The topic of soy can create a big debate among healthy folks, and the viewpoints can be extreme. Who knew a humble green bean could be so controversial? Some tout soy products as a panacea for health and wellness, while others swear that soy is a sure ticket to infertility and “man boobs”. What are the facts?

Aren’t Asian cultures particularly healthy because of consumption of soy?

Asians don’t actually eat as much soy as we think – only about 10-36 grams per day. In contrast, a cup of tofu or soy milk contains over 200 grams of soy. Besides, the most common soy foods in Asia are fermented products such as tempeh, miso and shoyu (soy sauce), while most Westerners eat unfermented, highly processed versions of soy. Unfermented soy contains enzyme inhibitors that block protein digestion (among other things we’ll get to below).

Isn’t soy healthy because it’s a natural plant product?

Most soy foods are highly processed and bear very little resemblance to the natural soybean (think soy hotdogs or TVP – textured vegetable protein). Just because something is touted as a “health” food, doesn’t really make it healthy. Whole foods are always the best way to get your food nutrition – the more processed a food is, the less natural and ultimately less healthy it is.

What’s so wrong with soy hotdogs and TVP anyway? Aren’t they good, protein-rich, meat substitutes?

Soy is more filler than food. For many years, the protein left over from the extraction of soy oil was sold to farms as animal feed. After some time, the food industry figured out how to make this highly processed soy protein palatable to the human tongue and began to aggressively market it in foods like soy dogs, soy meat substitutes and the like. Sure, there’s protein, but it also takes quite a bit of sugar, salt or MSG to make soy protein actually taste good. The healthiest foods are whole foods, not processed ones.

How will a diet heavy in soy impact my health?

Unfermented soy can inhibit protein absorption, cause flatulence and increase the chance of developing kidney stones. The processing of soy may remove some of these problems. Soy also inhibits growth. Even within the animal feed industry, the amount of soy protein that can be fed to animals has to be limited or the animals themselves will suffer problems with growth and fertility.

What’s up with genetically modified soy?

Most soy grown in the world is genetically modified (GM) – with 87% of American soy being GM. And what’s the big deal about that? Not a lot of research has been done on the effects of GM foods, but one particular study on rats showed that unborn babies and young infants were particularly harmed by the effects of genetically modified soy.

But aren’t a lot of infants fed soy-based formulas?

Soy infant formula, a common alternative to cow’s milk for lactose-intolerant babies, contains endocrine disruptors and phytoestrogens, plant hormones which have been shown to cause premature puberty in young girls and delayed puberty in adolescent boys. It’s a bit like giving a baby birth control pills. Soy infant formula also contributes to soy allergies. (Breast milk is undoubtedly the best food for babies, and if that’s not an option, goat’s milk is the next best thing to try.)

Speaking of allergies…

Soy is among the 8 most common food allergens, with reactions being particularly common among children.

Would this have anything to do with pesticides?

That remains uncertain. However, unless you buy strictly organic, you can bet your soy products are heavily contaminated with pesticides. As a matter of fact, soy is the most contaminated crop we grow in the United States. And don’t forget, non-organic soy is almost certainly genetically modified as well.

How has the demand for soy affected the Amazon rainforest?

The huge global demand for soy (for use in processed foods, animal feed and biofuels) is eating up the rainforest, because farmers have been financially motivated to clear more rainforest land in order to plant this export crop. More deforestation, more global warming.

But still, aren’t soy farms providing jobs?

Actually, for many, soy farming is less like employment and more like slavery. Although slavery was officially outlawed in Brazil over 130 years ago, debt bondage for over 25,000 people continues on Brazilian soy plantations. This is not the kind of farming industry I want to support.

Bottom line: soy is not the magical health food that many tout it to be. Let’s be clear, however, that fermented soy products don’t carry the same negative consequences as unfermented, highly processed soy foods. So if you’re shopping for miso or tempeh, make sure to choose brands that are organic and not genetically modified. And if you’ve been depending on tofu (an unfermented food) for vegetarian protein, try out some of these other vegetarian proteins instead.

Image: Umeboshi Panda

Soy: It’s everywhere. It’s eaten in copious amounts by bodybuilders, as a meat substitute by vegans and vegetarians, and unwittingly in a wide variety of processed foods by most people.

We’ve been told that soy is good for us and the fact of lower incidences of cancer and heart disease in Asian populations is cited as proof. The truth is there is no historical precedent for the amount of soy we consume in modern processed foods. Though soy did originate in Asia, it is used sparingly in Asian cuisines and more often in its traditional forms, like miso, tofu, natto, and tempeh.

According to the United Soybean Board’s own website, soy protein (processed soy) serves as a functional ingredient in the following foods and for the following applications:

Baked Goods – used to hold moisture, extend shelf life, improve texture and mouthfeel, and improve manufacturing, handling, and machine ability.

Breakfast Cereals – used to boost protein value and quantity.

Pasta – to boost nutritive value, especially in school lunches.

Beverages and Toppings – to whiten coffee creamers, emulsify, provide texture, and add protein content.

Meat, Poultry and Fish Products – to enhance moisture holding, texture, cohesion, yield, shelf life, and nutrition.

Dairy-Type Products (scary in itself) – soy protein lowers cost, improves nutrition and reduces allergenic response.

Here’s a quote from the Soybean Board website: “Processed and whole meat products can be improved by adding soy protein, which provides the product flexibility and cost stability consumers demand.”

Now, from the list of uses above and this quote, it looks to me like soy protein is a mighty functional food for the food processing industry. How did so many consumers become convinced that soy protein is a functional food for them?

Nearly 60 percent of the foods sold in supermarkets and natural food stores contain soy. Much of this is disguised in cookies, crackers, burgers and other meat products. It’s also a main ingredient in protein bars, meat substitutes, and any number of other foods.

Why is the food industry putting soy in everything?

If we look at how soy protein is made, it might give you some idea.

After soy vegetable oil is made, there is a lot of soybean meal left over. This defatted soybean meal is mixed with an alkaline solution to remove the fiber, and then washed in an acid solution to separate out the protein. The protein curds are then dipped into another alkaline solution and spray-dried at extremely high temperatures. Then it is spun into protein fibers using textile industry technology.

The food industry has figured out a way to utilize a highly processed industrial byproduct by putting it in food to extend shelf life, yield, and nutritional content. And then they’ve funded a lot of studies and spent a lot of advertising dollars to convince us that this substance is good for us.

You’ve seen some of the conflicting research (summarized below). You’ll have to decide for yourself which studies you believe and what dietary decisions are right for you.

Personally, I’m sticking to real food as close to its natural state as possible and avoiding processed foods of all types. And when I eat soy, it will be in small quantities in its traditional forms. Check back on Friday for a recipe using tempeh, a fermented soy product that originated in Indonesia.

Here is a brief summary of the claims made on either side of the bean pod along with some links to help you do your own research. The truth usually lies somewhere in between.

The “Soy is good!” camp: Soy contains isoflavones that prevent cancer, heart disease, osteoporosis and more. Soy’s phytochemicals protect against heart disease. Men who drink two servings of soymilk every day are 70% less likely to develop prostate cancer. Soy is a low fat form of protein. Soy lowers bad cholesterol. Soy prevents breast cancer. Soy builds strong bones.

The “Soy is bad!” camp: Soy doesn’t lower cholesterol as much as we first thought. The estrogens in soy can lead to breast cancer. Soy can decrease sperm count and libido. Soy can prevent ovulation. Soy can cause thyroid problems, constipation and other digestive problems. Soy is a common food allergy.

Further reading:

Mothering

Soybean Board

Woman to Woman

Steady Health

Images: Obesityhelp