High and irregular salivary cortisol predicts 11‑year cognitive decline

A new study published in JAMA Network Open found that irregular patterns and consistently higher levels of the stress hormone cortisol in saliva are linked to later cognitive decline. Researchers measured salivary cortisol over several days and followed participants for years, noting that those with more erratic cortisol rhythms and elevated concentrations were more likely to experience memory and executive function deficits as they aged.

The analysis also revealed racial differences in cortisol patterns. Black participants exhibited lower overall cortisol levels and a smaller diurnal variation compared with white participants. These findings suggest that the biological stress response may differ across populations, potentially influencing the risk of age‑related cognitive impairment.

The authors caution that while the association between cortisol dysregulation and cognitive decline is clear, further research is needed to determine whether modifying cortisol rhythms could reduce the risk of dementia and to explore the underlying mechanisms driving the observed racial disparities.