“Eating Dirt Benefits Kids” is Basically Made Up

Sometimes people imply that epistemic spot checks are a waste of time, that it’s too easy to create false beliefs with statements that are literally true but fundamentally misleading. And sometimes they’re right.

On the other hand, sometimes you spend 4 hours and discover a tenet of modern parenting is based on absolutely nothing.

[EDIT: this definitely was a tenet among my friends, but apparently is less widespread than I thought.]

Sorry, did I say 4 hours? It was more like 90 minutes, but I spent another 2.5 hours checking my work just in case. It was unnecessary.

Intro

You are probably familiar with the notion that eating dirt is good for children’s immune systems, and you probably call that Hygiene Hypothesis, although that’s technically incorrect. 

Hygiene Hypothesis can refer to a few different things:

  1. A very specific hypothesis about the balance between specific kinds of immune cells.
  2. A broader hypothesis that exposure to nominally harmful germs provides the immune system training and challenge that ultimately reduces allergies.
    1. One particular form of this involves exposure to macroparasites, but that seems to have fallen out of favor.
  3. The hypothesis that exposure to things usually considered dirty helps populate a helpful microbiome (most often gut, but plausibly also skin, and occasionally eyeball), and that reduces allergies. This is more properly known as the Old Friends hypothesis, but everyone I know combines them.
  4. Pushback on the idea that everything children touch should be super sanitized
  5. The idea that eating dirt in particular is beneficial for children for vague allergy-related reasons.

I went into this research project very sold on the Hygiene Hypothesis (broad sense), and figured this would be a quick due diligence to demonstrate it and get some numbers. And it’s true, the backing for Hygiene and Old Friends Hypothesis seems reasonably good, although I didn’t dig into it because even if they’re true, the whole eating dirt thing doesn’t follow automatically. When I dug into that, what I found was spurious at best, and what gains there were had better explanations than dirt consumption.

This post is not exhaustive. Proving a negative is very tiring, and I felt like I did my due diligence checking the major books and articles making the claim, none of which had a leg to stand on. Counterevidence is welcome. 

Evidence

Being born via c-section instead of vaginally impoverishes a newborn’s microbiome, and applying vaginal fluid post-birth mitigates that

This has reasonable pilot studies supporting it, to the point I mentioned it to a pregnant friend.

There are reports that a mother’s previous c-sections lower a newborn’s risks even further, but I suspect that’s caused by the fact below

Having older siblings reduces allergies

Study. The explanation given is a more germ-rich environment, although that’s not proven.

Daycare reduces later allergies, with a stronger effect the earlier you enter, unless you have older siblings in which case it doesn’t matter

Study. Again, there are other explanations, but contagious diseases sure look promising.

Living with animals when very young reduces allergies

This one is a little more contentious and I didn’t focus on it.  When the animal appears seems to matter a lot.

One very popular study used to bolster Dirt Eating is a comparison of Amish and Hutterite children. Amish children get ~⅙ of the allergies Hutterite children do, which pop articles are quick to attribute to dirt “because Amish children work on farms and Hutterite children don’t.” But there are a lot of differences between the populations: dust in Amish homes have 6x the bacterial toxins of Hutterite homes, the children have much more exposure to animals, and drink unpasteurized milk. 

Limitations of Farm Studies

Even if Amish children did eat more dirt and that was why they were healthier, there’s no transfer from that to urban parks treated with pesticides and highway exhaust. They might be net positive, the contaminants might not matter that much, your park in particular might be fine, no one has proven this dirt is harmful, etc. But you should not rest your decision on the belief that that dirt has been proven beneficial, because no one has looked.

Mouse Studies

There are several very small mouse studies showing mice had fewer allergies when exposed to Amish dirt, but:

  1. They are very small.
  2. They are in mice.
  3. The studies I found never involve feeding the mice dirt. Instead, they place it in bedding, or directly their nasal passages, or gently waft it into the cage with a fan. 

So eating dirt is bad then?

I don’t know! It could easily be fine or even beneficial, depending on the dirt (but I suspect the source of dirt matters a lot). It could be good on the margin for some children and bad for others. Also, avoiding a constant battle to keep your toddler from doing something they extraordinarily want to do is its own reward. What I am asserting is merely that anyone who confidently tells you eating arbitrary dirt is definitely good is wrong, because we haven’t done the experiments to check.

I think any of [communicable diseases, animals, unpasteurized milk] have more support as anti-allergy interventions than dirt, but I hesitate to recommend them given that a high childhood disease load is already known to have significant downsides and the other two are not without risks either.

Epilogue

The frightening thing about this for me is how this became common knowledge even, perhaps especially, among my highly intelligent, relatively authority-skeptical friends, despite falling apart the moment anyone applied any scrutiny. I already thought the state of medical knowledge and the popular translation of that knowledge was poor, but somehow it still found a way to disappoint me.

My full notes are available in Roam.

This post was commissioned by Sid Sijbrandij. It was preregistered on Twitter. I am releasing it under the Creative Commons Attribution 4.0 license. Our initial agreement was that I would be paid before starting work to avoid the appearance of influence; in practice I had the time free and the paperwork was taking forever so I did the research right away and sat on the results for a week.

Thanks to Miranda Dixon-Luinenburg⁩ for copyediting.

Consider Taking Zinc Every Time You Travel

Zinc lozenges are pretty well established to prevent or shorten the duration of colds. People are more likely to get colds while travelling, especially if doing so by plane and/or to a destination full of other people who also travelled by plane. I have a vague sense you shouldn’t take zinc 100% of the time, but given the risks it might make sense to take zinc prophylactically while travelling.

How much does zinc help? A meta-analysis I didn’t drill into further says it shortens colds by 33%, and that’s implied to be for people who waited until they were symptomatic to take it: taken preemptively I’m going to ballpark it at 50% shorter (including some colds never coming into existence at all). This is about 4 days, depending on which study you ask.

[Note: only a few forms of Zinc work for this. You want acetate if possible, gluconate if not, and it needs to be a lozenge, not something you swallow. Zinc works by physically coating your throat to prevent infection, it’s not a nutrient in this case. You need much more than you think to achieve the effect, the brand I use barely fits in my tiny mouth.]

Some risk factors for illness in general are “being around a lot of people”, “poor sleep” and “poor diet”. These factors compound: being around people who have been around a lot of people, or who have poor sleep or diet, is worse than being around a lot of well-rested, well-fed hermits. Travel often involves all of these things, especially by air and especially for large gatherings like conferences and weddings (people driving to camp in the wilderness: you are off the hook).

I struggled to find hard numbers for risk of infection during travel. It’s going to vary a lot by season, and of course covid has confused everything. Hocking and Foster gives a 20% chance of catching a cold after a flight during flu season, which seems high to me, but multiple friends reported a 50% chance of illness after travel, so fill in your own number here. Mine is probably 10%.

If my overall risk of a cold is 10%, and I lower the duration by 50%/4 days, I’ve in expectation saved myself 0.4 days of a cold, plus whatever damage I would have done spreading the cold to others, plus the remaining days are milder. Carrying around the lozenges, remembering to take them, and working eating and drinking around them is kind of inconvenient, so this isn’t a slam dunk for me but is worth best-effort (while writing this I ordered a second bottle of zinc to sit in my travel toiletry bag). It’s probably worth a lot for my friends with a 50% risk of illness, have unusually long colds, or live with small children who get cranky when sick. You know better than me where you fall.

Things that would change this cost-benefit estimate:

  • Seasonality
  • Personal reaction to zinc, or beliefs about its long term effects
  • Covid (all the numbers I used were pre-covid)
  • Different estimates for risk of illness during travel
  • Different estimates for the benefit of zinc
  • Personal susceptibility to illness

Caveats: anything that does anything real can cause damage. The side effects we know about for zinc lozenges are typically low, but pay attention to your own reaction in case you are unlucky. I remain an internet person with no medical credentials or accreditation. I attempt to follow my own advice and I’ve advised my parents to do this as well, but sometimes I’m rushed and forget.

ETA: I originally wrote this aimed at friends who already believed zinc was useful but hadn’t considered prophylactic use, and as such didn’t work very hard on it. I mistook some rando meta-analysis for a Cochrane review, and didn’t look further. There’s a pre-registered study that has come out since showing no effect from zinc. There could be other studies showing the opposite, I haven’t looked very closely. Plausibly that makes publishing this irresponsible- you definitely should judge me for mistaking a review that mentioned Cochrane for an actual Cochrane review. OTOH, writing too defensively inhibits learning, and I want to think my readers in particular are well calibrated on how much to trust off the cuff writing (but I hindered that by mislabeling the review as from Cochrane).

Review: The End Is Always Near

The date is November 10th, 2019. Covid has plausibly started, but I don’t know it yet. I am a huge fan of Dan Carlin’s Hardcore History podcast, and have been conducting my own lit review on civilizational collapse. I have been eagerly anticipating Carlin’s upcoming book, The End is Always Near, for months (affiliate link). I am in a coffee shop with a friend, very excited to have a dedicated time to read and Epistemic Spot Check it. 

I do not remember what I read. I remember that I lost all interest in Carlin’s podcast afterward, and was so sure I’d remember the problem that I didn’t write it down, which led to 2 years of awkwardly saying “yeah his book was so terrible I lost interest, no don’t remember why, yes I see how that’s less useful for you.” I never checked any claims it made; I’d have records of that, which means that whatever the problem was, it wasn’t just a factual error

I sat down today to read enough of the book to remind myself of why I so vehemently disliked it, and in the course doing so discovered that I had written down the problems in Goodreads, but had forgotten that along with everything else. (I also got the date wrong: I remember starting it in January, but that doesn’t fit because I know I was reading one of its sources in December). My review, in its entirety:

I went in wanting a meaty history book with many claims I could follow up on. In the first few chapters I could only extract a few claims, always what other historians thought (but without countervailing arguments), and it never coheres into models or cruxes.

Mystery solved, I guess. It’s not actually clear to me I should have given up on the podcast based on this, since I don’t remember it having the same problem. But since I already went through all this trouble, let me read a chapter or two and see if I agree with my pre-covid assessment.

Claim: “In many earlier eras of history writing, a large part of the historian’s or author’s goal was to impart or teach some sort of moral lesson, usually by historical example.” (footnote on page 1)

Ah yes, the before times, when people manipulated nominally factual data to their own ends. So glad we grew out of that in … *checks watch* … hmmm, must be broken.

Claim: Sparta super kicked ass (page 7)

Bret Devereaux spent a long time debunking this and I spent a somewhat shorter time checking his work (it passed). Carlin also repeatedly says “Spartan” when he means “Spartan ruling class”, which is a common mistake but I think a revealing one.

Okay, I have finished chapter 1, which is seven pages long. It is titled “Do Tough Times Make for Tougher People?”, a reference to this meme:

I do not know if Carlin thinks tough times create tougher people. If you put a gun to my head I would say “Probably, except for if literally anything else is involved, perhaps?”  I do not know how he defines toughness. This is dumb. Toughness is easy to define, he shouldn’t have to spell it out, and yet I’m rereading the pages trying to figure out a coherent definition that makes sense and is meaningful all the way through. I feel fuzzy and slippery and then angry that I feel that way.

Contrast that with Devereaux’s 6 part series, The Fremen Mirage, which addresses the same question. Devereaux takes a strong stance (“no they fucking don’t”) and spends only two paragraphs before defining exactly the argument he is making. Then he spends a while complaining about people who cite “…weak men create times…” without strict definitions. 

Devereaux’s Fremen Mirage is full of claims that are both load-bearing (as in, if they were wrong, the argument would collapse) and capable of being resolved one way or the other. It’s tractable to check his work and come to a conclusion. Meanwhile, I did write down some claims from chapter one of The End… but… none of them matter? Of the things that could be called cruxes, they’re all vague and would at best take a lot of work to develop an informed opinion on. But I think that’s optimistic, and most of them are not actually provable or disprovable in a meaningful way.

So there you go. The End is Always Near was not even tractable enough to be worth checking.

Thanks to Miranda Dixon-Luinenburg, Justis Mills, and Daniel Filan for copyediting. Patreon patrons you’re off the hook for this one since it was so short.

Review: Martyr Made Podcast

Update (2022-11-01): I stand by what I said about Darry Cooper’s long-form history podcasts but his stuff on current events has gotten increasingly deranged, well beyond what even Twitter can justify.

Introduction

Sometimes I consume media that makes factual claims. Sometimes I look up some of these claims to see how much trust I should place in said media, in a series I call epistemic spot checks. Over the years, I’ve gone back and forth on how useful this is. Focusing on evaluating particular works instead of developing a holistic opinion on an entire subject does feel perverse to me. OTOH, sometimes non-fiction is recreational, and I don’t think having some of my attention directed by people I find insightful and trustworthy is a bad thing, as long as I don’t swallow their views unquestioningly. Additionally, there’s a pleasant orderliness to doing ESCs, like the intellectual equivalent of cleaning my house. It’s not enough in and of itself, but it can free up RAM such that there’s room for deeper work.

I started listening to Darryl Cooper’s Martyr Made last year as part of a deep dive on cults, but kept going because I found him incredibly insightful. After listening to the 30+ hours of the God’s Socialist sequence, I Googled around and found a few accusations of racism against Cooper. I didn’t believe the accusations then, and I still don’t. People can go through the motions of saying what other people tell them to, but they can’t fake what Cooper does, which is to approach every human being as someone worthy of respect and compassion, whose actions are probably reasonable given their incentives. I value that a lot more than proper signaling.

Some time later I found an archive of Cooper’s deleted Twitter logs, and, uh, I get where people are coming from on the racism thing. I still absolutely believe in his respect and compassion for everyone except members of the USSR leadership (and even then, he’ll say very nice things about the intentions of early communists).  However, the thing about doing that genuinely instead of choosing a side and signaling allegiance is that it doesn’t compress well to 140 characters, and he said a bunch of things that were extremely easy to round to terrible beliefs. I might also have mistaken him for racist, if all I had was his Twitter. But given the podcasts, I am very sure that he respects-and-has-compassion-for every human being.

[Between when I started listening and when I published this Cooper returned to Twitter, which I have mixed feelings about. Namely “I think this is bad for him intellectually and emotionally” vs. “He’s talking to me! Hurray!”]

I’m not a big fan of emotion in my history podcasts. Martyr Made is an exception. Cooper goes hours out of his way to make sure you understand how something felt, without ever coming across as dishonest or manipulative. Some of that is that he often uses himself as an example and is very upfront about his flaws. Some of that is the aforementioned respect and compassion seeping into everything he does. Some is good writing. 

For example, God’s Socialist is nominally about Jim Jones and the Jonestown massacre, but Cooper doesn’t believe Jonestown makes any sense unless you understand the 60s, hippies, the Civil Rights movement, and the Black Power movement. The prologue consists of a description of various race riots/race wars, the contemporary and just-pre-Civil-Rights-movements, and easily 15 minutes on his interactions with some homeless people in his neighborhood. For the last of these, he observes that though he’s occasionally kind, he mostly just ignores the individuals in question, and that sometimes he thinks that on Judgement Day the only thing that’s going to matter is how he failed to really help those men- whatever he did, it was for the wrong motives and much too little. I wrote a bunch of angry notes about how virtue ethics was bullshit while listening to this part, but by the end it became clear that he wasn’t making a call to any particular action, it was just an honest accounting of suffering in the world. He was walking me through it because he felt it was necessary to understand Jim Jones, whose first acts as an adult were taking care of people most of society was stepping over. 

All of this is to say: Martyr Made is one of my favorite pieces of nonfiction in the world. I’ve learned so much from it both factually and emotionally, but I felt vulnerable talking about that until I was absolutely rock solid on the author’s epistemics. I finally had time to do an epistemic spot check on the start of God’s Socialist (still my favorite sequence in the series), and I’m extremely relieved to announce that he nailed it, although just like my ESC of Acoup, it is not so amazingly perfect that the follow up wasn’t worth doing (and I assume Cooper would agree with that, just like Bret Devereaux did).

A word on ESCs: there’s a range of things it can mean to check someone’s epistemics. Sometimes it means checking their simple concrete facts. You would be amazed how many problems this catches. Another is to check leaps of logic: they can have their facts right but draw wildly incorrect inferences from them. Finding these requires more cognition, but is also fairly easy. Cooper did great on both of these, which was not surprising. My concern was always that his facts were literally true but unrepresentative. Accurate-in-spirit representation is one of the hardest things to judge, especially about really contentious issues like racial violence where second opinions are just another thing to fact check. What I can say is that everything I checked I was either able to concretely verify, or was extremely consistent with what I was able to find but was open to other interpretations, because it’s a contentious area with motivated record keeping.

The God’s Socialist sequence of Martyr Made is 30 hours long. I have ESCed the prologue, which is 90 minutes long, and some especially load-bearing claims I remembered from later in the podcast. I also happen to have already read one of Cooper’s most quoted sources, The Warmth of Other Suns (affiliate link), back in 2014. 2014 is a long time ago and I didn’t ESC Warmth at the time, but what Cooper quoted was generally in accordance with my memory of it, on both a factual and model level.

Without further adieu…

The Claims

Claim: A 2007 report from the Southern Poverty Law Center on Latino-on-Black violence in Los Angeles (1:02)

He reads this report very nearly word for word. All the differences I caught were very minor wording issues that didn’t change the meaning. I also checked some of SPLC’s claims

SPLC: “Since 1990, the African-American population of Los Angeles has dropped by half as blacks relocated to suburbs”, “Now, about 75% of Highland Park residents are Latinos. Only 2% are black. The rest are white and Asian.”  (8:17)

This was shockingly annoying to verify because I could find stats by year for LA county but not LA the city, and the county includes the suburbs. I did verify that:

  • In 2000 (seven years before the SPLC report came out), Highland Park was 72.4% Latino and 2.4% black (source).
    • Note that if you read the Wikipedia article it says 8.4% black, but it cites my source above. This is plausibly an issue of how to assign mixed-race people (since Wikipedia’s percentages add up to >100%), or the ongoing confusion about how Latino is an ethnicity, not a race.
    • However, that particular neighborhood was already 2.2% black in 1990, although it was a little whiter and less Latino (source).
  • An LA time article also describes South LA shifting from an approximately 1:1 ratio of Latino and Black residents to 2:1 (Highland Park is in northeast LA).

Claim: A number of specific incidents of Latino-on-Black violence in Los Angeles, and some nebulous statistics

I Googled several of these as they came up and they always checked out, although LA’s a big city and Cooper is looking over a long time period, so it would be easy to cherry pick.

Cooper also gave some statistics on hate crime. However, these were always either for a particular neighborhood (too small, data liable to be noisy), or not quite as damning as his tone suggested they were. I found some statistics that came out the same year this episode did that support the general concept that Latino-on-Black violence happens, but I don’t trust the LAPD’s truthseeking on hate crimes. 

Which is to say, Cooper’s claims are well sourced and completely consistent with the available data, but the data is poor and his opinions are more controversial than he acknowledges. I’m sure someone with different motivations could use the same data to make the opposite case, or a different one entirely. Here’s an article published the same year as the SPLC report, calling the claims ridiculous. My tentative take on this is that racial tensions were high and spilling over into violence, but the claims that “all black people in LA were greenlit” (meaning, gang members had the okay from leaders to shoot them) and “all black people in Latino neighborhoods in LA were greenlit” are clearly insane; the murder rate would be much higher if that were true. 

Claim: Quote from Warmth of Other Suns: “In 1950, city aldermen and housing officials proposed restricting 13,000 new public housing units to people who had lived in Chicago for two years. The rule would presumably affect colored migrants and foreign immigrants alike. But it was the colored people who were having the most trouble finding housing and most likely to seek out such an alternative.” (23:00)

This quote is accurate, but my memory of it wasn’t: I had in my notes that this proposal was enacted, and only rechecked the recording when I couldn’t find any such record and wanted to see if he cited a source. His source, Warmth of Other Suns, cites a 1950 newspaper article that I couldn’t find online (it probably exists in ProQuest’s Historical Newspaper archive, but I lack access despite trying ProQuest via multiple libraries).

Claim: Description of the Cicero Riots of 1951 (31:00)

Everything he says is in accordance with the Wikipedia article: it was a horrific multi-day riot and lynching episode triggered by a black family moving into a white neighborhood. 

Cooper doesn’t mention this, but fun fact: according to Wikipedia, the landlord allowed the family to move in not for any noble anti-racism or even free-market motivations, but to punish the neighborhood for fining her for something else. 

Claim: Southern white people did not want black people to leave during the Great Migration, because they needed them as labor (35:00)

Warmth of Other Suns says the same, although that’s not independent confirmation because it’s at least one of Cooper’s sources as well. Wikipedia agrees.

Claim: Northern union leaders were resistant to black migrants because they reduced labor’s power (43:00)

I could not find a smoking gun on this, which makes sense because labor is not going to want to admit it. However I found a number of articles, modern and contemporary, on companies bringing in black workers from the south as strikebreakers, and it would be extremely weird if that didn’t upset union leaders. 

Claim: Jim Jones began as a dynamic and promising civil rights movement leader, branched out into communism (1:05:20)

Yup.

Claim: Jonestown residents were mostly poor and black, and disproportionately children (1:17:00)

Yup and yup.

Note that this was not true of the leadership of Jonestown, which was overwhelmingly white. Cooper gets into this later in the sequence.

Claim: Jim Jones led successful efforts to integrate businesses in Indianapolis (memory)

This claim came later in the sequence. It and the similar claim below were very significant to me and a number of changes in my own models rest on them, so I expanded the scope of the project to include them.

There are many sources repeating this claim, including Wikipedia, some book, and r/HistoryAnecdotes, and none denying it. I am a little suspicious because everyone seems to agree on exactly how many restaurants he integrated, but no one names them. They do name a hospital, but it seems like maybe “integrated” means “he accidentally got assigned to a black ward (because his doctor was black) and refused to leave”. But it’s not surprising that restaurants he integrated either no longer exist or don’t want to be remembered as “the place that excluded minorities until forced to change by the guy who later led America’s largest simultaneous suicide”.

Claim: Jim Jones helped members of his racially-integrated church tremendously (memory)

I found many secondary or tertiary sources saying this and no arguments against, but the only primary sources I could find joined the church in California. I couldn’t find any reports from people who joined while the church was in Indiana. That doesn’t seem damning to me; it’s kinda hard to tell people your lights got turned back on by Jim Jones before he was famous. This interview with a woman who joined in California and narrowly escaped the mass suicide confirms everything it can: she was a true believer in a bunch of good things but also kind of a joiner who ping-ponged between organizations until she found peace with People’s Temple. Another CA joiner talks about joining because her sister needed a rehab program and was recommended to People’s Temple’s program. 

Claim: Jim Jones adopted multiple children of color (memory)

True. The Jones family adopted three Korean children, one part-Native American child, and one black child, who they named James Jones Jr (they also had one biological child and adopted a white child from a People’s Temple member. There are also some People’s Temple kids of unclear paternity).

I recognize that transracial adoption is contentious and actions that were considered progressive and inclusive 60 years ago are now viewed as bad for the children they were supposed to benefit. I also get that lots of adoptive white parents were unprepared to deal with the realities of racism, or harbor it themselves, and that harmed their kids. The whole mass suicide thing casts some doubt on Jim Jones as a parent too. Nonetheless, a white man naming his black son after himself in 1961 was an extraordinarily big deal for which he undoubtedly paid a very high price, and from all this I have to conclude that fighting racism was extremely important to early Jim Jones.

Summary

Overall all of the claims were at least extremely defensible. I wish Cooper acknowledged more of the controversy around his interpretations, but I also appreciate that he comes to actual conclusions with models instead of spewing a bunch of isolated facts. I also wish he provided show notes with citations, because he’s inconsistent about providing sources in the audio.

Doing this check reinforced my belief that having one source for any of your beliefs is malpractice and processing multiple sources is a requirement, however I will very happily continue to have Cooper as a significant source of information, and if I’m totally honest I’m not even going to check all his work this extensively. 

Thanks to Eli Tyre for research assistance, my Patreon Patrons for financial support of this post, and Justis Mills for editing.

Exercise Trade Offs: Follow Up 2

When I did the original math I felt a little pang that I didn’t check the source of the 1o minutes of exercise = 1 microlife value, but the result was so overwhelming it didn’t matter. When I added in the time to travel and actually exercise it became a much closer thing, so the error bars on that estimate began to matter. Thanks to reader Steve B. I was able to access the appendix of the microlife article that provided sources for the value of exercise, which turns out to be these two papers.

Both papers are strictly correlational (average exercise per week vs. lifespan), making no attempt to correct for the fact that healthier people will find it easier to exercise and are more likely to do other life-extending things. Exercise was determined by self report, and it looks like those microlifes come from a reduced chance of dying during the study, rather than being tacked on to the end of your life.

There’s a lot of evidence that exercise reduces various markers and effects change associated with a longer life, so I’m pretty sure it’s still good, but I no longer have any faith in this particular number.

Alternate Views On Long Covid

Scott Alexander has published a post on long covid, which he rates as much more frequent and dangerous than I do. Scott and I spent a while hashing this out in private, and our cruxes seem to come down to:

  1. I think his studies are too small and sample-biased to be meaningful.
  2. He thinks my studies (especially Taquet) didn’t look at the right sequelae.
  3. I was only looking at cognition (including mood disorders), whereas he looked at everything.

Scott also didn’t do age-specific estimates, although that’s not a crux because I expect other post-infection syndromes to worsen with age as well.

I intended to include fatigue in my analysis of cognitive symptoms but in practice the studies I weighted most highly didn’t include them. Scott’s studies, which he admits are less rigorous although we differ on how much, did include them. Why the hell aren’t the large, EHR-based studies with control groups looking at fatigue?

Also, this isn’t relevant to the covid disagreement, but I baffled by the medical systems’ decision to declare chronic Lyme in particular as the definitely psychosomatic syndrome, given that Lyme is closely related to syphilis, which we know damn well has a long dormant period and a stunning array of possible long term consequences.

Although I didn’t update much on this particular disagreement, I have a lot of respect for Scott and encourage anyone making decisions based on bloggers’ estimates of the risk of long covid to check out his post as well.

Exercise Trade Offs: Followup

Last week I did some math on the risk/reward profile of exercising indoors (risking covid exposure) vs. outdoors (risking exposure to smoke from the CA fires), and found the numbers for the day I did the math (low-for-fire-season pollution outside, sparsely populated indoor gym) overwhelmingly favored exercise of any kind over not exercising, and any other factor was overwhelmed by how likely it was to create friction to exercising. 

Over on Facebook, a friend pointed out that I’d left out the biggest cost of exercise: the time in which it took place. I then realized a full accounting would also include the time to get to the gym and the risk of getting hit by a car en route. And was I sure the micromort estimate for exercise incorporated the risk of injury? (no, because the data is hidden in an appendix BJM paywalled and sci-hub doesn’t have. If you have BJM access and would like to help me out by emailing me (elizabeth@acesounderglass.com) the appendix for this article it would be much appreciated. EDIT: received and responded to. Thanks Steve!). But exercise has benefits beyond dying later, and I wasn’t fully accounting for any of those either. And time spent at or traveling to work out isn’t exactly lost: zipping around on my scooter is fun, and leaving my house regularly on some sort of schedule has been good for me. This gets unwieldy really quickly.

Nonetheless, time spent traveling and the accompanying risk of car accidents seemed really significant, so I updated the spreadsheet to incorporate it. Ignoring any positive effects beyond the microlives, this was enough to make going to my gym for cardio net costly (note: because the spreadsheet measures in micromorts a positive number is bad), although going to the gym for weights and my nearby friend’s backyard for cardio still come out ahead.

I still think gym cardio is net beneficial for me because I think my exercise is much more impactful than average. But I don’t think it’s so much more beneficial than my friend’s backyard treadmill, so I’m going to emphasize the latter except on very bad smoke days.