But in at least one area, taxi drivers do quite well. A new study, released today in The BMJ, shows that taxi drivers die at lower rates from Alzheimer’s disease than people in other professions — potentially because the job involves exercising the parts of the brain that are responsible for navigation day in and day out.

Understanding the reasons behind this association could have important implications for everyone else, too, said Anupam B. Jena, a physician and economist at Harvard who worked on the new study. “Are there things that you could do over your lifetime that might reduce the risk of dementia?”