Mild cognitive impairment, dementia risk tied to physical jobs

The study’s corresponding author, Dr. Vegard Skirbekk, explained to Medical News Today that the purpose of the study was to better understand the risks for Alzheimer’s disease and related dementias over the course of one’s life.

“Understanding [Alzheimer’s disease and related dementias] risks in a life-course perspective may be important for both the general public and health service providers. The causes of dementia late in life could plausibly be found earlier in life,” said Dr. Skirbekk.

Dr. Roseanne Freak-Poli, a life-course epidemiologist and senior research fellow at Monash University in Australia, not involved in this research, endorsed the study’s life-course approach, saying it provides a “more comprehensive understanding of how occupational histories affect cognitive health.”

As it is, she noted, “we know that the physical activity intensity of our jobs is likely to decrease as we get older, so looking across the life course provides a better understanding than measurement at just one time point.”

Brain health coach Ryan Glatt, director of the FitBrain Program at the Pacific Neuroscience Institute, also not involved in the research, said he was most interested in the study’s finding regarding the link between intermediate occupational physical activity and MCI.

As to why people with intermediate occupational activity are more likely to experience MCI, Dr. Skirbekk said: “We believe that it is to a large extent a matter of degree; the greater the physical strains, the higher the risks later in life.”

“Whether that is MCI or dementia, I don’t think this article is sensitive enough to determine,” observed Glatt. “This is a very large survey. It’s just kind of a signal.”

The researchers considered education, income, marital status, health, and lifestyle-related factors in their analysis.

“I think what this really might be signaling is a relationship between what kinds of people and which sociodemographic statuses are working these types of jobs,” Glatt told us.

The authors themselves write that “the association between occupational [physical activity] and late-life cognitive impairment could be confounded by differences in socioeconomic status.”

In addition, asked Glatt: “Is it possible that more physically demanding jobs, let’s say construction work, could be more stressful? Yeah, absolutely. Is there a likelihood of maybe exposure to certain environmental toxins in certain jobs that might have physical activity possibly?”

“I don’t think I could just go up to someone and say, ‘Hey, I think you should find a desk job because this job is going to give you dementia,’” said Glatt.

So, what can a person with a physically demanding job do to protect their cognitive health?

Dr. Skirbekk said, “we believe that when one has autonomy and can take breaks, as well as having a sense of control over one’s physical demands, may lower risks.”

Meanwhile, Dr. Skirbekk added, following standard advice for dementia risk factors makes sense: “Avoid smoking, excessive alcohol intake, social isolation, [prevent or treat] high [blood pressure], diabetes, depression, [avoid] physical inactivity, use hearing aids in case of hearing impairment, and reduce exposure to air pollution.”

Glatt suggested making sure one gets structured exercise on their time off, even if their job is physically demanding. He recommended aerobic exercise, strength training, and neural motor exercise.

Sleep, he said, is also critical to cognitive health: “A lot of people have theorized and have researched that when individuals are more physically and cognitively active, it increases the hunger and the drive for sleep.”

It is also the case, he said, that this study is part of larger conversations we need to be having. “Occupational risks are really interesting, environmental exposures are interesting, job stresses are interesting: the relationship between what’s good about a job, and what’s bad about a job.“

He called for “more occupational research on what kinds of jobs contribute to longevity, as well as health outcomes.“

“And I think if we are able to understand the relationships between those factors better — such as physical activity and stress and cognitive activity — I’m hopeful we can understand yet another factor of what might contribute to someone’s brain health journey.“

– Ryan Glatt