Stress could promote the development of Alzheimer’s disease, study finds

People who experience stressful experiences during their lives may have a higher risk of developing Alzheimer’s disease at a later age. To reach this conclusion, the authors of this study published in Annals of Neurology relied on 1,290 participants, volunteers without cognitive disorders at the time of the study, but who had cases of Alzheimer’s in their family. They were questioned about the presence of stressful events during their life (death of a loved one, period of unemployment, illness, etc.), their frequency and their age at the time they experienced them. Researchers at the Barcelona Institute for Global Health (ISGlobal) also carried out clinical tests (lumbar punctures and MRIs) to detect biomarkers of Alzheimer’s disease.

Childhood and midlife, pivotal periods

Analyzing all this data, the researchers found that the accumulation of stressful experiences during midlife was associated with higher levels of β-amyloid protein (Aβ), which plays a key role in the development of Alzheimer’s disease. “We know that midlife is a time when Alzheimer’s disease pathologies begin to accumulate. It is possible that these years represent a vulnerable time where psychological stress can have a lasting impact on brain health.“, says Eleni Palpatzis, researcher at ISGlobal and first author of the study in a statement.

The childhood period should also be monitored. Experiencing stressful events at a young age is associated with a higher risk of developing neuroinflammation later in life. “Inflammation is recognized as a key molecular response in neurodegenerative diseases and these findings are consistent with emerging evidence suggesting that childhood trauma is linked to increased inflammation in adulthood.”.

Differences according to sex

Researchers have also found that the effects of stressful experiences may differ by gender. In men, a greater number of stressful events was linked to an increase in amyloid beta (Aβ), the accumulation of which marks the starting point of the disease. In women, they noted a reduction in the volume of gray matter in the brain. Gray matter is made up of nerve cells and plays a crucial role in our cognitive functions such as reading, calculation, attention and memory.

Individuals with a history of psychiatric disorders appeared to be more susceptible to the effects of stressful life events. These people have a higher level of stress linked to increased levels of beta-amyloid proteins and tau, a protein abundant when one is affected by Alzheimer’s disease, thus promoting its development. Additionally, these participants had lower gray matter volumes.

This study, however, has certain limitations. Research has found that relying on participants’ memory to remember stressful events can bias results. Additionally, measuring stress does not necessarily take into account the personal impact it has or the severity of events.

“Our study reinforces the idea that stress may play an important role in the development of Alzheimer’s disease and provides initial evidence regarding the mechanisms behind this effect, but additional research is needed to replicate and validate our findings. initial results“, says Eider Arenaza-Urquijo.

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