A recent study published in the Journal of Breast Cancer Research suggests that recreational physical activity (RPA) during adolescence may help reduce biomarkers associated with breast cancer risk. While previous research has linked teen physical activity to lower breast cancer risk, the underlying biochemical mechanisms have remained unclear.
The study focused on three key indicators of breast cancer risk in teenage girls: oxidative stress, inflammation, and breast tissue composition (BTC). Researchers also explored how breast tissue composition during adolescence interacts with inflammation and oxidative stress.
The study analyzed data from 191 Black/African American and Hispanic (Dominican) girls aged 11 to 20 from an urban population-based cohort. Participants were categorized based on the number of hours they engaged in organized and unstructured recreational activities in the previous week: none, less than two hours, and more than two hours.
Breast tissue composition was measured using optical spectroscopy, evaluating chromophores linked to mammographic breast density, including percent water content and collagen content (positively associated) and lipid content (negatively associated). Blood samples were tested for inflammatory markers such as TNF-α, IL-6, and high-sensitivity C-reactive protein, while urine samples measured 15-F2t-isoprostane, a reliable indicator of oxidative stress.
The findings revealed that over half of the participants (51%) had not engaged in any recreational physical activity in the previous week. Specifically, 73% had not participated in organized activities, and 66% had not engaged in unstructured activities.
Teen girls who participated in more than two hours of organized recreational activity weekly showed lower urine concentrations of 15-F2t-isoprostane (B: -0.50, 95% CI: -0.95, -0.05) and reduced breast water content compared to inactive peers. These associations remained significant even after accounting for body fat percentage.
The study also found that higher levels of urinary 15-F2t-isoprostane were associated with increased breast collagen content (B: 0.15, 95% CI: 0.00, 0.31). However, inflammatory biomarkers did not show a correlation with physical activity, and when adjusted for body fat, they were not linked to breast tissue composition.
Overall, the study suggests that recreational physical activity in adolescence is associated with lower oxidative stress and favorable breast tissue composition, independent of body fat. Researchers note that further longitudinal studies are needed to determine the long-term implications of these findings for breast cancer risk later in life.
