Plant Estrogens Explained: Are Phytoestrogens Safe or Dangerous?

Today’s topic is something that seems to always end up being discussed in my classes and when I am working with clients.  In the late 1990s early 200s, there was an incredible negative campaign against soy, tofu, and other soy products.  I would take the bet that this all came down to money.  Money that the meat and dairy industry stood to lose if people started adopting soy-based products and reduced their consumption of meat and dairy products. 

As a result of this anti-soy narrative campaign, soy got a very bad rap.  Especially related to women and breast cancer.  And then they aimed it at men too – one of the things men are most sensitive about – man-boobs. 😊

Once this false information got into people’s heads it has been darn near impossible to convince people otherwise.

I’m going to do my best to bring you the science and the facts. No money has changed hands for this blog today.😊

Let’s start with estrogen and it’s even more confusing cousin, phytoestrogen.

If you’ve ever been told to avoid soy, skip flax, or fear plant estrogens because they’ll “mess with your hormones,” you’re not alone.

But here’s the short version before we go any further:

👉 Phytoestrogens are not the same as human estrogen.👉 And for most people, they’re not dangerous.

In fact, they can be helpful — especially during perimenopause and menopause.

First… what ARE phytoestrogens?

Phytoestrogens are natural compounds found in plants.

“Phyto” = plant“Estrogen” = because their shape is loosely similar to estrogen

That’s it. They are not human hormones.

They’re found in foods like: Flax seeds, soy foods (tofu, tempeh, edamame), chickpeas and lentils, whole grains, and seeds

Very important fact:  They do not behave like the estrogen your body makes.

Think of them more like a gentle dimmer switch, not an on/off button

The big misunderstanding (this is where fear comes from)

Here’s what many people think happens: “If I eat plant estrogens, they’ll flood my body with estrogen.”

That’s not how this works.

Phytoestrogens are much weaker than your body’s estrogen — hundreds to thousands of times weaker.

They don’t override your hormones.They don’t “take over.”They don’t force your body to do anything.

Instead, they interact gently with estrogen receptors and often help balance things out, especially when estrogen levels are fluctuating (hello perimenopause).

Why phytoestrogens can actually HELP during midlife

Okay, here’s where it gets interesting (but I nerd out on this stuff so all of it is interesting to me).

During perimenopause and menopause:

• Estrogen levels become unpredictable

• Some days are high, some days are low

• The body struggles to find balance

Phytoestrogens can:

• Lightly mimic estrogen when levels are low

• Gently block stronger estrogen when levels are high

That’s why researchers sometimes call them estrogen modulators, NOT estrogen boosters.

To put it simply:👉 They help smooth the roller coaster.

What about soy? (because like I mentioned before, everyone asks)

Soy is probably the most misunderstood food on the planet. Whole soy foods like tofu, tempeh, edamame and miso have been eaten safely for thousands of years.

Large population studies show that people who regularly eat whole soy foods tend to have:

• Lower rates of breast cancer recurrence

• Better heart health

• Fewer menopausal symptoms in some cases

Soy does not:❌ feminize men❌ cause breast cancer❌ “shut down” your hormones

Context matters. Whole food matters. Amount matters.

When phytoestrogens become a problem (rare, but worth saying)

Issues tend to show up when:

• People take high-dose isolated supplements

• Diets are extremely restrictive or unbalanced

• Gut health is compromised (because the gut helps process hormones)

Whole soy-based food ≠ supplement.

This is why I always say:👉 Eat the food. Skip the mega-dose pills unless medically guided.

The gut connection (because of course there is one)

Your gut plays a huge role in how phytoestrogens behave.

If you recall from my previous blogs on gut health, the microbiome in your gut help:

• Activate beneficial plant compounds

• Support hormone balance

• Reduce inflammation

A healthy gut makes phytoestrogens work better. and guess what supports gut health?Fiber. Plants. Real food. 😊

The simple takeaway

Phytoestrogens are:✔ gentle✔ food-based✔ naturally balancing✔ not the same as estrogen

They’re not something to fear, especially when they come from whole plant foods.

For many women, they’re part of what makes plant-based eating feel supportive during hormonal transitions.

Want a simple way to support mood & hormones with food?

You may want to check out my FREE 7-Day Serotonin Reset Plan.

It’s designed to:

• Support gut–brain balance

• Calm the nervous system

• Stabilize mood and energy

• Use whole-food, plant-based meals (no extremes)

No restriction.No hormone fear.Just real food that works with your body.

👉 You can download the FREE 7-Day Serotonin Reset here: CLICK HERE FOR YOUR FREE PLAN

NOTE: Because I am all about empowering others to make decisions based on sound science, I’ve put together some key scientific references (and key takeaways) I have collected and reviewed over the years that contain the science to back up what I have discussed today in my blog. You can read for yourself and come to your own conclusions based on scientific-peer-reviewed published literature.

OVERALL SAFETY & HORMONE EFFECTS

1.     Messina M. Soy and Health Update: Evaluation of the Clinical and Epidemiologic Literature. Nutrients. 2016 Nov 24;8(12):754. doi: 10.3390/nu8120754. Key takeaway:Comprehensive review concluding that soy foods do not feminize men, disrupt hormones, or impair fertility, and are safe for long-term consumption.📌 Often cited to debunk estrogen myths.

2.     Hamilton-Reeves JM, Vazquez G, Duval SJ, Phipps WR, Kurzer MS, Messina MJ. Clinical studies show no effects of soy protein or isoflavones on reproductive hormones in men: results of a meta-analysis. Fertil Steril. 2010 Aug;94(3):997-1007. doi: 10.1016/j.fertnstert.2009.04.038. Epub 2009 Jun 12. Key takeaway:No changes in testosterone, estrogen, or sperm quality in men consuming soy.📌 This paper directly addresses the “soy feminizes men” myth.

🌸 MENOPAUSE & WOMEN’S HEALTH

1.     Messina MJ, Wood CE. Soy isoflavones, estrogen therapy, and breast cancer risk: analysis and commentary. Nutr J. 2008 Jun 3;7:17. doi: 10.1186/1475-2891-7-17. Key takeaway: Soy isoflavones act as selective estrogen receptor modulators (SERMs) — gently balancing estrogen activity rather than overstimulating it.

2.     Chen LR, Ko NY, Chen KH. Isoflavone Supplements for Menopausal Women: A Systematic Review. Nutrients. 2019 Nov 4;11(11):2649. doi: 10.3390/nu11112649. Key takeaway: Soy isoflavones modestly reduce hot flashes and may support symptom relief without the risks associated with hormone therapy.

🎗️ BREAST CANCER (THE BIGGEST FEAR AREA)

1.     Nechuta SJ, Caan BJ, Chen WY, Lu W, Chen Z, Kwan ML, Flatt SW, Zheng Y, Zheng W, Pierce JP, Shu XO. Soy food intake after diagnosis of breast cancer and survival: an in-depth analysis of combined evidence from cohort studies of US and Chinese women. Am J Clin Nutr. 2012 Jul;96(1):123-32. doi: 10.3945/ajcn.112.035972. Epub 2012 May 30. Key takeaway: Higher soy intake was associated with lower mortality and recurrence in breast cancer survivors.📌 One of the most important human studies in this area.

2.     Shu XO, Zheng Y, Cai H, Gu K, Chen Z, Zheng W, Lu W. Soy food intake and breast cancer survival. JAMA. 2009 Dec 9;302(22):2437-43. doi: 10.1001/jama.2009.1783. Key takeaway: Soy consumption is safe for breast cancer survivors and may offer protective benefits.

3.     American Institute for Cancer Research (AICR) https://www.aicr.org/resources/blog/soy-and-cancer-myths-and-misconceptions/ Expert consensus statements on soy. Key takeaway:Whole soy foods do not increase breast cancer risk and are safe before and after diagnosis.

❤️ CARDIOVASCULAR & METABOLIC HEALTH

1.     James W. Anderson, M.D., Bryan M. Johnstone, Ph.D., and Margaret E. Cook-Newell, M.S., R.D. Meta-Analysis of the Effects of Soy Protein Intake on Serum Lipids. August 3, 1995 N Engl J Med 1995;333:276-282 Key takeaway:Soy protein significantly lowers LDL cholesterol. 📌 One of the earliest landmark soy studies.

2.     Jenkins DJ, Mirrahimi A, Srichaikul K, Berryman CE, Wang L, Carleton A, Abdulnour S, Sievenpiper JL, Kendall CW, Kris-Etherton PM. Soy protein reduces serum cholesterol by both intrinsic and food displacement mechanisms. J Nutr. 2010 Dec;140(12):2302S-2311S. doi: 10.3945/jn.110.124958. Epub 2010 Oct 13. Key takeaway: Replacing animal protein with soy improves lipid profiles and cardiovascular risk markers.

🦠 GUT HEALTH & INFLAMMATION

1.     Guo C, Huo YJ, Li Y, Han Y, Zhou D. Gut-brain axis: Focus on gut metabolites short-chain fatty acids. World J Clin Cases. 2022 Feb 26;10(6):1754-1763. doi: 10.12998/wjcc.v10.i6.1754. Key takeaway: Soy foods provide fiber and polyphenols that support gut microbiota and reduce inflammation, key for mood and metabolic health.

🏛️ MAJOR HEALTH ORGANIZATION POSITIONS

1.     Melina V, Craig W, Levin S. Position of the Academy of Nutrition and Dietetics: Vegetarian Diets. J Acad Nutr Diet. 2016 Dec;116(12):1970-1980. doi: 10.1016/j.jand.2016.09.025 Key takeaway: Soy foods are nutrient-dense, safe, and beneficial sources of protein across the lifespan.

2.    Harvard T.H. Chan School of Public Health https://nutritionsource.hsph.harvard.edu/soy/ Key takeaway:Soy foods are associated with lower heart disease risk, improved metabolic health, and no hormonal harm.