Wait... You can die from Alzheimers?

This article is light on a lot of details, I'd be cautious about believing this in any significant way. Taxi driving in London is known to have a heavy cognitive load because of the training and skill required. Where I live taxi and rideshare services now rely exclusively on software for route finding. But even in London the causality may run the opposite way - without exceptional hippocampal function you may not be able to become a taxi driver. So the activity is not necessarily neuroprotective, but the selection process may weed out vulnerable people.

Secondly the odds ratio is not impressive here. The non-taxi groups get Alzheimer's at a rate of 1.66%. the taxi groups get it at 1%. So this not a stochastic difference, just a decrease in the rate. I'm on vacation so I'll leave it to someone else to look up the study numbers and punch them into a calculator.

Also of interest is the occupational definition of how long someone needs to be a "taxi driver" to be classified that way. If someone has declining cognitive performance they may be streamed into another occupation before retirement or diagnosis. And so on.

Absolutely, people do it all the time

Why couldn't you?

Yes. It's horrible. Swallowing and choking hazards are associated with end stages.

Your closing paragraph is where I was thinking too - maybe taxi drivers die of other causes before alzheimers has a chance, or they retire earlier (your point) or selection bias (again your early point).

So many other ways to possibly explain it, especially given the rate difference.

But that's how it is today, lots of mediocre studies produce headlines with "could" or "may", etc.

It's hell in the classroom. Shoddy science and shitty interpretations get amplified through a network of popularizers and social media commentary experts. It's tough to pull people back to the data and the assumptions and limitations of study methods.

I thought it just caused a cognitivie decline, and wasn't lethal by itself alone but could lead to getting hurt because of the confusion it can cause. 🤷‍♂️

Kinda like how AIDS doesn't kill you directly, it just makes it super easy for other illnesses to kill you cause your body can't fight them.

100% of deaths are caused by heart failure. Everything else is a contributing factor.