I am often asked if the tinctures I formulate for my patients have estrogen in them. “Don’t some plants have estrogens? Isn’t that bad?” The answer is more complicated and lengthy than one would think so I decided to share my thoughts on paper.
The term “phytoestrogen” refers to one chemical component of some herbs which have some binding affinity to estrogen receptors. Usually this chemical component is either genistein or daidzein, but sometimes they are compounds that can act as aromatase inhibitors, and are usually one of many compounds found in the herb in question. Phytoestrogens do bind to estrogen receptors, but they bind much more weakly than your body’s own estrogen and so by occupying the receptor site and only weakly binding to it (meaning it pops on and off), it actually prevents your body’s estradiol from binding more tightly to that receptor. In the presence of elevated levels of estrogen this has an antagonistic effect. In the post-menopausal woman who has very little or no estrogen levels this can be a mild agonist effect- the body is getting some estrogenic activity, though much weaker than actual estrogen.
Phytoestrogens are nothing to be afraid of, they are found in most plants and vegetables and in fact, many of the herbs that I regularly prescribe are herbs that in the past have been more of a significant part of our diets as humans. Foods like flax, soy, and legumes have famously high levels of phytoestrogens. Modern chemistry is just scratching the surface of the mechanisms behind the multitude of compounds in a single herb. However, traditional use (centuries of clinical experience) of that herb can be quite detailed and specific.
Also, I rarely, if ever, prescribe one herb in isolation; usually I’m blending a few together to either address multiple issues, or enhance a desired effect. For example, all the phytoestrogenic activity possible will not be effective if there isn’t adequate gastrointestinal function to absorb the herb. Once it is absorbed, the liver has to process it and turn it into its active form, so often I will include a liver and gut supporting herb in my formula – but not always the same ones. Sometimes an herb will have a secondary indication – for example, say an herb is both a phytoestrogen and supports lung function in people with asthma. I definitely will add that herb over another one if my patient also has low estrogen symptoms and asthma.
Anyhow, this is just a small peak into my mind when I’m thinking about formulating a tincture for one of my patients. This is, by the way, one of my favorite things about practicing naturopathic medicine. I promise I’m not sneaking estrogen into your formulas, and hopefully after reading this you will understand a bit more about the term “phytoestrogen”.
Dr. Jamie Brinkley, ND