Flax Seed and Tamoxifen
I read with interest the suggestion that women on Tamoxifen should limit their intake of isoflavones, such as those in soy foods. Does the same apply to flax seed, if one is taking Tamoxifen?
After doing some research I have to recommend being cautious about adding flax to one's diet when on Tamoxifen for the same reasons we caution against soy foods with Tamoxifen.
Like soy foods, flax contains weak plant estrogen hormones, which attach to the estrogen hormone receptor sites thus blocking the stronger "human" estrogen. Since they are weaker they do not appear to have the same effect as "human" estrogen hormone. However, Tamoxifen also functions by attaching to estrogen receptor sites. Thus to get the most benefit from Tamoxifen it is recommended that the intake of weak plant estrogens be restricted. Conversely, for a woman who is not on Tamoxifen or who doesn't have a history of estrogen positive breast, the weak flax estrogen may protect against breast cancer.