Scientists suspect regularly driving from memory may boost brain power as a new study shows taxi drivers and ambulance drivers much less likely to develop Alzheimer’s disease
Taxi drivers could be less likely to develop Alzheimer’s disease because of how they memorise routes, research suggests.
Scientists suspect that regularly driving from memory may boost brain power as a new study shows taxi drivers and ambulance drivers are much less likely to develop the form of dementia as they age. They analysed data on nine million death certificates in the US and looked at 443 different occupations.
After adjusting for age at time of death and other factors, 1.03% of taxi drivers died from Alzheimer’s disease while among ambulance drivers, the rate was just 0.74%. This compared to 1.69% for the general population as a whole
Study lead author Dr Vishal Patel, a resident physician at Brigham and Women’s Hospital in Boston, Massachusetts, said: “The same part of the brain that’s 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. We hypothesised that occupations such as taxi driving and ambulance driving, which demand real-time spatial and navigational processing, might be associated with a reduced burden of Alzheimer’s disease mortality compared with other occupations.”
The study, published in The BMJ, was observational so the researchers cautioned that it cannot confirm a direct link. The scientists are now calling for more research to prove if frequent spatial processing tasks may lower our Alzheimer’s risk.
The analysis of US death certificates from 2020 to 2022 did not establish a lower risk of Alzheimer’s in other transport workers, such as bus drivers or aircraft pilots, “possibly due to their reliance on predetermined routes”. It suggests regular drivers may boost their brains in a way which reduces Alzheimer’s risk.
Senior study author Professor Anupam Jena, a physician at Massachusetts General Hospital, said: “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. We view these findings not as conclusive, but as hypothesis-generating, but they suggest that it’s important to consider how occupations may affect risk of death from Alzheimer’s disease and whether any cognitive activities can be potentially preventive.
“The idea is that the driving activities of those who are largely using predetermined routes are different than those who are using more on the fly decision-making that requires navigational and spatial memory. A previous study of bus drivers in London found no changes in the hippocampus, which suggested to them that the predetermined routes were not as important for the way in which the brain was used and was shaped.
“Now the question is whether or not if people stop using GPS will this have a protective effect on them. I think it’s very hard to go from our study to that question simply because what we observe in taxicab drivers reflects a career of use of the brain that is very particular. “The people who we studied are those who for the majority of their lives were not using GPS very much simply because of the age at which they died. If we look 20 years out from now or 30 years out from now that would be different, since all of these folks probably use GPS quite a bit now and have been for the last 10 years.”
Some experts believe the study may not actually be showing that it was the driving that boosted brain power – suspecting instead a phenomenon called “reverse causation”.
Prof Robert Howard, expert in old age psychiatry at University College London, said: “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.”
Prof Tara Spires-Jones, of Edinburgh University and President of the British Neuroscience Association said: “It is also worth noting that the age at death of taxi and ambulance drivers in this study was around 64-67 years of age, while for all other occupations this was 74 years of age. This is a serious limitation of the study as the age of onset of Alzheimer’s is typically after 65 years old, meaning that the taxi and ambulance drivers might have gone on to develop Alzheimer’s if they lived longer.”
