Welcome to Part Three of Xenoestrogens and Phytoestrogens. If you missed the first two articles you can read them here and here. To conclude our mini series, we are talking about phytoestrogens today. We will be  addressing how they effect our body, and if there are benefits to consuming them.

What Are Phytoestrogens?

The word phytoestrogens comes from the Greek word “phyto,” or plant, and “estrogen,” the hormone that causes fertility in all female mammals. Phytoestrogens have also been termed dietary estrogens because they’re not created by the human endocrine system. They can only be ingested or consumed.

Phytoestrogens are naturally occurring substances which our body was programmed to recognize as we all have estrogen receptors ERAlpha and ERBeta. Instead of being true endocrine disruptors phytoestrogens are selective to which they bind to.

Once bound, isoflavones do not act like typical estrogen agonists, but rather more like selective estrogen receptor modulators

This means most phytoestrogens, including soy,

“have pro-estrogenic effects in some organs (protecting bones and reducing hot flash symptoms), but anti-estrogenic effects in others (protecting against breast and endometrial cancer)”.

What Are Phytoesrtogens Made Up of?

  • Isoflavones: The most studied type of phytoestrogen. Foods that contain isoflavones include soy and other legumes.
  • Lignans: A diverse class of phytoestrogens. Foods that contain lignans include flaxseeds, whole wheat, vegetables, strawberries and cranberries.
  • Coumestans: Although there are a variety of coumestans, only a few mimic estrogen’s effects. Foods that contain coumestans include alfalfa sprouts, clover sprouts and soybean sprouts.
  • Stilbenes: Resveratrol is one of the most common dietary stilbenes. Foods that contain resveratrol include nuts and red wine.

Soy (including processed soy) is big source when it comes to phytoestrogens :

Genetically Modified Soy is found in upwards of 60% of processed foods

Textured soy protein (50–70% soy protein) is a meat substitute found in hotdogs, hamburgers, sausages and other meat products while soy protein isolate (90% soy protein) is used to enrich energy bars, sports drinks, infant formula, cereals, granola bars, imitation dairy products, ice cream, cheese and even doughnuts.

As of 2010, about 93 percent of the soy in the U.S. was genetically modified —

Are They Dangerous? Should You Avoid Them?

The answer is likely complex and may depend on age, health status, and even the presence or absence of specific gut microflora.

And if they are Organic or not…

Phytoestrogens are often good antioxidants and anti-inflamatory agents; genistein and resveratrol are particularly powerful in this regard. These estrogen receptor (ER)-independent properties of genistein, resveratrol and other isoflavones, indicate that they have the potential to affect a wide array of intracellular signaling mechanisms important for regulating cellular growth and protection

What Are The Benefits of Phytoestrogens?

 May Reduce or Prevent Certain Types of Cancers

A 2009 study of over 5,000 women diagnosed with breast cancer showed a significant decrease in death and recurrence of the disease of the patients on a diet rich in non-soy phytoestrogens, a finding that echoed a 1997 questionnaire study of breast cancer patients.  Another project, spanning nine years and following 800 women, showed a 54 percent decrease in the occurrence of endometrial cancer in women eating a diet high in phytoestrogens.

A Dutch study comparing plasma isoflavone levels in women with and without breast cancer found that high plasma levels of genistein were associated with a 32% reduction in breast cancer risk.

Enhance Heart Health

Phytoestrogens, at least, can potentially reduce atherosclerosis and atherosclerosis-related diseases through multiple mechanisms, by regulating serum lipid metabolism, arterial vessels, cytokine levels, and coagulation/fibrinolysis system.

Improve Health During Menopause

One recent meta-analysis reported that isoflavone supplementation was associated with a 34% reduction in hot flashes.

Consumption of 30 mg/day of soy isoflavones (or at least 15 mg genistein) reduces hot flashes by up to 50%.

Prevent and Increase Bone density

At least one study has found that post-menopausal women consuming high quantities of soy foods have better femoral and/or lumbar spine density compared to women who consume less soy

These results suggest that the phytoestrogens including coumestrol and isoflavones in soybeans may exert effective prevention against bone resorption in estrogen deficient conditions.

Lowers Cholesterol Levels

For example, 31–47 grams of soy protein daily reduced blood cholesterol by 9%, triglycerides by 10% and LDL cholesterol by 13%, on average.

Who Shouldn’t Consume High Amounts of Phytoestrogens?

In a 2008 clinical case report, physicians at SUNY Downstate Medical Center treated three women (aged 35–56) for a similar suite of symptoms including abnormal uterine bleeding, endometrial pathology and dysmenorrhea. In all three cases, symptoms ameliorated after soy intake was reduced or eliminated, demonstrating that consumption of particularly high isoflavone levels can compromise female reproductive health.

However, it is unclear if the soy that was used in this study was genetically modified or contained levels of pesticides or if the soy was fermented or processed…

What About Men?

According to some studies that have been done, Men should probably be more concerned about consuming milk products effecting their prostate, rather than soy…

Here’s an excellent link to a video explaining more.


Researchers have no final verdict on phytoestrogens and therefore tell us to be cautious. However, many of the studies that were done in the US which led them to believe a negative outcome of phytoestrogens, are not clear on whether or not they were done with organic produce or with genetically modified substances. There’ s a possibility that their studies are conflicting due to the xenoestrogens sprayed on the phytoestrogens.

Unless you are consuming high amounts of phytoestrogens, ( more than 30 cups of soybeans a day) you may need not to be concerned.

 In Japan, one of the healthiest places on Earth, soy is a prevalent staple. However, the soy there is not genetically modified.

Everything in CLEAN moderation. Its not so much Phytoestrogens themselves that we need to be concerned about but rather we should consider the quantities, types, where they come from and how they are consumed.

For a list of foods that breakdown the types of Phytoestrogens in them, and the amount Phytoestrogens in each type of food click here. 

For those of you that would like to get more info about soy, that summarizes a lot of the information you just read about, there is a great video you can check out here.

Photo Cred: Here

Article Sources: 1, 2, 3, 4, 5, 

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