Notes on Estrogen, Phytoestrogen and Xenoestrogen
Phytoestrogens are plant components which have the same receptor sites as estrogen. That means they can hook up to the same receptor sites in our cells. Unlike the estrogen that our own body produces, phytoestrogens are much smaller in effect. This means that when there is too much estrogen in our body, phytoestrogens will hold the place of an estrogen receptor site and render it inactive. During times of too much estrogen, the body will not recognize it as estrogen. However, during the times of life when there is not enough estrogen (ie. post-menopause) using phytoestrogens can have the opposite effect. The phytoestrogens will attach to the estrogen receptor sites, but because there is little naturally made estrogen available, the body recognizes it as estrogen. So, it can have the effect of increased estrogen in the body.
Then there are xenoestrogens. They are chemical constituents found in common pollutants (such as gasoline, plastics, pesticides) that we ingest through our foods, water or breath in through our air. Xenoestrogens can bind to the same receptor sites as estrogen and phytoestrogens. Unfortunately, they do not benefit us in any way. Some studies have shown that any given xenoestrogen may not adversely affect us on its own, however, it has also been shown that two or more in combination can have 1000 times the effect. These chemicals are unpredictable, and all the possible results of coming into contact with them are not fully known. We simply have not had the time to fully study the question.
We are not able to completely avoid these contaminants, which is another good reason to use phytoestrogens. Again, phytoestrogens will use up receptor sites, which in turn, diminishes the effects of xenoestrogens. Some foods and simple herbs to turn to when looking for phytoestrogens are as follows:
Phytoestrogenic foods are the basis for a healthy diet and a long life. The first food listed is the highest in phytoestrogens. The best diet contains not just one but many choices from each list:

