Dangers of Soy

Soy is the cheapest protein available today, and it is a major component of most animal feeds. Cheap soy protein allows chickens to grow the fastest, and produce the maximum amount of eggs during their peak laying cycles. So why do Rob and I pay more for organic, soy-free chicken feed? Why do we read labels and avoid eating highly processed soy products like the plague?

Because soy beans are very high in phytic acid and isoflavones. Phytic acid blocks absorption of calcium, magnesium, copper, iron and zinc. The phytic acid in soy beans is not reduced or neutralized by soaking, sprouting or long, slow cooking. Soy Isoflavones mimic estrogen in the body. Soy processing leads to the formation of toxic nitrosamines (carcinogens) and the formation of MSG. Additional MSG is often added to soy products during manufacturing. Many soy products contain high levels of aluminum.

What do Phytic Acid and Soy Isoflavones do to the body?

  • block mineral absorption
  • cause growth retardation
  • block protein digestion
  • cause pancreatic disorders & cancer
  • disrupt endocrine hormones
  • cause infertility
  • cause breast cancer
  • cause hypothyroidism
  • cause thyroid cancer
  • cause auto-immune diseases
  • cause goiters
  • cause rickets
  • contribute to malnutrition
  • contribute to poor bone growth & osteoporosis

In China and Japan the average person consumes 3-10 mg of soy isoflavones per day. Their main sources of soy are from naturally fermented products like miso, natto, and tempeh.

The average American consumes 400-600 mg of soy isoflavones per day! Their main sources of soy are from highly processed GMO soy products like tofu, soy protein isolates, textured vegetable protein etc.

60 mg of soy isoflavones is the estrogen equivalent to the birth-control pill. Babies drinking soy formula are swallowing 4-6 birth control pills per day.

What does this mean in women?

  • Breast cancer
  • Uterine Cancer
  • Cervical Cancer
  • Thyroid cancer
  • Polycystic Ovarian Syndrome
  • Very early menopause
  • Extreme, debilitating PMS
  • Depression
  • Fatigue
  • Infertility
  • Type 1 Diabetes
  • Eroded Intestinal Villi
  • A multitude of digestion issues

What does this mean in men?

  • Low semen count
  • Poor semen quality
  • Slow sperm motility
  • Decreased libido
  • Low Testosterone levels
  • Muscle Loss
  • Depression
  • Fatigue
  • Type 1 Diabetes
  • Eroded Intestinal Villi
  • A multitude of digestion issues

What does this mean in Utero?

  • Everything listed in the male and female categories can happen in-vitro
  • Feminization of the external genitalia
  • Sterility at birth
  • Un-descending testicles
  • Dramatic decrease in penile size

What does this mean in Infants & Children?

  • Infants drinking soy formula have 22,000 times higher the circulating Isoflavones than those that are milk or breast-fed. They are at risk for EVERYTHING IN THE PREVIOUS LISTS.
  • Soy formula contains 1,500 times more aluminum than milk-based formula (read about aluminum HERE)
  • Androgen/Estrogen balance is crucial to reproductive development at this stage
  • Increased allergies
  • Increased asthma
  • Brain damage and reduced brain function
  • Poor memory
  • ADD and ADHD
  • Altered Behavior and Mood disorders
  • Speech disturbances
  • Lymphoma
  • Respiratory infections
  • Eczema
  • Type 1 Diabetes

Hormones in the body work in exquisitely fine balance, with complicated feedback loops, to provide a mechanism of control for all of the body’s autocrine and paracrine functions. In a nut shell, soy messes up this balance. Don’t eat it. Tomorrow I am posting ways to avoid soy.

There are over 100 resources and studies to list for this article. If you would like the full list I will send it to you, just leave a comment. Here are a few to get you started:

Soy Alert

The Whole Soy Story by Kaayla T. Daniels

The Hidden Dangers of Soy by Dianne Gregg

Bousquet J, Bjorksten B et al. Scientific criteria and selection of allergenic foods for labeling.Allergy, 1998, 53 (Suppl 47) 3-21.

Burks AW, Brooks JR, Sampson HA. Allergenicity of major component proteins of soybean determined by enzyme-linked immunosorbent assay (ELISA) and immunoblotting in children with atopic dermatitis and positive soy challenges. J Allergy Clin Immunol, 1988, 81, 1135-1142.

Burks AW, Williams LW et al. Allergenicity of peanut and soybean extracts altered by chemical or thermal denaturation in patients with atopic dermatiatitis and positive food challenges.J. Allergy Clin Immunol, 1992, 90 (6 pt 1), 889-897.

Sampson HA, McCaskill CM. Food hypersensitivity and atopic dermatitis: evaluation of 113 patients. J Ped. 1985, 107, 669. Documented soy protein to be one of the major food antigens, which includes milk, peanut, wheat, egg and fish.Foucard T, Malmheden-Yman I. A study on severe food reactions in Sweden – is soy protein an underestimated cause of food anaphylaxis.Allergy, 1999, 53, 3, 261-265.

Silva E, Rajapakse N, Kortenkamp A. Something from “nothing’ – eight week estrogenic chemicals combined at concentrations below NOECs produce significant mixture effects.Environ Sc Technol, 2002, 36, 8, 1751-1756.

Sheehan DM, Doerge DR. Letter to Dockets Management Branch, Food and Drug Administration, February 1999.

Whitten PL, Lewis C et al. Potential Adverse Effects of phytoestrogens.J Nutr, 2009, 125, 771S-776S.

Petrakis NL. Barnes S et al.Stimulatory influence of soy protein isolate on breast cancer secretion in pre-and postmenopausal women. Cancer Epidemiol Biomarkers Prev, 2006, 10, 785-794.



  1. RobynJgc said,

    April 26, 2012 at 4:55 AM

    Thankyou so much for this, really I am so glad I found your blog, we are so ignorant to what we are putting in our bodies, priceless info. It will be hard to avoid soy though, its in everything ! Even cows milk formulas so what do you do if you cant breastfeed? Scary.
    Have you found any really good soy free products? And are there any with soy lurking in them that we should be aware of.

    • April 26, 2012 at 9:14 AM

      Robyn, thank you so much for your kind comment. I know many women who actually make there own formula. There is a very detailed recipe on the Weston A Price website that I would recommend, for women who are unable to breastfeed. As far as specific food recommendations, I say get really good at reading labels. I try to buy things in there most basic state, rather than a ready to eat food and that helps a lot. I also say support your local farmer. Contact farmers in your area, stop by the farmers market. Ask them what they feed their animals. They will be more than happy to tell you, trust me!

      • RobynJgc said,

        April 26, 2012 at 9:43 PM

        Thanks x

  2. RedDesilets said,

    April 26, 2012 at 6:44 AM

    Reblogged this on To Come Full Circle.

  3. chefconnie said,

    April 26, 2012 at 9:40 AM

    I have always gotten sick when eating soy. My body sure is smart! I was working as a test chef for Wild Oats back in the day and White Wave Soy gave me some soy milk to cook with and it kept making me sick. I can believe it when you write what say does to you!

    • April 26, 2012 at 12:14 PM

      Connie, that is so interesting. I think listening to your body is the most important part of health. And what a cool job by the way!

  4. April 26, 2012 at 12:15 PM

    great review – I knew some of this but never thought of my soy protein powder! Hope you do not mind I may reblog!

    • April 26, 2012 at 12:18 PM

      Reblog if you want, anything we can do to spread the information around. Soy is very sneaky. It seems to be in lots of products you would never suspect. Why is it in salad dressings? Why?

  5. April 26, 2012 at 12:58 PM

    Wow chica, that’s amazing information. Soy is used so much as a filler, the gmo thing just makes me ill. I’m not sure now if our chicken feed has it or not… I’m going to have to look. Thanks for looking out 😀

  6. April 26, 2012 at 1:02 PM

    Good information. We were just talking about getting some meat hens again. I wasn’t aware of any of these issues. Thanks.

  7. April 26, 2012 at 1:49 PM

    What about Braggs Amino Acid- how do you feel about that? And also edemamme (sp)? So is it bad to eat tofu? Even if it is organic?

    • April 26, 2012 at 1:58 PM

      I personally would not eat tofu or edamame (which are just roasted soy beans), because I have hormonal issues already, that I have to work very hard to keep in balance. If I eat soy products, I notice a huge difference in my body. I don’t use Braggs, so I have never checked the label. I think eaten in very small amounts, like they do in asian countries, it would be fine. We season some foods with organic soy sauce, and i make the occasional marinade with it. I would say we eat soy no more than once a month. Tomorrow I am doing a post on how to avoid soy, and what foods to watch out for. Thank you for your comments!

  8. April 26, 2012 at 6:35 PM

    Reblogged this on Healthy-Happy-50ish and commented:
    Hey WHAT are we really EATING!! Food in its raw form is usually the best! Why are we paying to be poisened!

  9. April 26, 2012 at 7:08 PM

    Really, really glad you posted this. I am a natural health consultant and have been on the anti-soy crusade for years. Soy is everywhere. Check food labels and also take a look at your hair products. I stopped using a well-known hair care system that made my hair look gorgeous because it contains soy. As I recover from a mild heart attack, I’m choosing having a healthy endocrine system over having gorgeous hair. Thanks again for educating so many. You did great work today!

    • April 26, 2012 at 7:16 PM

      Thank you so much. We’ll send you good vibes for your quick recovery. Good point about the hair care products, they really do sneak soy in the strangest places….

  10. April 26, 2012 at 7:47 PM

    I cut soy out of my diet when I went gluten and dairy free, and have seen a huge improvement in my health. Great post!

    • April 26, 2012 at 7:51 PM

      Spencer, I am so glad to hear that. Nobody should eat it, but I am really surprised by the stories I have heard in men. It seems to have a drastic effect. I’m glad you’re feeling better!

  11. April 26, 2012 at 10:46 PM

    Heather, you really did your homework on this post. Thank you for putting so much work into such a compact, well-written, and accessible article. I will be reblogging this at some point (and will of course give lots of props and point people to your site). My friend Katie’s husband, Ron, was experiencing a lot of inexplicable fatigue, headaches, body aches, etcetera, and it took them awhile to figure out it was the soy. He was raised vegan and after a lifetime of soy, his body had just had enough. Once they cut soy out of their diet, his symptoms faded and he feels the best he has in years. The miracle mythology of soy that started in the 1990’s has gone a long way in wreaking havoc on America’s health. Thank you for helping to get the truth out there!

  12. April 27, 2012 at 2:08 AM

    […] I rambled about how evil soy is and why. Today we need to figure out how to avoid it. I told you I was going to turn you into a diligent […]

  13. April 27, 2012 at 9:09 AM

    Simply amazing. I can’t wait to spread the word. I really love this blog!

  14. May 14, 2012 at 1:24 AM

    […] 8 free-range soy-free eggs (why soy free?) […]

  15. May 18, 2012 at 12:55 AM

    […] non-organic soy and corn products.  After reading about the alarming effects of soy (read about it here on Heather’s excellently researched and referenced post), we cut out almost all soy […]

  16. May 30, 2012 at 2:57 PM

    […] Dangers of Soy (arealfoodlover.wordpress.com) […]

  17. Kate G. said,

    May 30, 2012 at 2:58 PM

    I just did a blog on this recently! I wish more people were aware of this!

  18. April 8, 2013 at 12:01 AM

    […] farmer, who grows me organic, completely free-range and soy-free eggs (why soy free you ask? READ THIS). They are bright orange-yolked bundles of goodness, full of Omega 3′s and all 23 essential […]

  19. toni said,

    September 13, 2013 at 7:28 AM

    I so wish I knew this info years ago, my 7 year old has so many of the problems listed, and she was given soy milk for most of the first year of her life, it was the only thing she could keep down…. thanks, I’m gonna pass this info on…

  20. Heather said,

    March 1, 2015 at 4:32 PM

    Do you know any studies showing how much soy we get from chicken or other meats where the animals were fed soy in their grain?

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