The key facts

  • Seven observational studies were combined, with follow-up lasting from 13.7 to 30.1 years; dementia was diagnosed in 1,143 people
  • After adjusting for education, smoking, physical activity, and vascular disease, the risk was 18% lower in the group with more mentally demanding work
  • The authors emphasize that the study does not prove that work itself prevents dementia

Mentally demanding work is linked to an 18% lower risk of dementia

People whose jobs require active thinking and independent decisions are less likely to develop dementia in old age — this is the conclusion reached by an international team of researchers who analyzed data from nearly 108,000 people. The study was published in the journal BMJ in 2021; attention to its findings was recently renewed by a ScienceAlert article, as reported by Gazeta.Ru.

How the study was conducted

The scientists combined seven long-term observational studies. Depending on the participant group, follow-up lasted from 13.7 to 30.1 years, during which dementia was diagnosed in 1,143 people. People with high and low cognitive stimulation at work were compared; not only intellectual demands were taken into account, but also the opportunity to make independent decisions. After adjusting for education, smoking, physical activity, vascular disease, and other factors, the relative risk was 18% lower in the group with more mentally demanding work.

Possible mechanism and limitations of the conclusions

Additional analysis revealed an association between this type of work and lower levels of certain blood proteins that can interfere with the formation of neural connections. The authors view this as a possible clue to the mechanism, not as proof that the proteins themselves explain the result. The study itself does not show that work alone prevents dementia, and it does not allow attributing such an effect to any intellectual habit: other characteristics of a person and their life may simultaneously influence both career choice and brain health. Earlier, as Gazeta.Ru notes, scientists proposed prescribing physical activity as medicine for the brain.