Understanding Soy: There are many myths and controversies surrounding the legume

What delivers quality protein, omega-3 fats, omega-6 fats, potassium, magnesium, iron and B-vitamins? It’s soy, a nutrient-rich legume (also called edamame) that is consumed around the globe. Today, it has expanded from just a soy bean or tofu into a wide collection of foods, including soy milk, soy sauce, tempeh, veggie burgers, soy protein powder and more.

Over time, soy has had a lot of confusion and controversy surrounding it. That confusion stems from several factors. Some studies on soy are done on animals, but soy is metabolized differently by animals. There are also many different types of soy foods and products, and they are not all created equally.

Let’s look at some of the most common soy myths and provide up-to-date facts and research.

All soy or soy products are the same.

Part of the confusion around the safety of soy is that there are many different types of soy foods and products, including fermented soy foods, non-fermented soy foods and soy ingredients. Fermented soy foods include: natto, miso, tempeh, soy sauce and fermented tofu. Non-fermented soy foods include: soy nuts, soy milk, edamame, soy flour and tofu. There are also soy-based ingredients, such as soybean oil, soy lecithin and soy protein powder.

Yet, when research is done on a soy product, the sharing of the results tends to boil down the whole group of foods and products as “soy,” rather than focusing on the specific food or product that was studied. This is important because not all foods that contain soy are the same; some ingredients are more processed than others and do not contain plant-based estrogens (known as phytoestrogens).

All soy is GMO (genetically modified organism).

There are many soy foods made from soybeans or soy ingredients that are non-GMO. If you buy soy foods or products that are USDA certified organic, this will ensure that they exclude GMOs, as USDA organic regulations exclude them.

Soy increases breast cancer risk.

The controversy around soy and breast cancer is largely because soy contains plant-based dietary estrogens, which have an estrogen effect on the body. Higher levels of estrogen in the blood are linked to an increased risk of breast cancer in women later in life. How is plant-based estrogen different? A big difference is that the plant compounds in soy exert a mild estrogen-like effect on the body.

Another piece of the controversy surrounding soy and breast cancer comes from a study with rodents that had a soy-supplemented diet. The study found that soy increased breast cancer in rodents. Yet, remember, animals metabolize soy differently than humans, so the data can’t be directly transferred or correlated to humans.

But research has found that there are positive, and even protective, benefits to including soy foods in your eating routine. For example, the Shanghai Women’s Health Study (American Journal of Clinical Nutrition 2009) found that women who consumed a high amount of soy foods consistently during adolescence and adulthood had a substantially reduced risk of breast cancer. Additionally, three studies that looked at a combined total of 9,000 breast cancer survivors found that eating soy lowered the risk of the reoccurrence of breast cancer, even in women with estrogen receptor-positive tumors.

The protective benefits of soy could be in part due to its antioxidant and anti-inflammatory properties.

Some soy foods or products are better to consume than others.

It is best to mostly consume nutrient-rich soy in the form of whole foods like edamame, roasted soybeans, tofu (bean curd), tempeh or soy milk. There is limited research on the impact of concentrated soy isoflavones and supplements (such as soy protein powder) on the health of men.

Tips on Incorporating Soy into your Eating Routine

When adding soy, focus on including mostly soy foods and beverages like edamame, tofu or soy milk. Minimize highly-processed forms of soy, such as soybased chicken nuggets or other meat substitutes.


Look for shelled or unshelled (in the pod) edamame in the produce or freezer section of the grocery store.

Edamame Preparation tips:

Steam the edamame until they are warmed through, then lightly sprinkle with sea salt and serve as a side dish or appetizer for a protein and fiber boost. You can also place the edamame on a baking sheet and sprinkle with a light drizzle of olive oil and garlic powder. Roast at 425 degrees for 15-20 minutes until they are lightly toasted. Finish with a little salt and cracked pepper.


Cooking tofu for the first time may seem intimidating, but when you learn quick and easy ways to enjoy it, it can be a great addition to your eating routine. Think of tofu as a blank canvas – it does not have much flavor and it will take on the flavors of what you cook it with. Look for tofu in the produce section or “health food” refrigerated sections at the grocery store.

There are different textures of tofu: extra-firm, firm, silken (soft). Extra-firm tofu is great for marinating, firm tofu works well for adding to stir-fry and silken is best to stir into dishes or sauté with vegetables to have as an “egg-like” scramble.

Tofu Preparation tips:

Remove extra-firm tofu from its package and place on clean towels or paper towels to absorb the liquid. Cut into 1-inch cubes and marinade in Italian dressing for 30 minutes. Next, cook the cubes of tofu in a skillet and turn throughout the cooking process until they are lightly browned. Serve on a whole grain roll with a drizzle of Italian dressing.

Soy Milk

You can drink soy milk in place of regular milk or even use it in smoothies. One cup of soy milk has 8 grams of protein. There are many different flavors of soy milk; opt for those
that are unsweetened to avoid added sugar.

Smoothie Recipe:

Blend 1 cup of unsweetened chocolate soy milk with one frozen banana (peel removed) and 2 tablespoons of creamy peanut butter. Blend until icy and smooth.

The bottom line is that whole soy foods can have beneficial effects on the body, likely because of the fiber, protein, nutrients and plant compounds they provide. Yet, as with most anything, if incorporating some soy foods is good, it does not mean that more is better.


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