2014-11-20 10:18:30
By Emma Wilkinson Health reporter, BBC News
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."