Going through a divorce in middle age speeds up the ageing of men’s brains increasing the risk of mental decline later in life, according to new research.
A single stressful experience – such as a marital break up or the death of a family member – ages the brain by four months, say scientists.
Conflict, bereavement and financial hardship are known to slow people down physically.
But such traumas known as fateful life events (FLEs) have the same effect on mental powers.
First author Dr Sean Hatton, of the University of California, San Diego, said: “Having more midlife FLEs, particularly relating to divorce, separation or a family death, was associated with advanced predicted brain ageing.”
Stressful experiences are known to impact brain function, which can itself lead to dementia.
Other research has suggested plausible links between stress and chronic inflammation, which could accelerate the development of Alzheimer’s
The study published in Neurobiology of Aging showed major adverse occurrences measurably accelerated ageing in the brains of older men.
This held even when other factors linked to risk of ageing such as cardiovascular disease, alcohol consumption, ethnicity and socioeconomic status were taken into account –
Specifically, one such event was associated with an increase in predicted brain age difference of 0.37 years.
In other words, it caused the brain to appear about four months older physiologically than the person’s chronological age.
The findings published in Neurobiology of Aging were based upon MRI (magnetic resonance imaging) brain scans of 359 men aged 57 to 66 participating in the Vietnam Era Twin Study of Aging (VETSA).
Participants were asked to list life changing events over the past two years, which were compared to a similar measure collected five years previously when they joined the study.
The summaries encapsulated stressful midlife events that had occurred in the first two and last two years of the past seven years.
All participants underwent MRI exams and further physical and psychological assessments within a month of completing the most recent self-reports.
The MRIs assessed physiological aspects of the brain, such as volume and cortical thickness – a measure of the cerebral cortex or outer layer of the brain linked to consciousness, memory, attention, thought and other key elements of cognition.
These neuroanatomical measurements were then analysed using advanced software to predict brain age.
Last year a larger US study of 1,320 people who underwent a series of neurological tests examining several areas, including memory, suggested the death of a child, divorce or losing a job could age the brain by at least four years.
That team found 27 stressful events that could be links to poorer cognitive function in later life among the participants, whose average age was 58.
Dr Hatton said exposure to chronic stress has long been associated with biological weathering and premature ageing.
This is linked, for example, to oxidative and mitochondrial damage in cells, impaired immune system response and genomic changes.
The researchers said the findings provide a possible link between molecular ageing and brain structure changes in response to major stressful life events.
They pointed out it was a snapshot of older, mainly white, males. It is not known whether similar results would be found in women or other ethnicities.
Additional, broader studies involving greater and more diverse numbers of participants were needed to further validate the findings.
But the researchers suggest using tools to predict brain age could be clinically useful in helping patients understand their brain health relative to their age and in clinical trials where it might improve study design and recruitment.
By Ben Gelblum and Mark Waghorn