Overview
- Girls reporting at least two hours of organized activity in the prior week showed lower breast water content, a tissue measure correlated with lower mammographic density.
- The same activity threshold was associated with reduced urinary 15-F2t-isoprostane, indicating lower systemic oxidative stress.
- Researchers found no association between recent activity and inflammatory markers such as CRP, IL-6, or TNF-α.
- Inactivity was widespread in the cohort, with 51% reporting no recreational activity in the past week and 73% reporting no participation in organized activities.
- The study, published in Breast Cancer Research, is cross-sectional and based on self-reported past-week activity, so it cannot determine causation or future cancer risk.