through all that to get a diagnosis and it can be hard to find a doctor that cares, but I truly believe it's worth it to know. Especially since celiac is becoming more and more common. I'm not a fan of Wheat Belly, (also see Dr. Deans' review) which essentially took a blog with some interesting ideas, and I suspect the publisher said "find everything that could possibly be bad about wheat and mention it without any nuance whatsoever." You can write such a book about almost any food. It reminds me of Whitewashed, which is about milk. I'm still waiting for the book about how evil shrimp is because some people are allergic to it.
Shrimp is Actually EVIL SEA BUGS THAT CAUSE LEAKY GUT- the book
On that note, a professor associated with the grain industry recently published a critique of the book. There are some good points there on Davis' hyperbole, misuse of studies (not citing the follow-up that disproves his theory, irrelevant in vitro studies, studies on genetically engineered mice) and use of the same tactics that plant-based zealots use (acidification! AGES! glycemic!), but right off the bat I spotted a bunch of mistakes. One of the most obvious is that the author mentions the Joe Murray study on historical blood samples. It says "the analysis shows that 0.2% of recruits had the gene in 1950 compared with 0.9% of recent recruits." And then it goes on to say increase prevalence might be due to better identification and awareness. But that study specifically refuted that, as it was not even studying genes, it was studying antibodies. It was an important study in pointing to increased prevalence, which should surprise no one who studies autoimmune diseases, most of which have increased in prevalence.
“This tells us that whatever has happened with celiac disease has happened since 1950,” Dr. Murray says. “This increase has affected young and old people. It suggests something has happened in a pervasive fashion from the environmental perspective.”
Dr. Murray lists several possible environmental causes of celiac disease. The “hygiene hypothesis” suggests the modern environment is so clean that the immune system has little to attack and turns on itself. Another potential culprit is the 21st century diet. Although overall wheat consumption hasn’t increased, the ways wheat is processed and eaten have changed dramatically. “Many of the processed foods we eat were not in existence 50 years ago,” Dr. Murray says. Modern wheat also differs from older strains because of hybridization. Dr. Murray’s team hopes someday to collaborate with researchers on growing archival or legacy wheat, so it can be compared to modern strains.
Murray's team also used those blood samples to show that the undiagnosed airmen were more likely to have died young, possibly as a consequence of undiagnosed celiac. Undiagnosed celiac is frankly dangerous, particularly since it takes so little gluten to cause damage. There is still an argument about whether or not gluten is bad for everyone, but we aren't going to win over the medical profession if we use hyperbole instead of saying "hey did you consider whether or not your patient with diabetes/ibs/osteoporosis/arthritis/etc. might have celiac or wheat sensitivity?"
So if you suspect that wheat is an issue for you, I strongly recommend taking time to get a firm diagnosis so you can know if you need to be 100% gluten-free.
Wait, based on some news articles I've read lately, I thought non-celiac wheat sensitives were a bunch of wilting prima donnas intent on eating an annoying hipster diet that excludes wheat, an important nutrient that people have been eating for a really long time or something like that. And since their diet excludes sandwiches and pizza, they must be UnAmerican.
But in the medical research community, there is growing recognition that non-celiac wheat sensitivity is a real thing that affects quality of life and even mortality risk when it leads to intestinal inflammation. Stephan Guyenet posted about the last promising study.
This new study is very interesting, but highlights some limitations in dealing with problems like this. This study was on patients who already had been through the wringer test-wise and all had
Um, how many people here with IBS have ever been offered this standard of care? Anyone had a doctor who offered to supervise a double-blind placebo controlled wheat challenge? Maybe things are different in Italy.
Once they were in this study, these patients got more tests including biopsies of the duodenum and colon, HLA genotyping, as well as skin-prick and blood tests. Then these people had to eat a minimum quantity of wheat daily as they were observed. Then they did a regular elimination diet that excluded wheat, cow's milk, eggs, tomato, and chocolate. Then they got to do a fun exciting double-blind placebo controlled wheat challenge again.
Wheat challenge was performed administering a daily dose 13 g of flour, equal to about 20 g of bread. A total of 12 capsules daily were given subdivided in three times daily, away from meals. DBPC for cow’s milk was performed by administering capsules coded as A or B containing milk proteins (casein from bovine milk, lactoalbumin, lactoglobulin – daily dose 6 g, equal to about 200 ml of cow’s milk) or xylose, respectively. A total of 6 capsules daily were given subdivided in three times daily, away from meals.
Patients used a survey to track their symptoms. They used celiac disease and IBS patients without wheat sensitivities as controls.
Among those who were wheat sensitive, a high number of them tested positive on the cytomteric basophil activation test, and many also tested positive for serum IgG and IgA AGA tests. Many of these patients suffered from anemia and weight-loss. Biopsies showed eosinophil infiltration of the duodenal and colon mucosa.
, despite not having the type of villous atrophy damage associated with celiac.
There seemed to be two groups of IBS wheat-sensitive patients- those with wheat sensitivity alone and those with wheat sensitivity AND multiple other sensitivities to cow's milk and other foods. The later group was also more likely to also have other types of allergies (non-food allergies, skin allergies, etc.) and a family history of allergies.
Further studies will have to look more into the mechanism in which wheat causes damage in these patients. The researches propose one mechanism in their conclusion
Obviously, other hypotheses must be considered; experimental models have demonstrated that gluten sensitization of DQ8 mice increases acetylcholine release by the myenteric plexus and this can lead to consequent in vivo dysmotility ( 27 ). In this model, gluten did not cause villous atrophy, but there was evidence that coexistent triggers, e.g., intestine-damaging drugs or dysbacteriosis, can lead to a more severe intestinal impairment ( 28 ). Clearly, wheat antigens may also act in a similar manner.
Acetylcholine is responsible for ahem, moving things along, so it might explain why wheat causes diarrhea in some people.
Also, it is notable that this study used wheat rather than gluten, so it might be other components of wheat like fructans that are responsible for the symptoms.
The researchers say
the very high frequency of self-reported wheat intolerance, which we observed in our patients, should induce clinicians to pay full attention to patient suggestions
I wonder how long it will take the average doctor to catch on?
I like to blog about a lot of fancy stuff, but in reality, it's not every day I'm making braised local grass-fed oxtails and wild caught sea bass. Life gets in the way. But that doesn't mean you have to totally lose all the benefits you would get from a top-notch diet. Over the years I've figured out how to degrade my diet gracefully.
As I mentioned in my previous blog post on mammals, primates have an evolutionary strategy that involves fallback foods. These are resources of low-preference that are eaten when preferred foods are not available. These foods allow primates to survive when things get rough.
I have my own fallback foods. They are for when I just don't have time to go to the butcher shop. Or I've worked so long that the idea of cooking a meal from scratch and then doing dishes seems daunting. These foods have to be
Since I moved to Chicago and Trader Joes is a normal grocery store instead of a series of endless loopy lines like it is in NYC, my fallback diet has been based on stuff from Trader Joes. Typically smoked wild salmon, Applewood sliced roast beef, pre-cooked beets, and random cheese and fruits. A typical meal like this would be a few slices of gouda, a clementine, a few slices of roast beef, some beets, and some of the wild salmon with mustard on rice crackers. I have to say that this tastes better than typical primate fallback foods like tree bark.
When I worked at an office last, it was next to a Fairway and often for lunch I'd just go to the deli and ask for a half pound of sliced roast beef, a half pound of cheese, and then buy some random pre-sliced fruits and vegetables. One time a coworker implied that eating a block of cheese might be a bad idea, but nothing ever happened to me.
The next level of degradation is a little riskier. It's when you are on holiday in France. Or it's Thanksgiving. Maybe you want to eat some things that are normally not part of your diet. There are good reasons that they are not part of your diet, but there are better reasons that you want to indulge. The things I think about here is
I made a silly graphic for paleohacks yesterday and weirdly, people were impressed. It was made with default Smartart in Powerpoint :)
I also recommend the Highbrow Paleo Guide to Binge Drinking.
Q: What extreme techniques are you talking about?
A: New strains have been generated using what the wheat industry proudly insists are “traditional breeding techniques,” though they involve processes like gamma irradiation and toxins such as sodium azide. The poison control people will tell you that if someone accidentally ingests sodium azide, you shouldn’t try to resuscitate the person because you could die, too, giving CPR. This is a highly toxic chemical.
But the plants generated from this technique (it's not just used for wheat) don't contain sodium azide...these techniques are used to accelerate mutation rate, so selective breeding projects that once took hundreds of years now that ten years: "The process leaves no residual radiation or other obvious marks of human intervention. It simply creates offspring that exhibit new characteristics." I guess your view on this depends on your intrinsic conservatism. But it's one of the techniques that has produced sustainable yield increases in the developing world without GE, expensive hybrid seeds, pesticides, or synthetic fertilizer.
I hope nobody told Dr. Davis that we used NPK fertilizer or animal poo to make plants grow faster. If you eat that stuff you could die too.
Don't get me wrong. I don't eat wheat. Even the good old fashioned Weston A Price fermented breads make my stomach malfunction, and yes even the most ancient wheat varieties do this to me. I also lost a good amount of weight removing it from my diet. But I prefer the paleo approach because it emphasis that wide variety of foods someone can be sensitive to, as well as the importance of good foods like fish roe, liver, and grass-fed beef. Paleo isn't just about demonizing wheat and frankly I know some serious Crossfitters who drink real beer with real wheat often and are very lean and have excellent blood lipids.
I'll get around to reviewing this book eventually, but from an agriculturalist's perspective I remain skeptical of it. In the past I've taken his blog less and less seriously because of his rather conventional views on meat:
Atkins Diet Common Errors: Excessive consumption of animal products–Non-restriction of fat often leads to over-reliance on animal products. Higher intakes of red meats (heme proteins?) have been strongly associated with increased risk for colon and other gastrointestinal tract cancers. It is not a fat issue; it is an animal product issue. We should consume less meat, more vegetables and other plant-sourced foods.
It seems that celiac disease is on the rise and is becoming a major public health issues. I remember when I was a kid at summer camp we all ate at the same table. By the time I was a camp counselor there was a special "peanut-free table" and admission to it was enforced through inspection. I am imagine at my children's camps there will probably be a new gluten-free table.
But celiac incidence has risen and fallen in several cases, most notably in Sweden. In the 1980s, the incidence rate among children under two increased fourfold, then suddenly declined around 1995. Epidemiologists looked for what else had changed during this time and came up with two major factors
breastfeeding, the other was use of gluten-containing infant cereals. Further study into the matter produced a rather strong body of evidence that breast-feeding protects against celiac disease. A possible mechanism is the gut flora. I have written before about the unique properties of prebiotics in human breast milk and their role in establishment of gut flora. C-sections also interrupt establishment of gut flora, and not surprisingly they have also been connected to celiac.
One of my favorite quotes is by Joan Gussow: "I trust cows more than chemists."
I also trust millions of years of human evolution more than chemists. Breast milk is the perfect and most appropriate food for human infants. I become quite disappointed in continous misdirection in citing rare cases in which breast-feeding is literally impossible, such as adoption or after breast-cancer. In countries where breast-feeding is considered the default and formula is considered a last resort, such as Norway, breast-feeding rates are very high (around 99% of women breast feed in the first week) and many out of the remaining 20% receive donor milk. As long as formula is considered a good alternative, governments, employers, and hospitals will have an excuse not to provide support.
A poor evolutionary nutrition narraive posits that because we didn't have X food in the paleolithic, we are maladapted to it. I think Mat Lalonde covered issues with this nicely at AHS and in the latest Paleo Solution podcast.
John Hawks, a biological anthropologist at the University of Wisconsin-Madison, notes that many HLA genes pre-date humans' split from Neanderthals and Denisovans, and that the differences may have arisen by chance as the groups evolved.
Hawks, too, has been digging into the archaic genomes, and his team has already discovered that Neanderthals and Denisovans lack certain forms of genes that may help modern humans to fend off epidemic diseases, such as measles. This is hardly surprising: the low population density of hunter-gatherers meant that epidemics were unlikely, so they probably would not have benefited from these immune genes.
But Hawks's team is now using the find to test whether the defensive genes are linked to autoimmune diseases. In September, Hawks and his colleague Aaron Sams are scheduled to present data at a meeting of the European Society for the Study of Human Evolution in Leipzig, Germany, showing that the Denisovans lacked nearly all of the gene variants linked to coeliac disease, a gut autoimmune disorder present in modern humans. Hawks suspects that the variants may actually be in the same genes that are linked to epidemic resistance — if they are, further study could reveal how recently such autoimmune diseases arose in humans.
Haha, it would be funny if an adaptation to civilization (diseases worsened by high population density), would also turn out to be a maladaptation as civilization progressed.
"This whole gluten intolerance thing is just a Western upper middle class fad. People are just orthorexic. Why would gluten intolerance increase all the sudden?"
Well, actually it's not a Western upper middle class fad. People in poor countries can be celiac, but they just die and people think it's from something else. When you are a refugee wasting away from chronic diarrhea, that's not so abnormal unfortunately. When you are in Central Illinois and suffering from the same, it is abnormal and you see a doctor and hopefully get a diagnosis.
Why is gluten-intolerance increasing? Doctors are more aware than ever of this condition and are doing more tests. More tests = more diagnosis. Symptoms that were dismissed as "IBS" or one of many other made-up symptom cluster illnesses are being re-diagnosed as gluten intolerance.
So what's the population with the highest level of celiac disease? Preschoolers on the Upper East Side? Nope, the Saharawi, an Arab-Berber refugee population. And maybe they aren't the highest since they were just unlucky enough to be refugees served by doctors interested in celiac research. Testing found that 5.6% of them have celiac. Unfortunately processed wheat flour is their staple food (I wonder when that started?). Before celiac was diagnosed, people thought their children were merely dying from a malnourishing diet or GI illness. Researchers are now finding celiac hotspots across the Middle East, India, and Africa.
This is interesting because so much government food aid contains gluten. How many of the children you see on those "save the children" campaign ads are really suffering from celiac like this child?? How many such starving children will be given gluten-containing food aid and will die as a result?
Another major question is why celiac disease incidence is so high in the region that gave birth to agriculture? The theory that CD was higher in populations that have adopted agriculture more recently like the Irish or the Finnish has not survived now that other populations have been examined more closely. The Finnish and Irish have high levels of CD because they have high DIAGNOSIS levels. Finnish children are tested at birth.
Tis the season of sanity in the paleorealfoodblogosphere?
First we have the brilliant Chris Masterjohn taking down a gluten is evil OMG study that's been widely cited by bloggers including me. Admittedly I didn't read it because back then I wasn't in school. Chris did and it turns out it's not a high quality or conclusive study. Oops.
Maybe gluten is teh evil, but that study doesn't prove it.
It just goes to show that we have to be just as critical of studies that support our viewpoints as we are of studies that don't.
I've posted many times before how I am infuriated by people who call Eskimos/Inuit or Kitvans "paleolithic cultures."
I've written about how many such cultures consist of former farmers (agricultural regression) and some are mislabeled hunter-gatherers when really they are horticulturalists! And also that some forest hunter-gatherers have had long symbiotic relationships with farmers and anthropologists aren't even sure if humans can survive in such forest environments without such relationships*. Prof Gumby at PaNu emphasizes the further point that many of them are in marginal environments.
I'll add a further point that even more have been decimated or otherwise affected by pathogens introduced by outsiders. Anthropologist Thomas Headland, who lived for many years with a tribe called the Agta and raised his children among them, put it poignantly:
There were less-rosy sides to the way our children grew up, too, of course. They suffered from the local diseases, especially malaria (all five of us), and two of our children had primary complex tuberculosis. (TB is the number one killer of Agta adults.) And they may still suffer some psychological trauma over the deaths of many Agta with whom they were close: the majority of their childhood playmates are today dead. (Agta life expectancy at birth averages only 21.5 years.)
Survival International is a charity that helps advocate for tribal cultures. Reading the stories on this site makes it clear that most of these tribes are in highly marginal situations politically, physically, environmentally, and socially.
We do not object to calling these people hunter-gatherers, as long as it is made clear that they are modern-day hunter-gatherers, people who have evolved right along with the rest of us into the 20th century.
Yes, we can learn some things from them, but hopefully these hypotheses will be tested by real science. As I said before "Choosing plant foods because of their history without taking biochemistry into account is dogma, not science." Some paleo authors make this mistake, assuming that we should base our fat content of our diet on some very limited surveys of modern game or ancient bones. That's why I always recommend the books of Gary Taubes to newbies. Even if our ancestors ate low fat, that doesn't mean high-fat is bad or that low-fat is good. Hopefully Taubes' newest easier shorter book Why We Get Fat will bring sanity about fat to more and more people.
Unfortunately, some paleo folks are too arrogant to accept modern science. They are stuck in anthropology, which I love, but that's just part of the picture.
As a bonus, Denise Minger has a good post up on stupid vegetarian studies.