Seth's Blog

As you may know, an Italian surgeon named Paolo Zamboni has proposed that multiple sclerosis (MS) is often due to poor blood drainage from the brain. Improving drainage, he and his colleagues found, reduced MS symptoms. The surgery is called liberation therapy. From this article (thanks, SB) I learned of evidence contradicting Zamboni’s findings:

The studies were independently conducted case–control experiments designed to determine whether abnormal outflow of blood in the head and neck is actually a defining feature of MS. Two of the studies appeared to confirm Zamboni’s observations; the pooled results identified 31 cases of CCSVI out of 35 MS patients and none in 45 matched controls. Yet three other studies, from Germany, Sweden and Holland, with a pooled set of 97 MS patients and 60 matched controls, found no significant evidence of a difference in blood flow between those with MS and those without. In fact, when Doepp et al. attempted to replicate the Zamboni trial they did not find a single case of CCSVI in either the 56 MS patients or the 20 controls examined.

Wow. What intense disagreement. The failure-to-replicate studies used different ways of measuring blood flow so the disagreement is less stark than it appears from this description. But it is still remarkable.

This is highly newsworthy. I can’t think of another case where two different labs have gotten such different results. Unfortunately the article is appalling in its one-sidedness (e.g., liberation therapy is said to have “known risks, unknown  benefits”).

This article by Eoin O’Connell reports a study in the American Journal of Clinical Nutrition (the top nutrition journal) that found a correlation between meat consumption and weight gain: The more meat you ate, the more weight you gained over five years. Meat is fattening! reported several newspapers.

Mr. O’Connell did something unusual for a health journalist: He thought for himself. I don’t mean he applied a formulaic criticism (e.g., “correlation does not equal causation”). That’s not thinking, that’s knee-jerking. Mr. O’Connell read the paper. And he noticed an interaction: The correlation between meat consumption and weight gain depended on activity level. The study involved about 400,000 people. The researchers put each person in one of four activity levels: inactive, moderately inactive, moderately active, and active. There was a correlation between red-meat consumption and weight only for the two most active groups (moderately active and active). The original article reported that this interaction was significant:

The relation between red meat and weight gain was also stronger in physically active subjects compared with moderately inactive or inactive subjects (P values for interaction = 0.02)

The obvious implication of this interaction, as Mr. O’Connell says, is that meat caused muscle gain. Weight differences between more-meat and less-meat eaters were due to differences in muscle mass. This puts an entirely different spin on the results. The alternative explanation is quite plausible. I once had a grad student who was a vegetarian. When he was an undergrad, he told me, he and his roommate would go to the weight room and do similar sets. His roommate, who ate meat, rapidly gained muscle; he did not. Of course, meat = animal muscle.

Mr. O’Connell continued to the really interesting part of his article:

Perhaps not so surprisingly, the consideration that muscle is a form of weight gain does not appear in the newspaper articles but much more surprising is the fact that it does not appear in the original journal article either.

The AJCN article has fifty authors. Not one of them, apparently, noticed this all-important point! Nor did the reviewers for this prestigious journal. The article concludes: “Our results are therefore in favor of the public health recommendation to decrease meat consumption for health improvement.” No, they’re not, if the more meat, more muscle explanation is correct.

Most prestigious journal. Fifty authors. Huge expense. Total F-up in the sense that the final conclusion is probably wrong. (To be fair, the paper has plenty of value in other ways.) Congratulations, Mr. O’Connell, for noticing.

You have surely heard the phrase economies of scale — meaning that when you make many copies of something each instance costs less than when you make only a few copies. Large companies are said to benefit from “economies of scale” — so there is pressure to become bigger. Every introductory economics textbook says something like this. (more…)

Seeing Alex Chernavsky’s ten years of weights inspired David Hogg, a professor of entomology at the University of Wisconsin, to send me his weight data for the past nine years — see above. Like Alex, he found that the Shangri-La Diet worked where other methods failed. (more…)

In this interview, Tucker Max talks about eating paleo.

Once I started doing this, I started feeling so much better. My brain felt like it worked better. Everything about me improved. So I kinda went down the rabbit hole, and I started reading up on diet and nutrition from alternate sources. Art De Vany, Robb Wolf, and Loren Cordain, they didn’t invent it but they kinda popularized the concept of paleo eating. I realized that if you’re just a normal person, and you have the normal ideas about diet and nutrition, everything you know is wrong.

If you ask me, Tucker’s enthusiasm/support for paleo is huge. Max Planck said progress happens funeral by funeral.  I say it happens keg party by keg party — college students, more than anyone else, have open minds. A friend told me that when she was a freshman in college, her sociology professor criticized the textbook. Whoa! she thought. Textbooks can be criticized!? She had thought they were beyond criticism. As far as I can tell, American college students respect Tucker more than they respect anyone else. (My Tsinghua students may favor Nassim Taleb.) For example, this recent tweet: “TuckerMax is my idol. and he’s on this paleodiet…so i think im going to do it too.”  I found no tweets about the dietary influence of Michelle Obama (“coolest First Lady ever“).

In spite of what the interview was shortened to say, Tucker got the idea of eating flaxseed oil from this blog, especially Tyler Cowen’s experience. He wrote to me about it at the time. I posted his comments about dental health (here and here) and sports injuries (here, here and here) under the name Anonymous.

I am pleased to announce that Tucker will be talking at the upcoming Ancestral Health Symposium at UCLA. The title of his talk is::

From Cave to Cage: Mixed Martial Arts in Ancestral Health

Sorry Tucker Max fans, symposium tickets are sold out. But after the conference you will be able to see the talk on the website.

Tucker’s latest book is Assholes Finish First.