A new study led by scientists at Columbia University in New York City has revealed that recreational physical activity in adolescent girls may impact their breast tissue composition and biomarkers of stress, two key predictors of breast cancer risk.
“The importance and urgency of this research are underscored by the rising incidence of breast cancer in young women and the alarmingly low levels of recreational physical activity observed both in this study and among adolescents across the United States and globally,” said first author Rebecca Kehm, assistant professor of epidemiology at Columbia Mailman School of Public Health.
Using a large sample of African American and Hispanic (Dominican) girls who participated in the Columbia Breast Cancer and the Environment Research Program Study, the authors examined each participant’s self-reported past-week engagement in recreational physical activity, as well as data from clinical visits that included blood and urine collection and breast tissue assessments. The girls included in the study were originally recruited between 1998 and 2006 from prenatal clinics serving urban neighborhoods in New York City.
Participants who reported engaging in at least two hours of recreational physical activity in the prior week had lower percent water in breast tissue and lower concentrations of urinary biomarkers linked to stress compared to girls who reported no past-week exercise. These findings align with prior research in adult women that shows higher levels of physical activity are associated with lower mammography breast density, which in turn, is associated with lower breast cancer risk.
Notably, 51 percent of all participants reported no recreational physical activity in the prior week. Nearly three-quarters of participants said they did not participate in organized activities, while two-thirds said they did not participate in unorganized activities.
“Our study population of urban Hispanic (Dominican) and non-Hispanic Black/African American adolescent girls is critical to include in breast cancer research,” said Dr. Kehm. “These groups not only have been historically underrepresented in studies, but they face higher risks of developing breast cancer at younger ages and of experiencing more aggressive subtypes. At the same time, Black and Hispanic girls consistently report lower levels of recreational physical activity than their non-Hispanic White peers.”
In addition to authors from Columbia University, the research team included scientists from the Princess Margaret Cancer Centre and the University of Toronto in Canada, as well as the Icahn School of Medicine at Mount Sinai in New York.
