May 1, 2024
The more your work challenges your brain, the less likely you may be to develop memory and thinking problems down the road, according to a new report. The study found that older men and women who had worked for many years in jobs that required nimble thinking and completing novel tasks were less likely to develop dementia compared to their peers who worked in less mentally challenging jobs. They were also at lower risk of developing mild cognitive impairment, a brain disorder marked by serious memory problems that often precedes the onset of Alzheimer’s disease.
“We examined the demands of various jobs and found that cognitive stimulation at work during different stages in life — during your 30s, 40s, 50s and 60s — was linked to a reduced risk of mild cognitive impairment after the age of 70,” said study author Dr. Trine Holt Edwin of Oslo University Hospital in Norway. “Our findings highlight the value of having a job that requires more complex thinking as a way to possibly maintain memory and thinking in old age.”
The findings add to growing evidence that mental stimulation is good for the brain and may help to ward off Alzheimer’s disease later in life. Tasks that challenge the brain are thought to bolster brain cells and the connections between them and build so-called cognitive reserve. According to the cognitive reserve hypothesis, brains with more cognitive reserve are better able to defend against the ravages of Alzheimer’s disease. As brain cells die because of the progression of Alzheimer’s, enough healthy cells and connections remain to compensate for the loss, at least for a time, the thinking goes.
For the current study, researchers looked at more than 7,000 men and women aged 70 and older who lived in Norway. They reviewed participants’ work histories, starting in their 30s and continuing into retirement, and ranked them according to how mentally stimulating their jobs were.
Jobs that ranked lower in mental stimulation included those that involved a greater degree of routine and repetitive tasks. Some of those jobs were manual, such as factory work, while others were more analytical, such as bookkeeping and filing. The most common jobs for the group with the lowest cognitive demands were mail carriers and custodians.
More mentally challenging jobs generally involved more novelty and problem solving and typically required higher levels of education. Such jobs required analyzing information, thinking creatively outside the box, maintaining personal relationships, or motivating or coaching others. Included in this group were doctors, lawyers, researchers, accountants, computer programmers and those in public relations. The most common such job in the study group was teaching.
Study participants completed tests of memory and thinking skills. The researchers found that among those who had jobs with the lowest cognitive demands, 42 percent had mild cognitive impairment, compared to only 27 percent among those with the most mentally challenging jobs. After considering a variety of factors that may influence brain health, including education, income and lifestyle factors like smoking, they determined that the group with the lowest cognitive demands at work had a 66 percent higher risk of developing mild cognitive impairment in old age than the group with the highest cognitive demands at work, and a 37 percent greater chance of developing dementia. Having more education did counter the impact of a repetitive job, but not completely.
“These results indicate that both education and doing work that challenges your brain during your career play a crucial role in lowering the risk of cognitive impairment later in life,” Dr. Edwin said.
The study does not prove that stimulating work prevents mild cognitive impairment; it only shows an association. But the findings are consistent with other research showing that many years of schooling may lower your risk of Alzheimer’s disease late in life. Education is thought to build cognitive reserve, and it doesn’t have to stop with graduation from school. Mental challenges throughout life, whether it’s through an intellectually challenging job or mentally stimulating hobbies like reading or solving puzzles, are all thought to be good for the aging brain.
Alzheimer’s is a years-long process, and many factors likely determine who develops dementia, including advancing age and the genes you inherit. Mental demands throughout life, the findings in this study suggest, may be another one of the factors impacting cognitive health later in life, and may ultimately affect the risk of developing Alzheimer’s disease or at what age symptoms first appear.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Trine H. Edwin, MD, PhD; Asta K. Håberg, MD, PhD; Ekaterina Zotcheva, PhD; et al: “Trajectories of Occupational Cognitive Demands and Risk of Mild Cognitive Impairment and Dementia in Later Life: The HUNT4 70+ Study.” Neurology, April 17, 2024
