Northwestern University researchers say intergenerational impacts of environmental factors could help explain black-white differences in U.S. cardiovascular health.

"A pregnant African-American mother's experience of well documented stressors, including social forces such as discrimination and racism, could have lingering effects on diseases like hypertension, diabetes and heart attacks in her children," co-authors Christopher Kuzawa and Elizabeth Sweet said in a statement. They argue that social forces, rather than genes, may underlie the problem of racial inequity in heart attacks and strokes.

A second study states that the average birth weight among African-American babies is approximately 10 percent less than white infants. Study co-author Grazyna Jasienska said this may also be the result of conditions experienced by their ancestors during slavery.

Current socioeconomic conditions are, on average, worse for African-Americans, can explain only part of the observed birth weight variation, Jasienska said. Prior studies have shown that contemporary black women born in African countries ancestral to slave populations, but who live in the United States, give birth to children with significantly higher weight than U.S. black women who have slave ancestry.

The findings are published in the American Journal of Human Biology.