The researchers concluded that the key to reducing the risk of Alzheimer’s was not driving itself but continuous real-time navigation: the constant work of locating yourself in space, tracking a destination and updating a mental map as conditions change. Drivers whose jobs relied on fixed or predetermined routes, like bus drivers and aircraft pilots, didn’t seem to experience a similar advantage. Researchers believe the association between navigation-heavy work and lower Alzheimer’s risk centers on the hippocampus, a part of the brain that governs memory and spatial navigation. It’s one of the first brain regions that Alzheimer’s damages: Problems with spatial navigation and orientation are among the earliest signs of the disease, sometimes surfacing before obvious memory loss.
In one landmark 2000 study, neuroscientists compared the brains of licensed London taxi drivers with those of people who did not drive cabs. Their findings provided the first evidence via structural imaging that regions of the adult brain can measurably change under sustained navigational demand. To earn a license, 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.
The researchers found that London taxi drivers had measurably more gray matter in the posterior hippocampus, a brain area tied to storing large-scale spatial maps. That volume tracked with experience: The longer someone had driven, the larger that part of the brain. The change was built through practice, not inherited. While people who are good at navigation might gravitate to this kind of job, the job itself does have an impact on the brain. Together, these two studies make a coherent case: Work that intensively exercises the hippocampus may reshape it, and that reshaping may protect against one of the most feared diseases of aging.
