Major adverse life events, such as divorce, financial hardship, or the death of a loved one, can measurably accelerate aging in the brains of middle-aged men, according to a new study published in the journal Neurobiology of Aging.
The findings remained strong even after controlling for such factors as cardiovascular risk, alcohol consumption, ethnicity, and socioeconomic status, all of which are associated with aging risk.
Previous research has shown that negative life events are linked to an acceleration of physical aging. In the new study, researchers at the University of California (UC) San Diego School of Medicine found that such negative fateful life events — or FLEs — also appear to specifically accelerate aging in the brain.
The study was led by senior author William S. Kremen, Ph.D., professor of psychiatry and co-director of the Center for Behavior Genetics of Aging at UC San Diego School of Medicine.
The findings show that, on average, one FLE was associated with an increase in predicted brain age difference (PBAD) of 0.37 years. In other words, a single negative event caused the brain to appear physiologically older by approximately one-third of a year than the person’s chronological age, based upon magnetic resonance imaging (MRI).
The researchers evaluated 359 men, ages 57 to 66, who were enrolled in the Vietnam Era Twin Study of Aging (VETSA). The participants were asked to make a list of life-changing events they had experience over the past two years. They had participated in a similar activity five years prior when they joined VETSA.
The findings were based on stressful midlife events that had occurred in the first two and last two years of the past seven years. All participants underwent MRI exams as well as physical and psychological assessments within one month of completing the most recent self-reports.
The MRIs analyzed the 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 analyzed using advanced software to predict brain age.
“Having more midlife FLEs, particularly relating to divorce/separation or a family death, was associated with advanced predicted brain aging,” said Sean Hatton, Ph.D., a postdoctoral scholar at UC San Diego School of Medicine and the study’s first author.
Exposure to chronic stress has long been linked to biological weathering and premature aging, including oxidative and mitochondrial damage in cells, impaired immune system response, and genomic changes, noted Hatton. The study’s authors say their findings offer a potential link between molecular aging and brain structure changes in response to major stressful life events.
The researchers caution that the study was a snapshot of a narrow demographic: older, predominantly white, males. It is unclear whether females or other ethnicities would show similar findings.
Further research involving greater and more diverse numbers of participants is needed to further validate the results, say the authors. But they add that using tools to predict brain age could help patients understand their brain health relative to their age. Such tools could also be used in clinical trials to help improve study design and recruitment.