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.”