Higher Cortisol Linked to Faster Cognitive Decline

Higher cumulative physiologic stress, as indicated by salivary cortisol levels, was linked to faster cognitive decline in older adults, according to a prospective study. The research, published in JAMA Network Open, analyzed data from 1,044 participants aged 65 and older who were part of the Rush Memory and Aging Project. Participants provided saliva samples annually for up to 10 years to measure cortisol, a key stress hormone.

Individuals with the highest cumulative cortisol exposure demonstrated significantly worse composite global cognition scores compared to those with the lowest exposure. This association remained even after adjusting for factors such as age, sex, education, and depressive symptoms. The study's findings suggest that chronic stress, reflected in elevated cortisol, may accelerate the aging process in the brain and contribute to neurodegenerative changes.

The researchers utilized a composite measure of cognition that included assessments of global cognition, memory, and executive function. The study's design allowed for the examination of longitudinal changes, providing insights into the temporal relationship between stress and cognitive aging. The cumulative cortisol measure was derived by summing the area under the curve of cortisol levels over the study period, reflecting sustained exposure to stress.

While the study highlights a significant association, it is observational and does not establish a causal link. However, the findings align with existing research on the detrimental effects of chronic stress on brain health. The authors suggest that interventions aimed at reducing chronic stress could potentially play a role in mitigating age-related cognitive decline and supporting brain health in later life. Further research is warranted to explore the specific biological mechanisms underlying this relationship and to develop targeted interventions.