Flax Helps Protect Against Breast Cancer by Influencing Estrogen Metabolism

admin — Thu, 18 Jun 2009 18:23:07 +0000

Breast cancer is hormone-sensitive, meaning that in the early stages, tumor growth is influenced by the sex hormones, particularly estrogen and its metabolites. The biologically active form of estrogen is estradiol, which is oxidized mainly in the liver to estrone. Estrone can be converted to two metabolites with different biologic effects- 2-hydroxyestrone has little biologic activity, while 16∝-hydroxyestrone enhances estrogen activity and promotes uncontrollable tumor cell growth or cell proliferation, as it is called. Women who produce more 16∝-hydroxyestrone may have an increased risk of breast cancer. Two clinical studies found postmenopausal women who ate a diet supplemented with 10g or 25g of milled flax for 7 weeks or 16 weeks2 increased the excretion of 2-hydroxyestrone in their urine, without increasing the excretion of 16∝-hydroxyestrone. In these studies, flax consumption shifted the balance toward production of the relatively inactive metabolite of estrogen, thus supporting a role for flax seed in breast cancer prevention.

Dr. Diane H. Morris

Flax Lignans Have Anticancer Effects in Breast Tissue

admin — Tue, 16 Jun 2009 16:40:27 +0000

Flax Lignans Have Anticancer Effects in Breast Tissue

Large-scale population studies show that diets right in lignans are associated with a reduced risk of breast cancer. Flax and its lignans help protect against breast cancer by altering the metabolism of estrogen and by decreasing cell proliferation, according to findings from a small number of clinical studies. The animal data is strong- flax and its main lignans interfere with cancer processes and inhibit metastasis of mammary (breast) tumors to the lungs and other organs. One animal study found that the combination of flax and tamoxifen was better at decreasing tumor size in mice than tamoxifen alone. Eating flax regularly may reduce breast cancer risk and improve the clinical prognosis for women with breast cancer.

Whole flax seeds and milled flax are excellent sources of lignans. Indeed, flax is the richest known dietary source of lignans. Lignans are phytoestrogens- plant compounds that can affect estrogen metabolism in animals and humans. The main flax lignan is secoisolariciresinol diglucoside (SDG). SDG is converted to the enterolignans or mammalian lignans- namely, enterodiol and enterolactone- by the action of bacteria in the colon. Human and animal studies support a role for flax and its lignans in breast cancer prevention and control.

Dr. Diane H. Morris

Thompson LU, et al. Nutr Cancer. 2006; 54:184-201
Morris DM Flax- A Heath and Nutrition Primer. Winnipeg, MB: Flax Council of Canada, 2007.

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Flax Helps Protect Against Breast Cancer by Influencing Estrogen Metabolism

Flax Lignans Have Anticancer Effects in Breast Tissue