The Truth About Soy


Wow.  This was a legitimate eye-opener for me.  So far I’ve written The Truth About Honey and The Truth About Eggs and I kind of knew what the outcome would be.

For this particular blog post, however, I have researched the topic of soy products without an expectation of a negative or positive outcome.  Before I even started writing this piece, I decided that if I found valid research demonstrating that soy is harmful for me, I’d stop eating it.  On the flip side, if I found that the research out there depicts the consumption of soy as being safe or even healthy, then I’d continue to eat it and let everyone who reads this blog know it’s okay.

Please read this until the end.  It’s a total shocker.

There are so many theories about soy that I honestly didn't know what to believe.  Have you heard the myth about dudes getting man boobs if they eat tofu or drink soy milk due to the alleged high amounts of estrogen in it?

On the contrary, what about Asian cultures that eat soybeans and tofu?  Surely Eastern civilizations that have histories longer than the rest of the world, and health better than most, must know something we don’t.

I’m not sure about you, but I’m ready to confront the confusion and get some solid answers.  When I’m researching these “Truth Series” topics, I’m not just Googling whatever outcome I’m hoping to find.

I’ve been a mission asking health professionals for trustworthy resources; I’ve been digging through scientific journals; scanning blog after blog after blog (sometimes leaving comments that get me a little too fired up); reading their resources; and scouring YouTube (yes, there are reliable sources on there) for more bite-sized, clear-cut ways of digesting the truth.


Soy and Health

Let’s start out with some facts that I thought you’d find interesting in an article from Soy Connection by the United Soybean Board:

  1. Traditional soyfoods have been consumed in East Asian diets for centuries
  2. In the Japanese culture, the average diet is made up of 10g of soy protein per day, which is 10% of total protein needed in a human diet
  3. In 1999, as part of the process for approving the coronary heart disease-health claim, the U.S. Food and Drug Administration (FDA) extensively reviewed the scientific literature and concluded that soyfoods are safe for all except those who are allergenic to soy protein

Okay, that's an interesting start, but what about the estrogen and man-boobs stuff?

The article also states, “Many of the proposed benefits of soyfoods are attributed to their uniquely rich isoflavone content. However, isoflavones, which are diphenolic molecules with estrogen-like properties, are also the primary reason for concerns about the potential adverse effects of soyfoods.”

Aha! There we go…“estrogen-like properties.”  How much do those “properties” affect us, though?


The article continues, “Soy protein is added to foods primarily for its functional properties, i.e., to improve shelf stability and texture. Consequently, U.S. daily per capita soy protein intake is only 1 to 2 g per day, representing about 2% of total protein intake… Since soy protein intake is low, isoflavone intake is also very low.”

That’s starting to sound reassuring, but is it convincing enough?  Is this low isoflavone level low enough to be safe for humans?

Let’s check out a peer-reviewed article published by the US National Library of Medicine National Institutes of Health titled Soy and Health Update: Evaluation of the Clinical and Epidimiologic Literature.

This article breaks down 25 years worth of studies that investigate the health indications of soy consumption and specifically how isoflavones impact animals in the testing done with soy.  The article specifically highlights that the concerns that have arisen from these studies are due to the animal testing involved.

So, to break it down (aka cutting the jargon and saving you the 45 minutes it took me to read this article), people are actually getting worked up about the impact isoflavones are having on animals by assuming it has the same negative effect on humans, which many other research studies prove it doesn't.


Isoflavones do not impact humans in the same biological way that they impact animals making the accusations that soy gives humans man-boobs totally fallacious.  The truth is that it may cause rats and mice to develop mammary tumors, which may translate to reproductive issues. 

So, it appears as if modern marketing has heard one thing, mixed it up, and ran with it.  Soy = rat reproduction problems = human man boobs. Hmmm…

Also, just to acknowledge the elephant in the room: I believe animal testing is wrong and it sucks and is totally unethical.

Let’s keep moving…

To make sure we don’t miss the health-related factoids noted in this article, it mentions many times how soybeans have been proven to:

  • Provide notably higher quality protein content than some plant and animal proteins
  • Be low in carbohydrates, which is proven advantageous for people with diabetes
  • Be a good source of essential fatty acids (omega-3 & omega-6)
  • Be a good source of potassium, iron, calcium
  • Allow calcium absorption at the same level as cow milk
  • Lower LDL-cholesterol (which, remember, is from animal product consumption)
  • Significantly reduce the risk of developing invasive breast cancer & prostate cancer
  • Alleviate hot flashes & improve arterial health in menopausal women

TRUTH:  That article was funded by the United Soybean Board.  I mentioned them as the publisher from the start, but the reason I’m readdressing it is because it’s apparent they want soybeans to come out on top in this fight.  You know that means they’ll do whatever they can do shape the information that way.

Cue: Devil’s advocate…just to spice things up, ya know?


This Harvard Medical journal says that a person would have to ingest 50g of soy to exhibit the health benefits listed above.  Who is really going to eat a pound and a half of tofu or drink eight 8-ounce glasses of soy milk a day?

If we sift through what this journal is saying, they actually don’t seem to be so opposing afterall:

 “Even though soy protein has little direct effect on cholesterol (which means it doesn’t come from animals – wahoo!), soy foods are good for the heart and blood vessels because they usually replace less healthful choices, like red meat, and because they deliver plenty of polyunsaturated fat, fiber, vitamins, and minerals, and are low in saturated fat.”

This is where I started lurking around on other blogs to see what they’ve found about tofu.  Most of their sources were similar to mine, which ultimately stated eating tofu is completely safe to eat.

Here’s the kicker though…

Soy, The Environment, and The Animals

One of the blogs I stumbled upon discusses soy and the environment, a factor I completely forgot to consider at first.  Alas, this is why we research.

The multiple-hour-rabbit-hole-information-hunt this sent me on was exhausting, but the patterns were clear on ONE thing:

Animal agriculture is destroying our planet.

What does soy have to do with animal agriculture and the destruction of our planet you ask? 

Rainforests, jungles, forests, wild lands are being destroyed, stripped, and desecrated for the purpose of growing soybeans and grains to feed livestock.


The amount of soy that humans can eat barely makes a mark on the map.  When people say, “Don’t eat soy, it’s destroying the environment,” ask them if they eat meat.  Growing cheap crops like soybeans across native lands is making exotic wild animals go extinct, become homeless, and suffer, but it’s due to the demand for animal products.

So, let’s cut to the chase now…

Here are my conclusions:

  • Non-genetically modified soy is absolutely fine for you and me to consume (the genetically modified stuff is usually for animals anyways)
  • If I ate my weight in soybeans, I’d still be 100% okay; so would my boyfriend (aka he wouldn't grow man-boobs)
  • Eating soy has been framed to be healthy because it’s the better alternative to cholesterol-ridden animal products leading to better health statistics
  • The demand for meat means a demand for soy, which means continued destruction of the planet
  • Humankind's demand for soy directly is disproportionate to the demand for the soy grown for animal agriculture aka us buying it from the store for our homes is not contributing to the destruction of the Amazon; us buying meat is

What can you do now?

Humans eating any substitutions for animal products, such as plant-based items including non-genetically modified soy products (tofu, tempeh, etc.), shifts the demand from environment-destroying meat to planet-saving alternatives that have a far smaller carbon footprint.

You vote with your dollar and each person’s vote can make a difference.  Pay attention to the products you buy and what movements you’re putting your hard earned votes towards.

Please comment below and let me know how this article affected you.