Mentally Stimulating Work Helps Prevent Dementia

According to the researchers, of the over 7,000 participants in 305 occupations who were followed from their 30s until they retired, those with the least mentally challenging jobs were found to have a 66% greater risk of mild cognitive impairment, and a 31% greater risk of dementia after the age of 70 years old compared to those with the most mentally challenging jobs. 

“It really shows how important work is,” said Dr Trine Edwin, a geriatrician and postdoctoral fellow at Oslo University Hospital. “It’s important to go to work and use your brain, and to use your brain to learn new things.”

“Many other studies on this topic have just looked at the most recent jobs that people have,” Trine said, “but due to the national database we have in Norway we were able to follow people over much of their lifetimes.”

Analysis of data showed that most participants worked jobs with similar degrees of cognitive demands throughout their lives. Among the various jobs ranked, the most mentally stimulating were those involving creative thinking, problem-solving, explaining ideas, analyzing information, and interpersonal skills, such as teachers and university lecturers, while the least stimulating were those that involved routine, repetitive manual tasks, such as cleaning, roadwork, and delivering the mail. 

After reaching 70 years old the participants underwent standard memory and thinking tests, then they were classified as having either no cognitive impairment, mild cognitive impairment, or dementia. Further analysis revealed that of those who had worked in the least cognitively challenging jobs 42% were diagnosed with mild cognitive impairment compared to 27% of those who had worked in the most cognitively stimulating jobs, and higher education accounted for 60% of the protective effect seen among those with mentally stimulating jobs.

“There were lawyers, doctors, accountants, technical engineers, and people in public service in this group, but the most common occupation was teaching,” Trine said. “Teachers have a lot of interaction with students and parents and have to explain and analyze information. It’s not so routine-oriented.”

Previous research has shown that education can have a significant protective effect against age-related cognitive decline, this is partially because better-educated people are more likely to lead healthier lives. However, better education also appears to build a cognitive reserve which may help to stave off mental decline similar to the way that exercise helps to delay frailty. 

“It means that education is very important, but it’s also what you do afterwards: it’s how you use your brain when you are working. You are building your cognitive reserve at work by being cognitively active,” said Trine. “It’s not that you are doomed or you are not – we can empower people for their later cognitive health with education and tasks that are cognitively stimulating.”

 “It is not just that more educated people do more cognitively stimulating jobs – they do – but cognitive stimulation in work through problem-solving and new situations has an effect by itself,” said Prof Gill Livingston, Professor of the Psychiatry of Older People at the University College London. 

“This is a lot of cognitive stimulation, as most people work many hours for many years,” she said. But work may not have as big an impact as education, she added, because the brains of children and young adults may change more than those in adults to increase cognitive reserve.”

“Our results show the value of having an occupation that requires more complex thinking as a way to maintain memory and thinking in old age,” said Trine. “The workplace is really important in promoting cognitive health.”