Is it possible to navigate your way to better brain health? That was the tantalising question raised by a recent study in the British Medical Journal, which found that being a taxi or ambulance driver may offer protection against dementia.
Researchers from Harvard University studied the working lives and causes of death in millions of Americans. After comparing some 400 occupations, they found that taxi and ambulance drivers were the least likely to die from Alzheimer’s disease.
Being good at finding your way around might help you stick around longer. That’s the theory, anyway. Bus drivers, for example, don’t seem to have the same protection, possibly because they tend to drive the same routes.
“Our findings raise the possibility that frequent navigational and spatial processing tasks, as performed by taxi and ambulance drivers, might be associated with some protection against Alzheimer’s disease,” the authors wrote.
It’s potentially a significant finding because dementia is a big killer. Between 2012 and 2021, nothing killed more people in the UK than dementia. According to Alzheimer’s Research UK, in 2023 alone, 75,000 Brits succumbed to it.
As we get better at surviving cancer, heart disease and other chronic illnesses, we're living for longer and that comes with a higher risk of dementia. So, should we be deleting our map apps and orienteering our way to a longer, healthier life?
Well, this isn’t the only evidence that navigation is good for long-term brain health. Older studies have found that training to be a London cab driver changes the structure of the brain.
London cabbies famously have to do ‘the Knowledge’, a notoriously difficult test of their grasp of the capital’s streets.
Researchers at UCL found that when drivers trained for the test, their hippocampus became larger, like a bicep that’s done a lot of dumbbell curls. The hippocampus plays an important role in navigation and spatial processing, but it’s also the first region of the brain to begin to shrink and fail when Alzheimer’s sets in.
“There’s evidence that spatial orientation and navigation are among the first things to decline,” says Hugo Spiers, a professor of cognitive neuroscience who runs the Taxi Brains project at UCL.
“[Their decline] may even predate the loss of memory.” If frequent navigation increases the size of the hippocampus, then it might offer a kind of physical and cognitive reserve that protects you against the disease. It could be part of a broader approach to brain health.
“We know that if you have a higher level of education, for example, you start off with more cognitive reserve,” Spiers says. “Having an education, thinking more, having a job that requires the kind of things that get disrupted in Alzheimer’s, does seem to be beneficial.”
There is a caveat to the Harvard study, though. While researchers found that taxi and ambulance drivers were less likely to die of Alzheimer’s, they were also more likely to die young.
That’s an issue because Alzheimer’s is a disease that becomes more likely the older you get. If people in those professions aren’t living long enough to get Alzheimer’s, that could explain some of the results.
“The paper isn’t an advert for becoming a taxi driver – unfortunately they’re dying earlier” Spiers says. “Importantly, however, the researchers reran their analysis correcting for age and still found a significant effect.”
Another thing to consider is that the study looked at historical mortality data. It’s likely that many of the drivers considered in the study weren’t using GPS to get around, like so many of us do today. “That’s interesting context because these results might change as society changes,” Spiers says.
He believes we could all do with sharpening our navigation skills – and one of the best ways is to get outdoors.
If I was triangulating lots of the evidence we’ve seen in recent years, one of the best things you can do for your brain is to go for a run or a walk in nature,” Spiers says. “Go to a forest, if possible, and try to get a bit lost. Don’t rely on GPS, find your own way.”
He says that means you’re not only thinking spatially, you’re also being active and engaging in nature, all things known to be good for healthy ageing. Go with friends for an extra boost because having more social connections also helps against Alzheimer’s.
So, where to then, mate?
About our expert
Hugo Spiers is a professor of cognitive neuroscience at UCL. He runs the Taxi Brains project at the university. His work has been published in Nature, Proceedings of the National Academy of Sciences of the United States of America and Public Library Science, to name a few different journals.
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