# Associations of Lifetime Cumulative Estrogen Exposure with Lifecourse Social Exposures, Cognitive Decline, and Dementia Risk Among Postmenopausal White, Black, and Latina Women

## TL;DR

Higher lifetime estrogen exposure is linked to better memory and lower dementia risk in postmenopausal women, with social factors like education and income playing a role.

## Contribution

This study reveals how estrogen exposure and social factors jointly influence cognitive decline and dementia risk across racial and ethnic groups.

## Key findings

- Greater estrogen exposure is associated with better memory performance in Black and Latinx women.
- Higher socioeconomic status is linked to greater estrogen exposure and better cognitive outcomes.
- Estrogen exposure partially mediates the relationship between social factors and dementia risk.

## Abstract

Greater lifetime exposure to estrogen may protect women from cognitive decline and dementia later in life. Gender-related social factors also influence women’s cognitive outcomes; however, little is known about how these biological and social influences work together. We examined the extent to which cumulative estrogen exposure and lifecourse social exposures jointly influence late-life memory trajectories and dementia risk among a community-based sample of White, Black, and Latina women.

Participants were 3,688 postmenopausal women in the Washington Heights-Inwood Columbia Aging Project. Lifetime cumulative estrogen exposure was estimated based on age at menarche and menopause, breastfeeding duration, and hormone replacement therapy (HRT) use. Lifecourse social factors included birth cohort, childhood SES, educational and occupational attainment, and later-life income. Multiple-group growth models and Cox regression models were estimated across racial and ethnic groups.

Greater lifetime estrogen exposure was independently associated with higher baseline memory performance among Black and Latinx women, slower memory decline among White women, and lower dementia risk among Latinx women. Later birth year and higher lifecourse SES were associated with greater lifetime estrogen exposure, with associations varying in magnitude across racial and ethnic groups. Associations between lifecourse SES and each cognitive outcome were partially mediated by estrogen exposure indicators.

Cumulative estrogen exposure is socially patterned. We found that lifecourse social factors and estrogen exposure synergistically contribute to women’s late-life cognitive health outcomes. Understanding how sex-linked biology and gender-related social forces intertwine is essential for developing interventions to decrease dementia risk among women.