Epidemiologist Adana Llanos Investigates the Synergy of Society and Biology

People of color in the United States experience an array of widely documented disparities in health outcomes, from higher infant and maternal mortality to shorter lifespans. Yet race is a social construct, not a biological fact. Epidemiologist Adana Llanos has set out to detail—at the molecular level—how the experience of structural racism might affect cancer outcomes among Black and Latinx women. “The thing about studying racial disparities and health outcomes is that race is not the risk factor,” says the associate professor of epidemiology, who was born in Trinidad and Tobago. “Race wouldn’t exist without sociopolitical systems of power, oppression, and racism.”

Llanos, who joined Columbia Mailman School of Public Health in 2021, investigates such questions as how U.S. federal policies that disenfranchised Black neighborhoods beginning in the 1930s affect breast cancer outcomes to this day and how experiences with racism at multiple levels—including interpersonal, community, and health system levels—impact a person’s experience of cervical cancer survivorship.

Q: What’s been missing from the conversation about social determinants of health and disparities in cancer outcomes?

Llanos: What I think might help is if we understood how social determinants of health affect or interact with molecular and biological aspects of health and cause disease in populations. How do neighborhood factors affect biomarkers in blood, in our tissues, the microenvironment within tumors? If we understood the underlying mechanisms, we might better understand ways to address inequitable outcomes, especially in those observed among racial and ethnic minority groups and other marginalized groups.

Q. How do those principles affect your studies of the breast cancer microenvironment?

Llanos: I’ve been studying the connection between biomarkers of obesity and adiposity with breast cancer since I was a PhD student. Now I’m focusing in on gene expression patterns within the tumor microenvironment and why people with higher body weight tend to have worse outcomes. We’re going to study adipose tissue, the metabolically active tissue that probably explains a lot of the relationship between higher body fatness and poor cancer outcomes.

Q. You’ve also done some work on beauty products and cancer. Why?

Llanos: Bringing my whole self to my work is important and valuable. I’m a Black woman who’s interested in beauty and fashion. As a member of the board of directors of a community-based organization focusing on cancer in Black and Latinx women, I would be invited to events with the community and people often asked whether deodorant, hair dye, or other personal care products cause breast cancer. Their concern made me think maybe we as scientists should be asking these questions. As a co-investigator of the Women’s Circle of Health Study, I was able to start looking at the relationship between hair product use and breast cancer risk in a large study that enrolled 4,000 women in New York City and New Jersey. Back in the seventies, there were studies that suggested a correlation; ours was the first that addressed risk among Black women. Of any demographic in the U.S., Black women spend the most money on cosmetics and hair products, and we also tend to have the worst outcomes for numerous health conditions. So, if harmful exposures from these products might be contributing to health inequities, that is worth studying.

Q. What did you learn about the health risks of these products?

Llanos: We found a relationship between hair dye use and breast cancer risk in both Black and white women. Darker shades of hair dye were associated with increased risk, and that effect was stronger in Black women. On the other hand, we didn’t find a strong association of chemical relaxer use with breast cancer risk in Black women, which was surprising. More recently, we focused only on people with breast cancer and found that longer-term and earlier use of hair dyes and relaxers is associated with more aggressive tumor features.

Q. How do your findings affect beauty product consumers?

Llanos: Increasingly, consumers want products that are non-toxic, eco-friendly, and Earth-conscious. I had the pleasure of serving on the Non-Toxic Black Beauty Advisory Committee with the Breast Cancer Prevention Partners’ Safer Cosmetics Campaign, which will soon launch a new website that will explain the Nontoxic Black Beauty Project. The site will also have a list of Black-owned, nontoxic beauty brands and a red list of chemicals of concern, which should be avoided because of their links to disparate health outcomes.

Q. What values inform your teaching and mentoring?

Llanos: It’s really important for me, as a Black scholar, someone from a group that continues to be underrepresented in academic research, to encourage up-and-coming scholars from underrepresented groups to really understand how important they—and their perspectives—are to the field. This summer I’ve been working with two amazing undergraduate interns on an ongoing project related to personal care product use and exposures to toxic chemicals. They will be creating infographics to better describe and explain our findings and others from the scientific literature to lay audiences and members of the communities we serve.