Should we eat soy?

With all the soy hype and positive press a few years ago, I’d been making a conscious effort to include this so-called “wonder food” in my diet.  This all changed when I was enlightened during a 2-day wellness course a few years ago.  What I learned in that room has completely changed the way I look at food, corn and soy in particular.

I’d like to preface my spiel by saying this…what is written here is one foodie’s perspective who tries to make the best choices based on the information/research at her disposal.   Based on this, I’ve decided to eat soy in moderation and choose fermented soy products where possible.  

Read on and you’ll see why… 

Let’s start with the basics.

What is soy?   

Soy (or soybean) is a type of legume which is high in protein and contains plant-based estrogens called phytoestrogens.

A closer look:

1) Phytic acid present in soy, binds with certain nutrients and inhibits their absorption in the intestinal tract. 

  • Phytic Acid or phytates are a fiber present in the bran or hulls of all seeds.
  • Non-fermented soy products have one of the highest phytate levels of any grain or legume.
  • Essential minerals whose absorption is impacted include calcium, magnesium, copper, iron, manganese and especially zinc (the “intelligence mineral” is needed for brain and nervous system development and functioning).
  • Phytates in soy are highly resistant to normal phytate-reducing techniques such as long, slow cooking.  Only long periods of fermentation will greatly reduce soy’s phytate levels, but will not eliminate them.  See below for examples of fermented soy products.
  • Note:  It’s not just soy. Phytates are present in all grains and legumes.   In fact, grain and legume-based diets high in phytates contribute to widespread mineral deficiencies in third world countries. 

2)  99% of soy is genetically modified (GM)

  • As we know from the GMO post, bacteria, viruses and other genes have been artificially inserted to the DNA of soy, corn, cottonseed and canola plants.  
  • The risks of genetically modified foods are still unknown but could include triggering allergic reactions and others.

3)   Soy has one of the highest percentages of pesticide contamination

4)   Soy may impact thyroid function

  • Some research suggests that soy blocks actions of the thyroid and can lead to hypothyroidism (4 TBSPs a day can have an effect on your thyroid).  Isoflavones are inhibitors of the thyroid peroxidase which makes T3 and T4.
  • This is most likely to occur in that segment of the population that is iodine deficient. For some, soy can inhibit their body’s ability to absorb thyroid medication properly.

5) Soybean contains large quantities of natural toxins

  • These include potent enzyme inhibitors that block the action of trypsin and other enzymes needed for protein digestion.

6) It doesn’t stop there…

  • Soybeans contain hemagglutinin, a clot-promoting substance that causes red blood cells to clump together.
  • Soy infant formula has estrogen which can cause early puberty.  Children fed soy have 20,000 times the amount of estrogen in their body.  It’s like giving that baby 5 birth control pills per day! 
  • Soy foods are processed with hexane (this is a gasoline product and an environmental pollutant).  Hexane is used to extract the oils from the soybean itself.
  • The negative effects of soy have most often been observed when consumption levels exceed 30 mg, the amount of soy isoflavones found in just 5-8 ounces of soy milk.

I also learned that the American Heart Association backtracked on its earlier support of soy, and is now saying that there is no evidence that soy has specific benefits for heart health or for lowering cholesterol.

What to do about it?

Try to limit non-fermented soy products including: 

  • Tofu and TVP (Textured Vegetable Protein) – they are loaded with MSG and aluminum
  • Fresh green soybeans
  • Whole dry soybeans
  • Soy nuts
  • Sprouts
  • Soy flour
  • Soy milk

Instead opt for fermented organic soy including: 

  • Natto
  • Miso
  • Tempeh
  • Tamari (soy sauce)
  • Fermented tofu and soymilk
Danielle Binns, CNP, BA