People with mentally taxing jobs, including lawyers and graphic designers, may end up having better memory in old age, research suggests.

A study of more than 1,000 Scottish 70-year-olds found that those who had had complex jobs scored better on memory and thinking tests.

One theory is a more stimulating environment helps build up a “cognitive reserve” to help buffer the brain against age-related decline,

The research was reported in Neurology.

The team, from Heriot-Watt University, in Edinburgh, is now planning more work to look at how lifestyle and work interact to affect memory loss.

Those taking part in the study took tests designed to assess memory, processing speed and general thinking ability, as well as filling in a questionnaire about their working life.

The analysis showed that those whose jobs had required complex skills in dealing with data or people, such as management and teaching, had better scores on memory and thinking tests than those who had done less mentally intense jobs such as factory workers, bookbinders, or carpet layers.

Protective effect

To rule out that those with more complex jobs may have had higher thinking abilities in the first place, the researchers looked at scores they had achieved in the Scottish Mental Survey in 1947, when they were 11.

They found that the benefit was reduced, but there was still an association between having a mentally stimulating job, such as those including negotiation, mentoring or synthesis of data, and better cognitive ability years after retirement.

Study leader Dr Alan Gow said: “Our findings have helped to identify the kinds of job demands that preserve memory and thinking later on.”

He added it was rare for these sorts of studies to be able to account for prior ability.

“Factoring in people’s IQ at age 11 explained about 50% of the variance in thinking abilities in later life, but it did not account for all of the difference.

“That is, while it is true that people who have higher cognitive abilities are more likely to get more complex jobs, there still seems to be a small advantage gained from these complex jobs for later thinking skills.”

Brain changes

While the study did not look at biological reasons for the protective effect of certain jobs, potential explanations include that structural changes within the brain mean less damage is accumulated over time.

Dr Simon Ridley, head of research at Alzheimer’s Research UK, said the study added to the growing evidence about factors that affect brain health as we aged.

“Keeping the brain active throughout life could be helpful and different types of work may play a role.

“However, it’s important to note that this study points to a small and subtle association between occupation and later-life cognition rather than offering proof that people’s occupation has a direct influence.”