Exercise changes the way the body breaks down estrogen, increasing the ratio of ‘good’ to ‘bad’ estrogen metabolites, and so may lower the risk of breast cancer, new research suggests.
Among previously sedentary young women, regular, intense physical activity was found to be associated with a significant increase in the 2-hydroxyestrone to 16α-hydroxyestrone ratio (2-OHE/16α-OHE ratio) (at P=0.043), reported Mindy Kurzer, PhD, of the University of Minnesota in Minneapolis, and colleagues.