Women born in the most sexist U.S. states experience faster memory decline in later years compared to women born in the least sexist states, a new study by researchers at Columbia University Vagelos College of Physicians and Surgeons has found.

The difference between being born in the most versus the least sexist state was equivalent to nine years of cognitive aging.

The study is one of a growing number of studies that have investigated links between structural sexism and health. Structural sexism, like structural racism, does not refer to personal incidences but to inequality in resources and power that stem from social policies and societal norms. Hate crimes or slurs are individual acts of racism or sexism; unfair lending practices and underrepresentation in government are structural. Previous studies have found that exposure to greater structural sexism in adulthood is associated with higher mortality rates, increased risk of chronic health conditions, and less accessible and affordable health care for women.

The new study, the first to look at structural sexism and cognitive health, found that memory performance among women age 65 and over declined faster in those born in U.S. states with greater structural sexism compared to those born in states with less structural sexism. The study calculated each state’s level of structural sexism during the decades the women were born based on male-to-female ratios in the labor force, the number of females in state legislatures, poverty rates, and other factors. The researchers then looked at relationships between structural sexism levels and memory performance among 21,000 people in the Washington Heights-Inwood Columbia Aging Project and the Health and Retirement Study.

The study also found that the association between structural sexism and memory performance was highest among Black women. “It is likely that, for women racialized as Black, the intersectional impact of sexism and racism creates a unique form of oppression that has greater salience for cognitive health than sexism or racism alone,” says Jennifer Manly, professor of neuropsychology, senior author of the study.

“Our findings suggest that addressing social inequities may be a powerful way to lower the burden of Alzheimer’s among women,” says study leader Justina Avila-Rieger, an associate research scientist in the Gertrude H. Sergievsky Center Columbia, whose studies focus on sex, gender, racial, and ethnic disparities in Alzheimer’s disease. “Alzheimer’s is a huge societal problem, particularly among women, who account for two-thirds of Americans with the disease. It’s imperative that we gain a better understanding of what is causing this discrepancy and what can be done about it.”

Sign up for the Daily Dose Newsletter and get every morning’s best science news from around the web delivered straight to your inbox? It’s easy like Sunday morning.

Studies of why Alzheimer’s disease affects women more than men have largely focused on sex-linked biological differences, such as hormones and genes. The new study suggests that one of the most important and underappreciated risk factors may be systemic sex and gender discrimination.

How structural sexism contributes to memory decline is not clear. “What we do know is structural inequalities shape individual health outcomes by creating barriers to health-enhancing opportunities and resources,” says Avila-Rieger. “Eventually, these exposures produce disparities in chronic physical health conditions that directly influence brain health, the onset of cognitive impairment and, ultimately, dementia.”

In future studies, Avila-Reiger plans to look at the effects of exposure to structural sexism at different stages of life. “It’s possible that early life exposure may be a critical period for structural inequality, with direct or indirect consequences that accumulate over time,” she says. “We also need to tease apart which aspects of structural sexism have the most impact on cognitive health. This is important in terms of making recommendations to policy makers.”