Why London taxi drivers rarely die of Alzheimer's

Memorizing city layouts doesn't just get you across town—it physically expands your brain and helps guard against Alzheimer's.

A study analyzing death certificates from nearly 9 million Americans found that taxi and ambulance drivers have the lowest risk of dying from Alzheimer's among 443 occupations. Roughly 1 in 100 died of the disease, compared to 1 in 60 overall. The benefit didn't apply to bus drivers or pilots on fixed routes. Researchers link the defense to real-time navigation, backing up landmark research on London cabbies who grow extra gray matter while memorizing 25,000 streets to pass "The Knowledge."

Why it matters: Active navigation exercises the hippocampus, the primary region that Alzheimer's targets early on. Continuously building mental maps reshapes this area through practice, creating a buffer against cognitive decline.

Recent studies show you don't need a taxi license to get a boost. Analyzing data from over 22,500 people, researchers predicted lower Alzheimer's rates with 84% accuracy in ZIP codes with complex, landmark-rich street layouts that force everyday navigation.

Ditching turn-by-turn GPS once in a while might be the simplest brain exercise available.