Soy is one of our biggest mistakes as a food source. In North America it is used by many vegetarians as a complete source of protein. Soy has traditionally been a part of Japanese and other Asian countries’ cuisine. So what went so wrong when it made its way into Western diets?
First we need to understand how soy is consumed in Asian countries. If we use Japanese cuisine as an example, it can be seen that much of the soy consumed is in fermented form such as soy sauce, natto, tempeh or miso. It is consumed as a condiment in small amounts, and is eaten together with iodine-rich foods such as fish, seaweed or stocks made with these foods.
Unfermented soy is found in tofu, soy milk, soy formula and many processed, packaged foods.
Mistake #1: Eating Unfermented Soy
In North America and other western countries we tend to use unfermented soy products such as tofu, or products made from isolated soy protein powder such as soy milk, soy infant formula, imitation meat products and as an emulsifier in many packaged foods.
Unfermented soy is high in phytates and lectins, which can be problematic for human health.
Phytate (or phytic acid) is a substance that is particularly high in soy and that binds to minerals such as iron, magnesium, calcium and zinc, making it difficult for us to absorb these minerals, contributing to mineral deficiencies. (1)
Soy contains a lectin called agglutinin. This lectin has been well researched for its effects on intestinal permeability (leaky gut)(2)(3)(4). Want to make your gut leaky? Eat unfermented soy!
Phytates and lectins get broken down by fermentation, which makes traditionally prepared soy foods a better option for mineral absorption and gut barrier integrity. As a bonus vitamin K is formed during the fermentation process, so you get some additional nutrient value from fermented soy.
Fermentation increases histamine though, so would not be suitable for anyone with Histamine Intolerance or Mast Cell Activation.
Mistake #2: Not Eating Soy with Foods Containing Iodine
Iodine rich seaweed and fish.
Another problem with soy is that it can impact your thyroid function(5). Soy is considered to be a goitrogen. Goitrogens interfere with iodine uptake in the thyroid. When your thyroid gland can’t take in iodine it can’t make thyroid hormones. Thyroid hormones affect every cell in the body, so a reduction is problematic, especially for things like weight management, energy levels and body temperature.
These effects can be offset by consuming iodine.
For this reason, soy should be consumed with fish, seafood or seaweed, as has always been done in Asian cuisine.
Fermentation actually increases goitrogenic activity (6), so if you have existing hypothyroidism, stay away from soy!
Mistake #3: Eating Soy as a Main Source of Protein
Have you ever seen someone eat a soy burger or maybe a soy hotdog? Chug down a glass of soy milk? Add some soy cheese to their sandwich at lunch? Maybe that is or was you.
That starts to add up to a lot of soy. Mistake #1 and #2 have outlined why soy can be problematic for your health, but factor in the quantity that some people are eating and those problems just get bigger.
Asian cultures have always used fermented soy as a condiment, yet somehow when Western countries decided to embrace soy they thought that it would be good to consume large amounts. I’ve been there, so I speak from personal experience.
I used to make chilli from a tofu and seasoning blend. I’d fry up slabs of tofu to go with dinner. And I’d eat the occasional imitation meat product (but that was rare, because they were pretty gross!) I tried soy based cheese too — also gross!
I can’t help but wonder now if my hypothyroidism didn’t begin when I was a vegetarian in my 20s, and regularly consuming tofu.
Mistake #4: Eating Highly Processed Soy
Soy oil gets used in a lot of industries to make adhesives and sealants. Plastics can be made from soy oil as well and are used for things like the seats in your car and the wire insulation in your car. It can also be used in body care products such as soaps, lotions and cosmetics.
To get the oil from soy it has to be heavily processed by hexane extraction, degumming and refining. The leftover defatted product is the soy protein that gets added to our foods.
It’s this protein that gets used in infant formula, soy milk, imitation meats, and as an emulsifier in many processed, packaged foods. This processed soy is still high in lectins (7), and I’m guessing very few people are adding iodine containing foods to their imitation meat meals to make them safer for thyroid health.
The companies producing soy oil are pretty happy though. They get to sell off what would otherwise be garbage. As a nutrition practitioner I don’t recommend eating heavily processed foods of any kind, including industrial waste products.
If you want to find out more about the damage plant-based meats are having on our environment and our health then I would encourage you to watch the Sacred Cow documentary or read the book of the same title. I liked the book better, but I always do. It is well researched and backed by good scientific literature.
Mistake #5: We Made Soy an Environmental Disaster
In 2018 94% of all soy planted was GMO (genetically modified). GMO soy is specifically modified to be able to withstand the herbicide Roundup (the active ingredient is glyphosate). It is designed this way so that crops can be heavily sprayed to kill weeds without killing the soy plants themselves.
Glyphosate shows up in our soil, water, plants and animals. It was considered to be safe, but current research is showing that it is damaging to microbes in soil (8), to the entire animal kingdom, (9), and to human health (10). Glyphosate can trigger an immune response and mast cell degranulation, resulting in inflammation (11).
As plants develop glyphosate resistance, alternative herbicides such as dicamba get used, and soybeans are now genetically modified to withstand dicamba. Dicamba comes with its own impacts on plant life, and farming communities(12).
Summary
Traditional food preparation methods have a lot of wisdom built into them. Stick with them!
If you are going to eat soy, then eat organic, fermented forms in small quantities with fish, seafood or seaweed.
Don’t eat soy at all if you have thyroid problems, leaky gut, or histamine or mast cell related health issues.
Eat pastured or grass-fed meat! It’s a great source of complete protein, and doesn’t have any of the problems associated with soy. No phytates, no lectins, and it supports thyroid function and repairs leaky gut. And it tastes great!
The weather here is Calgary is turning spring-like, so why not ditch the soy and fire up the barbecue!
Happy, Healthy Eating!
Tracey