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.
With all these success stories about people feeling better on various diets, I think we forgot the people who sometimes feel worse. Probably because those people give up and don't stick around. I'm known many people who have adopted paleo, primal, ancestral, low-carb, gluten-free, or whatever diet. And instead of feeling better, they have all kinds of problems, particularly stomach problems.
There are many reasons why this happens, here are a couple I tend to come across:
1. They hose their digestive system with "cleanses." For example, the Master Cleanse, which involves fasting on just lemon juice, maple syrup, and cayenne for a few days to a week. Now I love spicy food. And I love acidic food. But out of the context of real whole meals, there is plenty of evidence they can be irritants, particularly in the digestive lining. There is no evidence that the Master Cleanse will remove some nebulous "toxins," but you are not only disturbing your gut microbiota (both good and bad) and irritating the mucous membranes of your gut, but also depriving yourself of real nutrients your body uses to maintain its defenses. You'll come out of it with possibly increased gut permeability and a devastated population of gut microbes. If you've already tormented your poor gut with this, you might need to eat a gentle diet (FODMAPS, for example) and take probiotics until your gut becomes less inflamed and repairs itself. People do often feel better on cleanses though in other ways, but that's because they are excluding many foods and yes, there is some value in breaking up pathogenic biofilms in the gut, but there are possibly more sustainable and gentle ways to do so based on preliminary scientific studies.
2. Speaking of FODMAPs ( Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols. ), another reason people might feel worse is that many so-called safe or good foods on these diets are difficult for many people to digest. A lot of books talk about how difficult it is to digest grains, but many plants have similar complex carbohydrates that can cause gas, bloating, and other GI symptoms. Rice, for example, is mostly nutritionless, but has had most of its complex carbohydrates polished away. If you take it out of your diet and replace it with "grain-free cauliflower 'rice'", you are consuming a massive amount of Oligosaccharides. I personally had a lot of bloating from foods like this. Remove them from your diet and then add them back in slowly one at a time to see what you can tolerate.
3. They forget any food can be toxic. Gluten, for example, seems to take a beating in the "toxic" department with nearly every book talking about how bad it is and how many people have celiac, which shows how gluten is a terrible non-food that no one should ever eat. But plenty of people are allergic to shrimp and we don't talk about how we aren't meant to eat shrimp because of that. I also see people talking about toxic lectins and phytic acid, but these aren't just in grains, they can be in any plant food. Peanuts and gluten are particularly bad because their biochemical structure causes problems for many people, but you can be sensitive to any food. Even beef. Once you take off the blinders, maybe you should consider whether or not you are feeling sick because a "safe" food isn't so safe for you? Or maybe you shouldn't be eating bread made out of an entire cup of walnuts, which might overload the capacity of your body to deal with the phytic acid and other assorted irritants in nuts.
4. They think fermented foods are always good. Sauerkraut? It's a cure-all! Why not eat it with every meal? Unfortunately, we do not have the robust digestive systems of our ancestors. If your gut is damaged, contamination of fermented foods by mold or sensitivity to histamine can be a real issue. You might have to remove them from your diet or at least find a source that is less likely to be contaminated. Additionally, fermentation does not always remove all FODMAPs, so many FODMAPs sensitive people will have digestive symptoms when eating things like sauerkraut.
5. They put massive amounts of fat on top of everything. So you heard fat has been unfairly maligned? Time to put massive amounts of coconut oil, butter, coconut milk, lard, and other fats on top of all your food right? Well, maybe slow down a bit and give your body some time to adjust to a higher-fat diet before you make your diet mostly fat, because adding in it all at once all the sudden can cause GI problems. For a long time I was one of those people who thought that only carbohydrates could cause GI symptoms and contribute to dysbiosis, but fat definitely can increase levels of endotoxins and increase gut permeability as well, and it seems that phytochemicals may inhibit that process. So, instead of chugging that can of coconut milk before your workout, maybe consider having a normal meal that includes a variety of other foods as well. In the end, while it might sound like heresy, some people actually might not do very well on high-fat diets. Try replacing processed carb foods in your regular diet with fruits and tubers instead of with fatty foods.
6. They take massive amounts of supplements. When you are taking ten different supplements, the odds that you are taking one that is irritating your stomach get pretty high. Mineral supplements like magnesium and iron are top offenders, as are supplements that contain FODMAPs in the form of prebiotics like inulin. Stop taking the supplements until your stomach sorts out and then add them back in one at a time to see which ones you can tolerate. With iron, it is probably advisable to get it from food, since excess iron can feed pathogenic gut bacteria.
7. Undereating can be just as problematic as overeating, particularly on a new diet. If you undereat, your body won't be able to maintain its systems effectively, which can make your digestive system prone to irritation. Counting calories may not be perfectly accurate, but it can help you get an idea of whether or not you aren't giving your body enough nourishment.
8. Excessive amounts of protein all at once. One friend recently told me he was having stomach problems on paleo. Turns out he was mainly eating chicken , which was providing massive amounts of protein without much fat, probably leading to a type of mild "rabbit starvation." As arctic explorer Vilhjalmur Stefansson wrote:
But it has been found in various parts of the world that a diet of lean meat exclusively will cause diarrhea in from three days to a week. If no fat can be added to the lean, the diarrhea becomes serious and will lead to death. A well known field where such deaths occur is the northern edge of the forest in Canada where Indians are sometimes unable to find any food except rabbits. The expression "rabbit starvation," frequently heard among the Athapsc Indians north-west of Great Bear Lake, means not that people are starving because there are no rabbits but that they are going through the experience of starvation with plenty of rabbit meat. For this animal is so lean that illness and death result from being confined to its flesh.
in this situation, it would be wise to add some fat, carbohydrate, or both to the diet to normalize things. You might be able to tolerate higher protein if you add it in slowly. You are probably not going to die, it's more likely you will discontinue the diet when your roommate orders pizza and you feel better after a few slices.
9. They have food poisoning. I'll never forget several years ago in college when I was having worsening IBS symptoms and I kept trying to fix them with diet until I ended up in the ER. A stool culture revealed I had salmonella and needed antibiotics. If you symptoms keep getting worse, it might be time to go to the doctor and ask for a stool culture.
10. These diets can't fix everything. I know several people for whom no dietary tweaking worked and they were later diagnosed with serious IBD. They are doing better on medicine. In the old days, they probably would have died. Many many people died in the past from diarrhea. Don't beat yourself up if you can't eat your way out of a very serious illness. Some people can, some people can't. Modern medicine can make your life better if you are one of the latter. Even if you don't have a serious stomach disorder, there are tons of non-diet things that can cause stomach problems, like sleeping poorly or thyroid conditions.
Any others I'm missing that caused you problems?
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.
Now that it's been over four years since I first heard about "paleo" diets, I have been reflecting on how such diets have worked for me. When I first heard about paleo, I definitely thought it was a solution to all my problems and it worked really well for most of them. The original bane of my life in the pre-paleo era, GERD, is gone. But my IBS symptoms were harder to fix and even now I find myself experimenting. In the beginning, I often thought the solution was more "purity" in my diet. I thought if I just were better at my diet, then my problems would go away. But IBS is too complex for that. And it doesn't seem to care about evolution all that much. While evolution can be useful for hypothesizing, my gut is the product of a C-section birth, a subpar diet for almost two decades, and many many courses of evolution. I think of my maternal grandmother who is in her nineties and claims to have only had a stomachache once in her life. Compared to her stomach, my own stomach is a rather unfortunate thing.
So when I ate a pure "paleo" diet, what happened? My stomach problems got WORSE.
Luckily I found the SCD (specific carbohydrate diet). It's really for people with worse problems than mine, but it clued me into some of the things that were going on, namely that there was something wrong with how I process certain carbohydrates. Well, not just me, but my own microbiome in my gut. They were taking something I was eating and having a party consuming it and belching out all kinds of bad things. Bloating, cramping, gas, bouts of IBS-C and IBS-D were the result.
Unfortunately SCD is both too strict and not strict enough. The "legal" list of SCD foods, like the typical "paleo" list, contains foods I cannot digest properly. The specific carbohydrates I'm sensitive to are not the same as those that the SCD concerns itself with. I ended up just going carnivore for awhile, which helped with a great many things, but I had other symptoms on that diet (like extremely low blood pressure) and it is on the pretty extreme of restrictive. I also think that some products of carbohydrate fermentation are important.
I have no idea where I first encountered FODMAPs, which stands for
But the theory is similar to the SCD, which is that for certain people, certain carbohydrates aren't processed correctly by the gut and end up feeding bad bacteria. But I think it was more useful for me because it breaks down the issue into a variety of potential baddies to experiment with. Lactose intolerance is the most famous type and all the other types are similar in that they can be dose-dependent. That's why I was so confused at first. Sometimes I'd eat potentially bad food X and feel fine and other times I'd feel terrible. Amount effects it, but that's the tip of the iceberg, because the context can affect it too. For example, with fructose, the amount of glucose ingested at the same time can affect tolerance.
So far you can see where my experiments have left me vs. the typical paleo diet:
It seems I have some fructose intolerance, but my tolerance is comparatively high. I can eat an apple, but if I start eating a bunch of dried apples (more concentrated fructose), then I start getting into problems.
Then there are foods that I can tolerate almost none of, such as brassica vegetables like cauliflower. Many "paleo" recipes use cauliflower in place of rice. I am much worse off if I eat that compared to real rice and in fact I've found that rice soothes my stomach quite nicely when it's upset, particularly when cooked in broth as a congee.
I'm still torn about wheat. I think I've tried every possible type of wheat at this point, including wheat that was fermented to remove gluten and a variety of "heritage" wheats. I still didn't tolerate it, which makes me think that it was never about gluten for me, but about fiber.
It's also pretty important to self-experiment and not just write entire foods off because they contain something that might be the culprit in causing you problems with another food. Onions are a major issue for me, but I've found I can tolerate them pretty well if they are cooked into oblivion (for example, in a sauce), which frees me to enjoy certain delicious Indian dishes. Tomatoes are only an issue for me raw.
I think this jives very well with the evolutionary idea that cooking was important in human evolution because it transferred digestion to the small intestine rather than the large. That seems to be exactly what is happening here. The large intestine is where fermentation takes place, so if fermentable carbohydrates are the issue, then cooking them to make them more available to the small intestine could help. Of course there is all kinds of fancy cooking science here I'm not getting into, which I need to research further. There is also the issue of tolerance improving if you manage to heal the gut lining and balance the gut bacteria somehow. I think that overall my tolerance has improved as I've eaten healthier. I used to not tolerate spicy food at all, which was practically a tragedy for me since I love it, but now I eat it quite often without an issue.
But people are always asking me to do an IBS post or series. And I kind of can't because it's been just all one weird experiment of me trying to figure out what I can tolerate and at what level. That's why I'm such a huge proponent of self-experimentation and not such a huge fan of dietary dogma.
When I first moved into the college dorms, one of my favorite meals was Special K (with those freeze-dried "berries") floating in tan-colored soy milk. It was healthy and I thought it tasted pretty good. Looking back I shudder because it was quite clearly the culprit in many of the stomach issues I had, as it was rich in the dreaded Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols (FODMAPS).
Once I realized that soymilk was one of the major causes of the bloating and other fun stuff I struggled with, I never bought soy milk again.
But I've never been anti-soy. In fact, I can't imagine life without the culinary treasures of soy sauce and miso. For me, changing my diet was about shifting staples, not clamping down on the margins. I'm only willing to do that if absolutely necessary. I don't think soy is a problem unless you are getting a large percentage of your calories from it.
And through my explorations of Asian cuisine I've come to appreciate soy for what it, which is a potent substrate for fermentation. That's why soy milk upset my stomach so much. But luckily, long ago someone figured out how to ferment it outside the body, creating rich salty flavors that characterize miso and soy sauce.
It's by no means a recent food. There is new evidence that humans were using wild soybeans 9000 years ago and that domestication occurred 5,500 years ago.
American vegetarians embraced Asian soy products a long time ago, but it wasn't until I started actually eating authentic Asian food that it struck me on how much they were missing out on. In Asian cuisine, soy is an extender of animal and seafood products, creating potent health and flavor synergies.
If you think tempeh is just some bland crappy paste-board-like soy concoction, you need to fly to Amsterdam and have homemade tempeh in a rich briny fermented shrimp and black pepper sauce. I've never ever had tempeh like that in America.
And I've found that even unfermented soy doesn't really bother my stomach. Oh, but only when it's served in a Korean restaurant that makes broth from scratch, boiling animal bones for days to achieve a creaminess, then boiling fresh homemade tofu and chunks of ox blood in the broth. It's digestible and much more delicious than it sounds, particularly when you pour some of the homemade kimchee into the broth.
Another unsung hero in Korean cooking is fermented soybean-red pepper paste, Gochujang, which makes sriracha seem bland. It works so well with beef that it's heresy to put it on some vegetarian brown rice gunk. It almost always contains barley though, so stay away from it if you don't eat wheat, though I'd wonder how much of it could be harmful because fermentation can destroy gluten.
And really, there is nothing like liver or beef belly marinated in soy sauce. I know some folks use coconut aminos because they think they are reacting to soy sauce, but I don't think there is much in most soy sauce to react to, except for amines, which are present in coconut aminos too.
But Asian food hasn't been immune for the industrialization of soy products, which leads to general mediocrity and upset stomachs all across the globe. The latest issue of my new favorite magazine, Lucky Peach, has an amazing article about miso. There are a great many types of miso, but the miso that most Asian restaurants serve is a powdered, pasteurized, fortified, bleached concoction that barely deserves to be called shinshu miso. But it's bland, ships easily, stores easily, and requires no skill to make into soup.
The same thing has happened to broth and many other traditional foods. It's hard to find a restaurant that makes its own broths with bones rather than a powder containing MSG and other assorted non-food additives. Many Koreans now make a Gochujang that isn't fermented at all.
The only good trend is the post-WWII trend of combining butter with miso or soy sauce. You can create some incredibly rich and wonderful sauces this way. I just now enjoyed some scallops with a soy-sauce browned butter glaze.
For me the fascinating thing about soy sauce and miso is how deep and rich the flavors are, yet they do not compel me to overeat. I think it's a function of their complexity. They are delicious, but have an underlying funkiness. It's important, like fish sauce is to SE Asian cooking, but you definitely don't want to overdo it.