The Soy Decoy: Don’t Be Deceived

Guest Post by Katie Fox

I know it goes against everything we hear these days about healthy eating, but I’m here today to tell you that I don’t eat soy products, and I don’t think you should eat soy products, either.

There.  I came right out and said it.  Might as well get the controversy right out in the open from the start, right? (wink)

Honestly, I’m not looking for a fight.  In my real off-line life, I almost never talk about dietary choices with people unless they flat-out ask me my opinion.  Diet is a really personal thing, and people often feel defensive if their choices are questioned.  But the soy issue really concerns me, so I decided to take this opportunity while guest-posting here at Keeper of the Home to talk about the side of soy we don’t usually hear about.

You’re about to read a lot of big, scientific-sounding words, but don’t let it phase you.  I’ve tried to put everything into plain-Jane language,  for me as much as for anyone else – I’m definitely no scientist!  But I believe there are at least three good reasons for avoiding soy, and it’s important to understand them.  Here they are.

1.  Soy Disrupts Our Sex Hormones

Soy is known as a phyotestrogen.  This means that it contains natural compounds that mimic estrogen in our bodies.  This sounds like good news for some people, such as post-menopausal women.  But what are the effects of phytoestrogens on babies, little boys and little girls, young women and young men?

For babies on soy formula, a 1994 study shows that they are consuming the hormonal equivalent of up to 10 contraceptive pills a day. Little systems can’t handle that overload; it puts children at risk for everything from early-onset puberty to permanent endocrine damage. This might surprise you: the governments of Israel, Switzerland, the UK, and New Zealand have all issued statements against the use of soy formula for babies.

Little boys who consume soy may have higher risks of testicular cancer, and little girls may face higher risks of breast and ovarian cancers, due to longer exposure to sex hormones.  There is also a possible link between soy and lower sperm counts in young men.

Just 100 grams of soy contains the hormonal equivalent of one contraceptive pill.  Considering all the hormonal diseases that are running rampant today in the West (including infertility), it seems wise to check our consumption of soy.

2.  Soy Disrupts Our Thyroid

The thyroid is part of the endocrine system, just as the sex hormones are, so these two issues are intimately related.  The phytoestrogens in soy also act upon the thyroid to have a goitrogenic effect, which means they depress thyroid hormone production, slow down thyroid metabolism, and potentially cause an increase in the size of the thyroid (known as a goiter, hence the term goitrogenic).  All of that adds up to one thing: hypothyroidism.

I have suffered from hypothyroidism since 2001, possibly earlier.  There are many symptoms of this disease, and it is often overlooked or misdiagnosed as depression (which at first happened to me).  In fact, some experts estimate that there are as many as nine million undiagnosed cases of hypothyroidism in the United States alone.  If you have any hypothyroid symptoms, try to eliminate soy from your diet right away.

3.  Soy Contains Anti-Nutrients

Anti-nutrients are chemicals and compounds that prevent nutrients from being properly used by the body.  Here are two examples of anti-nutrients found in soy:

Protease Inhibitors
Soy contains protease inhibitors, which frustrate the body’s digestion of protein.  Studies show that this could cause the pancreas to be over-worked in the digestion process, and eventually lead to pancreatic dysfunction.   Protease inhibitors are found in especially high amounts in raw soy – one reason raw soybeans are considered toxic.  Heating and processing the soy lessens the amount of protease inhibitors considerably, but it is never completely eliminated.

Phytic Acid (or Phytates)
Soy (and many other grains, as well) contains phytic acid, which acts like a magnet for many important minerals, such as calcium, magnesium, zinc, and iron, therefore preventing their absorption into the body.  Though phytic acid can also help with ridding the body of unnecessary and/or unwanted heavy metals such as lead and mercury, this cleansing effect is bad news for those who rely heavily on soy for mineral content in their diet, such as those in developing nations.

Image by little blue hen

What About Soy in Asian Cultures?

Many people are understandably surprised when they discover the negative effects of soy, and often point out that Asian cultures have eaten soy for thousands of years, with seemingly great health benefits.  There are two important factors to consider here.

1.  Asian cultures have historically eaten soy primarily in its fermented forms: miso, tempeh, soy sauce, and tamari are all fermented soy products.  The fermenting process significantly lessens the protease inhibitors and phytates in soy, almost to the point of elimination.  Tofu is the only non-fermented form of soy that has been historically common in Asian cultures.

2.  Traditionally, Asian cultures have eaten these soy products in small amounts, more as sauces and condiments than main dishes. A typical starter of soup with three cubes of tofu is very different from a tofu-based entree where tofu is acting as a meat substitute.  The average Asian diet in China, Indonesia, Korea, Japan, and Taiwan includes between nine and 36 grams of soy per day.  Compare that to a cup of tofu (252 grams) or soy milk (240 grams).

In our home, we do eat small amounts of fermented soy, such as tamari and miso, very occasionally.  But we completely avoid the newer forms of highly processed soy products such as soy milk, soy protein isolate (common in protein and energy bars), soy protein powder, and soy cheese. These are totally outside the historical understanding and consumption of soy in Asian cultures.  In addition, some of them, such as soy protein isolate, contain much higher concentrations of phytoestrogens than less-processed, more traditional soy forms.

A Few Last Things To Consider

The soy industry is just that – an industry, with the goal of making money.  They are desperate to convince us that soy is a miracle health food, and they have invested millions of dollars in marketing to do just that – quite successfully, I would add.  For every risk I mentioned above, there is another study that contradicts that risk and wants to call me crazy.

Soy is not without its benefits, I admit.  But I encourage you all to check out the facts for yourself.  There is just too much evidence of unnecessary risk for me to consider soy products to be an acceptable food source in our home. What about you?

Learn more about soy from these sources, which I used in writing this article:

Nourishing Traditions, by Sally Fallon
The Whole Soy Story, by Kaayla T. Daniel, PhD
Whole Soy
Soy Online
Soy Alert: Health Food or Danger?
Natural Health News: Be Aware of Soy Risks
Do Soy Foods Negatively Affect Your Thyroid?
Wikipedia: Soybean

Have you ever heard about these risks associated with soy?  What do you think?

**A note from Stephanie: For those curious about my stance on soy, I think that Katie has summed it up very well. I could have written this post myself, and would have said very similar things. Our family also avoids all processed, more modern forms of soy and only consumes naturally fermented and organic soy in very minimal amounts.**

Katie Fox loves to learn about natural living, and believes that caring for the earth and caring for yourself don’t have to be mutually exclusive. She loves to help other people understand how they can both contribute to and benefit from a switch to a more natural and organic lifestyle. She is a stay-at-home mom and a native Texas girl, happily married to her best friend. She is the editor of the popular blog, Simple Organic.

Image by Jenny Lee Silver

About The Author

This post was brought to you by one of Keeper of the Home's fantastic guest posters!

Read Newer Post
Read Older Post


  1. I’m glad to see there are other people who agree with me! It’s amazing how many foods contain soy. I have been buying a certain brand/type of canned tuna forever because it stated on the contents: contains fish. Most say fish, soy. The other day I was in the grocery and saw a 4 pack of the tuna that I normally buy the single can of and the contents stated: fish, soy!!! Picked up the single can and yes, it stated only fish!!! I think we still have a long way to go in regulating packaged foods in America! Jillian Michaels has a lot to say about soy and fake ingredients in our foods. Her book is a good read.

  2. I know it’s an old post but this article is very important. Soy gradually made me very sick as a vegetarian.

    Soy is dangerous. It’s being snuck into many foods that claim to be soy-free, even flour is cut with soy. Look at all your breads, cookies and crackers. All your mixes. If you want to live longer and heathier, be less swollen and fuffy, don’t eat anything soy. BTW, you can get chocolate with no soy at Trader Joes for a reasonable price. Stay away from
    Soy oil, or “mixed vegetable oil”
    Almost all mixes have soy.
    Your allergy to soy will build and you will get sicker and sicker.
    Mass food manufacturers use it because it is very cheap and adds a bit of fat, protein and texture to breads, etc. That’s why it’s taken over. If you are vegetarian eating a lot of soy, you are out of your mind.
    This has nothing whatsoever to do with organic vs. not organic. The problem is that soy has naturally occurring bad constituents in it.

  3. I love this post! I have two little boys and I was shocked the “bad side” of soy! Thank you so much, great information :)

  4. Let’s not forget that most soy products are made with genetically modified soybean seeds that are being overproduced to the ruin of the lands in the midwest. Grown with heavy pesticides and processed insanely.

    Thanks for the post. I love it!

  5. I have been allergic to soy for over thirty years. It is in almost everything these days. It is one of the top eight food allergies, so why is it one of the top additives? I have been cooking from scratch consistently since last November due to a new nutritionist that doesn’t allow any food additives, anything that is chemical sounding in food, including artificial sweeteners. I am doing this because I have a lot of weight to lose, but I am focusing on long term changes in food. I haven’t had carbonated drinks since November, I have wanted salads and vegetables instead of the less healthy carbs, and now my body won’t tolerate fried foods at all. Your body wants changes and will help you if you are serious about this.

  6. My granddaughter (who actually had very little exposure to soy other than in processed foods) has developed a soy allergy my son had the same thing happen to him when he was around 5 (again no big exposure). It has made us very aware of how many food products include soy in them. My daughter has actually found that it is extremely difficult for them to eat in restaurants or even order take out food because most of it has some soy in it. Soy is in things like bread that it didn’t used to be because it is cheap. Government subsidies have made soy a cheap food source and an easy way to extend food with a cheap ingredient. We either make our own bread products or buy local breads that don’t include soy when my dd and gd are around. My daughter makes her own pizza dough, her own tortillas, etc. because all of the commercial ones have soy. Nearly all chocolate also has soy lecithin in it. We’ve found only a very few types that don’t, other than straight cocoa powder of course.

    What has been really frightening is the expansion of soy in processed foods. When we had to eliminate soy from my son’s diet it was a much smaller deal than it’s been for my granddaughter. The number of products that didn’t used to have soy and now do is really really shocking.

    All of this really encourages us in our “cooking from scratch” resolve.

  7. It is so great to hear someone else expressing concerns over soy. My son would not breastfeed and the nurses in the hospital decided he was lactose intolerant and switched him to soy formula within a day of his birth. Being uninformed at the time, I continued with the soy formula until we took my son, at about 9 months, to a Dr who practiced both mainstream Western medicine and holistic Naturopathy. It was she who advised us to take my son off of soy formula because of the hormone reasons mentioned in this post. I mentioned to her that when my son was about a month old, he had milk leaking from his breasts. His pediatrician at the time told me it was normal because he was “coming off” of my hormones. But the naturopath and I both now believe it was from his little body being bombarded with the phytoestrogens from the soy formula. My son is now almost 4. Last year we had him tested for allergies and found out that he has a low-grade soy allergy. So those nurses could have potentially put his life in danger by switching him.

  8. Katie H says:

    First, I want to say that in general I agree that overconsumption of soy is not a good thing. Anything can be abused but that doesn’t make it definitely and completely bad. I agree that soy is not my preferred source of “dairy-like” nutrition. But…I now have a young daughter who is allergic to cow milk protein. Rice and almond milks are simply not nutrition dense (fat and protein to be specific) enough to be a viable alternative at this time. Other animal milks are usually just as intolerable as cow’s milk in those who are allergic to them. All food sources have their place. Abuse of any of them can and usually will cause problems .

    Regarding thyroid function, one poster was concerned that her post pregnancy hypothyroid was caused by her soy consumption. I also am hypothyroid. For me it was Hashimoto’s Thyroiditis. In this, the thyroid can be high and low in cycles for years and then in finally craps out. Often right after a pregnancy. This is quite possibly what happened. They aren’t sure why this timing exists but that it’s likely due to the dramatic hormonal changes we go through after delivery. Our hormones (estrogen etc….) and thyroid are so connected! Rest assured it would have happened at some point pregnant (soy) or not. (as an aside, now that I’m on thyroid replacement, I don’t have PCOS symptoms anymore, I have regular periods, stopped miscarrying, and get pregnant easily). For history I was BF and never drank soy milk.

  9. Elizabeth says:

    My mom is soy intolerant. She doesn’t live with me, but I have a tendency to keep an eye out for it and avoid soy anyway. I’ve also read this information on soy in the book “150 Healthiest Foods On Earth.” Very interesting. I think we Americans have a tendency to latch on to the latest and greatest “superfood” in the hope that if we consume enough of it, we don’t have to worry about our diets filled with fast food, processed food, etc. Change is slow going in my house, but it is going.

  10. Thanks for posting on what I have long suspected. I was visiting one of your pages via a google search for tshirt repurposing. When I saw the link for dangers of soy I had to check it out. I have been suspicious of soy ever since the hoopla of its benefits for postmenopausal women. Exactly what you stated in point number one. I simply chose to avoid it personally. I have mentioned my concerns to a few close friends. Thanks for speaking up on this!

  11. While avoiding the obvious soy products like soy milk, tofu, soy based formula and meat substitutes is a good start, there is so much hidden soy in almost everything we consume it’s scary. Soy byproducts are used in most commercial cereals, baked goods, mixes, even heavy cream and chocolate bars and other things you’d never dream of it being in. The following items frequently seen in ingredient lists are cover-up names for soy by-products:

    Monosodium glutamate or MSG
    Hydrolyzed plant protein or HPP
    Hydrolyzed vegetable protein or HVP
    Vegetable oil
    Vegetable shortening (like Crisco and the other solid white shortenings in a can)
    Vegetable broth
    Protein concentrate
    Protein isolates
    Guar gum, vegetable gum
    Gum arabic
    Glycerol monostearate
    Natural flavorings
    Thickening agents
    Liquid smoke
    Vitamin E
    Citric acid (can be derived from fruit, corn, or soy)
    Thiamine mononitrate

    Read all labels carefully….the rule of thumb is the more processed it is, the greater chance of it having some form of soy in it even if it’s not obvious. And, some manufacturers aren’t even required to list certain ingredients if they are considered “proprietary!” Hence the vague and ubiquitous “natural flavors” seen on ingredient lists. And that’s not even including the soy byproducts that are in our beauty and hygenic supplies…..lotions, creams, shampoos, makeup. It’s literally EVERYWHERE.

  12. We have had store bought cow’s milk, raw cow’s milk, soy, rice, almond…
    It’s interesting that you would pick cow’s milk over soy. A pregnany cow would have much more estrogen (mammal estrogens, not plant estrogens) in her system than any soy beans. Just like eating red meat, it wou add even more horomones to your body (even from an ‘organic’ cow) than you’d be hoping for.
    I’ve battled with endometriosis for years and avoid all forms of meat and animal milk now, and never had soymilk or many soy products growing up. My son gets a combination of organic foritfied soy and almond milk now instead of cow’s milk.
    Every plant contains phytoestrogens, broccoli is also loaded with these imitation estrogens, as well as all grains, fruits, and nuts. Consumption of phytoestrogens from other sources of fruits and veggies is four times higher than that of soy.

    While I agree with the dangers of over-comsuming anything, this seems to be just one side of the story :(

  13. Very interesting post, I’d never really considered this before. I am a HUGE soymilk drinker. I have a question then, what do you think about cows milk, because hearing all the negative things about drinking that was what originally made me switch to soymilk. I suppose a cup of cows milk every now and then would be more natural than soymilk?? It’s so hard to know what to do when there’s so much information out there.

  14. Thanks for reminding me of the dangers of soy. I first learned about it in the book, The Mood Cure by Julia Ross. We have been using soy milk for a while now since we decided to go vegetarian in nearly all our meals. We also drink almond milk and coconut milk. I will be eliminating soy milk (there will be weeping and gnashing of teeth from my kids).

  15. Great site! I have already bookmarked your page…Now I don’t have enough time to read on,however, by skimming through I must say…I’m impressed.

  16. THANK YOU! I have been convinced of this for so long and am so thankful that people like you and scientist are finally beginning to weigh in on this!!

  17. great article at putting many concerns with soy in understandable language. I have friends that are very knowledgeable about nutrition and shared this with me a few years ago. however, I tried almond milk and was appalled by the amount of sugar in it. I’ll stick with regular milk for now. we don’t drink much of it and only have cereal a few times a week so I’d rather do that.

  18. We were big into soy in this house until about a year ago. My daughter, now 11, was raised on soy formula, then soy milk, soy yogurt, soy ice cream, “vegetarian” entrees made from soy, etc. My daughter has steadily gained weight over the years to the point now of obesity, and I always wonder if it wasn’t the constant soy that messed her up (thyroid?) from the inside out. Wish I could tell every parent “don’t do it!” when it comes to soy…
    .-= lisa´s last blog ..Enchilada Salad =-.

  19. Thanks for raising awareness on this important topic! Is there such a thing as an “acceptable” amount of soy, an amount that won’t do much damage? It’s easy to avoid it when eating at home, but I also live in China, and when eating with local friends it’s impolite (and culturally insensitive sometimes) to turn down foods that they offer. Like someone who commented above, from what I’ve observed, the local Chinese I know here do consume a lot of non-fermented soy products: there are soy milk stands everywhere, all kinds of soy milk makers available in stores (one of the hottest appliances around here!), not to mention lots of tofu dishes offered in restaurants and homes. So it will be unavoidable to consume some, but I just want to know, for peace of mind, what is too much!?! Thanks!

  20. I was given soy formula as an infant and was diagnosed at age 27 (I’m 29 now) with hypothyroidism. I’m wondering if there is a connection. Thanks for this detailed article!

  21. My 2 cents worth. I am an ovarian cancer survivor with a BRCA 1 mutation. Breast and ovarian cancers can be estrogen receptive. I avoid all soy in hopes of preventing a recurrance. Just a warning.

  22. We don’t consume soy, either. And for those wanting a milk substitute I’d highly recommend coconut milk.
    .-= Kate´s last blog ..Early Signs of Bad Health =-.

  23. Not related to soy, but I saw a commercial this weekend that compared 2% milk to french fries – stating that they had the same amount of fat. Even if that were true (and I doubt it), you can’t tell me that french fries have the same nutritional value with all that grease and salt as milk! Made me so mad I wanted to spit! (commercial was for some low-fat, “healthy” milk brand).

  24. Great topic! We stopped soy several years ago, even my kids thought Mom had gone bonkers.
    But as more info came out they finally jumped onto my bandwagon. I have a daughter with thyroid problems, and just recently have met many young women with the same thyroid problems in the same neighborhood. One of them cut soy out of her diet and is totally recovered. We live on what used to be croplands, so we worry about what pesticides were used. What kind of dirt did my kids play in…
    We still meet many people who think soy is wonderful, the magic health food. We play it by ear on whether to mention our opinion. Even then, I just state what we do, and encourage people to do their own research so they can make a wise and educated decision.

  25. Deborah Duke says:

    My son is allergic to dairy (including goat’s milk). He is also allergic to nuts, eggs, wheat, and anything else with gluten. Needless to say, soy has been a part of his diet, and when we are cooking for everyone, it becomes a part of the entire family’s diet. Should I be looking into rice milk as an alternative?

    Also, if you have any suggestions for a substitute for butter, I’ve been wondering about that for some time. :)

    • @Deborah Duke, I would definitely check out rice milk or possible hemp milk. Also, depending on how you’re using it, coconut oil and coconut cream can be a good substitute for butter – or sometimes people can tolerate ghee even if they can’t tolerate butter. Hope that helps! We can”t do gluten either so I know a little bit about food allergies – it can be so frustrating. Good luck!