Cortisol is a hormone that is naturally produced by the body in response to stress.
Researchers from ECU’s School of Medical and Health Sciences measured the cortisol and memory function of 416 healthy adults over six years.
They also scanned the brains of the participants to measure their levels of the plaque Amyloid Beta (Aβ).
The accumulation of Aβ in the brain is closely associated with the development of Alzheimer’s disease.
The researchers found that among adults with high levels of Aβ in their brain, those with higher levels of cortisol experienced a greater rate of memory decline than those with low levels of cortisol.
Lead researcher Associate Professor Simon Laws said the results may suggest that high levels of cortisol may accelerate the cognitive decline in preclinical Alzheimer’s disease (before clinical symptoms begin to show).
“These findings, when taken together with other substances in the blood, may pave the way for us to be able to better predict cognitive decline in preclinical Alzheimer’s patients,” he said.
Associate Professor Laws said that while the study didn’t establish a direct link between stress and Alzheimer’s disease, reducing stress was still a good idea.
“Alzheimer’s disease is extremely complicated so it’s perhaps not as simple as reducing cortisol to lower your chances of developing it. What this research does suggest is that this may very well be another health benefit, in addition to other well proven health benefits that result from minimising stress in your life”.
“Stress is hard to avoid but taking time out with your loved ones, relaxing with a good book or taking up a hobby are all good ways to reduce your levels of stress and reach a good work-life balance.”
As well as taking steps to reduce stress, Associate Professor Laws said that these findings have provided support for clinical trials of drugs that modulate cortisol levels to ascertain if they may be useful in delaying cognitive decline in people with preclinical Alzheimer’s disease.
Plasma cortisol, brain amyloid-β, and cognitive decline in preclinical Alzheimer’s disease: A 6-year prospective cohort study was recently published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.
Participants were recruited from the Australian Imaging Biomarker and Lifestyle study of Aging (AIBL).
The study was conducted in collaboration with The Florey Institute of Neuroscience and Mental Health and Yale University.
Edith Cowan University