Taxi drivers rarely die of Alzheimer's

(theconversation.com)

108 points | by jader201 6 hours ago

16 comments

  • cortic 3 hours ago
    Taxi Drivers: The mean age at death is approximately 67.8 years.

    General Population: in the same dataset, life expectancy averaged 74 years.

    The average age at which patients are typically diagnosed with Alzheimer's disease is 79.

    People in these jobs don't live long enough on average to get diagnosed, at the same rate. The same effect will happen in any job that lowers your life expectancy.

    • xvedejas 20 minutes ago
      And how would you control for the causal possibility that those who will eventually develop Alzheimer's early on might tend to have undetectable memory issues that prevent them from becoming taxi drivers in the first place? You can't control for profession, since that's behind the very claim itself.
      • cortic 2 minutes ago
        Its even worse than that, i can imagine people with undiagnosed early Alzheimer's self selecting for car accidents and cardiac issues through additional stress of mental fatigue while their brain tried to compensate for loss of function.

        So you have people self selecting out of the profession, self selecting for early death within the profession, and on top of that, a general life expectancy discrepancy that is near impossible to adjust for.

      • boelboel 9 minutes ago
        This is mentioned in the article as well.
    • specproc 1 hour ago
      Studies typically use regression to account for stuff like that. CBA to look at the article, but I bet any money that's controlled for.
      • vlovich123 51 minutes ago
        > After adjusting for age, sex, race, ethnicity and education, roughly 1 in 100 taxi and ambulance drivers died of Alzheimer’s, compared with 1 in 60 people overall.

        So no indication they accounted for the expected lifespan of the profession.

        • danw1979 41 minutes ago
          Adjusting for age seems like an indication to me
          • _kulang 22 minutes ago
            Adjusting for sample/population age is the simplest interpretation of that
        • j45 47 minutes ago
          Seems like a fair point.
      • rf15 53 minutes ago
        > CBA to look at the article

        then don't post

    • harrall 44 minutes ago
      The study accounts for that.

      Delay your aging by using your brain a fuck ton, all the time, learning brand new things nowhere near anything you already know.

    • glitchc 3 hours ago
      They are likely studying individuals that retired without getting fatally stabbed or shot on the job.
      • stackskipton 3 hours ago
        It's not violence from the job but their job was generally bad for their health in other ways. Sitting all day without getting up and driving around with windows down getting all this UV.

        Also, older ones were exposed to a ton of cigarette smoke.

        • minraws 3 hours ago
          Also road accidents.
          • boelboel 12 minutes ago
            I could imagine taxi drivers have fewer fatal/grave road accidents than the average person or at most slightly more. They tend to drive in cities, are more trained, can't drink or do drugs on the job. For London only 1 taxi driver has died in a traffic accident since 2020.
      • mito88 26 minutes ago
        survivorship bias
    • TacticalCoder 3 hours ago
      That's very interesting but why do taxi drivers have a job that lowers life expectancy? Is it because they're sitting too much? Or because they're inhaling CO from cars too much? Or staying inside (the car) too much? Or is it just stressful?

      For from the look of it it doesn't look like an exceptionally hard job (btw a brother of mine did years of "VTC": "Vehicule de Tourisme avec Chauffeur", basically high-end taxis without the "taxi" logo).

      • id 3 hours ago
        Because it doesn't pay very well. Being affluent increases life expectancy.
        • inglor_cz 1 hour ago
          1. They are hardly in the bottom quintile, where the income effect is large enough that it could actually shave 7 years off their life. I'd expect nightly work, irregular sleep patterns, too much fast food and maybe a higher frequency of smoking to do their part.

          2. The original study didn't just study taxi drivers, but also ambulance drivers. I doubt that their life expectancy is that much lower.

      • coldtea 2 hours ago
        >For from the look of it it doesn't look like an exceptionally hard job

        Define "hard job". Carrying heavy objects?

      • wilburx3 3 hours ago
        Getting stabbed in the neck by filthy street urchins.
        • smt88 1 hour ago
          Probably not smart to post something like this on the same message board you’re using to get a job
    • cromka 2 hours ago
      " (...) After adjusting for _age_, sex, race, ethnicity and education, roughly 1 in 100 taxi and ambulance drivers died of Alzheimer’s, compared with 1 in 60 people overall."
      • dinfinity 1 hour ago
        Yep.

        "For each occupation, we first calculated the percentage of deaths due to Alzheimer’s disease and the mean age at death in years (ie, average life expectancy). We plotted the association between these two variables, with each observation reflecting a single occupation. The purpose of this analysis was to illustrate the need to account for the person’s age at death since the risk of Alzheimer’s disease rises with age and therefore Alzheimer’s mortality would naturally be lower in occupations with a lower life expectancy."

    • Barrin92 3 hours ago
      As the paper points out that's accounted for in the analysis, because shockingly enough to most internet commentators researchers know that they need to control for confounding variables

      https://www.bmj.com/content/387/bmj-2024-082194

      • jrflo 3 hours ago
        Always insane to me how people will just read the headline of an article and point out "flaws" based on what they assume the article says
        • cromka 2 hours ago
          People jump the gun to show their perceived intellectual superiority. Typically same kind of people are last to admit of a mistake.
        • Nasrudith 21 minutes ago
          They got trained to said assumptions by bad sensationalist 'science journalism'. Remember how power lines caused brain damage in children? Not through the magnetic fields or anything like that, but the lowered property values.
    • coldtea 2 hours ago
      Ah, the typical cheap HN reaction to a paper, along with "correlation is not causation", and as usual, for things already factored in into it.
      • mr_mitm 49 minutes ago
        Next up: "I didn't do a statistical analysis but the sample size seems small"
    • nuxi 2 hours ago
      De Niro is 82, no Alzheimer's. /s
      • sillyfluke 1 hour ago
        He was method acting, so I'll allow it.
  • walthamstow 5 hours ago
    > In one landmark 2000 study, neuroscientists compared the brains of licensed London taxi drivers with those of people who did not drive cabs.

    Location is very important here. London cabbies have to pass The Knowledge which is an extremely difficult memory exam that only people with particular kind of brain can do.

    • neuralkoi 12 minutes ago
      They have to memorize 25,000 streets. The test is no joke. [0]

      [0] https://www.youtube.com/watch?v=ur61kzXjvN8

    • graemep 4 hours ago
      The first study referenced is in the US, and across 443 occupations.
    • cromka 2 hours ago
      > that only people with particular kind of brain can do.

      That's yours speculation, isn't it?Because if so, it would corroborate the same conclusion, i.e. if you exercise your memory regularly, you are less likely to develop Alzheimer's.

    • genxy 3 hours ago
      People who would pass The Knowledge test might already develop dementia at a much lower rate.
      • inglor_cz 1 hour ago
        Plausible, but then you'd expect to find the same effect in other people who passed similarly demanding tests once. For example in people who studied something geometry-heavy.

        Also, The Knowledge Test is, IIRC, passed only once and then you do not have to retake it for the rest of your career.

        If a test passed in your 20s or 30s predicted accurately a much lower incidence of Alzheimer's in your 60s, that would be a remarkably strong early signal. Not impossible, but worth extra scrutiny. For the vast majority of old age conditions, we cannot predict them so long in advance.

    • artisinal 5 hours ago
      Indeed. Elsewhere in the world taxi drivers just follow the GPS.
      • SoftTalker 4 hours ago
        We had taxis long before GPS.

        When I was in my early 20s I had a job delivering pizza. I very quickly learned the delivery area, I knew pretty much every street and alleyway and shortcut to get from one place to another. Much smaller than London but I think the human brain is very good at remembering routes and where things are in an area, as this would have been an evolutionary advantage (go out hunting and be able to find your way back). No GPS, didn't even carry a map with me. We had a large map on the wall at the store, and if I had to deliver to a street I didn't recognize I'd find it on the map, see where it was relative to the streets I did know, and then I never had any problem finding places.

        • pryelluw 4 hours ago
          Same. First thing they had me buy was a map book with all the local neighborhoods. The map on the wall helped get shortcuts from others. This is where I learned the difference between the different kinds of shortcuts. Some saved time, others distance, and some even potholes. It was a fun time.
        • OptionOfT 4 hours ago
          My 2019 car had the cardinal directions in the mirror (N, NE, E, ES, S etc). My 2025 does not anymore. I hate it. I think it helps to get that baseline of orientation, and then you look at the street numbers, and it all starts to come together.
          • toast0 49 minutes ago
            Suction cup compasses are ~ $10 on amazon if it bothers you. Won't be in the mirror though.
          • clickety_clack 4 hours ago
            Pretty much my only issue with CarPlay is that I can’t seem to set the map so that north is up. It turns everything into “third right ahead” instead of “this is just 2 blocks east of that coffee shop I was at last week”.
            • kccqzy 55 minutes ago
              CarPlay is merely the technology of having your phone take over a screen in the vehicle. It’s not a mapping map. Plenty of mapping apps support north up.

              But in any case, I found that if you want to remember routes, it is far better to study the route before you begin driving, and then not rely on CarPlay altogether. This gives you much higher awareness of street names and directions.

        • al_borland 2 hours ago
          I suspect GPS has made this much worse. I shining example was an Uber I got in Chicago, where GPS doesn't work well due to all the buildings. The guy drove around the same block 3 times, blindly following the GPS. It was infuriating.
          • SoftTalker 2 hours ago
            And Chicago is one of the easier cities to navigate, as it's almost entirely a grid.
            • walthamstow 2 hours ago
              Yeah I don't think grids are comparable to old world cities like London
    • BrandoElFollito 2 hours ago
      There is (or at least - was) a similar test for Paris taxi drivers. They needed among others to explain turn by turn the drive between two places indicated by the examiner.

      Today this knowledge is arguably less useful.

  • estetlinus 3 minutes ago
    > London cabbies must memorize more than 25,000 streets within a 6-mile radius of Charing Cross, a challenge known as “The Knowledge” that takes three to four years.

    What the hell. I passed all the test for driving cabs in Stockholm, Sweden. I had to memorize 20 regions in the city. I wonder if this requirement applies to all taxi drivers, including Uber.

  • YmiYugy 3 hours ago
    I find the title highly misleading. The actual claim is a 40% lower chance (1 in 100 as opposed to 1 in 60) for taxi and ambulance drivers when compared to the average. That’s a big drop but the title implies that Alzheimer’s is rare in taxi drivers specifically and I don’t think the difference warrants that claim whatsoever.
  • chuckadams 5 hours ago
    The ones that do stopped being taxi drivers.
    • cobertos 4 hours ago
      True, though the article does also mention another study not based on taxi drivers, but just living in high spatial complexity ZIP codes puts you at a lower risk.

      > Research on cognitive maps points toward the same conclusion as the study on taxi drivers. In 2023, researchers ran a machine learning model on more than 22,500 people in a national dataset and were able to predict which ZIP codes had higher rates of Alzheimer’s with 84% accuracy based on how complex the environment was. Those living in spatially complex surroundings – the kind that force active map building, such as dense street networks with numerous intersections, diverse points of interest and landmarks, and multiple path options – were less likely to develop Alzheimer’s.

      • david-gpu 2 hours ago
        A dense street network with complex intersections also means living in walkable urban cores vs car-centric suburbs.
      • Palomides 3 hours ago
        or there's a million confounding factors around people living in dense cities versus rural areas
      • smolder 3 hours ago
        I know an 80 year old who was a commercial truck driver for decades and still has a strong mental map for a pretty vast area. Anecdata, but I find it interesting.
    • cjbgkagh 5 hours ago
      I would assume that the task of being a taxi driver would act as a near constant test for Alzheimer’s, would be interesting to do GWAS studies on older taxi drivers and compare against taxi drivers who quit earlier in their careers.
    • mattlondon 4 hours ago
      I guessed the probably died in a car accident or of something related to pollution exposure or being sedentary their entire adult lives.
    • don_esteban 4 hours ago
      Yeah, that was the first thing that comes to mind.

      And the second thing: What about modern taxi drivers that rely almost exclusively on GPS?

  • amelius 5 hours ago
  • yfontana 1 hour ago
    Something interesting that the original study looked at, but isn't mentioned in the linked article: this effect was not observed for non-Alzheimer's dementia deaths. There seems to be something specific to spatial reasoning and Alzheimer's.
  • lambdaone 57 minutes ago
    I wonder if the same is also true of other high-spatial-complexity activities like rock climbing and professional dancing? (Exercise level would of course be a counfounding varable to be eliminated in these cases.)
  • Havoc 5 hours ago
    Seems strange to me that a specific type of thinking could influence something where most causes being investigated are physical
    • teeray 4 hours ago
      Unless the arrow of causality is the other way: those that would tend to develop memory problems do not become or remain as Taxi drivers.
      • jvanderbot 4 hours ago
        Right, so we're speedrunning the studies here. Best to just stopover on TFA and see what they found.

        For example, airline pilots do not have a reduced level of alzheimers deaths, and that _certainly_ is not a place where you can coast with dementia.

        And taxi drivers have _increasing_ anti-Alzheimer signals - with time, the areas that are known to diminish grow _more_.

    • jkahrs595 5 hours ago
      Not strange when you realize thinking is also physical.
    • cesarvarela 4 hours ago
      Wouldn’t thinking be like exercise for the mind? And we know what happens to people that don’t exercise
    • toomuchtodo 5 hours ago
      Perhaps specific types of thinking cause somewhat sustained brain activity during waking hours that mitigates adverse physical changes leading to Alzheimer’s.

      The opposite of this is how sleep and unconsciousness allows the brain to perform cerebrospinal fluid transfer based maintenance routines via the glymphatic system, and why sleep is important to neural health.

      https://www.science.org/content/article/scientists-uncover-h...

  • al_borland 5 hours ago
    My grandfather was a taxi driver and delivery driver for many years. He made it to 93 and I don't recall him dealing with any cognitive decline. He used to tell me different routes to get to a stadium that was closed before I was even born.
  • fitsumbelay 3 hours ago
    First rule of attentioneering - If it bleeds, it ledes

    Second rule - Got edge case? Got headline!

  • OutOfHere 2 hours ago
    Eating eggs actually lowers the risk of Alzheimers.
  • arielweisberg 5 hours ago
    Can video games provide similar benefits?
    • jader201 5 hours ago
      I’m sure Crazy Taxi provides the same benefits! :)
      • moduspol 2 hours ago
        If you can survive the high blood pressure!
    • bloomca 5 hours ago
      The thing about taxi drivers is that they have something at stake, while video games have no fail state effectively. You can be punished in-game, but overall it does not matter.

      Also video games in general are pretty derivative, so playing the same genre probably won't help much after a certain point. But playing different ones can be very helpful, I imagine (same with other mediums).

      • wavemode 3 hours ago
        Yeah but, Taxi drivers usually don't hop around from place to place. They work in a specific metro area.
        • bloomca 3 hours ago
          I assume there is enough variation to be aware of -- seasons change, constructions, car crashes, so you need to alter the route a bit. Today you have the maps with navigation, but I assume you still need to be quite aware on where to park, where is the best entrance to some places, etc. So you basically need to keep some fresh info on top of your mind.
    • dragontamer 4 hours ago
      Maybe when played at a high level. But too many games are too casual without much mental effort.

      I mean, they should be. Games are for fun, not for work.

  • tokai 5 hours ago
    Taxi driver also live shorter lives than average, which would fit with lower levels of alzheimers. But interesting link nonetheless.
    • kelnos 55 minutes ago
      Age and life expectancy was controlled for in the study.
  • bpodgursky 5 hours ago
    Guys... Alzheimer's is 60-80% heritable, and driven largely by APOE genotype. No, you cannot get out of it with One Quick Trick. We have to find therapeutics to make real progress here.

    This kind of misdirection is not helpful to the research community, or encouraging politicians to fund effective projects. Everyone WANTS a quick lifestyle change and will latch onto these things, but this is a real biological disease that needs real molecular fixes. Sorry, it's just how it is.

    • jmcgough 4 hours ago
      Half of people with Alzheimer's carry at least one APOE ε4 allele. However, a full quarter of the population carries that mutation, and most carriers never go on to develop Alzheimer's. Lifestyle matters a lot here.

      This kind of misdirection is not helpful for educating people on changes they can make now to reduce their risk, rather than waiting for a silver bullet. Alzheimer's research is well-funded in the US as the octogenarians running our congress are personally invested in it.

      • detourdog 3 hours ago
        My understanding is that there are forms of dementia more tied to genetics than "Alzheimer's". One that has links to genetics is Frontal temporal Dementia.
      • bpodgursky 3 hours ago
        To the extent that lifestyle helps, which is not zero, you need to exercise. "Become a cabbie" is NOT an intervention that is going to help whatsoever.
        • yfontana 1 hour ago
          > "Become a cabbie" is NOT an intervention that is going to help whatsoever.

          How about promoting spatial awareness and reasoning exercises (which is the actual suggestion of the article)?

    • kelnos 54 minutes ago
      I don't think "become a taxi driver" is a "quick lifestyle change".

      Studies like this are useful inasmuch as they help us understand a disease more fully. Not sure what you mean by "misdirection"; the study's methodology seems sound?