Should women with ER+ breast cancer avoid flaxseeds and flax oil that contain the phytoestrogens called lignans?
There is a recent preliminary small human study showing that ingestion of 25 grams of ground flaxmeal per day in women with newly diagnosed post-menopausal ER+ breast cancer decreases biological markers of tumor growth the same amount as the anti-estrogen drug tamoxifen during the time period between diagnosis and surgery. Tamoxifen treatment was not compared directly to flaxmeal in this study. The data are compared from two separate studies. In addition, this is such as small and early study that no recommendations for treatment with flaxmeal can be made based on these data. Much larger and longer head-to-head clinical trial studies in women would need to be done to offer this as a treatment option. However, these data look very promising that flaxmeal is not only safe but also potentially effective as a nutritional means for helping to treat ER+ breast cancer.
