Routine jobs raise the risk of cognitive decline by 66% and dementia by 37%, study says

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Working your brain hard at your job could pay off in more ways than boosting your career — it may also protect your cognition and help prevent dementia as you age, a new study found.

Having a routine job with little mental stimulation during your 30s, 40s, 50s and 60s was linked to a 66% higher risk of mild cognitive impairment and a 37% greater risk of dementia after the age of 70, according to the study, when compared with having a job with high cognitive and interpersonal demands.

“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 lead author Dr. Trine Edwin, a researcher at Oslo University Hospital in Norway. “The workplace is really important in promoting cognitive health.”

Years spent in school did help counter the impact of a repetitive job, but not entirely, Edwin said. Attending college, for example, reduced the impact of a repetitive job by about 60% but didn’t fully negate the risk.

“Staying actively engaged in life, maintaining a sense of purpose, learning new things and remaining socially active are powerful tools to protect against cognitive decline as we age,” said Dr. Richard Isaacson, director of research at the Institute for Neurodegenerative Diseases in Florida, in an email.

“Similarly, this study shows that being cognitively engaged at work can also have profound benefits in our fight against dementia,” said Isaacson, who was not involved in the new study.

“Just like we can use physical exercise to grow and maintain our muscles, exercising our brain through more engaging work assignments and ongoing collegial interactions seems to also help fend off dementia.”

Routine jobs are often repetitive

The study, published Wednesday in Neurology, the journal of the American Academy of Neurology, analyzed health and occupational data on 7,000 Norwegians who were followed from their 30s until they retired in their 60s.

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

To do the analysis, Edwin and her team categorized the cognitive demands of 305 occupations in Norway. Routine jobs that were not classified as “cognitively protective” often involved repetitive manual and mental tasks, such as is typical of factory work and bookkeeping.

“Most people in routine jobs in our sample included housekeepers, custodians, construction workers and mail carriers,” Edwin said.

More cognitively demanding jobs were not based on routine tasks, even though repetition was required at times. Daily duties would more often include creative thinking, analyzing information, problem-solving and explaining ideas and information to others. Interpersonal skills, such as coaching or motivating others, are also required in these types of 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,” Edwin said. “Teachers have a lot of interaction with students and parents and have to explain and analyze information. It’s not so routine-oriented.”

‘If you don’t use it, you lose it’

Many people in the study stayed in jobs with the same degree of complexity during their working lives. This consistency was a strength of the study in that it allowed researchers to study the impact of a job type over time, Edwin said. The study could not account for differences in duties within a certain job category, however.

“As they say, if you don’t use it, you lose it. This is similarly true for cognitive engagement throughout the lifespan,” Isaacson said.

“While I’d speculate that people at risk for Alzheimer’s would be well served by taking advantage of professional advancement opportunities, learning new job tasks, and refining their skills at work over a period of time, further studies will help clarify which specific activities have the most brain healthy benefits,” he added.

Adopting a brain healthy lifestyle, such as eating a Mediterranean-style diet, limiting alcohol and stopping smoking, staying on top of vascular risk factors such as high blood pressure, diabetes and high cholesterol, regularly evaluating and treating hearing and vision loss, all while “getting adequate sleep and managing stress can help people slam the breaks on cognitive decline,” he said.

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