Working with people and on complex tasks slows cognitive decline ⁰

Working on complex tasks and work that is based on interactions with other people rather than data or things appear to protect against cognitive decline, according to research presented at the Alzheimer’s Association’s International Conference in Toronto. Researchers in two separate studies claim that people whose work requires complex thinking and activities are better able to withstand the wider causes of cognitive decline. The results suggest that working with people, rather than data or physical things, contributed the most to the protective effect and could offset the widely reported effects of a Western diet on cognitive ability. Researchers found that people with increased white matter hyperintensities (WMHs) – white spots that appear on brain scans and are commonly associated with Alzheimer’s and cognitive decline – could better tolerate WMH-related damage if they worked primarily with other people rather than with things or data.

The two studies looked at how complex work and social engagement counteract the effects of unhealthy diet and cerebrovascular disease on cognition. One found that while a “Western” diet is associated with cognitive decline, people who ate such food could offset the negative effects and experienced less cognitive decline if they also had a mentally stimulating lifestyle. Occupations that afforded the highest levels of protections included lawyer, teacher, social worker, engineer and doctor; the fewest protections were seen among people who held jobs such as labourer, cashier, grocery shelf stocker and machine operator.

“You can never totally forget about the importance of a good diet, but in terms of your risk of dementia, you are better able to accommodate some of the brain damage that is associated with consuming this kind of (unhealthy) diet,” said Mr Matthew Parrott, a post-doctoral fellow at the Rotman Research Institute in Toronto, who presented the study.

Jobs involving “mentoring” – such as social worker, physician, school counsellor, psychologist, and pastor – were considered most complex, said Ms Elizabeth Boots, a research specialist at the University of Wisconsin and the study’s presenting author. Work involving taking instructions or helping was considered the least complex. The study, conducted by the Wisconsin Alzheimer’s Disease Research Centre and Wisconsin Alzheimer’s Institute, focused on people who were cognitively healthy but at risk for Alzheimer’s.

Four additional studies also presented at AAIC 2016 add to the current body of evidence that modifiable risk factors can help build resilience to age-related cognitive decline. According to these reports, formal education, complex work and newly-identified genes may increase resilience to cognitive decline and dementia, even in people at high risk for the disease because of unhealthful diet or blood vessel problems in the brain. Additionally, resilience factors may vary between men and women at high genetic risk of Alzheimer’s. Finally, a scientifically tailored cognitive training program led to a reduction in risk of developing cognitive decline or dementia over the 10-year course of a research study.

“These new data add to a growing body of research that suggests more stimulating lifestyles, including more complex work environments with other people, are associated with better cognitive outcomes in later life,” said Maria C. Carrillo, PhD, Alzheimer’s Association chief science officer. As each new study emerges, we further understand just how powerful cognitive reserve can be in protecting the brain from disease. As we’ve heard at AAIC this year, formal education and complex occupation could potentially do more than just slow cognitive decline – they may actually help compensate for the cognitive damage done by bad diet and small vessel disease in the brain. In metaphorical terms, we can see how cognitive reserve is taking on super power status,” Carrillo said. “It is becoming increasingly clear that in addition to searching for pharmacological treatments, we need to address lifestyle factors to better treat and ultimately prevent Alzheimer’s and other dementias.”