Phytoestrogens

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Phytoestrogens are a class of plant compounds that can be seen to have a moderating effect on estrogen levels. Buffering the effect of excess estrogen states and shoring up the body in states of deficiency. Phytoestrogens have been shown to have health benefits including being antioxidant, anti-inflammatory, immune modulating, neuroprotective, organ protective, and supporting bone and cardiovascular health. Phytoestrogens play a protective role against the development of breast and prostate cancer¹. Over 300 plant compounds have been identified as being phytoestrogen in effect.

The most common phytoestrogens include isoflavones (such as genistein and daidzein), coumestans and lignans. Keep in mind there are many others. These phytoestrogens are found in the following food sources:²

• Isoflavones are found in highest levels in legumes especially soy

• Coumestans are found primarily in legumes including alfalfa and clover and mung bean sprouts. They are also found in flaxseeds.

• Lignans are found in highest levels in flaxseeds. Other foods sources high in lignans include sesame seeds, kale and broccoli. The lignan content of other foods can be found HERE.

Phytoestrogens can be supportive to the body in states of estrogen dominance. Estrogen dominance may be associated with symptoms of PMS, fibroids, ovarian cysts, endometriosis, breast lumps, breast cancer, ovarian and uterine cancer. Estrogen dominance can be due to a number of factors, which we will explore in more detail next week, not the least of which is our exposure to environmental xenoestrogens as discussed in this previous post HERE. While some sources will classify phytoestrogens as xenoestrogens, this is incorrect and leads to much confusion. Xenoestrogens are synthetic industrial chemicals that mimic estrogen in destructive ways. Phytoestrogens are natural plant compounds that offer some protection against the destructive effects of excess estrogen states and xenoestrogens from our environment.

In addition to buffering the effect of excess estrogen states, phytoestrogens can be helpful to ease the symptoms as our estrogen levels drop in the transition to menopause. They have been shown to have a protective effect against osteoporosis, cardiovascular disease, cognitive function and certain hormonally dependent cancers.

While there has been controversy over the past thirty years regarding their effects on cancer, we now understand that not all phytoestrogens work the same way, and that their effects can depend on dose, duration of use and diversity of phytoestrogens consumed. Their anti-tumor effects appear to be most potent when a variety of phytoestrogens are consumed in combination together, where they work synergistically in low concentrations.

It’s important to keep in mind that their effect may be different from one person to the next based on that person’s overall estrogen load, their gut microflora, and the idiosyncracies of their liver metabolism based on genetic and epigenetic influences. So, listen to your body, consume a diet high in plant diversity and consume in moderate amounts. Favour whole food sources over isolated extracts.

A FEW TECHNICAL NOTES ON PHYTOESTROGENS

For those of you that want a deeper dive into the science - here we go…..

Research shows that phytoestrogens are acting as selective estrogen receptor modulators (SERM). This means that they are having an anti-estrogen effect on some estrogen receptors and an estrogen effect on other estrogen receptors.

Research has identified two different types of estrogen receptors that are affected by phytoestrogens - alpha and beta. Alpha receptors are found primarily in the endometrium, breast cells (especially those expressing cancer), the hypothalamus, as well as in specific areas of the ovaries and testes. Beta receptors are found in the kidney, lungs, brain, bone, intestinal mucosa, heart, the endothelial cells lining the blood and lymph vessels, ovarian granulosa cells and the prostate. In general, the beta receptors are the ones associated with having an anti-tumor effect on several forms of cancer including breast and prostate cancer. The alpha receptors on the other hand which when activated in excess (especially in the absence of adequate beta receptor activation) may promote estrogen dependent cancers. Most phytoestrogen rich foods and herbs stimulate both the alpha and beta receptors to some degree in varying proportions. When these are activated simultaneously, the beta receptors seem to inhibit the alpha receptors preponderance to cell proliferation.

The dose and duration of use is also significant when it comes to the way in which phytoestrogens impact these alpha and beta receptors. Past a certain level of intake the beneficial effect is lost, and it is overcome by the excess stimulation of the alpha receptors stimulating excess estrogen symptoms. It has also been shown that age affects the sensitivity of alpha and beta receptors. It appears that alpha receptors are more sensitive to stimulation in infancy. An example of the problems of excess phytoestrogen intake in this sensitive population can be seen in the use of soy based infant formulas. The amount of phytoestrogens that infants receive when consuming soy based formulas (especially relative to their body size) is high and has been associated with significant negative impacts on health.

THE CONTROVERSY AROUND SOY

Soy has received a lot of bad rap over the past decade and understandably so. Most soy produced in North America is now genetically modified (GMO) soy. This GMO soy is one of the main crops fed to animals raised in industrial farming. GMO soy is associated with gastrointestinal inflammation and allergenicity, as well as other health problems.

Not only is it one of the most common food allergens, it also contains anti-nutrients that impede proper digestive function and nutrition status. Traditional methods of fermentation seem to make the soy more easily digested. When we look at the way soy is commonly consumed in North America - GMO and often in the form of soy milk or soy protein isolate, it is very different from its use in traditional cultures.

Soy as consumed in traditional Asian cultures has been shown to have a beneficial effect on health outcomes. In these cultures, soy is consumed on average at about one ounce per day, about 30 grams (yielding on average 40-50mg of isoflavones daily), which is not a huge amount. This soy is traditionally consumed in a fermented form such as tempeh, miso, natto and tamari which makes it much easier to digest. When consumed in high levels, (especially in the absence of adequate beta receptor activation), soy can stimulate the alpha receptor in excess - which we want to avoid.

PHYTOESTROGENIC HERBS

With well over 300 phytoestrogenic compounds already having been identified in plants and foods, no doubt there are more that will turn up. As such, many herbs have been found to contain phytoestrogenic substances. There are numerous herbs that have been traditionally used throughout various cultures worldwide to allay symptoms of menopause. Many of these contain phytoestrogens including: Trifolium pratense (red clover), Humulus lupulus (hops), Salvia officinalis (sage), Turnera diffusa (damiana), Angelica sinensis (don quai) and Pueraria mirifica and Pueraria lobata (kudzu), Achillea millefolium (yarrow), Artemisia vulgaris (mugwort), Chaste tree berry (Vitex agnus castus), Astragalus membranaceus (Astragalus), Rheum rhaponticum (Rhubarb root), Glycyrrhiza glabra (Licorice), Medicago sativa (alfalfa)³.

One of my favourite herbs for menopause is red clover. It is a gentle and nutritive herb that can be effective to help reduce symptoms associated with menopause. Interestingly, it also has traditional use in the treatment of cancer. However, if you have a family history of estrogen dependent cancer be sure to consult with someone experienced in the use of herbs in order to receive more guidance.

There are many formulas on the market containing a wide range of herbs to support the transition to menopause. While the use of these formulas can provide much needed support, I believe these herbs are best used when tailored to your unique body type and health situation.

Some people may experience an aggravation of estrogen like symptoms when taking higher doses of some of these herbs. For example, I have seen excess intake of Medicago sativa (alfalfa), Angelica sinensis (don quai) and Pueraria mirifica (kudzu), as well as soy, create symptoms of breast tenderness and swelling in a few people over the years. These experiences lead me to be cautious in their use.

BOTTOM LINE

Here are some ways to experience the health benefits of phytoestrogens

• Consume a diverse diet rich in a wide range of plant foods. You might want to refer back to our Food chart HERE. Be sure to include also the cabbage family vegetables in the diet such as broccoli, kale, cabbage, brussels sprouts. See if you can work towards including 5 servings of vegetables and 2 servings of fruit daily

• Include 1-2 tablespoons of flaxseeds in the diet daily as well as other raw nuts and seeds especially sesame seed (tahini, gosmasio)

• Include 1/2 cup of cooked, non-soy legumes daily for overall health benefit for example chickpeas, black beans, mung beans, mung bean sprouts, lentils, pinto beans etc. These foods contain a wide range of phytoestrogens as well as many other plant compounds beneficial for health. For recipe ideas for legumes see this LINK. Populations including legumes in their diet on a regular ongoing basis experience health benefit from their intake related to bone and cardiovascular health

• If including soy in the diet, choose organic GMO-free soy and favour fermented versions such as tempeh and miso and don’t exceed 8 ounces weekly (225 grams or half a pound) on an ongoing basis

• Avoid the use of soy protein isolates and isolated extracts of isoflavones, favouring instead the use of whole foods and plants

• If you are experiencing troublesome menopausal symptoms consider consulting with an experienced practitioner to figure out the best herbal support for your unique body type

Join me next week as we go on to discuss estrogen in more detail

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9952119/

2. https://pubmed.ncbi.nlm.nih.gov/16898863/

3. https://pubmed.ncbi.nlm.nih.gov/27677719/