Intervention Study of Flaxseed in Postmenopausal Women: Effects on Hormonal Biomarkers of Breast Cancer Risk

摘要

The objective of this study is to determine if flaxseed supplementation to usual diet in postmenopausal women had a beneficial effect on important hormonal biomarkers of breast cancer risk. Participants received 6 weeks of usual diet plus 7.5 grams per day of raw flaxseed, followed by 6 weeks of usual diet plus 15 grams per day of raw flaxseed. Serum and urinary levels of hormonal biomarkers of breast cancer risk were assessed at baseline, 7 weeks and 13 weeks. There were small declines in serum levels testosterone, estrone and estradiol after six and 12 weeks of flaxseed ingestion among all women (n=47) but these were not statistically significant. Among overweight/obese women (body mass index > 25kg/m2) (n=23), there were more substantial declines in serum levels of testosterone, estrone and estradiol associated with consumption of a flaxseed diet. Serum levels of sex hormone binding globulin were essentially unchanged in normal and overweight/obese women. Additional analyses are underway to evaluate changes in urinary hormone metabolites associated with flaxseed intake.