Professional jobs that challenge the brain may provide the best protection against mental decline in old age, research suggests.

Memory and thinking ability is better preserved by solving problems, developing strategy, conflict resolution and information processing than less demanding work, a study has found.

Scientists regularly tested 1,054 people over the age of 75 for a period of eight years.

They also asked participants about their work history and categorised the kind of jobs they did into three groups − executive, verbal or fluid.

Executive tasks involved management, strategy development and resolving conflicts. Examples of verbal tasks included evaluating and interpreting information, while fluid tasks incorporated selective attention and data analysis.

A test called the Mini-Mental State Examination (MMSE) was used to assess memory and thinking ability.

The study found that people whose working lives included the highest level of all three types of task scored highest in the MMSE tests. They also showed the slowest rate of mental decline.

Memory and thinking ability is better preserved by solving problems

Older people who had an enriched work environment fared better on thinking and memory tests as they aged. Over eight years, their decline rate was half that of participants with a low level of mentally demanding work tasks.

High levels of executive and verbal tasks were distinctly associated with slower rates of memory and thinking loss.

Lead researcher Francisca Then, from the University of Leipzig in Germany, said: “Our study is important because it suggests that the type of work you do throughout your career may have even more significance on your brain health than your education does.

She added: “Challenges at work may indeed be a positive element, if they build up a person’s mental reserve in the long-term.”

The research is reported online in the journal Neurology.