Complex jobs may protect thinking skills in later life
One of the participations completing his cognitive tests at age 70

People in jobs that demand complex dealings with people or data are more likely to stay mentally sharp in later life, a study involving Heriot-Watt suggests.

Researchers from The University of Edinburgh and Heriot-Watt University found that people who had worked in challenging work environments which might involve complex work with people or data scored better in memory and thinking tests when they were over 70.

Our findings have helped to identify the kinds of job demands that preserve memory and thinking later on. 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 those complex jobs for later thinking skills.

Dr Alan Gow, Lecturer at Heriot-Watt University

The report, co-authored by Heriot-Watt's Dr Alan Gow, involved testing 1,066 people for memory, mental processing speed and general thinking ability.

The complexity of each participant's main job was judged according to the Dictionary of Occupational Titles, a guide used by employment services to define the structure and content of occupations.

Using statistical models the researchers analysed how a person's occupation were associated with the results of their cognitive ability tests. Importantly, the team were able to take into account the results of intelligence tests taken by study participants when they were 11 years old and lifestyle factors, such as education and the relative deprivation of their environment. Those factors are important as they predict the kinds of jobs people are able to attain.

They found that participants whose work had involved tasks such as analysing data or instructing, mentoring and negotiating with people gained a small advantage.

Analysis revealed that the complexity of their roles explained about two per cent of their performance on some of the thinking and memory tests.

Dr Alan Gow said, "Our findings have helped to identify the kinds of job demands that preserve memory and thinking later on. 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 those complex jobs for later thinking skills"

The group tested were part of the Lothian Birth Cohort 1936, a group of individuals who were born in 1936 and took part in the Scottish Mental Survey of 1947.

Individuals have been tested on a number of physical and mental functions as they grow older, including changes in reasoning, memory, speed of thinking, many aspects of fitness and health, eyesight, blood composition and genetics.

Professor Ian Deary, Director of the Centre for Cognitive Ageing and Cognitive Epidemiology at the University of Edinburgh, who led the research project, said, "It is interesting to see this new finding added to some other factors that seem to give a little boost to thinking skills in older age, such as not smoking, being physically fit and active, and knowing more than one language. It seems that having to exercise one's thought processes concerning data and people at work is helpful too. My team is now on the look-out for more such factors."

The study is published in Neurology®, the medical journal of the American Academy of Neurology and is part of a larger project called the Disconnected Mind that is supported by funding from the Age UK. Additional support was received from the Medical Research Council and the Biotechnology and Biological Sciences Research Council.

Professor James Goodwin, Head of Research at Age UK, said, "Understanding how and why our thinking skills change with age is a major current health challenge. The relationship between the work we do during our lives and our health in later life is a complex one, so this finding is a welcome step forward in understanding the effects of job type on mental health in older age. The more we can find out what influences cognitive ageing, the better the advice that we can give people about protecting their cognitive health."

You can read a copy of the paper online at Occupational complexity and lifetime cognitive abilities

Image: LBC1936 Research Team/The Wellcome Library