Teen Girls' Recreational Physical Activity Linked to Breast Tissue Composition, Oxidative Stress

FRIDAY, Jan. 23, 2026 (HealthDay News) -- Recreational physical activity (RPA) is associated with breast tissue composition and oxidative stress in adolescent girls, independent of body fat, according to a study published online Jan. 7 in Breast Cancer Research.Rebecca D. Kehm, Ph.D., from Columbia University in New York City, and colleagues examined the associations between RPA and three breast cancer biomarkers -- breast tissue composition, oxidative stress (assessed by measurement of urinary concentrations of 15-F2t-isoprostane), and inflammation -- in adolescent girls. The analysis included 191 Black/African American and Hispanic (Dominican) adolescent girls (aged 11 to 20 years).The researchers found that just over half of participants (51 percent) reported no past-week engagement in any type of RPA, while 73 percent reported no participation in organized activities. Compared with girls with no organized RPA, girls who engaged in two or more hours of organized RPA in the past week had lower percent water content in the breast (β, −0.41), which was not modified by percent body fat. Those engaging in two or more hours of organized RPA in the past week also had lower urinary concentrations of 15-F2t-isoprostane (β, −0.50). There was an association between higher urinary concentrations of 15-F2t-isoprostane and higher percent collagen content in the breast (β, 0.15). There was not an association between RPA and the measured inflammatory biomarkers."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," Kehm said in a statement.Abstract/Full Text (subscription or payment may be required).Sign up for our weekly HealthDay newsletter