The more you move, the less oestrogen circulates through your body. Biostatisticians at the University of Maryland will soon publish the results of a study they did in Medicine & Science in Sports & Exercise in which they discovered a relationship between oestrogen and activity after studying 452 women aged 40-72.
The researchers fitted the participants with an accelerometer which they wore for seven days. This enabled the researchers to estimate how many minutes a day the women were moving or sitting still. The women were post-menopausal and not taking synthetic hormones.
At the end of the seven days the researchers measured the amount of estradiol and estradiol metabolites in the women’s urine. The urine concentrations correlate with the blood concentrations.
The more movement the women had had (the higher the number of counts per minute registered by the accelerometers), the less estradiol and estrone the researchers found. So physical activity lowers the concentration of oestrogens in the body.
Being sedentary has the opposite effect. The more minutes the women spent sitting each day, the more estradiol and oestrone there was in their urine, as you can see in the figure above.
How exercise reduces the amount of estradiol and oestrone is shown in the table below. Physical activity increased the ratio between the amount of metabolised – and therefore less active – analogues of estradiol and oestrone and the amount of non-metabolised estradiol and oestrone in the urine.
Physical movement apparently activates the enzymes that metabolise – and neutralise – estradiol and oestrone. The figure below sketches the main processes involved in the metabolism of estradiol and oestrone.
The researchers think that their findings are mainly of interest for women who want to reduce their likelihood of developing breast cancer, but these new insights are probably also relevant for men who want to reduce the levels of oestrogens in their body.
Association of Active and Sedentary Behaviors with Postmenopausal Estrogen Metabolism.
Physical activity may reduce endogenous estrogens but few studies have assessed effects on estrogen metabolism and none have evaluated sedentary behavior in relation to estrogen metabolism. We assessed relationships between accelerometer-measured physical activity and sedentary behavior and 15 urinary estrogens and estrogen metabolites (EM) among postmenopausal controls from a population-based breast cancer case-control study conducted in Poland (2000-2003).
Postmenopausal women (N=542) were ages 40 to 72 years and not currently using hormone therapy. Accelerometers, worn for seven days, were used to derive measures of average activity (counts/day) and sedentary behavior (<100 counts/min/day). EM were measured in 12-hour urine samples using liquid chromatography-tandem mass spectrometry. EM were analyzed individually, in metabolic pathways (C-2, -4, or -16), and as ratios relative to parent estrogens. Geometric means of EM by tertiles of accelerometer-measures, adjusted for age and body mass, were computed using linear models.
High activity was associated with lower levels of estrone and estradiol (p-trend=0.01) while increased sedentary time was positively associated with these parent estrogens (p-trend=0.04). Inverse associations were observed between high activity and 2-methoxyestradiol, 4-methoxyestradiol, 17-epiestriol and 16-epiestriol (p-trend=0.03). Sedentary time was positively associated with methylated catechols in the 2- and 4-hydroxylation pathways (p-trend?0.04). Women in the highest tertile of activity had increased hydroxylation at the C-2, -4, and -16 sites relative to parent estrogens (p-trend?0.02) while increased sedentary time was associated with a lower 16-pathway:parent estrogen ratio (p-trend=0.01).
Higher activity was associated with lower urinary estrogens, possibly through increased estrogen hydroxylation and subsequent metabolism, while sedentary behavior may reduce metabolism.
PMID: 26460631 [PubMed – as supplied by publisher]