Oh, this is horrible, no joke:
What could go wrong with eating an extremely high-fat diet of beef, cheese, and sticks of butter? Well, for one thing, your cholesterol levels could reach such stratospheric levels that lipids start oozing from your blood vessels, forming yellowish nodules on your skin.
That was the disturbing case of a man in Florida who showed up at a Tampa hospital with a three-week history of painless, yellow eruptions on the palms of his hands, soles of his feet, and elbows. His case was published today in JAMA Cardiology.
The man, said to be in his 40s, told doctors that he had adopted a “carnivore diet” eight months prior. His diet included between 6 lbs and 9 lbs of cheese, sticks of butter, and daily hamburgers that had additional fat incorporated into them. Since taking on this brow-raising food plan, he claimed his weight dropped, his energy levels increased, and his “mental clarity” improved.
I’m uncomfortably reminded of my friend Seth Roberts, who died of heart failure not long after adopting a diet in which he ate half a stick of butter a day, which he claimed from self-experimentation to have improved his brain function.
The Florida man was ingesting a lot more than half a stick of butter per day; still, I was struck by his report of improved mental clarity, which uncomfortably echoed Seth’s claims from a decade earlier.
I feel some very small responsibility for this chain of events. Seth was a friend of mine at the University of California in the early 1990s–we taught a couple of courses together–and he kept me informed of his work on self-experimentation. In 2005 he published a research article on the topic, and I promoted it on the blog. Even then, his self-experimentation was unusual, but he hadn’t gone off the deep end. We had further blog discussion that year (also here), and Alex Tabarrok linked to it from his Marginal Revolution blog. From there it was picked up by Stephen Dubner and Steven Levitt in the New York Times. At the time I thought this multiple stage of amplification was pretty cool, and at this point Seth didn’t need my help to get publicity. Dubner and Levitt invited him to guest-blog on his diet at Freakonomics, then a year later Seth published a successful diet book, which I reviewed positively, as did Tabarrok. Around that time, I also published a couple of conversations with Seth on his research; see here and here. Seth also started his own blog and website where people using his diet could share tips and otherwise communicate. He was followed by mid-level celebrities such as Dennis Prager and Tucker Max.
Seth was an early figure in the paleo-lifestyle movement. Indeed, he was telling me his theories about the benefits of caveman diet and caveman lifestyle many years before I heard it anywhere else. In the late 1990s or early 2000s he even wrote a book on the topic, but he never found a publisher, and I guess he abandoned the project after publishing his diet book.
Going through the blog archives, I was surprised to learn that, as early as 2007, Seth was claiming cognitive benefits from oil consumption. He shared data showing it had improved his reaction time. I think this must have been a byproduct of him drinking oil as part of his weight-loss plan. Here’s what I wrote back in 2007:
Encouraged by the success of his self-experimentation to help his sleep, mood, and weight concerns, Seth Roberts has been experimenting with the effects of drinking flaxseed oil. . . . Commenting on another recent one of Seth’s self-experiments, I wrote,
Seth,
Not to be a wet blanket or anything, but aren’t you worried that your findings might be due to expectation effects: you knew which oil you were taking when doing the tests, right?
Seth replied,
Andrew, no, I’m not worried that the results are due to expectations. If the results always conformed to my expectations, I’d be worried, but they haven’t — see my post about eggs. Moreover, this particular result confirms a result that was a surprise. In other words, I’ve gotten the same result when I was expecting it and when I wasn’t expecting it.
I’m still concerned, though. Seth is saying that it’s not just an expectation effect because he wasn’t always expecting the results. But I could see a bias arising from positive feedback, as follows: You try a new treatment and then see what happens after, with no expectations except that things might change. There is some noise to this measurement–just at random, it will be higher or lower than before. Having seen this, you adjust your expectations; this then affects your next measurement, etc.
In retrospect, I think I was too mild. I suggested to Seth: “maybe you could get a partner in experimentation, someone who lives or works nearby, and he or she could give you a randomly assigned oil. That is, your partner would know which oil you’re getting, but you wouldn’t. In fact, you wouldn’t even know if you were being given something new that day.” Seth agreed but wrote, “they are low on my to-do list.”
Again, I wish I’d pushed back harder on that:
– A clean negative result could’ve given Seth (and me!) a healthy dose of skepticism and motivated him to think more carefully about his theories when deciding what experiments to try next.
– A clean positive result could’ve given him and his followers a level of confidence and motivated him to experiment more systematically, rather than spiraling out of control with goofy and possibly dangerous ideas such as eating a half a stick of butter a day.
We had another exchange in 2009, where, again, I said, “maybe this could all be a confirmation bias,” and, again, Seth pushed back, and, again, I now wish I’d taken a firmer line.
As the years went on, Seth gained confidence and his experiments became more and more dubious, culminating in the stick-of-butter thing which, maybe it wasn’t fatal, but maybe it was, and I doubt it was helpful, either to his well-being or others’.
This is a long chain of events, so I don’t feel a high degree of responsibility for my small part in encouraging the crazier aspects of the paleo lifestyle movement. But, to the extent that I was proud that my promotion of Seth’s work led to his media success, I should correspondingly feel bad about the negative consequences.
