Children born in the early- to mid-20th century experienced extraordinary levels of socioeconomic disadvantage (e.g., the Great Depression) and exposure to lead from everyday sources such as air and drinking water. Childhood is a critical period of brain development. Yet, limited information exists about whether these early life factors are associated with risk of developing dementia later in life. Studying whether early life factors influence dementia risk later in life is challenging, due to needing both high-quality data on childhood exposures and detailed cognitive health measures decades later.

To provide insights into how early-life conditions, including socioeconomic disadvantage and exposure to lead, might play a role in dementia’s development later in life, a new study, funded by the National Institute on Aging, is being led by researchers from the University of Minnesota (UMN) School of Public Health (SPH), the UMN Population Center, and Boston University. To conduct the study, researchers will link long-running health data, from participants of the Atherosclerosis Risk in Communities Neurocognitive (ARIC) study, to their historical U.S. Census records from the 1930s through the 1950s. This novel approach will allow investigators to capture objective measures of participants’ childhood environments—without relying on memory—while also leveraging decades of mid- and late-life clinical, imaging, and biomarker data on brain health available for participants of the ARIC Neurocognitive Study.

The study’s four specific aims are:

• Examine childhood socioeconomic conditions and dementia risk. Assess how individual and neighborhood-level socioeconomic status in childhood relates to dementia risk and markers of brain health later in life.
• Investigate childhood lead exposure and dementia risk. Evaluate how exposure to lead in childhood – available from historic information on sources like drinking water and air pollution – impacts dementia and neurological outcomes later in life.
• Understand how socioeconomic status and lead exposure interact. Determine whether children from lower-income backgrounds are more vulnerable to the harmful effects of lead exposure on brain health.
• Build a data resource for future research. Create an infrastructure to support future studies of historic early life exposures and health risk.

“By linking historical census records with decades of health data, we can better understand how childhood disadvantage and lead exposure shape dementia risk later in life” said Pamela Lutsey, SPH professor and lead researcher on the study “This is particularly important since Americans born in the 1970s were, as children, exposed to historically unprecedented levels of lead through leaded gasoline, and will soon enter the age at which cognitive decline becomes increasingly likely.”

“Just as critical, this project will create a resource that other researchers can use to explore the developmental origins of dementia and help inform interventions and policies aimed at reducing dementia risk,” said Lutsey.