Wheat: Much More Than You Wanted To Know

After hearing conflicting advice from diet books and the medical community, I decided to look into wheat.

There are two sets of arguments against including wheat in the diet. First, wheat is a carbohydrate, and some people support low carbohydrate diets. Second, something might be especially dangerous about wheat itself.

It was much easier to figure out the state of the evidence on low-carbohydrate diets. They seem to be at least as good and maybe a little better for weight loss than traditional diets, but this might just be because there are lots of carbohydrates that taste very good and when forced to avoid them, people eat less stuff. They may or may not positively affect metabolic parameters and quality of life. (1, 2, 3, 4). They don’t seem to cause either major health benefits or major health risks in the medium term, which is the longest term for which there is good data available – for example, they have no effect on cancer rates. Overall they seem solid but unspectacular. But there’s a long way between “low carbohydrate diet” and “stop eating wheat”.

So I was more interested in figuring out what was going on with wheat in particular.

Wheat contains chemicals [citation needed]. The ones that keep cropping up (no pun intended) in these kinds of discussions are phytates, lectins, gluten, gliadin, and agglutinin, the last three of which for your convenience have been given names that all sound alike.

Various claims have been made about these chemicals’ effects on health. These have some prima facie plausibility. Plants don’t want to be eaten [citation needed] and they sometimes fill their grains with toxins to discourage animals from eating them. Ricin, a lectin in the seeds of the castor oil plant so toxic it gets used in chemical warfare, is a pretty good example. Most toxins are less dramatic, and most animals have enzymes that break down the toxins in their preferred food sources effectively. But if humans are insufficiently good at this, maybe because they didn’t evolve to eat wheat, some of these chemicals could be toxic to humans.

On the other hand, this same argument covers every pretty much every grain and vegetable and a lot of legumes – pretty much every plant-based food source except edible fruits. So we need a lot more evidence to start worrying about wheat.

I found the following claims about negative effects of wheat:

1. Some people without celiac disease are nevertheless sensitive to gluten.
2. Wheat increases intestinal permeability, causing a leaky gut and autoimmune disease.
3. Digestion of wheat produces opiates, which get you addicted to wheat.
4. Wheat something something something autism and schizophrenia.
5. Wheat has been genetically modified recently in ways that make it much worse for you.
6. The lectins in wheat interfere with leptin receptors, making people leptin resistant and therefore obese.

I’ll try to look at each of those and then turn to the positive claims made about wheat to see if they’re strong enough to counteract them.

Some People Without Celiac Disease Are Sensitive To GlutenMostly true but of limited significance

Celiac disease is one source of concern. Everybody on all sides of the wheat debate agree about the basic facts of this condition, which affects a little less than 1% of the population. They have severe reactions to the gluten in wheat. Celiac disease is mostly marked by gastroentereological complaints – diarrhea, bloating, abdominal pain – but it is also associated with vitamin deficiencies, anaemia, skin reactions, infertility, and “malaise”. It can be pretty straightforwardly detected by blood tests and gut biopsies and is not subtle.

People start to disagree about the existence of “gluten sensitivity”, which if it existed would be a bad reaction to gluten even in people who don’t test positive for celiac disease. Many people believe they have gastrointestinal (or other) symptoms that go away when they eat gluten-free diets, but science can’t find anything wrong with their intestines that could be causing the problems.

A recent study somewhat vindicated these people. Biesiekierski 2011 describes a double-blind randomized controlled trial: people who said they had “gluten-sensitive” irritable bowel syndrome were put on otherwise gluten-free diets and then randomly given either gluten or a placebo. They found that the patients given gluten reported symptoms (mostly bowel-related and tiredness) much more than those given placebo (p = 0.0001) but did not demonstrate any of the chemical, immunological, or histological markers usually associated with celiac disease. A similar Italian study found the same thing, except that they did find a higher rate of anti-gluten antibodies in their patients. Another study found that non-celiacs with antibodies to gluten had higher rates of mortality. And another study did find a histological change in bowel barrier function on this group of patients with the introduction of gluten. And another study from the same group found that maybe FODMAPs, another component of wheat, are equally or more responsible.

The journal Gastroenterology, which you may not be surprised to learn is the leading journal in the field of gastroenterology, proclaims:

The current working definition of nonceliac gluten sensitivity (NCGS) is the occurrence of irritable bowel syndrome (IBS)-like symptoms after the ingestion of gluten and improvement after gluten withdrawal from the diet after exclusion of celiac disease based on negative celiac serologies and/or normal intestinal architecture and negative immunoglobulin (Ig)E-mediated allergy tests to wheat. Symptoms reported to be consistent with NCGS are both intestinal (diarrhea, abdominal discomfort or pain, bloating, and flatulence) and extra-intestinal (headache, lethargy, poor concentration, ataxia, or recurrent oral ulceration). These criteria strongly and conveniently suggest that NCGS is best understood as a subset of IBS or perhaps a closely related but distinct functional disorder. Although the existence of NCGS has been slowly gaining ground with physicians and scientists, NCGS has enjoyed rapid and widespread adoption by the general public.

But even this isn’t really that interesting. Maybe some people with irritable bowel syndrome or certain positive antibodies should try avoiding gluten to see if it helps their specific and very real symptoms. At most ten percent of people are positive antibody testing, and not all of those even have symptoms. That’s still a far cry from saying no one should eat wheat.

But the anti-wheat crowd says an alternative more sensitive antibody test could raise sensitivity as high as a third of the population. The test seems to have been developed by a well-respected and legitimate doctor, but it hasn’t as far as I can tell been submitted for peer review or been confirmed by any other source. Meh.

That’s boring anyway. The real excitement comes from sweeping declarations that the entire population is sensitive to wheat.

Wheat Increases Intestinal Permeability Causing A Leaky GutProbably true, of uncertain significance

There are gluten-induced mucosal changes in subjects without small bowel disease. And gliadin increases intestinal permeability in the test tube, which should be extremely concerning to any test tubes reading this.

But probably the bigger worry here are lectins, which include wheat germ agglutinin. WGA affects the intestinal permeability of rats, which should be extremely concerning to any rats reading this. The same substance has been found to produce pro-inflammatory cytokines and interfere with the growth of various organs including the gut.

So there’s pretty good evidence that chemicals in wheat can increase intestinal permeability. Who cares?

For years, “leaky gut syndrome” was an alternative medicine diagnosis that was soundly mocked by the mainstream medical establishment. Then the mainstream medical establishment confirmed it existed and did that thing where they totally excused their own mocking of it but were ABSOLUTELY OUTRAGED that the alternative medicine community might have in some cases been overenthusiastic about it.

Maybe I’m being too harsh. The alternative medicine community often does take “leaky gut syndrome” way too far.

On the other hand, it’s probably real and Nature Clinical Practice is now publishing papers saying it is “a key ingredient in the pathogenesis of autoimmune diseases” and “offers innovative, unexplored approaches for the treatment of these devastating diseases” and gut health has been deemed “a new objective in medicine”. Preliminary changes to intestinal permeability have been found in asthma, in diabetes, and even in depression.

But it’s not yet clear if this is cause and effect. Maybe the stress of having asthma increases intestinal permeability somehow. Or maybe high intestinal permeability causes asthma somehow. It sure seems like the latter might work – all sorts of weird antigens and stuff from food can make it into the bloodstream and alarm the immune system – but right now this is all speculative.

So what we have is some preliminary evidence that wheat increases intestinal permeability, and some preliminary evidence that increased intestinal permeability is bad for you in a variety of ways.

And I don’t doubt that those two facts are true, but my knowledge of this whole area is so weak that I wonder how much to worry.

What other foods increase intestinal permeability? Do they do it more or less than wheat? Has anyone been investigating this? Are there common things that affect intestinal permeability a thousand times more than wheat does, such that everything done by wheat is totally irrelevant in comparison?

Do people without autoimmune diseases suffer any danger from increased intestinal permeability? How much? Is it enough to offset the many known benefits of eating wheat (to be discussed later?) Fiber seems to decrease intestinal permeability and most people get their fiber from bread; would decreasing bread consumption make leaky gut even worse?

I find this topic really interesting, but in a “I hope they do more research” sort of way, not an “I shall never eat bread ever again” sort of way.

Digestion Of Wheat Produces Opiates, Which Get You Addicted To WheatProbably false, but just true enough to be weird

Dr. William Davis, a cardiologist, most famously makes this claim in his book Wheat Belly. He says that gliadin (a component of gluten) gets digested into opiates, chemicals similar to morphine and heroin with a variety of bioactive effects. This makes you addicted to food in general and wheat in particular, the same way you would get addicted to morphine or heroin. This is why people are getting fat nowadays – they’re eating not because they’re hungry, but because they’re addicted. He notes that drugs that block opiates make people want wheat less.

Does Wheat Make Us Fat And Sick, a review published in the Journal of Cereal Science (they have journals for everything nowadays) is a good rebuttal to some of Davis’ claims and a good pro-wheat resource in general.

They say that although gliadin does digest into opiates, those opiates are seven unit peptides and so too big to be absorbed from the gut to the bloodstream.

(note that having opiates in your gut isn’t a great idea either since there are lots of nerves there controlling digestion that can be affected by these drugs)

But I’m not sure this statement about absorption is even true. First, large proteins can sometimes make it into the gut. Second, if all that leaky gut syndrome stuff above is right, maybe the gut is unusually permeable after wheat consumption. Third, there have been sporadically reported cases of gliadin-derived opiates found in the urine, which implied they got absorbed somehow.

There’s a better counterargument on the blog The Curious Coconut. She notes that there’s no evidence these peptides can cross the blood-brain barrier, a precondition for having any psychological effects. And although the opiate-blocker naloxone does decrease appetite, this effect is not preferential for wheat, and probably more related to the fact that opiates are the way the brain reminds itself it’s enjoying itself (so that opiate-blocked people can’t enjoy eating as much).

And then there’s the usual absence of qualifiers. Lots of things are “chemically related” to other chemicals without having the same effect; are gliadin-derived opiates addictive? Are they produced in quantities high enough to be relevant in real life? Corn, spinach, and maybe meat can all get digested into opiates – is there any evidence wheat-derived opiates are worse? This is really sketchy.

The most convincing counterargument is that as far as anyone can tell, wheat makes people eat less, not more:

Prospective studies suggest that weight gain and increases in abdominal adiposity over time are lower in people who consume more whole grains. Analyses of the Physicians’ Health Study (27) and the Nurses’ Health Study (26) showed that those who consumed more whole grain foods consistently weighed less than those who consumed fewer whole grain foods at each follow-up period of the study. Koh-Banerjee et al. (27) estimated that for every 40-g increase in daily whole grain intake, the 8-y weight gain was lower by 1.1 kg.

I’ll discuss this in more detail later, but it does seem like a nail in the coffin for the “people eat too much because they’re addicted to wheat” theory.

Still, who would have thought that wheat being digested into opiates was even a little true?

Wheat Something Something Something Autism And SchizophreniaDefinitely weird

Since gluten-free diets get tried for everything, and everything gets tried for autism, it was overdetermined that people would try gluten-free diets for autism.

All three of the issues mentioned above – immune reactivity to gluten, leaky guts, and gliadin-derived opiates – have been suggested as mechanisms for why gluten free diets might be useful in autism.

Of studies that have investigated, a review found that seven reported positive results, four negative results, and two mixed results – but that all of the studies involved were terrible and the ones that were slightly less terrible seemed to be more negative. The authors described this as evidence against gluten-free diets for autism, although someone with the opposite bias could have equally well looked at the same review and described it as supportive.

However, a very large epidemiological study found (popular article, study abstract) that people with antibodies to gluten had three times the incidence of autism spectrum disease than people without, and that the antibodies preceded the development of the condition.

Also, those wheat-derived opioids from the last section – as well as milk-derived opioids called casomorphins – seem to be detected at much higher rates in autistic people.

Both of these factors may have less to do with wheat in particular and more to do with some general dysregulation of peptide metabolism in autism. If for some reason the gut kept throwing peptides into the body inappropriately, this would disrupt neurodevelopment, lead to more peptides in the urine, and give the immune system more chance to react to gluten.

The most important thing to remember here is that it would be really wrong to say wheat might be “the cause” of autism. Most likely people do not improve on gluten-free diets. While there’s room to argue that people might have picked up a small signal of them improving a little, the idea that this totally removes the condition is right out. If we were doing this same study with celiac disease, we wouldn’t be wasting our time with marginally significant results. Besides, we know autism is multifactorial, and we know it probably begins in utero.

Schizophrenia right now is in a similar place. Schizophrenics are five to seven times more likely to have anti-gliadin antibodies as the general population. We can come up with all sorts of weird confounders – maybe antipsychotic medications increase gut permeability? – but that’s a really strong result. And schizophrenics have frank celiac disease at five to ten times the rate of the general population. Furthermore, a certain subset of schizophrenics sees a dramatic reduction in symptoms when put on a strict gluten-free diet (this is psychiatrically useless, both because we don’t know which subset, and because given how much trouble we have getting schizophrenics to swallow one lousy pill every morning, the chance we can get them to stick to a gluten-free diet is basically nil). And like those with autism, schizophrenics show increased levels of weird peptides in their urine.

But a lot of patients with schizophrenia don’t have reactions to gluten, a lot don’t improve on a gluten free diet, and other studies question the research showing that any of them at all do.

The situation here looks a lot like autism – a complex multifactorial process that probably isn’t caused by gluten but where we see interesting things going on in the vague territory of gluten/celiac/immune response/gut permeability/peptides, with goodness only knows which ones come first and which are causal.

Wheat Has Been Genetically Modified Recently In Ways That Make It Much Worse For YouProbably true, especially if genetically modified means “not genetically modified” and “recently” means “nine thousand years ago”

If you want to blame the “obesity epidemic” or “autism epidemic” or any other epidemic on wheat, at some point you have to deal with people eating wheat for nine thousand years and not getting epidemics of these things. Dr. Davis and other wheat opponents have turned to claims that wheat has been “genetically modified” in ways that improve crop yield but also make it more dangerous. Is this true?

Wheat has not been genetically modified in the classic sense, the one where mad scientists with a god complex inject genes from jellyfish into wheat and all of a sudden your bread has tentacles and every time you try to eat it it stings you. But it has been modified in the same way as all of our livestock, crops, and domestic pets – by selective breeding. Modern agricultural wheat doesn’t look much like its ancient wild ancestors.

The Journal Of Cereal Science folk don’t seem to think this is terribly relevant. They say:

Gliadins are present in all wheat lines and in related wild species. In addition, seeds of certain ancient types of tetraploid wheat have even greater amounts of total gliadin than modern accessions…There is no evidence that selective breeding has resulted in detrimental effects on the nutritional properties or health benefits of the wheat grain, with the exception that the dilution of other components with starch occurs in modern high yielding lines (starch comprising about 80% of the grain dry weight). Selection for high protein content has been carried out for bread making, with modern bread making varieties generally containing about 1–2% more protein (on a grain dry weight basis) than varieties bred for livestock feed when grown under the same conditions. However, this genetically determined difference in protein content is less than can be achieved by application of nitrogen fertilizer. We consider that statements made in the book of Davis, as well as in related interviews, cannot be substantiated based on published scientific studies.

In support of this proposition, in the test tube ancient grains were just as bad for celiac patients’ immune systems as modern ones.

And yet in one double-blind randomized-controlled trial, people with irritable bowel syndrome felt better on a diet of ancient grains than modern ones (p < 0.0001); and in another, people on an ancient grain diet had lower inflammatory markers and generally better nutritional parameters than people on a modern grain one. Isn’t that interesting?

Even though it’s a little bit weird and I don’t think anyone understands the exact nutrients at work, sure, let’s give this one to the ancient grain people.

The Lectins In Wheat Interfere With Leptin Receptors, Making People Leptin Resistant And Therefore ObeseCurrently at “mere assertion” level until I hear some evidence

So here’s the argument. Your brain has receptors for the hormone leptin, which tells you when to stop eating. But “lectin” sounds a lot like “leptin”, and this confuses the receptors, so they give up and tell you to just eat as much as you want.

Okay, this probably isn’t the real argument. But even though a lot of wheat opponents cite the heck out of this theory, the only presentation of evidence I can find is Jonsson et al (2005), which points out that there are a lot of diseases of civilization, they seem to revolve around leptin, something common to civilization must be causing them, and maybe that thing could be lectin.

But civilization actually contains more things than a certain class of proteins found in grains! There’s poor evidence of lectin actually interfering with the leptin receptor in humans. The only piece of evidence they provide is a nonsignificant trend toward more cardiovascular disease in people who eat more whole grains in one study, and as we will see, that is wildly contradicted by all other studies.

This one does not impress me much.

Wheat Is Actually Super Good For You And You Should Have It All The TimeProbably more evidence than the other claims on this list

Before I mention any evidence, let me tell you what we’re going to find.

We’re going to find very, very many large studies finding conclusively that whole grains are great in a lot of different ways.

And we’re not going to know whether it’s at all applicable to the current question.

Pretty much all these studies show that people with some high level of “whole grain consumption” are much healthier than people with some lower level of same. That sounds impressive.

But what none of these studies are going to do a good job ruling out is that whole grain is just funging against refined grain which is even worse. Like maybe the people who report low whole grain consumption are eating lots of refined grain, and so more total grain, and the high-whole-grain-consumption people are actually eating less grain total.

They’re also not going to rule out the universal problem that if something is widely known to be healthy (like eating whole grains) then the same health-conscious people who exercise and eat lots of vegetables will start doing it, so when we find that the people doing it are healthier, for all we know it’s just that the people doing it are exercising and eating vegetables.

That having been said, eating lots of whole grain decreases BMI, metabolic risk factors, fasting insulin, and body weight (1, 2, 3, 4,5.)

The American Society For Nutrition Symposium says:

Several mechanisms have been suggested to explain why whole grain intake may play a role in body weight management. Fiber content of whole grain foods may influence food volume and energy density, gastric emptying, and glycemic response. Whole grains has also been proposed to play an important role in promoting satiety; individuals who eat more whole grain foods may eat less because they feel satisfied with less food. Some studies comparing feelings of fullness or actual food intake after ingestion of certain whole grains, such as barley, oats, buckwheat, or quinoa, compared with refined grain controls indicated a trend toward increased satiety with whole grains. These data are in accordance with analyses determining the satiety index of a large number of foods, which showed that the satiety index of traditional white bread was lower than that of whole grain breads. However, in general, these satiety studies have not observed a reduction in energy intake; hence, further research is needed to better understand the satiety effects of whole grains and their impact on weight management.

Whole grains, in some studies, have also been observed to lower the glycemic and insulin responses, affect hunger hormones, and reduce subsequent food intake in adults. Ingestion of specific whole grains has been shown to influence hormones that affect appetite and fullness, such as ghrelin, peptide YY, glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1, and cholecystokinin. Whole grain foods with fiber, such as wheat bran or functional doses of high molecular weight β-glucans, compared with lower fiber or refined counterparts have been observed to alter gastric emptying rates. Although it is likely that whole grains and dietary fiber may have similar effects on satiety, fullness, and energy intake, further research is needed to elucidate how, and to what degree, short-term satiety influences body weight in all age groups.

Differences in particle size of whole grain foods may have an effect on satiety, glycemic response, and other metabolic and biochemical (leptin, insulin, etc.) responses. Additionally, whole grains have been suggested to have prebiotic effects. For example, the presence of oligosaccharides, RS, and other fermentable carbohydrates may increase the number of fecal bifidobacteria and lactobacilli (49), thus potentially increasing the SCFA production and thereby potentially altering the metabolic and physiological responses that affect body weight regulation.

In summary, the current evidence among a predominantly Caucasian population suggests that consuming 3 or more servings of whole grains per day is associated with lower BMI, lower abdominal adiposity, and trends toward lower weight gain over time. However, intervention studies have been inconsistent regarding weight loss

The studies that combined whole and refined grains are notably fewer. But Dietary Intake Of Whole And Refined Grain Breakfast Cereals And Weight Gain In Men finds that among 18,000 male doctors, those who ate breakfast cereal (regardless of whether it was whole and refined) were less likely to become overweight several years later than those who did not (p = 0.01). A book with many international studies report several that find a health benefit of whole grains, several that find a health benefit of all grains (Swedes who ate more grains had lower abdominal obesity; Greeks who ate a grain-rich diet were less likely to become obese; Koreans who ate a “Westernized” bread-and-dairy diet were less likely to have abdominal obesity) and no studies that showed any positive association between grains and obesity, whether whole or refined.

I cannot find good interventional trials on what happens when a population replaces non-grain with grain.

On the other hand, Dr. Davis and his book Wheat Belly claim:

Typically, people who say goodbye to wheat lose a pound a day for the first 10 days. Weight loss then slows to yield 25-30 pounds over the subsequent 3-6 months (differing depending on body size, quality of diet at the start, male vs. female, etc.)

Recall that people who are wheat-free consume, on average, 400 calories less per day and are not driven by the 90-120 minute cycle of hunger that is common to wheat. It means you eat when you are hungry and you eat less. It means a breakfast of 3 eggs with green peppers and sundried tomatoes, olive oil, and mozzarella cheese for breakfast at 7 am and you’re not hungry until 1 pm. That’s an entirely different experience than the shredded wheat cereal in skim milk at 7 am, hungry for a snack at 9 am, hungry again at 11 am, counting the minutes until lunch. Eat lunch at noon, sleepy by 2 pm, etc. All of this goes away by banning wheat from the diet, provided the lost calories are replaced with real healthy foods.”

Needless to say, he has no studies supporting this assertion. But the weird thing is, his message board is full of people who report having exactly this experience, my friends who have gone paleo have reported exactly this experience, and when I experimented with it, I had pretty much exactly this experience. Even the blogger from whom I took some of the strongest evidence criticizing Davis says she had exactly this experience.

The first and most likely explanation is that anecdotal evidence sucks and we should shut the hell up. Are there other, less satisfying explanations?

Maybe completely removing wheat from the diet has a nonlinear effect relative to cutting down on it? For example, in celiac disease there is no such thing as “partially gluten free” – if you have any gluten at all, your disease comes back in full force. This probably wouldn’t explain Dr. Davis’ observation – neither I nor my other wheatless-experimentation friends were as scrupulous as a celiac would have to be. But maybe there’s a nonlinear discrepancy between people who have 75% the wheat of a normal person and 10% the wheat of a normal person?

Maybe there’s an effect where people who like wheat but remove it from the diet are eating things they don’t like, and so eat less of them? But people who don’t like wheat like other stuff, and so eat lots of that?

Maybe wheat in those studies is totally 100% a confounder for whether people are generally healthy and follow their doctor’s advice, and the rest of the doctor’s advice is really good but the wheat itself is terrible?

Maybe cutting out wheat has really positive short-term effects, but neutral to negative long-term effects?

Maybe as usual in these sorts of situations, the simplest explanation is best.

Final Thoughts

Non-celiac gluten sensitivity is clearly a real thing. It seems to produce irritable bowel type symptoms. If you have irritable bowel type symptoms, it might be worth trying a gluten-free diet for a while. But the excellent evidence for its existence doesn’t seem to carry over to the normal population who don’t experience bowel symptoms.

What these people have are vague strands of evidence. Something seems to be going on with autism and schizophrenia – but most people don’t have autism or schizophrenia. The intestinal barrier seems to become more permeable with possible implications for autoimmune diseases – but most people don’t have autoimmune disease. Some bad things seem to happen in rats and test tubes – but most people aren’t rats or test tubes.

You’d have to want to take a position of maximum caution – wheat seems to do all these things, and even though none of them in particular obviously hurt me directly, all of them together make it look like the body just doesn’t do very well with this substance, and probably other ways the body doesn’t do very well with this substance will turn up, and some of them probably affect me.

There’s honor in a position of maximum caution, especially in a field as confusing as nutrition. It would not surprise me if the leaky gut connection turned into something very big that had general implications for, for example, mental health. And then people who ate grain might regret it.

But stack that up against the pro-wheat studies. None of them are great, but they mostly do something the anti-wheat studies don’t: show direct effect on things that are important to you. Most people don’t have autism or schizophrenia, but most people do have to worry about cardiovascular disease. We do have medium-term data that wheat doesn’t cause cancer, or increase obesity, or contribute to diabetes, or any of that stuff, and at this point solely based on the empirical data it seems much more likely to help with those things than hurt.

I hope the role of intestinal permeability in autoimmune disease gets the attention it deserves – and when it does, I might have to change my mind. I hope people stop being jerks about gluten sensitivity, admit it exists, and find better ways to deal with it. And if people find that eliminating bread from their diet makes them feel better or lose weight faster, cool.

But as far as I can tell the best evidence is on the pro-wheat side of things for most people at most times.

[EDIT: An especially good summary of the anti-wheat position is 6 Ways Wheat Can Destroy Your Health. An especially good pro-wheat summary is Does Wheat Make Us Fat And Sick?]

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62 Responses to Wheat: Much More Than You Wanted To Know

  1. Brandon says:

    Re: your title. Actually, that’s pretty much exactly as much as I wanted to know.

  2. Chris Billington says:

    There’s another, incredibly common ailment, the management of which often involves avoiding wheat: fructose malabsorption, where the gut can’t absorb fructose well and so bacteria feed on it and cause gastrointestinal symptoms.

    About 30% of randomly chosen people test positive for fructose malabsorption. It’s so incredibly common and yet doctors rarely test for it. Awareness is increasing though.

    Management involves avoiding foods with more fructose than glucose (glucose aids absorption). The worst offenders are garlic, onion, apples, pears, and anything sweetened with fructose. Garlic and onion are so much worse than obviously sweet things like apples, because they contain fructans, which are long-chain polymers of fructose and hence contain many more fructose molecules despite not tasting sweet.

    Anyway, wheat contains fructans. However since a lot of bread also contains glucose, a given fructose malabsorbant person may or may not have issues eating wheat in bread (depending on how well glucose aids absorption for them, it seems to vary from person to person). Some avoid it altogether, for others (like me), it’s fine unless you have absolutely tons of it.

    There are a lot of related chemicals poorly absorbed by the gut, and so fructose malabsorbant people are often recommended to trial a low FODMAP diet and slowly reintroduce things to see what they can and can’t handle.

    I suspect that this very common condition would play a pretty big role in society’s tolerance of wheat!

    • Scott Alexander says:

      That’s interesting, but once again seems limited in utility to people with specific gastrointestinal complaints who are looking for a cure.

      • Chris Billington says:

        Well, it’s a continuum thing, different people have different levels of sensitivity. When I say 30% of people have it, that’s the proportion of people who blow above a threshold on a hydrogen breath test, whereas practically everyone blows nonzero hydrogen after eating fructose (the hydrogen is produced by gut bacteria metabolising it).

        I wouldn’t be surprised at all if it turns out that people without specific symptoms still have worse absorption of nutrients in the presence of fructose, and that this could affect their health long term.

        On a further note, just based on the ambient sounds whenever I’m sitting in a public toilet cubicle, it even seems that the majority of people have some sort of gastrointestinal issue.

    • Anonymous says:

      Are there any negatives from fructose malabsorption that aren’t the symptoms? Is there a reason to care about this if one is not experiencing symptoms?

      • Chris Billington says:

        Sortof, but not really. Any other problems generally follow on from the digestive symptoms. Generally having food spend less time in your gut is a bad thing, as you can’t absorb as much of the nutrients in a shorter time.

        I suppose it’s possible that someone might have very mild symptoms, in that food goes through their gut twice as fast say, and they might not notice this as a problem, but it could still affect their health.

        If you actually do have the full symptoms though, the loss of water from bowel movements can give you electrolyte (amongst other) deficiencies. In my own case, I’ve been potassium deficient in the past, and have been on a low fructose diet for about a year, since I got diagnosed. Potassium levels were measured just the other week, and they’re *still* low, even though my digestive symptoms are much better. This could of course be unrelated, but is some evidence that something is still causing me to lose electrolytes faster than my copious banana consumption can replace them.

  3. J says:

    You lost all credibility when I realized you’re a wheat tentacle denier.

  4. Daniel Speyer says:

    Could the something something between wheat and autism involve gut bacteria? It seems plausible that chemicals in wheat that don’t directly affect eukaryotes could still do something there.

  5. Fnord says:

    Regarding the “people who started a wheat free diet lost a bunch of weight” claim, wasn’t there a theory that ANY significant, intentional dietary change is likely to cause people to lose weight?

    You gave up a bunch of stuff that you liked eating, so you’re eating less. And because you have to pay special attention to meal planning in order to eat at all, portion control becomes less of a hassle. And this wondrous state of affairs lasts until you adjust to the new regime and find a bunch of new-diet-compliant foods that you like, whereupon you adopt the gluten-free (or whatever) equivalent of your original unhealthy eating habits.

    • I had a similar thought. In fact, I’ve wondered if banning yourself from all but the most heavily processed food could make you lose weight almost as well as any other diet.

      • rehana says:

        Conversely, I’ve wondered if all fad diets work until convenience food manufacturers learn to accommodate them.

    • meyerkev says:

      So for what it’s worth, the selling point for Atkins IS NOT that it makes you lose weight, it’s that it makes you lose weight FAST early on.

      A pound is 3500 calories. Using http://thedietfix.com/calculator.aspx, at my fattest, I was apparently eating 3500 calories a day.

      So if I cut back from 3500 to 2000, I’m going to lose 3 pounds a week right up until my metabolism freaks out because I’m only eating 2000 calories a day. And uh, as someone with scale addiction, the only thing more volatile than the stock market is your weight. Which means that I get depressed after *only* losing 1 pound last week (or gaining 2), and stop. A pound gets lost in the noise.

      Whereas if I was 320, dropped to 310 quickly, slowly dropped to about 300 over the next month and a half, and then am getting depressed about *only* losing 1 pound last week, I can mentally compare 299 to 320 and say that this weight-loss thing is really working and I should keep at it.

      And that’s exactly what happened. Took a few months after college, but:
      * Dropped 10 pounds in 2 weeks.
      * Dropped another 15 over the next 2 months.
      * Broke my ribs, only gained 5 back.
      * Within 6 months of starting my diet (and keep in mind that I’m not doing the food journal or any of that, just “Hey, let’s have a couple big pieces of chicken” instead of “Hey, let’s make a pot of rice”), having taken about 2 months off for ribs, I had dropped 50 pounds.

      8 months after starting this (WITH 3 months off between ribs and January laziness), I’m down 65 pounds. And I’m not even doing the actual diet.

      Data is not plural of anecdote, but I keep hearing a lot of anecdotes, so it MAY be worth trying for a week or 2.

      /And always keep in mind: You have to live like this forever. Massive “Biggest Loser”-style weight loss screws with your metabolism. And if you can’t live like this, you can’t keep weighing this.

    • Eliezer Yudkowsky says:

      There are 2 hypothesized effects which make any diet appear to work, 3 if we’re talking about low-carb. That’s why, 20 pounds later, I’m still not sure if my Super Ketonic Dietary Replacement Fluid has validated its underlying theory.

      1) Seth Roberts’s flavor-calorie association effect. Food raises our set point, which naturally drops continuously, in accordance with how much we’ve learned to associate that flavor with calories, possibly because that signals food availability to us. Eating any new unfamiliar food, that is getting lots of calories with an unfamiliar taste, produces easy weight loss. Then your body forms a flavor-calorie association and the weight loss stops.

      2) Micronutrient deficiency – I read about this in the Jaminets, don’t know if it’s original to them. The foods you eat are subtly deficient in something your body knows how to sense, so it makes you want to eat more. Shifting to a new set of foods corrects that deficiency, and your body has stores of some key micronutrients, so you experience less hunger for a while until a new micronutrient deficiency builds up and the diet appears to stop working.

      3) By far the best-understood phenomenon here is the “honeymoon effect” of very-low-carb diets which deplete glycogen from muscles. The glycogen comes with water. That’s going to account for 5-15(!) pounds of immediate weight loss on any very-low-carb diet.

      Protein-deficient diets, especially low-carb ones, will also produce weight loss due to muscle tissue loss.

      • Ialdabaoth says:

        I’ve personally been a proponent of theory 2 since I was a small child – I could distinguish between “hungry” and “craving” very easily, and spent a few years between the ages of 8 and 12 learning to associate certain cravings with certain foods. I’ve always been remarkably fit, but whether that’s a result of that process or just natural metabolic luck would require a LOT of effort to test.

      • Douglas Knight says:

        For your particular case, how plausible is the micronutrient explanation? If there are subtle micronutrient problems, wouldn’t they be much worse for diets that are homogeneous and artificial? Moreover, that such diets do not have an anti-honeymoon period seems like a general argument against the theory. However, there is a complementary theory of microtoxins, where artificial diets should shine.

  6. Daniel says:

    “… whole grain is just funging against refined grain…”

    The verb “to funge against” is one of my pet peeves. “To displace” exists, means the same thing, and can be understood by everybody even if they haven’t read that one blog post where it was introduced. Can we use the less jargon-y word please?

    • Douglas Knight says:

      “Fungible” isn’t jargon!
      It’s a perfectly normal word in every dictionary!
      meaning exactly the opposite of how cfar abuses it.

      • Daniel says:

        I agree that the adjective “fungible” isn’t jargon, but it’s not hugely well-known (unfortunately) and it’s not obvious that it’s the origin of the verb “to funge against” on first sight.

    • Said Achmiz says:

      I agree. Less unnecessary jargon, please.

    • Rachael says:

      I disagree. I’ve never seen any blog post in which “funge” was defined, but I’ve seen it used quite a lot on this blog, and I find it clear from context and etymology what it means. (There are other words in that category. “Utilons” springs to mind. I’m guessing that was coined on LessWrong, but it’s only a guess. I find its use here and on occasional people’s LiveJournals contextually and etymologically clear.)
      In this case “funge against” is more informative and explanatory than “displace” would be.

      • Daniel says:

        “In this case “funge against” is more informative and explanatory than “displace” would be.”

        I’m surprised by this. What would you infer from the sentence “Whole grain is just funging against refined grain” that you wouldn’t infer from “Whole grain is just displacing refined grain”?

        • Rachael says:

          The latter just reads like an assertion, leaving open the question of why. The former sounds like it’s placing the statement in the context of a more general claim that whole grain and refined grain are interchangeable, substitutes in the economic sense, so that is why eating more of one would cause you to eat less of the other and vice versa. It also connotes symmetry in a way that “displace” doesn’t.

          You could drink lots of cola, feel full up because of the gas, and so eat less grain. In that case the CO2 would displace the grain, but I wouldn’t say it funged against it.

          Of course speakers’ intuitions about the meanings of words vary slightly, and it might be that my understanding of “displace” is weaker than yours is.

        • Daniel says:

          That’s interesting, I only read into “funged against” what (as far as I can tell) you read into the word “displaced”. If I were to infer extra meaning into it, it would be that X funges against Y only if X and Y are fungible. However, that seems too strong: for instance, in the SSC post where the term is introduced, it is claimed that e-cigarettes might funge against normal cigarettes. However, those definitely aren’t fungible: they have importantly different qualities, and many people would prefer an e-cigarette to a normal one, or vice versa. Wikipedia’s list of examples of things that are and are not fungible seem to support my understanding of the word (http://en.wikipedia.org/wiki/Fungibility#Examples). In fact, I wouldn’t even say that they were interchangeable, which means that as far as I can tell, they couldn’t funge against each other by your definition.

          Question: Would you say that e-cigarettes could not funge against normal cigarettes, or that e-cigarettes and normal cigarettes are interchangeable, or am I missing something?

        • Rachael says:

          Hmm – looking at it more closely, I think you’re right that funge and fungible don’t carry exactly the same sense, but I still think funge is a useful word. I had inferred its meaning from context and informed by the *similar* meaning of fungible, but not consciously realised it didn’t mean quite the same.
          I would say e-cigarettes funge against normal cigarettes, but indeed, they’re not actually fungible. You’re right, this is confusing, I just hadn’t realised it.

      • Daniel says:

        Perhaps we could say “e-cigarettes are substituted for cigarettes”? Although it then becomes a bit awkward to say “e-cigarettes are substituted for non-smoking”, but then again I think “funge against” looks awkward there anyway.

        EDIT gah this was supposed to be a reply to Rachel’s “Hmm – looking at it more closely…”

    • David Hart says:

      Is it necessary? No. But it is a cool word. And in a language where for a majority of the concepts you desire to express possess an elevated Latinate form and also in a tongue where most of the thoughts you want to say have an earthy Germanic shape (i.e. we already have two words for almost everything), having another excess word is not going to hurt us 🙂

  7. St. Rev says:

    Miscellaneous remarks lightning round:

    Wheat is even more of a grotesque Frankenfood than you note here. Modern strains are monstrous mutant hybrids, containing the complete genomes of three different species, one of which isn’t even from the same genus. (See also the dastardly rutabaga.)

    Irrelevant but interesting to me: Most religions (and many subreligious movements) have extensive taboos about animal foods, but the ancient Daoists warned against grains instead. This may have reflected the late introduction of bread wheat into east Asia.

    On the gluten/lectin/leptin/etc. issue: Guyenet blogged extensively on traditional plant food processing methods (particularly soaking and fermenting) and their possible role in mitigating against poison load. It’s clearly important in at least some cases (even modern Westerners still soak beans and discard the soak water). “Traditional” peoples would usually have consumed wheat calories in the form of beer and/or sourdough bread. Worth reading.

    More useless anecdata: I can eat refined wheat products, but whole wheat products give me the whole IBS package of fun.

    • St. Rev says:

      nb. I am being sarcastic except not really about wheat being a Frankenfood. The hybridization events took place many thousands of years ago. It’s GMOs all the way down.

  8. Rachael says:

    >It means a breakfast of 3 eggs with green peppers and sundried tomatoes, olive oil, and mozzarella cheese for breakfast at 7 am and you’re not hungry until 1 pm.

    Again anecdotally, but I don’t find this. If I eat a meal with no carbs, I’m still hungry at the end of the meal, never mind four hours later. It’s a shame, because I do think protein and vegetables are generally better sources for most of your calories.

    • St. Rev says:

      My own experience with low-carbing is that it takes a few days of abstention before that effect kicks in. Put more concretely, it takes me three days before I start experincing the mysterious sensation of ‘satiety’. May be that glycogen stores have to be exhausted before things switch over to burning ketones.

  9. BenSix says:

    The “wheat is the root of all evil” – or should that be grain of all evil… – theory has always stumbled over the fact that it is consumed in so much larger quantities in nations outside of the US. The Bedouin Arabs used to eat over a loaf’s worth of bread every day, so if Davis was right about the scale of its evil they would have been fat and/or ill.

    (They were not, of course, though now, with modern diets and urban lifestyles, many of them are growing far more unhealthy.)

    On the other hand, it would not surprise me if people’s genetics make them more or less able to tolerate different nutrients. Darn genetics. They are tricksy things.

  10. mareofnight says:

    If it’s ok to ask, did you run across any articles connecting food to mental problems, where not eating the food did cause the problem to go away?

    One of my relatives and I are like this with corn syrup, sulfur dioxide preservatives, and a few other things. (Symptoms are moodiness and muddled thinking, respectively, and they’re very obvious – I’d be seeing a psychologist if I couldn’t fix it by controlling my diet.) I’ve tried to research it myself a few times, but I couldn’t find keywords that returned anything relevant. Seemed like it might be worth asking if you had any leads.

    • Scott Alexander says:

      I don’t know of anything like that, but I find it really fascinating. Can you explain a little more about which foods did that to you?

      • mareofnight says:

        Sure! I just didn’t want to leave a wall of text if you weren’t interested. Is it ok if we talk through some other method, though? I’m really open about telling people when they ask, but I hesitate to explain it all in public on the internet. (In case your software doesn’t show you my email, it’s mareofnight at gmail.)

    • It used to be that if I used wheat as a staple, I’d be more irritable in the sense of more inclined to obsess about things that irritated me. I cycled in and out of this a number of times.

      These days, the effect isn’t as strong or maybe not there at all, possibly because I’m on the other side of menopause.

      I’ve had enough experience with wheat and with hot flashes (some of which include irritability and some of which don’t) that I’m convinced irritability is a biochemical thing. Do you know of any research about irritability?

      • mareofnight says:

        I don’t know of any research on irritability, but I haven’t looked all that far. That’s interesting, though.

        This sounds a little like something that happens to both me and the relative I mentioned when we drink too much milk. She says she just gets irritable. I also get irritable (at its worst, I was feeling really, really angry about things like clutter being in my way and the wind blowing on me), but also depressed. It only got really, really bad if I was taking birth control at the same time, and it’s hard to say whether the hormones or the inactive ingredients in the pill (which included something with a chemical name similar to lactose) were causing the problem.

        I’ll ask her if wheat made her feel irritable too; I can’t remember what all changed when she stopped eating it.

        • So far as birth control is concerned, a friend of mine found out that birth control can cause zinc deficiency which can cause depression, and zinc supplements solved that.

          I hadn’t thought about different kinds of irritability, but physical stimulus irritability and verbal stimulus irritability might be different things.

          To be more specific about hot flashes, when they started, they were always infuriating. And why not? I hate being overheated.

          After some years, I started getting no irritability hot flashes, and I realized that the emotional part had a physical piece that wasn’t just about the temperature.

          Instead of stewing about the possible lack of research about irritability, I decided to check: Behold!. There seems to be rather a lot more about effects of irritability and drugs for irritability than about the physiology of irritability, but I only looked at three pages of results.

  11. Sarah says:

    IgG levels have a *huge* range. The difference between “produces antibodies” and “doesn’t produce antibodies” is not subtle. Celiac is usually tested with an antibody blood test (IgG and IgA). The guy you linked claims that antibodies often stay in the gut rather than getting all over the bloodstream, which means antibody blood tests would miss many cases. Does anybody know if this is even physically possible? Are antibody levels higher near the site of the allergen/pathogen than in the bloodstream?

    I have some data points pointing in that direction (I’ve been told that tumors and infected abcesses are surrounded by a concentration of antibodies). But, all in all, I don’t have a great model of what (in terms of immune signals) stays local and what gets all over the bloodstream.

  12. James says:

    In the random theories I saw the title of on the internet that sound vaguely plausible and didn’t investigate at all class, is that some of these effects may be from pesticides on the wheat.

    • James Babcock says:

      I haven’t read enough to reach a conclusion, but the accusations against glyphosate seem interesting. Also interesting is that, if it were in fact toxic and getting into food, then the anti-GMO movement would have been almost right; glyphosate resistance is one of the major genetic modifications done on crops, so GM crops are much more likely to have it used. (But this isn’t a difference in the genes themselves, it’s a difference in handling.)

      • Douglas Knight says:

        And how does this (idiotic) theory distinguish wheat from anything else?

        • Scott Alexander says:

          I appreciate your comments here which are always really perceptive, but could you tone it down a little with the “idiotic” and stuff like that?

  13. Eric says:

    The most worrying (to me) issue with wheat is claims some have made connecting it to heart disease. For example:


    What is your take on this?

  14. whales says:

    > (this is psychiatrically useless, both because we don’t know which subset, and because given how much trouble we have getting schizophrenics to swallow one lousy pill every morning, the chance we can get them to stick to a gluten-free diet is basically nil)

    Really? My understanding is that taking antipsychotics can be pretty awful, in ways that make it not remotely comparable to compliance with a diet. Implying that it is suggests a pretty severe lapse of empathy, and your tone here just makes it worse.

    • Scott Alexander says:

      No doubt some people with schizophrenia go off their medications because of side effects, but I ask my patients who go off antipsychotics why they did so and that is rarely their answer.

      I mostly see people go off antipsychotics because they decide “I’m all better now” or “drugs aren’t natural” or because they disimprove for some reason and start having delusions about the medications or their psychiatrist and then go off the drugs which makes it worse.

      I see this with about equal frequency on high-side-effect and low-side-effect antipsychotics, and even on antidepressants which have fewer side effects than any antipsychotic. Heck, forget psychiatry and ask your family doctor how many of her patients take antibiotics or blood pressure pills correctly as prescribed. Those often have few side effects and are prescribed to people with no cognitive problems, but we know that across all types of medicine only about 50% of prescribed medication is taken correctly.

      While some people do go off antipsychotics because of the side effects, I feel like there is a sort of political thing going on trying to claim that is the only or the major reason people go off their medications, and that does not accord with my experience. I will try to watch for this more carefully now that I am looking for it, and see if I can find any studies that give exact numbers.

      But regardless of how hard staying on antipsychotics may or may not be, gluten free diets are definitely really, really hard. It’s not just resisting the urge to eat bread or pasta or cake or cookies or crackers, ever, even once a year. It’s the fact that lots of non-bread stuff secretly has gluten in it – processed meats, cheeses, vegetables, whatever – and without exhaustively reading labels on everything you eat and never going out to restaurants, you’ll probably be consuming some by accident.

      Lots of schizophrenics have poor cognitive function, poor impulse control, substance abuse problems, and/or do not care for themselves and are cared for by people without much medical training and sometimes without much interest in the caretaker role. These factors can sometimes be overcome enough to get them to keep taking medication, but I really do think the chance of getting them to stick to a complicated diet is much lower.

      • whales says:

        Thanks for responding. And for not objecting to my rudeness. Maybe I let my irritation get in the way of what I was trying to say.

        I’m in agreement that, yes, it would probably be much harder to get a patient to stick to a gluten-free diet. And you’d know more than I do about why people go off their medications. I’m glad to know you’re being thoughtful about that question.

        But I think I failed to make my point, which was not so much about compliance rates, but more like this: A gluten-free diet is extremely difficult to maintain, but not at all unpleasant in the same way as many side effects. Comparing them as you did (“one lousy pill”) seemed dismissive of experienced suffering, and that’s particularly scary coming from someone in your position.

        I hope this doesn’t sound like a nitpick to you, but you didn’t (and still don’t) sound attuned to that idea, and that worried me. It does make more sense to me now that you were not thinking specifically about going off medication due to side effects. On the other hand, I still get an uncomfortable vibe that you’re looking at things exclusively in terms of “do they take the pills or not?” (Yes, I realize that you thought that’s what this was about, so of course you would talk about it; I’m saying that’s part of what worries me, even as much as the question does matter.) Does that make sense?

        Could you elaborate on “a sort of political thing”? I half suspect that my remarks could get dismissed under that ruling, being less obviously an empirical matter, but I’m not used to talking about this and don’t know what you’re referring to.

        (By the way, I’m certainly not trying to say it’s wrong or oppressive to prescribe things with bad side effects. The benefits seem to broadly outweigh the drawbacks, as you’re equipped to judge. But from my distant desk chair it seems like you could be more sensitive about the latter even if it doesn’t change the result of that calculation.)

        • Scott Alexander says:

          I am not trying to dismiss side effects, say I don’t care about them, or signal that I don’t know what they are.

          I am trying to say that in my experience, side effects are not the reason most people on antipsychotics come off their medication.

          If they come off their medication not because of side-effects but for general low consciousness or poor judgment, I think it makes sense to compare the relative ease of taking a pill to the relative difficulty of the diet.

          By “a political thing”, I think a lot of groups claiming to represent the mentally ill try to spin all of their decisions as rational responses to terrible doctors. So the main reason people go off their medication is that there are side effects, doctors don’t care about the side effects, whatever, and it has nothing to do with schizophrenia being a disabling illness that causes people to make poor judgments sometimes. Although once again I will try to stay aware of this, that is not my experience.

        • whales says:

          Yes, I already agree with what you are trying to say. The comparison makes sense in the way that you’re thinking about it. I also understand that you’re not trying to do those other things, and do not exactly mean to accuse you of them. I still feel I haven’t gotten my point across; I’ve sent you an email in case you want to continue the conversation.

          (I’m not trying to make that “political” case; thanks for explaining. I don’t understand the political motivations here, not being part of the scene. My default assumption would have been that these groups are genuinely trying to help people, but they sound liable to backfire by overstating their case, making doctors less likely to take accounts of mistreatment seriously. Anyway, I’m again glad to hear that you’re trying to be thoughtful about it.)

        • St. Rev says:

          @Nancy Lebovitz: ADHD meds feel totally incredibly awesome. Which is a problem in itself.

  15. Eliezer Yudkowsky says:

    So at this point my distrust of nutritional “studies”, in the field of dietary science (not science generally), is so great that if I and the people I know personally seem to mostly report the same phenomenon anecdotally, I assume the studies were glitched, cooked, selectively reported, outright faked etc., and I trust the other studies (there are always other studies) that seem consonant with the anecdotal evidence. The process whereby anecdotal evidence is reported is selective, but the fact that, e.g., it happened to you when you tried it so you could write a blog post about it, seems less subject to cooking than the process whereby studies are devised, adjusted for “control variables”, published, surveyed, the survey published, and then the survey cited often enough to notice.

    That said, I thought you tried the Jaminets’ PHD generally, not no-wheat in particular?

    Part of what I found convincing about the Jaminets’ story was that they depicted a world where there were enough complex interdependencies and fiddly little things where there were understandable reasons why studies gave conflicting results. Like studies on “eating more fat” where the fat eaten turns out to be soybean oil aka polyunsaturated omega-6 fat, or studies on Vitamin D that don’t come with corresponding amounts of Vitamin K. It’s not just a question of what “whole grain consumption” meant for refined grain consumption, there could be other fiddly things that also change. Insoluble fiber is not the same as soluble fiber and only some kinds of fiber get digested by your gut bacteria to butyrate (there are four kinds of “resistant starch” like that). A good controlled study would test whole grains against similar constituents of carbs and similar types of fiber, not just similar amounts of “fiber”.

    Sometimes this good evidence doesn’t exist, and sometimes we have to do with the evidence we have. But in a case like whole grains there may be powerful forces defining which studies are funded and published, and a free choice of control variables in correlational studies may ensure that plenty of studies which give the “right” answer will exist to be published. An alternative is to update hard on the nearby anecdotal evidence (not Internet anecdotes but the people we know personally, especially those who determined in advance to try the theory for the sake of testing it). Nearby anecdotal evidence may not be randomized, but at least it’s not cooked.

    • Sarah says:

      Yes, but you should also have a great fear of fiddly little things.
      You can find fiddly little things to explain everything.

  16. John Salvatier says:

    I would really really like your thoughts on the claim that depression is an inflammatory disease (http://www.biomedcentral.com/1741-7015/11/200). If its true, and that paper is written as if its basically confirmed, its one of those facts that makes you stop and say “okay, that’s a big clue about *something*, I just don’t know what”.

  17. pwyll says:

    Thanks Scott, I greatly appreciate these nutrition summary posts even if you often find that there’s not much evidence either for or against a particular proposition.

    Regarding weight loss on low-carb diets, I believe Stephen Guyenet among others has claimed that the fastest way to fatten rats is to give them a “cafeteria” diet with many junk food options, and that typically any dietary restriction, be it low-carb or low-fat, can result in weight loss simply due to the smaller number of food options available.

    As such, I suspect people see good results on Atkins because:
    1. Glycogen loss results in water weight loss
    2. You’re not eating sugar, and
    3. You’re not eating wheat.

    I do tend to agree with:
    1. Paul Jaminet’s argument that it’s a good idea to consume at least modest amounts of “safe starches” e.g. potatoes, rice, and cassava.
    2. Matt Stone’s assertion that low-carb diets are initially energizing (like caffeine) but eventually can cause burnout (like caffeine.)

  18. Duncan Wilson says:

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