Alzheimer's is an entirely different beast than normal mental atrophy and there are plenty of stories of otherwise intelligent people ending up with it.
I'm not saying you shouldn't try using your brain more but this is just like saying Stephen Hawking should have tried exercising more.
The article doesn’t say taxi drivers are immune to Alzheimer’s. It specifically talks about having more cognitive reserve, which means having “more brain” to atrophy. Essentially Alzheimer’s makes their hyper-developed hippocampus become that of an average’s person because they started off higher up.
Being intelligent doesn’t mean you still learn new things as you age. Using your brain doesn’t do anything, it’s using your brain in novel ways.
That companion is also bunk. Two entirely different diseases.
Could just be that whatever factor causes certain cabbies to live much longer than their cohort is also protective from Alzheimer’s. I guess they might have accounted for that too — I’ll have to look at the study.
Or, that if you can survive the thing that kills the rest of their cohort, it has beneficial tradeoffs. As in, perhaps smoking protects from Alzheimer's, if it doesn't kill you first.
Controlling for age in a profession with a high fatality rate like this seems like controlling for high alertness, consciousness, quick reaction times, and well restedness/low stress, low recreational drug and alcohol use.
Of those, sleep issues are highly correlated with Alzheimer's and also with auto accidents. Controlling for age alone here would select for low incidence of sleep issues.
The claim was learning is important. Not the ability to communicate with it. There are more than 7000 known languages in the world, study a different one every week...
Back in college (around 15 years ago), I read a few books on eminence by Dean Kieth Simonton. One thing that I remember, and that has always been in the back of my mind, is that certain studies found that (in the USA), children who grow up in bilingual and bicultural households tend to have a much greater chance of achieving some measure of eminence in their adult lives. I am not sure if this is true globally (nor if it is still true in the USA). But I suspect that there is a reason[0] why so many eminent people came from Austria-Hungary for _generations_ (even the generations after the collapse of that particular empire).
[0]: There were 10 distinct languages, making up 98% of all languages in the empire. My understanding is that most citizens had to learn German, even though only 20% of the population spoke German as a mother tongue. Also a few different language branches (Germanic, Ugric, Slavic, Romance), with one of those branches (Ugric) not being Indo-European at all. https://en.wikipedia.org/wiki/Ethnic_and_religious_compositi...
Delay your aging by using your brain a fuck ton, all the time, learning brand new things nowhere near anything you already know.