Taxi and ambulance drivers have the lowest Alzheimer's disease mortality rate

An analysis of U.S. death certificates found that taxi drivers and ambulance drivers, two groups whose jobs frequently require spatial and navigational processing, had the lowest rates of death from Alzheimer's disease. It was shown that

Of the approximately 9 million people who died with occupational information, 3.88% cited Alzheimer's disease as the cause of death. But a study led by Anupam Jena, MD, of Harvard Medical School and Massachusetts General Hospital in Boston, found that only 1.03% of taxi drivers and 0.74% of ambulance drivers died from Alzheimer's disease.

Of 443 occupations, Jena et al. reported that after adjusting for age and other variables, ambulance drivers (0.91%) and taxi drivers (1.03%) had the lowest mortality rates from Alzheimer's disease. . BMJ Christmas issuean annual collection of feature articles and original peer-reviewed research.

Other types of dementia did not show the same relationship with Alzheimer's disease. Additionally, other transportation-related jobs that do not require as much real-time spatial and navigational processing did not yield the same results as taxi and ambulance drivers. For example, bus drivers ranked 263rd.

Researchers noted that the hippocampus is a brain region used to create cognitive spatial maps. Alzheimer's disease is associated with the progression of hippocampal atrophy.

“Our findings highlight the possibility that neurological changes, such as in the hippocampus of taxi and ambulance drivers, may be responsible for the lower incidence of Alzheimer's disease,” Jena said in a statement. .

“We consider these findings to be hypothesis-generating rather than definitive,” he added. “But they suggest that it is important to consider how occupation affects the risk of death from Alzheimer's disease and whether cognitive activity could potentially be protective. ”

The study was prompted by previous research led by Dr Eleanor Maguire from University College London (UCL), which showed changes in the hippocampus of licensed taxi drivers over time.

In early research, Maguire's team found that London taxi drivers had the following symptoms: fairly large posterior hippocampus than others of similar age, education, and intelligence. But it wasn't clear whether the brain had changed after years of the cognitive demands of navigating the streets of London, or whether the taxi drivers' hippocampi were already larger than average.

London taxi drivers must pass a rigorous test that requires them to know the irregular layout of around 25,000 streets and the location of thousands of locations within a six-mile radius of Charing Cross station . This spatial learning is known as “knowledge” acquisition and typically takes several years. When Maguire and colleagues examined the brains of taxi drivers Before and after spending 3 or 4 years As they prepared for the test, they found that those who successfully passed the test had increased gray matter volume in the posterior hippocampus from baseline and altered memory profiles compared to controls.

Dr Hugo Spiers, also from UCL, said: “This was a very important finding because at that time there was no evidence of changes in the brain associated with things like training and proficiency.”

“For birds, squirrels and other animals, there is a growing field of research looking at how brain size relates to their behavior,” Spiers said. today's med page. “But this was a groundbreaking study, the first of its kind.”

Jena et al. analyzed 8,972,221 death certificates related to occupations registered in the U.S. National Vital Statistics System. The records were from January 2020 to December 2022. There were 16,658 deaths among taxi drivers and drivers, and 1,348 deaths among ambulance drivers.

The average age of death was approximately 68 years old for taxi drivers and 64 years old for ambulance drivers. Approximately 70% of both groups had less than high school education. Findings were adjusted for age at death, sex, race/ethnicity, and education.

In the total sample, 348,328 people were identified as having an underlying cause of death due to Alzheimer's disease. Sensitivity analyzes showed that ambulance and taxi drivers were consistently diagnosed with Alzheimer's disease, even when analyzes were limited to those who died at age 60 and older, and when Alzheimer's disease was identified as the underlying or contributing cause of death. had the lowest mortality rate.

Jena et al. stressed that the study was observational and did not prove cause and effect. They also acknowledged that they could not account for unmeasured confounders.

People at high risk of developing Alzheimer's disease may be less likely to become taxi or ambulance drivers, but this is unlikely given that Alzheimer's symptoms usually develop after working age. said the researchers. Additionally, death certificates may underestimate the number of deaths from Alzheimer's disease.