Using Skeptoid as a Reference is Not So Easy
by Eric Hall
September 5, 2011
Skeptoid episode on gluten free diets.I should have known better, but sometimes emotions do get the best of us. On Twitter, a user was attacking a celebrity I follow. Normally I don't get involved since a celebrity has to expect a certain level of negative response on social media from people that follow them. Well, this person was insistent on taking pictures of large pigs at a state fair and referring to the celebrity as these pigs. A quick look through his timeline suggested not only is this person mean to quite a few people, but he loves to push nutrition pseudoscience. So that is the realm I decided to challenge him on by sending him a link to the
I did get a response back with the suggestion that there is, "lots of back and forth research on gluten." Included in his response was an article on a website that was actually a response to Brian's episode on gluten free diets. So I thought I would check it out. Well @justinrwolfe on Twitter, let me do my best job as a skeptic to show you where the article fails the skeptical test.
First is the website as a whole. It is important to be skeptical of someone offering an opinion on anything when they are selling a product or products related to or counter to that opinion. Robb Wolf is in the business of promoting low carbohydrate, low gluten diets and selling books that say so. It wouldn't be very good for his business if he said there was nothing wrong with consuming gluten. This alone doesn't mean his opinion is wrong, but it should give us pause to be extra careful in considering his opinion and his sources.
The next thing Robb Wolf mentions is that he won't even consider a conversation unless someone discusses molecular biology and a list of molecular biology terms. This appeal to authority and appeal to novelty is a pretty common way to avoid real scrutiny. It's like how the Power Bracelet people do some hand-waving about quantum signatures and think using fancy terms makes them an expert. It doesn't. But, Robb Wolf "gives Mr. Dunning a pass" because one of the terms on the list is in the podcast.
Next, Mr. Wolf brings in a study done on human and rat intestinal cells. Mr. Wolf's biography on his site says he is a former biochemical researcher. I couldn't find much on his educational background other than what is on Wikipedia, which says he has a BS from California State University Chico. My background in physics might not be as good at reading medical studies, but somehow we picked out two different conclusions from the research. Mr. Wolf summarizes from the study:
Based on our results, we concluded that gliadin activates zonulin signaling irrespective of the genetic expression of autoimmunity, leading to increased intestinal permeability to macromolecules.While this is true, the authors of the study do make this claim that whether or not the cells had the genetic marker for celiac disease (CD), there was an expression of this immune response. However, the authors in the study then also state:
Despite the presence of a measurable zonulin response in both CD and nonCD subjects, CD patients appear to reach a critical threshold of intestinal permeability upon gliadin exposure that is not reached in non-CD intestinal mucosa.It seems to me that what the authors found was a common autoimmune response from all of the cells to gliadin (a component of gluten), but those cells that did not have the genetic markers for CD created enough zonulin only to be measured, but not enough to create an immune response.
The next article Mr. Wolf brings up is a publication of an on-going study of the so-called "hunter-gatherer" diet." It looks like Mr. Wolf just copied and pasted the abstract right from the NIH website to his own website, and I am not going to pay for the publication either. Certainly this is an interesting study. But I am not sure what this has to do with gluten. Yes, the diet would happen to avoid gluten, but the authors of the study are relating this to a leptin pathway. And that part of the study isn't even done. So far, this is what they know:
Our lab conducted a study on 24 domestic pigs in which a cereal-free hunter-gatherer diet promoted significantly higher insulin sensitivity, lower diastolic blood pressure and lower C-reactive protein as compared to a cereal-based swine feed. Testing should also evaluate the effects of grass lectins on the leptin system in vivo by diet interventions, and in vitro in various leptin and leptin receptor models. Our group currently conducts such studies.The study is not complete, and it isn't looking at gluten at all. Really, it could be a number of other factors such as the higher fiber and lower fat content of such diets, or the overall lower caloric intake. But these are conjectures about as much as trying to say that lack of gluten is the reason for the success in the 24 pigs in the study.
Mr. Wolf then cites another study which again wasn't studying gluten, but instead a diet lifestyle as a whole. I am not going to go through a detailed analysis. But note it was a small study (29 people). It again studied an overall diet, not specifically gluten-free. And it wasn't measuring any of the factors claimed by the gluten free diet people. So again, this doesn't really refute anything within the Skeptoid episode. It instead shows us some interesting overall nutritional study that should be further investigated.
Now Mr. Wolf gets into the section on anthropological considerations, and we get to the ad hominem attack. There was an attacking tone previous to this, but now Mr. Wolf gets right to it:
Folks ignorant of this fact...well, it's like the refrain from law enforcement "Ignorantia juris non excusat-Ignorance of the law does not excuse." but it DOES result in folks like me needing to actually do the research the [sic] Brian should have done before commentating on this subject.And:
Not trying to be a dick here, but Brian is neglecting those pesky 2-3 million years of human history BEFORE bread. That's part of the problem, when folks start talking about this stuff.So now since Mr. Wolf has nothing to really counter Brian's assertion that gluten was indirectly responsible for modern humans being able to migrate faster than previous to agriculture, he instead attacks him. Brian didn't ignore the 2-3 million previous years at all. He said at some point it changed.
Mr. Wolf's final attack on Brian is to start with a study on patients with CD. From what I can gather about the study, it was really a way to test CD patients for the ingestion of gluten to see if that was the cause of their relapsing acute pancreatitis. This is not in contradiction to the Skeptoid episode at all. Brian says for those with CD, a gluten free diet is the only treatment at this point. But Mr. Wolf finishes this section by stating Brian's research is poor. I'm not sure how the two things are related.
So to @justinrwolfe, my conclusion as an amateur skeptic is that Brian Dunning's conclusions about a gluten free diet are valid. Robb Wolf provided some very interesting nutritional information in his "response" to Brian's podcast, but he never really addressed anything wrong with Brian's research or Brian's conclusions. What I see is a thinly veiled attempt to use logical fallacies and misdirection to sell people on Mr. Wolf's nutrition plan. And his information may very well show that his diet can be a healthy one, but it is not due to the avoidance of gluten.
by Eric Hall
@Skeptoid Media, a 501(c)(3) nonprofit