Wednesday, February 27, 2013


Tam sent this article about gluten intolerance, etc., on Slate.

As she pointed out, the fact that 1% of people can experience life-threatening damage from gluten is a big deal.

The article states that 30% of people in a clinical trial who thought they were gluten intolerant "felt better with gluten-free diets," but I think it's important to note that the researchers were not studying gluten intolerance but wheat intolerance.  (Wheat contains gluten, but it also contains other things to which people might be sensitive, so wheat intolerance is broader than gluten intolerance.)  After going on an elimination diet (eliminating wheat, cow's milk, eggs, tomatoes, and chocolate), participants were given capsules containing either wheat or a placebo (xylose) and reported their symptoms. 30% of patients reported being asymptomatic (less than 10 in a 100-point symptom scale) on the elimination diet but reported symptoms (more than 30 on the scale) when the wheat was reintroduced.

One thing I wonder about that is relevant to the elimination/reintroduction paradigm they used (i.e., "double-blind placebo-controlled challenge") is whether wheat (or gluten) sensitivity follows a dose-response pattern - in other words, do some people tolerate a small amount of wheat (like found in a capsule) just fine, but start to suffer as their intake of wheat increases?  It seems to me that I can handle a little bit of wheat OK but that my body is unhappy with larger quantities.  (I've never figured out quite where my personal cut off point is, and it's complicated by the fact that for me there appear to be interaction effects between wheat consumption and other stuff going on in my body, such that sometimes eating wheat doesn't seem to give me symptoms, but in combination with other factors, wheat makes me feel pretty bad.  Due to not knowing how much is too much, and that in many ways it is easier to eliminate than moderate my consumption, I have often gone off wheat completely to manage my symptoms.  Right now I'm off wheat, and other high lectin foods, entirely.)

Aha:  I accessed the supplemental information through my university library and it states:  "Wheat challenge was performed administering a daily dose of 13 g of flour, equal to about 20 g of bread."  If I am understanding this correctly, people in the "wheat" group were only eating the equivalent of 20 g of bread, which is less than 1 slice (I see numbers for slices of wheat bread like 28 g for a 69 calorie slice, 42.5 g for a 100 calorie slice).  

At that relatively low level of wheat consumption, I'm not sure that I would have shown a significant increase in negative symptoms from the elimination stage to the reintroduction stage in this study.  I could easily not have shown up in the 30% at the level of wheat used in the experiment, but I think I might meet the wheat intolerance criteria if the level of wheat were higher. 

I thought the comment at the end of the article, "patients convinced they have gluten intolerance might do well to accept that their self-diagnosis may be wrong," was kind of goofy and unclear.  What's the big deal with thinking you have gluten intolerance when you don't?  You might have some other disease that you should be treating instead, but I get the sense that this article's position is more that a lot of people are just delusional rather than truly ill.  Wheat/gluten is not some kind of nutritional superstar that will cause health problems for people who eliminate it from their diet because of an incorrect belief that they are intolerant to it. 

Monday, February 18, 2013


UPDATE:  This link should work!

After the brief discussion about null hypothesis significance testing in the previous comments, I could not resist linking to this brilliant, insightful (and short!) article in Perspectives on Psychological Science.  It's probably a bit inside-baseball in its details for an audience of people who have not spent a lot of time in the psychology literature and publication racket, but I think most of my readers can appreciate it in a general way.

And how can we not love seeing the assertion "...economists are wrong about virtually everything" with the citation "(see Economics, all of it)."

So going back to the previous discussion of finding significant results in nutrition research, perhaps these people need to team up more with psychologists in conducting their research.

Sunday, February 17, 2013

In Which Tam Does My Work For Me

Tam is a grad student, which means she has a lot more time than I do.  I mean, I've got a book of several hundred sudoku puzzles to do and a slew of computer games I am working on and this presses on me.  (This leisure thing takes up a lot of time if you are really committed to it!)  So this week I've outsourced finding blog content to Tam (without her knowledge, but she totally came through).  So I present:

1) An awesome advice column "How to tighten up your game at work when you're depressed" from a site that looks worth spending a lot more time on. 

I think that a lot of people (esp. young ones, new to office work life) don't get it about how much appearances matter and how observing professionalism can be beneficial, even if you're not suffering from a serious mood disorder. 

I also found that this really resonated with me: "Jerkbrain Lie: Feeling depressed (lazy, horrible, avoidant) means that you can’t (get to work on time, complete work tasks, do writing that you need or want to do, do housework)."  For me, it's usually feeling anxious, stressed, sick, or reactant (just hating/resenting/etc. whatever idiotic thing my boss/advisor/professor/society/the angel of my better nature insists that I do) that presents itself as the big barrier, but it can function the same way.  I have found that controlling my behavior is a lot easier than controlling my feelings, so I make use of the "I don't have to like it, I only have to do it" mantra to pretty good effect.  I think it's important that people give themselves permission to not feel pumped and enthusiastic about something they are doing, and to not really enjoy the process at all.  And then afterwards, to feel like, "I did that and I didn't even want to" and maybe even "Thus I am a rockstar."  Because sometimes, just doing basic life tasks is rockstar material.  Today I am going to be a complete fucking rockstar and put some miles in on the treadmill even though I am feeling physically blah (because I know that moderate exercise is very helpful for improving my symptoms even though all I want to do is lounge about with my heating pad and a lot of dark chocolate).  I might not like doing it, but I don't have to.  

2) A blog post describing some newly published research supporting the “butter is better than high omega-6 veg/seed oils” argument.  The kicker: patients who were put on the safflower oil diet did have lower total and LDL cholesterol than those who kept their same diet, but they were more likely to die!  Oops!  

From the paper:  “As expected, increasing n-6 LA from safflower oil in the SDHS [Sydney Diet Heart Study] significantly reduced total cholesterol; however, these reductions were not associated with mortality outcomes (results not shown). Moreover, the increased risk of death in the intervention group presented fairly rapidly and persisted throughout the trial. These observations, combined with recent progress in the field of fatty acid metabolism, point to a mechanism of cardiovascular disease pathogenesis independent of our traditional understanding of cholesterol lowering.” 

(Plus: "All authors have completed the ICMJE uniform disclosure form ... and declare: support from the Life Insurance Medical Research Fund of Australia and New Zealand and the Intramural Program of the National Institute on Alcohol Abuse and Alcoholism for the submitted work; no financial relationships with any organizations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.")

So yeah, chasing a target cholesterol level with the assumption that it will keep you healthy/alive is not the smartest play here, which I think my readers already know even if their doctors do not.  Perhaps eventually medical practice and public policy will catch up with the science.

Monday, February 4, 2013

Oh Right That Also Causes Headaches

I was lying in bed at 2 p.m. with a mondo headache, very confused about its source, until I realized that I hadn't eaten anything for lunch yet.  I just ate some lunch and already the headache has retreated about 80%.  I know that being hungry can cause headaches in other people like Robert, but this isn't something I have a lot of experience with personally...because I have rarely been in a physical state in which hunger could reach this point without me already having collapsed from a blood sugar crash.  Strange.

A Blog I'm Reading

Tam recently introduced me to the blog Dances With Fat, written by a (once and future?) competitive dancer / activist / self-described "REALLY fat person".  It's a nice introduction to (one person's ideas about) size acceptance and health at any size.

Size acceptance is a civil rights movement making the pretty straightforward statement that the discrimination against and shaming of people on the basis of their body size is wrong and should stop.  Period.  Although DWF mostly talks about fat acceptance (which makes sense given the author's own size and the fact that it's overweight and obese people who bear the brunt of size prejudice), it also makes a point of including all body sizes in this, including middle-weight people feeling pressured to be even thinner and very small people who deal with assumptions about their health and behaviors and get the "eat a sandwich!" comments from people on the street.  There is also a personal side to size acceptance -- appreciating and loving your body, whatever its size, and not letting your size determine your self-worth.

Health at any size is the idea that rather than focusing on body size/weight/fat, people would be much better off pursuing healthy behaviors (e.g., exercising, eating fruit & veg, not smoking) that have an evidential link to important health outcomes, letting their body weight fall where it may.  The basic argument (as I understand it) for this approach to health is:

  • Being stressed, concerned, anxious, and unhappy with your body isn't very good for your physical or psychological health in its own right.  This kind of chronic stress is linked to all kinds of bad stuff.  I think the evidence for the chronic stress-unhealth link is quite clear, and I'm not aware of people attempting to make an opposing case.  And though I suppose someone could claim that being unhappy about their size is not actually stressful, I think that basically the entire literature of social psychology says that they're wrong, in addition to all the studies that have explicitly demonstrated this effect.
  • Losing weight, and maintaining that weight loss for any appreciable length of time, is practically impossible.  (Yep, there is the whole National Weight Control Registry thing, but that's not very many people -- like 5,000 or 10,000 people -- in the context of the gazillion of people who regain the lost weight.)  And the few people who do maintain a lower body weight typically engage in obsessive behaviors (e.g., extreme calorie restriction, huge amounts of exercise, avoidance of any/all social activities that could involve food) that would be diagnostic of an eating disorder in a person without a history of overweight.  Research is also increasingly showing that the bodies and brains of fat people who lost weight to achieve "healthy" weight X do not function like people who have weight X without dieting -- and these differences are the types of things that make weight regain much more likely.  Some of these differences seem to influence feelings of hunger, cravings, etc., that people can attempt to categorize as individual moral failings, and other differences have more direct effects on weight gain.  My guess is that people perceive dieting as successful because people are able to lose weight in the short term, and when they regain that weight, they see it as a personal failing rather than a failure of the diet.  I think that perspective is mostly wrong-headed -- if the vast majority of people can't get dieting to work long-term then I wonder how useful it is to blame the people rather than the dieting.  But regardless of where one assigns the blame for weight regain, it does strongly appear that long-term weight loss is just not gonna happen for the vast majority of people.  Thus, pining one's hopes of health on (and placing one's happiness hostage to) being a thinner person is not an effective approach.  Doctors, loved ones, etc., who push fat people to become thin "for their health" probably are sort of missing the boat here. 
  • The weight yo-yo caused by the weight loss/weight gain cycle is really unhealthy itself -- it's probably worse for your health to keep bouncing between higher weight and lower weight than just maintaining the higher weight.  I'm not as familiar with this literature, but it seems plausible to me that this could be true.  To the extent that it is true, it puts the nail in the coffin of weight loss as a prescription for health.
  • Finally, even if people could lose weight, body weight does not have a strong direct effect on a person's health.  This is a claim that I really don't know how to evaluate.  It does appear that some studies find that other things (e.g., healthy behaviors) have a much stronger effect on health outcomes than body weight, but I have also seen other research suggesting that body weight is a better predictor than behavior.  I think that if you're already fat (or whatever weight you are), the evidence suggests that trying to be the healthiest person you can be, without focusing on size, is a good approach.  The question that this "fat doesn't matter" claim brings up for me is, What are the implications of this for people who are not already overweight?  Should people stop trying to maintain their current weight? 
I have spent a fair amount of time reading the back entries on this blog and recommend that if you have an interest in these issues, you will find this worthwhile as well.  I don't claim to be 110% in agreement with her on everything, but it's good, thought-provoking stuff.  Here are some posts that I think make a good entry point to the blog, in addition to the embedded links above: