Overview
- Published in Breast Cancer Research, the cross-sectional analysis of 191 New York girls found that at least two hours of recent activity correlated with lower breast water content, a proxy for lower density.
- Girls reporting two or more hours of organized sports also showed lower urinary 15-F2t-isoprostane, an oxidative stress marker, with associations remaining after adjusting for body fat.
- The study observed no significant links between recent activity and systemic inflammatory markers, including CRP, IL-6 and TNF-α.
- Participants were predominantly Hispanic and Black, the average age was 16, and inactivity was common, with 51% reporting no physical activity in the prior week and 73% reporting no organized activity.
- Findings align with adult data tying higher activity to lower breast density and about 20% lower breast cancer risk, though the adolescent results cannot establish causation.