A longitudinal study tracking over 1,500 St Louis adults reveals that cumulative lifetime stress and chronic inflammation explain nearly half of the mortality differences between Black and White populations. Researchers found Black participants had significantly shorter survival times, with 25.3% dying during the study period compared to 11.9% of White participants.
The research examined multiple stress factors including childhood maltreatment, lifetime trauma, discrimination experiences, and socioeconomic indicators. Black participants reported substantially higher cumulative stress levels and showed elevated inflammatory markers, specifically C-reactive protein and interleukin-6 measured in blood samples. These biological differences accounted for 49.3% of the increased mortality risk among Black individuals.
Between 1999 and 2020, the Black U.S. population experienced more than 1.63 million excess deaths compared to the White population, with chronic conditions like heart disease being major contributors. This mortality gap emerges during the perinatal period and adolescence but becomes most pronounced in later life.
The findings support the weathering hypothesis, which proposes that cumulative exposure to structural and explicit discrimination increases stress and triggers biological consequences that contribute to premature health decline. Lead researcher Isaiah Spears and colleagues emphasize that more than half of the mortality differences remain unexplained, suggesting additional factors like toxicant exposure, healthcare access, and neighborhood conditions require investigation.
The researchers conclude that interventions addressing structural racism alongside treatments reducing inflammation may help narrow mortality disparities between Black and White Americans.
See: “Cumulative Lifespan Stress, Inflammation, and Racial Disparities in Mortality Between Black and White Adults” (January 26, 2026)Â