Share on Pinterest
Experts say constant stress can disrupt some biological processes in the brain. Getty Images
  • Researchers say chronic stress may be one of the factors involved in the development of Alzheimer’s disease.
  • They say constant stress can affect the brain’s immune system in a way that may lead to dementia symptoms.
  • Experts say people can reduce stress by exercising, developing good sleep habits, and setting aside time for relaxation.

Chronic stress may contribute to the development of Alzheimer’s disease.

That’s what researchers in Australia have determined in a new study.

The researchers say a link between stress and Alzheimer’s disease could be due to a response in a part of the body called the hypothalamic-pituitary-adrenal (HPA) axis, a pathway in the brain responsible for stress responses.

“What we know is that chronic stress does affect many biological pathways within our body. There is an intimate interplay between exposure to chronic stress and pathways influencing the body’s reaction to such stress,” said David Groth, PhD, a senior author of the study and an associate professor at Curtin University in Perth, Australia.

“Genetic variations within these pathways can influence the way the brain’s immune system behaves, leading to a dysfunctional response. In the brain, this leads to chronic disruption of normal brain processes, increasing the risk of subsequent neurodegeneration and ultimately dementia,” Groth said in a statement.

Both dysregulation of the HPA and raised levels of cortisol, a stress hormone, are common in people with Alzheimer’s disease. Experts say these elevated levels of cortisol may play a role in neurodegeneration.

“We don’t know what the chicken or the egg is here in regard to cortisol. As with most things involving complex degenerative diseases in the human body, there is likely a feedback loop where high levels of cortisol and neurodegeneration are feeding off of each other,” Dr. Ryan Townley, an assistant professor of neurology at the University of Kansas Alzheimer’s Disease Center, told Healthline.

“The brain is undergoing excessive stress in Alzheimer’s disease. In the early phases, there is hyperexcitability in the setting of early pathology,” he explained. “We often see weight loss occurring prior to dementia and a lot of this is muscle mass. Some in the field suspect this disease is more systemic than we currently realize and an overall stress response in the body could be part of this.”

Alzheimer’s disease is the most common form of dementia.

Almost 6 million Americans have Alzheimer’s disease. According to the Centers for Disease Control and Prevention (CDC), that number is expected to rise to 14 million people by 2060.

The cause of Alzheimer’s disease remains unknown, but researchers believe a number of environmental, lifestyle, and genetic factors may play a role. Increasingly, chronic stress is being recognized as a risk factor.

“Stress alone may not cause Alzheimer’s disease, but it’s likely one factor among many that determines whether the symptoms of Alzheimer’s disease will manifest earlier or later if someone was already going to get the disease. Patients with high levels of stress may have less of an ability to cope with the pathological changes of Alzheimer’s disease and their symptoms may be more prominent than those without high stress levels,” Dr. Irina Skylar-Scott, a clinical assistant professor of neurology and neurological sciences at Stanford University in California, told Healthline.

She says people shouldn’t think having high stress levels means they will develop Alzheimer’s disease.

“People who hear about this study should not assume that stress alone causes Alzheimer’s disease directly. We don’t have the evidence to support that yet. They can assume that high levels of stress can be mitigated. Fortunately, it’s one of the factors related to brain health that they can address directly,” Skylar-Scott said.

Townley says there are steps people can take to lower their stress levels and therefore their risk for developing Alzheimer’s disease.

He advises people to engage in physical exercise, try breathing exercises, schedule time for relaxation, improve sleep habits, make time for leisure activities, and laugh more often.

“Much of our diet, sleep habits, and stress response habits are modifiable and should be our focus,” he said.

“If we had a much larger push on the importance of diet, checking for and treating sleep apnea, physical exercise, mindfulness training, and treating chronic health conditions aggressively — high blood pressure, diabetes, and depression — we would make a large impact on risk reduction,” Townley said.