New research from Karolinska Institutet suggests that while mentally stimulating activities and life experiences can enhance cognition in memory clinic patients, stress may significantly weaken these benefits.
The study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, highlights the role of stress in cognitive decline and suggests stress management strategies could be crucial in Alzheimer’s prevention.
Cognitive Reserve and Its Protective Effects
Researchers have long observed that some individuals exhibit advanced Alzheimer’ s-related brain changes without displaying noticeable dementia symptoms during their lifetime. This phenomenon has been linked to cognitive reserve, a concept suggesting that higher education levels, complex jobs, social engagement, and physically active lifestyles may help protect brain function.
To investigate this further, scientists at Karolinska Institutet examined 113 memory clinic patients at Karolinska University Hospital in Sweden, analyzing their cognitive reserve, cognitive function, and biomarkers associated with Alzheimer’s disease. They also assessed physiological stress (measured through cortisol levels in saliva) and psychological stress (perceived stress levels) to understand how it might impact cognitive resilience.
Stress Undermines Cognitive Benefits
The study found that higher cognitive reserve was linked to better cognitive function, reinforcing that mentally and socially engaging activities help maintain brain health. However, elevated cortisol levels weakened this association, suggesting that chronic stress may counteract some of the protective effects of cognitive reserve.
“These results might have clinical implications as an expanding body of research suggests that mindfulness exercises and meditation may reduce cortisol levels and improve cognition,” said Manasa Shanta Yerramalla, lead author and researcher at Karolinska Institutet’s Department of Neurobiology, Care Sciences, and Society. “Different stress management strategies could complement existing lifestyle interventions in Alzheimer’s prevention.”
Implications for Alzheimer’s Prevention
Although the study was conducted on a relatively small group, researchers believe the findings could be generalizable to similar patient populations. Given that it also disrupts sleep—another key factor in cognitive function—the team controlled for sleep medications but noted that other aspects of sleep quality may still play a role in cognition.
“We will continue to study the association between stress and sleeping disorders and how it affects cognitive reserve in memory clinic patients,” Dr. Yerramalla added.
These findings suggest that its management interventions, such as mindfulness and relaxation techniques, could become a valuable addition to existing cognitive health strategies, potentially improving outcomes for individuals at risk of Alzheimer’s disease.
Reference: Manasa Shanta Yerramalla, Alexander Darin‐Mattsson, Chinedu T Udeh‐Momoh, Jasper Holleman, Ingemar Kåreholt, Malin Aspö, Göran Hagman, Miia Kivipelto, Alina Solomon, Anna Marseglia, Shireen Sindi. Cognitive reserve, cortisol, and Alzheimer’s disease biomarkers: A memory clinic study. Alzheimer’s & Dementia, 2024.
