Why Race and Ethnicity Matter in Medicine


With the rise of testing for genetic markers and mail-in genetic ancestry kits, we are gleaning more and more information from our DNA. But for the purpose of health care and research, the authors of a new commentary article in The New England Journal of Medicine say we still need to consider race and ethnicity.

Precision medicine based on our genomes may be the next big thing, but sweeping aside race and ethnicity “ignores the reality of U.S. social stratification and its implications for population health,” the authors wrote. Considering both types of data will help us better understand health differences among people and provide better care to all.

Professor Luisa Borrell (Graduate School of Public Health & Health Policy, The Graduate Center, CUNY) was lead author on the article.

Race and ethnicity can affect every aspect of a person’s life, including health. The practice of redlining, for instance, segregated cities by race and led to disinvestment in Black neighborhoods and worse health care access than in white neighborhoods. Genetic ancestry can provide a different kind of information, namely, health risks linked to genetic variants. The authors cite a study that found that “genetic variants at the 6q25 locus identified in Latina women are associated with protection against breast cancer and originate from Indigenous American populations,” for example.

While ethnicity and race are associated with genetic ancestry, they are not always the same thing, the authors said. Latinx people in the U.S. have a variety of ancestries, including Native American, African, and European, for example. This means that sometimes we need both to fully explain an issue. In a large-scale epigenetic study of minority children with asthma, Borrell and co-authors wrote, “ancestry explained 75% of the total variance in epigenetic patterns, suggesting that race/ethnicity, as a proxy for socioenvironmental exposures, explained the remaining 25%.”

But there are problems with both approaches that we need to address now before health disparities get any worse. Different health systems use different race and ethnicity classifications, and conscious and unconscious bias can cause disparities in level of care.

Meanwhile, biomedical studies on minority populations are underfunded and studies on genetic risk variants often don’t include people of color. “For example,” the authors wrote, “genetic variants within known cancer risk genes are well identified in populations of European ancestry, but often the same variants are classified as ‘variants of uncertain significance’ in people of non-European ancestry.” Uncorrected, these issues will widen the existing gap and prevent precision medicine from being accessible to all.

The relationship between race, ethnicity, and genetic ancestry, as well as the relationship between them and health care, is complicated, and it’s never a good idea to assume just one factor is responsible for a certain health issue. But if we use this information carefully and thoughtfully, it could help us defeat health inequities in the U.S.