Taxi drivers rarely die of Alzheimer’s – how complex mental maps and spatial reasoning protect your brain

A 2024 study revealed that taxi and ambulance drivers have a lower risk of dying from Alzheimer’s disease compared to workers in nearly every other profession. This surprising finding came to light as the researcher, who has spent over two decades working with maps and geographic information systems, pondered whether this mental exercise could have a protective effect on the brain.

The researchers concluded that continuous real-time navigation, such as finding routes between points A and B, may be responsible for reducing the risk of Alzheimer’s. This is believed to occur in the hippocampus, a brain region crucial for memory and spatial navigation, which is also one of the first areas to be damaged by Alzheimer’s.

London taxi drivers, who must memorize over 25,000 streets for their “The Knowledge,” demonstrated increased gray matter in the posterior hippocampus, a brain area linked to storing large-scale spatial maps. The amount of gray matter correlated with the duration of their driving experience. This suggests that spatial reasoning through real-life navigation could reshape the hippocampus and potentially protect against Alzheimer’s.

While map specialists such as cartographers, urban planners, and geospatial analysts also engage in sustained spatial reasoning, the impact of this work on the hippocampus is still unclear. Research has found that living in complex environments with intricate street networks and numerous landmarks can reduce the risk of Alzheimer’s, likely due to the mental exercise of building cognitive maps.

However, the effects of spatial reasoning through screens as opposed to in-person navigation remain untested. The implications of these studies extend beyond mapmakers and cab drivers, suggesting that mentally complex occupations could delay the onset of Alzheimer’s symptoms.