Some studies have shown that women with high levels of lignans in their bodies, as measured from urine and/or blood samples, have a reduced rate of breast cancer. Other studies show insignificant differences. Lignans are common in fruits and vegetables, with flaxseed having the highest levels of lignans in any food. (1) These studies do not mention any particular brand names of lignans; some of the studies indicate that the source of the lignans are from high dietary intake of lignans from fruits and vegetables. Supplementation of lignans may not necessarily produce the same results.
Estrogens bind to estrogen receptors within cells and when they attach, they produce their effects. Phytoestrogens also bind to estrogen receptors, but their estrogenic activity is much weaker than endogenous estrogens, and they may actually block the effects of potentially harmful estrogen in some tissues (1).
Estrogen receptors are present in numerous tissues other than those associated with reproduction, including bone, liver, heart, and brain (2). There are studies that indicate lignans have numerous benefits in these other tissues, as well as reproductive organ benefits. Two types of lignans, hydroxymatairesinol (HMR) and secoisolariciresinol (SDG), are plant estrogens that are converted to mammalian phytoestrogens.
The mammalian phytoestrogens enterodiol (END) and enterolactone (ENL) are produced in the colon by the action of bacteria on the plant precursors matairesinol (MAT), secoisolariciresinol (SECO), their glycosides (HMR and SDG), and other precursors in the diet. Both END and ENL have been shown to possess weakly estrogenic and antiestrogenic activities, and it has been suggested that the high production of these antiestrogenic mammalian lignans in the gut may serve to protect against breast cancer in women and prostate cancer in men. Various in vitro experiments suggested END and ENL significantly inhibited the growth of human colon tumor cells, and enterolactone inhibited the proliferation of breast cancer cells caused by E2. The protective effects of mammalian lignans may be due to their ability to compete with E2 for the type II estrogen receptor, to induce sex hormone binding globulin (SHBG), to inhibit placental aromatase, and to act as antioxidants. (3) PUBMED NLM Wang LQ..Department of Medicinal Chemistry, College of Pharmacy, University of Florida.
To Summarize: Lignans work in 5 different ways to possibly reduce the risk of breast cancer.
1. Lignans bind to estrogen receptors, causing endogenous (or naturally occurring) estrogen from having a place to act.
2. Lignans induce Sex Hormone Binding Globulin (SHBG). More SHBG ties up more estrogen.
3. Lignans are high in antioxidants. The highest of all fruits and vegetables. Antioxidants attack free radicals, which can be responsible for certain types of cancers.
4. Lignans block aromatase enzyme, which is responsible for some production of estrogen.
5. Breast cancer actually needs estrogen in order to grow. With diminished estrogen, cancer cells may start to die.
1) A French study conducted over 7 years with 58,049 women participants concluded….. “High dietary intakes of plant lignans were associated with reduced risks of breast cancer in a Western population that does not consume a diet rich in soy”. Published Journal National Cancer Institute 2007;99:475-86. Touilland, Thiebout, et al.
2) There is a substantial reduction in breast cancer risk among women with a high intake (as measured by excretion) of phyto-oestrogens - particularly the isoflavonic phyto-oestrogens equol and the lignan enterolactone. These findings could be important in the prevention of breast cancer. Ingram D Sanders K Kolybaba M Lopez D Case control study of phyto oestrogens and breast cancer In: Lancet (1997 Oct 4) 350 (9083):990 4
Important Note: The information provided in this article is for informational purposes only. This information should not be construed as medical advice. It is up to the individual reading this to seek expert medical advice and not rely on this information for diagnosis, treatment, prevention or attempts to cure any disease.