This column was featured in Issue 26. Subscribe today to get Issue 27, arriving early next month, and an issue every two months thereafter, delivered straight to your home or workplace.
‘You just piss it oot,’ my friend Stuart Ritchie has always told me. In a politer register, other friends have expressed scepticism too. But for a long time, despite the wisdom of my smartest scientist pals, I was an enthusiastic believer in supplementation. As recently as five years ago, I had a long list of supplements I recommended for normal people, based on my research. I no longer take anything and haven’t for a while, and I don’t think there is an especially good case for anyone to do so without having a specific justification, like bloodwork or the advice of a doctor.
My thinking in my supplement era was simple: there is no special reason to think everyone’s diets are giving them an optimal amount of every micro- or phytonutrient. It might be that the perfect amount is some way above the threshold for not being deficient. Therefore, I argued, with the right evidence it was worth punting on various supplements, like choline, vitamin K2 (menaquinones 4 and 7, naturally), fish oil or omega-3 fatty acids (prepared in the right way, of course), and potentially many more things. I took wheat germ (for its spermine and spermidine). I even took glycine, a slightly sweet amino acid prominent in skin and bone but not muscle meat, which people online claim improves their sleep.
I was an evangelist. My wild-eyed confidence and thorough research inspired many people over the years to take one thing or another that I recommended on my ever-permuting list. I had an easy audience, because there seems to be a near-universal drive toward supplementation, either as a kind of inherited folk memory of beriberi, pellagra, scurvy, and rickets, or perhaps as a natural human instinct – the same one that makes us want a pill when we leave the doctor’s office.
My method was tripartite. I reasoned that though we can’t be absolutely sure, a supplement was, on balance, likely worth taking if three things held. First, we have a plausible evolutionary story about how we originally evolved in an environment with more of it, and our modern diets do not. Second, there is a logical, not obviously disputed, story about how it works. Third, the balance of evidence suggests that consuming the nutrient at least correlates with good health, and ideally well-designed trials show that it actually causes good health.
With such a rigorous method, how did everything fall apart? It’s a sad story. Ultimately, it was both a bad methodology and I applied it badly. The core problem is the same problem for all theorizing, the same problem the methodology of science was designed to solve: it is very easy to validate one’s tender hypotheses by looking carefully for validating evidence. Another perhaps equally big problem is that most science is nearly useless.
Let’s start with the first problem. Basically, I have an underlying psychological... call it a trait rather than a flaw, though there is a case for either name. This psychological trait makes me take pleasure in having bespoke, rare, fresh, interesting opinions. You might call it metacontrarianism. I love to have original views, and it’s possible, I admit, that I get just a little bit invested in these opinions and in proving that they are right.
Now, this combines with another trait I have, this one definitely a flaw: food obsessiveness. I’m afraid that I was a pathologically, distressingly fussy child who would eat only a handful of plain foods. As a teenager, I forwent artificial colorings and flavorings completely, to an extent that made people think (rightly) that I was a freak. For years, I ate only during a six-hour window between 2pm and 8pm. At other times, I have obsessively counted calories, or completely avoided carbs. Currently, I just eat a lot of fiber. I follow dietary fads like I am constantly switching religions.
This naturally led me to search out evidence that would allow me to believe, with at least some reason, that we are short on vitamin K2 because our diet is lower in liver, alpine cheese, and grass-fed butter. My elegant evolutionary story combined with a plausible mechanism for how K2 would help us – preventing arterial calcification brought on by a diet with too much calcium – and with evidence that adults with more vitamin K2 are healthier. There are even academic studies showing that vitamin K2 improves health. Voila: I began taking a specific brand of vitamin K2 supplement (InnovixLabs Full Spectrum), which I judged to have the right balance of the rarer menaquinone-4 (this word on its own has a certain ring to internet users of the early 2010s) and the less rare menaquinone-7.
And so on for the other supplements. I had complex views on which ones were dangerous (copper), which were pointless (B vitamins except B12; creatine in omnivores), and which were essential (K2 menaquinone-4). This complexity was a great deal of what made the whole thing so enjoyable, akin to being into a fandom like Warhammer with a lot of lore, or a sport like baseball with very rich statistics.
Lore maximization reaches its apotheosis in the ideas of the late Dr Ray Peat, who has views so esoteric that even aficionados disagree on them. Some of my most enjoyable evenings have come from advancing Peatist views to uncomprehending, spluttering audiences. He advises consuming sugar, especially in the form of ice cream or orange juice, to speed up the metabolism, or even eating dessicated beef thyroid.
Though Peatism was pure affectation, it shined a light on what was really happening. I didn’t really believe in all the supplements I was taking – I just treasured the esoteric dietary knowledge, like a kind of modern-day druid. This blinded me to the fact that a big share of my research was confirmation bias.
But there was a more profound problem. People like the wise Stuart Ritchie and my colleague Saloni Dattani had been telling me for ages that science was overloaded with complete nonsense, which I accepted on an intellectual level but had not really absorbed into my intuitions. My feeling had always been that we could still draw conclusions if we had a big enough pile of papers. But now I have come to believe that something like 90 percent of research is nearly valueless.
Just as Peatism was undermining my emotional investment in supplementation, an intellectual justification for supplement scepticism appeared in the form of a blog post by Milky Eggs. The average paper in nutrition science is so bad, because of the usual range of poor research practices ranging from fraud to p-hacking, that even large bodies of research papers can have not just the wrong magnitude of effect, but the wrong sign. It is surprisingly easy to produce dozens of papers showing something false, and what’s more, there is a bandwagon effect, and people do it all the time.
The proposed mechanism through which amino acid glycine extends life is by inhibiting methionine (another amino acid)’s effect on a particular signalling pathway. But with evidence as weak and inconsistent as it is today, how can we be sure that any random amino acid we supplement is not really functioning as a methionine?
This isn’t to say that there are never beneficial supplements for normal omnivores, but I am now suitably chastened. Silly old Stuart, I always said – why does he think that everyone, just by ‘eating a balanced diet’ (me: chortle, snigger), will have maxed out their ability to absorb micronutrients? ‘Piss it oot’ indeed. Well, I’m afraid that Stuart has had the last laugh.
Ben Southwood is an editor at Works in Progress.
This column feels incomplete. Regardless, it's widely accepted medical advice in the northern hemisphere, that you should supplement vitamin D3 during the late fall to early spring, beyond that supplementation is probably less helpful.
Congratulations! You’ve arrived at your latest metacontrarianism! You are now confusing absence of evidence (although I’d disagree with you on much of that) with evidence of absence!
Why should I take this latest obsession as more valid than the prior ones?