Taxi and ambulance drivers show lower Alzheimer’s risk

Can navigating city streets and emergency situations protect against Alzheimer’s disease? A groundbreaking study reveals lower AD-related mortality in occupations with high spatial demands.

Study: Mortality from Alzheimer’s disease among taxi and ambulance drivers: population-based cross-sectional study. Image credits: WR7 / Shutterstock.com

A recent one BMJ study analyzes Alzheimer’s disease (AD)-related mortality among taxi and ambulance drivers, both occupations that require frequent spatial and navigational processing.

The hippocampus and AD progression

The number of deaths from AD has doubled over the past thirty years and is expected to increase as the population ages. Despite the increasing prevalence and morbidity associated with AD, there remains a lack of effective treatment and prevention strategies.

Previous research has shown that taxi drivers in London show improved functional changes in the hippocampus, a brain region responsible for episodic memory and learning. The hippocampus is often one of the first parts of the brain to become damaged in AD; therefore, it is worthwhile to investigate the risk of AD in individuals with certain occupations that require frequent spatial processing, such as taxi and ambulance drivers.

About the study

The current study assessed AD-related mortality among taxi and ambulance drivers using population-based mortality data from the United States. The operational hypothesis was that occupations that require frequent real-time spatial and navigational processing may be associated with a lower AD burden than other occupations.

Mortality data for deceased adults were obtained from the National Vital Statistics System from January 1, 2020 through December 31, 2022. The data includes 443 occupational groups; However, the researchers were particularly interested in examining data on ambulance and taxi drivers, occupations that involved extensive, unpredictable daily navigation.

For a more specific comparison group, airline pilots, bus drivers and ship captains were considered. The primary outcome variable was the percentage of deaths for each occupation with AD as the underlying cause of death.

Findings of the study

A total of 8,972,221 deceased people were identified, all of whom provided occupational information. The lowest average age at death among ambulance and taxi drivers was 64.2 years and 67.8 years, respectively.

These professions mainly employed men, with the exception of bus drivers, which was associated with a more equal representation of men and women. Airline pilots had higher levels of education, while other navigation occupations were more likely to report a high school education or less.

Of all study participants, almost 4% were found to have AD as the underlying cause of death. The unadjusted proportion of AD-related deaths was 1.03% and 0.74% among taxi and ambulance drivers, respectively, compared to 3.11%, 4.57% and 2.79%, respectively, for bus drivers, pilots and captains of ships. With a similar average age at death, AD-related deaths among taxi and ambulance drivers were lower than in other occupations.

The two occupations with the lowest adjusted percentage of AD-related are taxi and ambulance drivers at 1.03% and 0.91% respectively. In the general population, the adjusted rate of deaths due to AD was 1.69%. The adjusted odds ratio of death from AD was lowest among ambulance and taxi drivers compared to those of other occupations.

Sensitivity analyzes were conducted by restricting the sample to individuals who died at age 60 or older and when AD was cited as an underlying or contributing cause of death. In these analyses, taxi and ambulance drivers had the lowest proportional AD mortality.

Other transportation-related occupations with fewer navigation requirements did not show a pattern of lower AD mortality. Of the 443 occupations, bus drivers, ship captains and pilots ranked at number 263^rd23^rdand fourth for adjusted AD mortality.

When vascular and unspecified dementia was considered, the pattern of low AD mortality among taxi and ambulance drivers was absent. This observation suggests the role of the hippocampus in taxi and ambulance drivers in reducing the risk of AD.

Conclusions

The research results provide new insights into the possible relationship between taxi and ambulance driving and AD-related mortality. Nevertheless, additional research is needed to investigate whether specific occupations that require spatial cognitive work influence AD ​​risk and whether cognitive activities can prevent AD.

Apart from the absence of a causal relationship, another important limitation of the current study is sample selection bias. Individuals at high risk of developing AD are less likely to continue in the main occupations considered. The current study may also have underestimated the number of deaths due to AD in death certificates.