Is Soy Bad For Your Hormones? 6 Reasons Not to Eat Soy


Soy can either be good for you or be bad for you.

But…. 90% of the soy on the market is bad for you.

However, most Americans have been misled to believe that eating soy improves health.

In 1999, the FDA approved a message from the food industry that:

“Diets low in saturated fat and cholesterol that include 25 grams of soy protein a day may reduce the risk of heart disease.”

Since then, soybean consumption doubled. Approximately 31% of Americans consume soy foods or beverages at least once a week. Soy is now a billion-dollar industry and the United States is currently the largest soybean producer in the world, making up more than 35% of worldwide production in 2012.

The reason why people believed in the health benefits of eating soy and why it became so popular was due to pressure by the soybean industry and the discovery that people living in Okinawa, Japan had very long life spans and ate a lot of soy. However, the type of soy that they consumed was a lot different than the soy used in most foods today.
A little history lesson…..

Back in ancient China in the 1100’s BC, soybeans were designated as one of five sacred grains, along with barley, millet, rice, and wheat. Before then, soybeans were not eaten by humans, but were only used to help fertilize the land so that other crops could thrive. However, during the time of the Chou Dynasty, fermentation techniques were discovered. The Chinese learned that soybeans could be fermented, and thus the first soy foods (miso, natto, tempeh, and shoygu) were introduced into the human diet.

Unfortunately, traditional soy foods are rarely eaten by most Americans. Instead, unfermented soybeans that have been genetically modified are found in almost all soy products in the U.S.

The growth of genetically-modified soybean crops in the U.S. has increased dramatically since the early 1990’s when soybeans were promoted as a “health food.”

Because soybeans have been genetically modified to withstand the physically damaging effects of herbicides (“Roundup”), pesticides, and other toxins during the production process, there is an overabundance of soy (140 billion pounds per year) in the U.S.

So… What do we do with it all?

We sell it. The soy industry profits at the expense of the health of Americans.

 Most of the soy grown in the U.S. is sent to be used as animal feed and hydrogenated fats such as margarine. The rest is sent off to be added to or create processed foods.


Soy has also been pushed to replace traditional dairy ingredients and are marketed as high-end, “healthy” products such as soy baby formula, soy yogurt, soy ice cream, and soy milk. In every “health” food section there is also an area where you can find soy burgers and soy chicken nuggets. Soy products are heavily marketed to vegetarians as a high source of protein. In fact, vegetarianism is one of the biggest reasons why soy is in such high demand.

Enough history.. Let’s get down to the reasons why you should stop eating soy, or at least cut down on it.

6 main reasons why soy is bad for you are because:


1. They contain phytoestrogens that create hormonal imbalances.


Women have two main hormones that are responsible for maintaining their reproductive health: estrogen and progesterone. These two hormones are mainly secreted by the ovaries and are dependent upon each other to balance each other out. They work together to promote the healthy development of the female sex characteristics during puberty and to ensure fertility.

The soy used today contains a lot of phytoestrogens, which are plant-derived compounds that mimic the effects of estrogen in the body. As most of us know, estrogen is primarily a “female” hormone. One might think that consuming large amounts of soy to try to raise estrogen levels during menopause is a good thing. However…

A study at the Mayo Clinic found no benefits from soy in treating hot flashes, night sweats, and vaginal dryness in a group of menopausal women.

In addition, when women consume large amounts of soy foods, the phytoestrogens may block and replace naturally-produced estrogen, which may cause a hormonal imbalance in the body. This may lead to infertility, loss of libido, and researchers have also found a link to breast cancer.

Women with a history of estrogen receptor positive breast cancer have been warned not to eat soy because it could inhibit the recurrence of breast cancer because of its estrogen-like properties.

Although recent research suggests that soy consumption is not associated with recurrence of breast cancer, its sample only included estrogen receptor negative breast cancer survivors.

Another study by researchers at Georgetown Lombardi Comprehensive Cancer Center found that eating soy may prevent cancer, but if you’ve already been diagnosed with it, soy can fuel its growth. In other words, soy consumption may be protective only if started before cancer develops. Otherwise, it makes cancer worse.

With that being said, it’s probably best to avoid or limit soy consumption altogether.


2. They are GMOs can damage your digestive system.


In addition to possible hormonal imbalances caused by soy, it is also important to note that over 90% of soy today are genetically modified organisms (GMOs). If you’re wondering why soy was genetically modified and why it’s so bad, you will be shocked at the answer:

Soy grown in the United States was genetically modified to resist toxic herbicides (i.e. “RoundUp”), which means that soybean fields are sprayed with toxic herbicides and pesticides, but have been genetically engineered to not die in the process.

During the genetic modification process, genes from bacteria are injected into the soybean. These genes produce a protein that humans have never been exposed to as a source of food, which increases allergic reactions.

Have you ever noticed that a lot of food products that you buy are labeled with “may contain soy?” That’s because soy is one of the eight major allergenic foods. So many people are allergic to it, because of the protein from the bacteria gene used in the genetic modification process that humans weren’t previously exposed to.

Not to mention, research has proven that the gene from genetically modified soy transfers into our own gut bacteria in our and continues to function. That means that even if we haven’t eaten soy in years, we could still have an allergenic protein being produced in our gut.


3. They contain high levels of toxins that may cause gastric distress (upset stomach).


Lectins, which are a type of protein found in soybeans, are not digested in the human body. Because we aren’t able to digest them, we often produce antibodies to them, which stimulates an immune system response. In fact, the response can be so severe that poisoning can occur.

Have you ever wondered why you don’t see sprouted red kidney beans on store shelves? That’s because they contain a type of lectin called phytohaemagglutinin, which can cause poisoning with as little as four raw beans.
And, have you ever heard the phrase: “Beans! Beans! They’re good for your heart. The more you eat, the more you f@rt”?

It is the lectins in beans that can cause flatulence, GI distress, and “leaky gut.”

When food passes through our digestive system, very minor damage to the gut lining occurs. Our gut lining is responsible for keeping the bad stuff contained while letting the good stuff pass through. So, a healthy gut lining is important. Normally, our cells quickly repair the damage done during food passage. However, lectins slow this process down and our gut lining is compromised, which becomes what is known as “leaky gut.” When tiny food molecules are able to pass through the gut lining when they should have been kept out, our body sees them as foreign invaders and sends off an alarm to remove the “enemy,” which causes inflammation. Lectins also signal our body to empty our gut contents, which leads to cramping, diarrhea and sometimes vomiting.

Leaky gut may be associated with:

  • Inflammation
  • Joint pain
  • Bloating
  • Gas
  • Cramps
  • Food sensitivities
  • Diarrhea or irritable bowel syndrome
  • Hormonal imbalances such as PMS
  • Chronic fatigue
  • Skin issues
  • Autoimmune diseases such as rheumatoid arthritis, Hashimoto’s thyroiditis, lupus, and celiac disease
  • Mood disturbances such as depression or anxiety


4. They contain hemagglutinin, which affects blood clotting.


Hemagglutinin is a substance that causes red blood cells to clump together, increasing blood clotting. This can be dangerous for people on Coumadin (warfarin) therapy, which is an anticoagulant medication used to prevent or treat blood clots. Consuming soy can reduce its effectiveness by inhibiting the action of vitamin K, which promotes blood clotting. Although more research is needed to confirm the effects of soy on warfarin therapy, it’s probably best to stick to only fermented soy foods, since the fermentation process deactivates hemagglutinin.


5. They are said to contain “anti-nutrients.”


Soy foods are said to contain “anti-nutrients” such as phytates, oxalates, soyatoxins, saponins, protease inhibitors, and other compounds that may hinder absorption of iron, zinc, manganese, and calcium.

Excessive amounts of soy (more than 35 grams a day) may lead to gastric distress because they contain “anti-nutrients” that block the action of trypsin, which is an enzyme produced by the pancreas to aid in protein digestion. Since food proteins must be broken down into amino acids that your body can use for tissue growth, maintenance, and repair, not having enough active trypsin can hinder digestion and even damage the pancreas.

However, there is no research that has proven that consuming soy foods leads to mineral deficiencies, and as long as you are eating a balanced diet and not relying on soy as your primary food staple, you should be able to get plenty of minerals from the other foods that you eat. Plus, phytates are considered to be an anti-oxidant and may help fight some cancers. So, the “anti-nutrient” content in soy shouldn’t be the main reason for you to cut it out of your life completely.

Fermenting soy reduces the mineral-blocking effects of phytates and other “anti-nutrients,” so only choose non-GMO soy foods that have been fermented.


6. They contain goitrogens that may cause thyroid dysfunction.


The thyroid is one of the largest glands in the endocrine system and It produces hormones such as triiodothryonine (T3), thyroxine (T4), and calcitronin. It is also responsible for controlling how your body responds to other hormones and controls how fast your body uses energy. This is why those with hypothyroidism (underactive thyroid) tend to gain weight or have a difficult time losing it.

Soy contains goitrogens that can block the production of these hormones, leading to thyroid dysfunction or it can make existing thyroid dysfunction even worse.

Soy can have an estrogen-like effect, and many people with thyroid issues find that they are prone to “estrogen dominance” (a hormonal imbalance).

In fact, about two thousand years ago, monks were regularly fed tofu to aid in their sexual abstinence. More estrogen means less testosterone. Less testosterone means less sex drive.


Some soy products to avoid/cut down on are:

  • Soybeans/Edamame
  • Soy milk
  • Soy protein
  • Unfermented tofu
  • Soy nuts
  • Soy chips
  • Soy nut butter
  • Soy burgers
  • Soybean oil

Of course, most things are okay in moderation. However, if you’re eating more than 35 grams of soy every day, this could negatively affect your health.


SOME soy is GOOD

Now, there are a few types of soy that can be good for you, which is the type of soy that the people of Okinawa, Japan were and still are eating. Good soy is organic, fermented soy.

Organic means it was not genetically modified and was not grown in soil that was treated with chemical fertilizers and pesticides.

Fermented means that it went through a process that increased its amount of probiotics (good bacteria), lowered its amount of “anti-nutrient” substances that behave like toxins in the body, and lowered its amount of phytates that prevent the absorption of nutrients in the body. Fermented soy foods are easier to digest and also contain high amounts of vitamin K2, which is important for bone, cardiovascular, and brain health.


The top 3 fermented soy foods are:

  • Miso
  • Natto
  • Tempeh


Miso is a salty, fermented soybean paste that is typically used to season soups and sauces.
Natto are sticky, gooey fermented soybeans that are typically served over rice.
Tempeh is a firm fermented soybean cake with an earthy flavor.


There are plenty of reasons not to eat soy. Yes, most soy is genetically modified, non-organic, and contains “anti-nutrients,” phytoestrogens, hemagluttinins, goitrogens, toxins, and plenty of other long words that most people can’t spell or pronounce. However, these substances in your everyday meals shouldn’t be enough to cause any problems as long as you are eating them in small amounts. Most of us consume enough minerals from other foods that more than make up for the phytates found in soy. Most of us do not eat enough soy foods to cause hormonal imbalances in our bodies. There’s a big difference between drinking soy milk three times a day and eating a handful of edamame once a week. If you’re at a friend’s house for dinner and they serve a salad with a few soybeans on top, there should be no reason to panic. But ideally, we should only eat organic, non-GMO, fermented soybeans just as the long-living Japanese do/did.



You’ll learn exactly how to eat and exercise to get slim, lean, healthy, and confident in your own body. Without sacrificing time, money, or the foods you love.

This website is about learning how to make the right, easy changes in your lifestyle and get the greatest results.

Thousands of others have already changed their lives by following the simple, effective principles taught on this site, and you can too.

Be a part of the Dr. Carissa Community, follow and subscribe below.


The Skinny Kitchen Checklist


Are you enjoying this article?..


Then you'll surely enjoy Dr. Carissa's Free Report outlining the complete list of ingredients you must have (or not have!) in your kitchen in order to lose weight or maintain your ideal weight. 

You have Successfully Subscribed!


The Essential Cooking Course


Are you enjoying this article?..


Then you'll surely enjoy Chef Gui and Dr. Carissa Alinat's Free Report empowering you to cook delicious, healthy, and fat-burning foods in a matter of minutes.

You have Successfully Subscribed!