This blog is about the intersection between evolutionary biology and food. But also about practical applications, sustainable agriculture, and general tasty things.
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?
If you like shrews, especially if you like them parboiled, you'll want to devour a 1994 study published in the Journal of Archaeological Science. Called Human Digestive Effects on a Micromammalian Skeleton, it explains how and why one of its authors – either Brian D Crandall or Peter W Stahl; we are not told which – ate and excreted a 90mm-long (excluding the tail, which added another 24mm) northern short-tailed shrew (Blarina brevicauda).
This was, in technical terms, "a preliminary study of human digestive effects on a small insectivore skeleton", with "a brief discussion of the results and their archaeological implications". Crandall and Stahl were anthropologists at the State University of New York in Binghamton. The shrew was a local specimen, procured via trapping at an unspecified location not far from the school. For the experiment's input, preparation was exacting. After being skinned and eviscerated, the report says, "the carcass was lightly boiled for approximately 2 minutes and swallowed without mastication in hind and fore limb, head, and body and tail portions".
Here's how Crandall and Stahl handled the output: "Faecal matter was collected for the following 3 days. Each faeces was stirred in a pan of warm water until completely disintegrated. This solution was then decanted through a quadruple-layered cheesecloth mesh. Sieved contents were rinsed with a dilute detergent solution and examined with a hand lens for bone remains." They then examined the most interesting bits with a scanning electron microscope, at magnifications ranging from 10 to 1,000 times.
A shrew has lots of bony parts. All of them entered Crandall's gullet, or maybe Stahl's. But despite extraordinary efforts to find and account for each bone at journey's end, many went missing. One of the major jawbones disappeared. So did four of the 12 molar teeth, several of the major leg and foot bones, nearly all of the toe bones, and all but one of the 31 vertebrae. And the skull, reputedly a very hard chunk of bone, emerged with what the report calls "significant damage".
The vanishing startled the scientists. Remember, they emphasise in their paper, that this meal was simply gulped down: "The shrew was ingested without chewing; any damage occurred as the remains were processed internally. Mastication undoubtedly damages bone, but the effects of this process are perhaps repeated in the acidic, churning environment of the stomach."
Chewing, they almost scream at their colleagues, is only part of the story. In each little heap of remains from ancient meals, there be mystery aplenty. Prior to this experiment, archaeologists had to, and did, make all kinds of assumptions about the animal bones they dug up, especially what those partial skeletons might indicate about the people who presumably consumed them. Crandall and Stahl, through their disciplined lack of mastication, have given their colleagues something toothsome to think about.
The human stomach was more capable at digesting bones than they expected. This isn't terribly surprising to me, as many cultures consume whole bone-in animals and there is plenty of archaeological evidence for this. Here's a bit from John Speth's book:
Well-preserved prehistoric human coprolites (feces) recovered in large numbers from dry caves throughout western North America are full of pulverized bone fragments, including pieces of broken skulls, as well as fur and feathers, indicating that rodents, rabbits, birds, lizards, snakes, and amphibians were often cooked whole, pounded in a wooden mortar or on a milling stone, and then consumed in their entirety – bones, fur, feathers, and all, including the precious DHA in the brains (Reinhard et al. 2007; Sobolik 1993; Yohe et al. 1991).
It would appear that the Desha people at Dust Devil Cave ate rabbit legs more-or-less whole, then pounded the rest of the carcass before eating it... The consumption of wood rats (Neotoma spp.), also known as pack rats, has been noted ethnographically. They were regarded as good food by the Yaqui (Spicer, 1954: 49), constituted a staple for all tribes along the lower Colorado River (Castetter & Bell, 1951: 217), and many were eaten by the Tohono O’Odham. The Cocopah set fire to their nests, clubbing the rats as they emerged, undoubtedly fragmenting some bone in the process.
In the past, there was perhaps more focus on big game hunting. And while big game bones are nice, they are harder to process than little animal bones. Primates have probably been digesting little bones for much longer than they have been breaking open larger bones for marrow. Excessive focus on big game has led to ignoring the contribution of small game to human nutrition, which has also led to the misconception that women don't hunt since some anthropologists classified small game hunting as gathering.
It would be interesting to know if other primates can also digest bone. Chimpanzees seem to degrade the bones of other primates they hunt and consume (PDF). Salad lovers might be interested to know that when chimpanzees consume a meal of meat, they consume it with leaves.
It would also be fascinating to know if humans process the same ability as some other carnivores to use animal parts as de-facto fiber and ferment it into SCFA.
At some point in human evolution, humans developed technology to extract nutrients from bones more efficient than their own stomaches, which is referred to as "grease processing" in many archaeological papers, but is close to what we do in making broths today. It is understandable why humans developed this, considering a meaty meal for a chimpanzee can take nearly the entire day to consume. Frankly, while I like a 6-hour tasting menu sometimes, I don't have time for that very often.
But today, could many humans handle bone? With dietary and medical factors like widespread use of proton pump inhibitors reducing acidity of the digestive tract, are we losing this capability?
For the record, I have never eaten a whole rodent bones and all, though I have eaten many small whole bony fish. There is some indication that humans degrade fish bones more completely, leading to their relative scarcity in coprolites and underestimation of their importance in diet.
Perhaps whole rat eating is becoming trendy again though, a posh rat dinner was featured in the New York Times recently.
Mark Sisson posted a link to a sad essay called IBS Is Why I'm Still Single. Every day I'm able to eat and live normally, I am so grateful. You see, most of my life I had painful stomach problems. When I was four I remember crying in the bathroom. I remember at sleep away camp being too embarrassed to use the communal bathrooms and sneaking out in the middle of the night to the isolated outhouse. It wasn't until I was 15 or so that I was diagnosed with IBS. When I was a freshman in college it became so disruptive to my life that I was finally given Librax. At that point I was also on quite a bit of asthma medication. Then I started having serious heartburn. I went on proton pump inhibitors. At my low point I was on Allergra, Advair, Singulair, Albuterol, Librax, Nexium (Prilosec stopped working at some point), and continuously on and off antibiotics for various ailments ranging from yeast to sinus infections. I was miserable. I missed most of my classes.
The single part of that essay hit home because I remember my first Valentine's day with my first boyfriend. We had a delicious meal, but soon after I was bent double with incredible pain and spent most of the night in the bathroom. I didn't think I'd be able to do anything.
I honestly thought that my condition was caused by eating fat, tomatoes, and peppers. The handouts my doctor gave me insinuated as much. I really didn't like all the side effects of the medications I was on, but when I complained to one of my doctors he said I'd on them for the rest of my life. I tried all kinds of high-fiber low-fat veg*n diets to no avail.
I didn't want to live like this. But all the sudden my condition took a turn for the worst. I felt like my whole body was falling apart. One day I collapsed in the hallway of the dorm. I was diagnosed at the hospital with chronic salmonella. That's not something a 19 year old should have. Afterwards I had trouble with constant burping.
I vowed to do more research and found a small study on GERD and low carbohydrate diets. I also discovered Evolutionary Nutrition on Art De Vany's site through the blog Marginal Revolution. I learned about the Specific Carbohydrate Diet and wondered if my symptoms were caused by bacterial overgrowth. My first attempts to get off my medicines didn't work. I tried to eat low-carb in the dining hall, but I guess the foods had too much crap on them. Luckily, I took summer school and lived dining-hall free in graduate student housing, though my "kitchen" had only a microwave. Looking back, my diet wasn't all that great. I didn't know that much about cooking and nothing about meat. The first meat I bought was some sausage, which I tried to cook in the microwave only to get a massive bowl of exploding grease. Gross. I had to eat out a lot, but stayed mostly paleo and very low carb. I tried lots of remedies like probiotics and drinking apple cider vinegar after each meal. I started drinking kombucha. I read everything I could get my hands on about traditional nutrition. It seemed clear my illness was a modern disease.
I had a goal in mind: as a freshman I had tried spicy food for the first time and learned to love it, but I had thought it was causing all my problems. When it was clear that this was a secondary problem to the inflammation and dysbiosis, I decided to make eating it without pain a goal. I didn't reach that goal until six months into the regimen, but I've been eating delicious curries without incident ever since.
I've also been able to travel extensively without incident, something I thought I'd never do.
Unfortunately I still had some residual IBS issues. I realized a year ago that I was going to have to let go of beer and gluten-containing cheat meals. The IBS has been gone ever since, but I really do miss some of those foods.
So basically the principals I went on were that bacteria was at the root of most of my problems. Being born by C-section, a low-nutrient diet, and constant antibiotic use had put my gut ecology into an imbalanced state. Probably some of my medications made it worse, like Prilosec/Nexium, which is known to allow bacterial overgrowth. My principles were to first starve out the bad bacteria, which was inspired a bit by Hyperlipid, and then gradually try to balance the gut through gentle traditional probiotic and nutrient-rich foods. I suspect I had both hypochlorhydria and small-bacterial overgrowth, which was why I was so excited by the paper I just blogged about.
I'm still quite fiber-intolerant. I can't really do brown rice, quinoa, or many other fiber-rich grains. But I am able to eat a fair amount of carbs, which I'm happy with. As an aside, even some in the alternative health community are very wrong about IBS. Giving up simple sugar will do nothing, as they are digested in the small intestine, which is a point made by the SCD diet. It's the complex sugars that cause the problems in the lower intestine.
As for romance, duh it's easier when you aren't a miserable gas-filled bloated cramped up woman who alternates between diarrhea and constipation (with hemorrhoids) every two days...
So when people say paleo or traditional foods are trivial, I'm just happy I can live a relatively normal life thanks to them. So I thank these things for my good health
When I was a child I was obsessed with several things, but two of them were Motown Oldies and aliens. I also had a bad habit of hearing things rather strangely. A good example would be the song "It's in his kiss" by Betty Everett. For quite some time I thought it was actually "It's in his skin." Since I was also into aliens I kept thinking about would would be in his skin besides baby aliens? I must have seen that scene from Alien when my mother wasn't looking...
Today I found a paper that is about how your skin isn't just a reflection of whether or not aliens are gestating within you, but whether you have a healthy gut. This paper has almost all of the real food/paleo blogospheres interests: probiotics, cod liver oil, leaky gut, acne, stomach flora, depression, and aliens. Just kidding about the aliens. Unless you consider our gut flora aliens...who knows?
Either way, the authors have put together many interesting puzzle pieces to lend support to the idea that the bacteria in your gut are connected to the condition of your skin and your mood.
So first there is the association. I bet you are thinking that "of course people with acne aren't happy because acne sucks." But there are a lot of other medical conditions that probably suck more like epilepsy and diabetes. Mental health impairment scores, a measurement of distress, are higher for acne sufferers than from people with these conditions and many other unpleasant illnesses. The gut connection has also been documented, for example in a student of 13,000 adolescents that found that people with acne were more likely to experience stomach problems, in particular abdominal bloating. These and other studies are shining a light on this connection, but it has been theorized for a very long time. The authors of this paper particularly pay homage to a 1930 paper by dermatologists John H. Stokes and Donald M. Pillsbury that contained this hypothesis.
I would like to get ahold of this paper and have requested it at school. One of the main reasons is it apparently contains evidence that many people with acne have low stomach acid AKA hypochlorhydria. The idea that many people have a sub-clinical form of condition is popular in alternative health circles and I've looked for evidence for some time and it seems to be poorly studied.
Also, 80 years ago these dermatologists were thinking about stress altering gut bacteria and this leading to leaky gut (abnormal intestinal permeability)!! Whoa. These doctors were ahead of their time.
The lack of research into stomach acid in otherwise "healthy" people is unfortunate, but the growth of heartburn in America has given us some research that we can make some inferences with. For example, half of people on proton pump inhibitors, a heartburn medicine that gives you low stomach acid on purpose, have small intestinal bacterial overgrowth. Wow, I'm so glad I got off those...SIBO is connected with leaky gut pretty well in the medical literature.
SIBO has also been connected with depression. Most research needs to be done on specifically connecting acne to SIBO, but it's clearly something to investigate.
Studies found that people with acne have circulating endotoxins from gut bacteria in their blood, which healthy controls did not have. These endotoxins belong in the gut, not in the blood and it's likely they got there through abnormal intestinal permeability. Eventually the body develops reactions to these toxins, which have been connected to depression and anxiety.
There is also evidence that decreased digestive transit time can be caused by stress and this increased time can lead to bacterial overgrowth as well. Constipation has been connected to acne in several studies. Other studies showed that people suffering from constipation have low levels of good bacteria.
So what did they do about this issue in 1930? Their prescription was for fermented milk and cod liver oil...sounds kind of Weston A. Price-ish huh? But wait! Doesn't dairy CAUSE acne? Well Cordain and other paleo authors who have made that connection have rightfully said that dairy contains IGF-1, which IS connected to acne. BUT fermentation reduces this 4-fold. And studies on dairy and acne show the connection doesn't hold for fermented dairy. Dairy also contains the anti-inflammatory protein lactoferrin, which has shown to decrease acne.
A Russian study showed that drinking milk fermented with lactobactillus reduced acne and an Italian study showed that a probiotic with freeze-dried L. acidophilus and B. bifidum did the same. Saccharomyces cerevisiae has been found to improve both acne and constipation, as well as to improve the integrity of the gut lining. Surely more studies need to be done, but it sounds promising.
Interestingly probiotics might also help with depression. One study found that depression patients had low levels of lactobactillus. Some other studies have shown depression can respond positively to probiotic treatment. Why? They have been found to increase tryptophan levels, alter serotonin and dopamine turnover (those are the neurotransmitters that antidepressants alter), decrease negative response to stress, increase omega-3 tissue levels, decrease internal lipid oxidation and other good stuff. Unfortunately some of these studies were on mice, so we need more human studies. But there have been a few studies in humans and they have shown positive effects.
The authors of the paper make a valuable point which is that in many folk health theories there is a focus on things rotting in the gut which causes constipation which causes all manner of problems. Usually the thing they blame is meat. This has led to way too much focus on what ends up being a symptom which is ironically caused by things not rotting in your gut. But rotting is kind of a mean term for the valuable services that gut bacteria perform. They will rot your body, but that happens AFTER you die...
This research is especially important because common treatments for acne include some seriously harsh drugs with terrible side effects, as well as antibiotics, which might end up making other problems worse since they decrease all bacteria instead of improving the gut ecology.
Isn't it crazy that little tiny weird bacteria can affect your appearance and mood so much? Maybe I was right about the aliens...