Use It or Lose It

Looking healthy (medium.com)

U.S. researchers found that (pre-GPS) professional drivers had a lower incidence of Alzheimer's disease: [bold added]

A new study found that U.S. taxi and ambulance drivers had the lowest percentage of deaths attributed to Alzheimer’s disease among more than 400 occupations. The drivers mostly worked before GPS navigation systems were widely used.

The researchers hypothesize that taxi and ambulance drivers could have a lower risk of developing Alzheimer’s because they are constantly using navigational and spatial processing, says Dr. Anupam Jena, a professor of health at Harvard Medical School and associate physician at Massachusetts General Hospital and senior author of the study.

Those on-the-fly decisions about how to get from point A to point B when a road is closed or blocked may protect the drivers’ cognitive abilities, the researchers speculate.

“They’re making decisions literally every few seconds about where to go, where to turn,” says Jena. “The way that your brain is used over the course of your career or the course of your life might impact the likelihood that someone develops dementia.”

The research supports other evidence that education and brain stimulation may help to at least delay symptoms of Alzheimer’s. An earlier study concluded that dementia risk was lower among people with cognitively stimulating jobs compared with those whose jobs were more repetitive, according to the 2021 research in the journal BMJ that looked at the occupations of more than 100,000 people across multiple studies...

A well-known 2000 study found that London cabdrivers had an enlarged part of their hippocampus. That section of the brain plays an important role in many cognitive functions, including spatial and navigational memory. The hippocampus is typically among the first parts of the brain that Alzheimer’s affects, which is why trouble with navigation and remembering directions is often an early symptom, says Wolk.

The theory goes that the brain, like muscle, grows stronger and bigger with use and makes individuals more resistant to the maladies of aging. (Earlier this year we had commented on the hypothesis that the human brain had been shrinking over millennia because more of its functions have been off-loaded to technology.)

Whether true or not, it can't hurt to use our brains more, especially now that there are many enjoyable (puzzles, education, social interactions) activities to choose from. And certain professions--like taxi and delivery-truck driving--allow one to earn a living and keep one's brain healthier for longer.