Our life stories are made up of major experiences—especially social ones—that shape who we are.
Childhood hardships, the quality of education, the strength of our social networks, and even exposure to violence are not just memories; they can leave lasting marks on our health.
A new international study published in Nature Communications shows that these experiences accumulate over time and decades later may influence how the brain develops, functions, and ages.
The researchers looked at what they call the “social exposome”—a measure of all the social and environmental factors a person is exposed to across their lifetime.
These include access to education, food security, financial stability, assets, health care, childhood labor, socioeconomic status, traumatic events, and social relationships.
By studying 2,211 people from six Latin American countries, including individuals with Alzheimer’s disease, frontotemporal dementia, and healthy controls, the team discovered that adverse social exposomes are linked to poorer mental health, reduced thinking ability, and even physical changes in the brain.
The findings were clear: the greater the social adversity people experienced across their lives, the worse their brain health outcomes.
Those with more adverse exposomes not only showed weaker cognition and mental health in older age but also demonstrated lower brain connectivity and structural changes. Importantly, it was the accumulation of these experiences—not just individual hardships—that had the strongest link to brain health problems.
Latin America provided a key setting for this study, as structural inequalities, educational gaps, and limited health care access highlight how strongly social factors shape health outcomes in the region.
In people living with dementia, complex adverse exposomes—such as food insecurity, financial stress, and poor access to health care—were strongly associated with worse symptoms, reduced functional ability, and poorer brain structures on scans.
The study carries an important message: dementia prevention should start much earlier in life than previously thought.
While midlife health habits such as controlling blood pressure or diabetes are important, researchers argue that the foundation for brain health is laid in childhood. Reducing food insecurity, improving access to education, and ensuring health care in early life can help build “brain health capital” that protects people decades later.
Studies estimate that more than half of dementia cases in Latin America may be tied to modifiable risk factors like obesity, depression, and physical inactivity—all closely linked to the social exposome. Addressing these risks earlier could significantly reduce dementia rates in the region and beyond.
As first author Joaquín Migeot explained, “The interaction between modifiable risk factors and the social exposome offers a path toward precision dementia prevention tailored to each individual.” Lead author Agustin Ibanez added, “Our results call for models that recognize how lifelong social environments become biologically embedded in the brain, shaping how we age.”
The takeaway is powerful: the experiences and opportunities we provide throughout life, starting in childhood, can make all the difference for brain health and dementia prevention later on.
Source: KSR.
