By Deidre McPhillips, CNN
People with elevated stress levels are more likely to experience a decline in cognitive function, a new study found, affecting their capacity to remember, concentrate and learn new things.
Stress is known to take a physical toll on the body, raising the risk of stroke, poor immune response and more. It can also drive people to unhealthy behaviors like smoking and poor physical activity.
The study, published Tuesday in JAMA Network Open, did find that participants with elevated stress levels were more likely to have uncontrolled cardiovascular risk factors and poor lifestyle factors.
But even after adjusting for many of these physical risk factors, people with elevated stress levels were 37% more likely to have poor cognition, the researchers found.
People who struggle with memory slips can be stressed because of the challenges that brings. But the new study suggests that the connection goes the other way, too, with feelings of stress leading to harmful effects on cognition, said Dr. Ambar Kulshreshtha, an associate professor of preventive medicine and epidemiology at Emory University and co-author of the study.
“Stress not only worsens your current cognition, but it can actually have harmful effects in the long-term as well,” he said.
The new research is based on data from a long-term, federally funded study that aimed to understand disparities in brain health, especially among Black people and those living in parts of the South known as the “stroke belt.” Thousands of participants were asked for a self-assessment of stress and surveyed with a standardized assessment of cognitive function, with regular check-ins for more than a decade.
The relationship between stress and cognitive function is a “vicious cycle,” said Dr. Amy Arnsten, a professor of neuroscience at Yale School of Medicine.
“These stress-signaling pathways get released and they rapidly impair the higher cognitive functions of the prefrontal cortex that includes things like working memory,” said Arnsten, who has researched how stress affects the brain but was not involved in the new study.
“With chronic stress, you actually lose gray matter in the prefrontal cortex, in sadly the exact regions that are involved with inhibiting the stress response and those areas that give you insight that you’re needing help.”
In the new study, the link between elevated stress and lower cognitive function was similar for both Black and White people – but Black participants reported higher levels of stress overall.
“Black individuals report greater exposure to chronic stressors, such as discrimination,” the study authors wrote. “This finding suggests that high levels of perceived stress increase the risk of cognitive decline regardless of race.”
Previous research has found that Black adults are about 50% more likely to have a stroke than white adults, and older Black people are about twice as likely to have Alzheimer’s or another dementia.
Stress has also been found to increase steadily with age, but the study showed that the link between stress and cognitive function was relatively consistent across ages. Study participants ranged in age from 45 to 98 at the time of their latest assessment.
The chances of developing Alzheimer’s disease are higher for those with a family history, but it’s not the only risk factor.
There are about a dozen factors that have been identified as modifiable risk factors, or things that a person can change to lower their risk of developing dementia.
Stress should be considered one of those factors, Kulshreshtha said, and he and his fellow researchers called for regular screenings for stress in primary care settings – as well as targeted interventions – to help minimize that risk.
“For dementia, there’s barely a few treatments and they are so expensive and not readily available. So the best way to address dementia is by prevention,” Kulshreshtha said.
“Stress is ubiquitous. But there are tools to help with our ability to manage stress and reduce it.”