A new study published in the British Medical Journal found that taxi drivers and ambulance drivers have significantly lower death rates from Alzheimer's disease compared to the general population, according to The Independent. Analyzing nearly nine million death certificates from 2020 to 2022, researchers linked occupational data across 443 professions with Alzheimer's disease as a cause of death.
Among taxi drivers, 1.03% died from Alzheimer's disease, while ambulance drivers had an even lower rate of 0.74%, The Independent reported. This is significantly less than the overall population rate of 1.69%, suggesting a correlation between these occupations and reduced Alzheimer's mortality. The researchers adjusted for factors such as age, gender, education, and ethnic background to account for potential confounding variables, Medical Dialogues noted.
The study's authors hypothesize that the frequent use of navigational and spatial processing skills required in these professions may protect against Alzheimer's disease by enhancing the hippocampus, a region of the brain crucial for memory and navigation. Dr. Vishal Patel, the first author of the study, stated: "The same part of the brain that is involved in creating cognitive spatial maps—which we use to navigate the world around us—is also involved in the development of Alzheimer's disease," as reported by The Telegraph.
Previous research has shown that London taxi drivers have a larger than average hippocampus, which may support their navigational skills and contribute to their lower rates of Alzheimer's disease mortality, The Telegraph explained. The hippocampus is one of the first areas to deteriorate in Alzheimer's disease, and intensive use of this region may enhance its resilience.
However, the study is observational and cannot prove causation. "We do not consider these findings to be conclusive, but rather hypothesis-generating," the authors conclude. Experts urged caution in interpreting the results. "The authors of this interesting study are correct to be cautious about claiming that the navigational effort involved in their occupation protected taxi and ambulance drivers from Alzheimer's disease. It is just as likely that individuals with better navigational and spatial skills flourish in these jobs. The advent of satnav technology, with less reliance on inherent navigational abilities, is likely to reduce any such effects," said Professor Robert Howard, an expert in old age psychiatry at University College London, The Telegraph reported.
Similarly, Professor Tara Spires-Jones, President of the British Neuroscience Association, highlighted a limitation of the study. "The average age of death of the drivers in the study was 64-67, while in other professions it was 74. If they had lived longer, they might have developed Alzheimer's," she noted, as reported by Science Alert. She also noted that "the proportion of women taxi and ambulance drivers was 10-22 percent whereas in all other occupations this was 48 percent. This is important because women are more likely to develop Alzheimer's disease."
The study found that other transport occupations, such as bus drivers, aircraft pilots, and ship captains, did not show a comparable advantage in Alzheimer's risk reduction. Bus drivers had an Alzheimer's mortality rate of 3.11%, and airline pilots had a rate of 4.57%, STAT reported. The researchers suggest that the lack of lower Alzheimer's risk in these professions is "possibly due to their reliance on predetermined routes," according to Mirror.
"Our results highlight the possibility that neurological changes in the hippocampus or elsewhere among taxi and ambulance drivers may account for the lower rates of Alzheimer's disease," Dr. Anupam Jena of Harvard University said, The Telegraph reported.
The findings offer an interesting new perspective on the potential role of cognitive challenges in preventing Alzheimer's disease.
"This paper for me was one of these studies [where] I thought, 'I wish I'd been able to do that.' So I was really pleased to see this, and it fits what I suspected," said Hugo Spiers, a cognitive neuroscientist at University College London who has studied the brains of London taxi drivers, according to STAT.
The article was written with the assistance of a news analysis system.