Researchers recently showed that a lifestyle intervention (exercise) reduced the 'bad' estrogen and increased the 'good' estrogen. Premenopausal women (391 sedentary, healthy, young) were randomly assigned to 1 of 2 age-matched, body mass index-matched groups: a control group of 179 women and an intervention group of 212 women. Women in the intervention group performed 30-minutes of moderate-to-vigorous aerobic exercise 5-times a week for 16-weeks. The amount of 3 parent estrogens – estrone, estradiol, and estriol – and 9 estrogen metabolites were measured in subjects urine collected on 3 consecutive days prior to exercise and on 3 consecutive days at the end of the study.
This is what they found:
"... in healthy premenopausal
of 150 minutes of moderate-to-vigorous
per week for 16 weeks resulted in significant changes in estrogen metabolism in a
of breast cancer risk."
2-OHE1/16a-OHE1 increased significantly (P = 0.043), whereas E1 decreased significantly (P = 0.030) in control participants (n = 153). The change from baseline in 2-OHE1/16a-OHE1 was significantly different between groups (P = 0.045), even after adjustment for baseline values.
Alma J Smith, William R Phipps, William Thomas, Kathryn H Schmitz, and Mindy S Kurzer. The effects of aerobic exercise on estrogen metabolism in healthy premenopausal women. Cancer Epidemiol Biomarkers Prev. 2013;22:756-764.