Fort Berthold Diabetes Program

Soy Foods – What You Need To Know

By Shelby Stein, RDN, LRD – Community Dietitian

Is soy healthy or should I avoid it? This is one of the common questions I receive as a registered dietitian. To answer this, I am going to provide a look into soy and discuss some of the common myths and facts related to soy. The soybean is part of the legume family and is native to Eastern Asia. Soy is grown by farmers throughout the United States due to its edible bean, which is used to produce many food products, consumer goods, and animal feed. This article is going to focus on edible soy foods and human health. Soy beans are high in protein, fiber, heart-healthy fats, iron, and other vitamins and minerals. The protein in soybeans contains all of the essential amino acids, which makes the protein quality very high and similar to that of animal proteins. 

We can think about soy foods in three categories, traditional soy foods, soy-based foods, and soy ingredients. Traditional soy foods, most of which were traditionally consumed in Asia, are now becoming more popular in the U.S. These include tofu, tempeh, soymilk, edamame, miso, and soy sauce. Tofu is also known as soybean curd and can be for a variety of culinary uses; it comes in the form of a block that can be soft, firm, or extra firm in texture or can be silken, which results in a very creamy tofu. Tempeh is fermented soybeans formed into a block or cake. Edamame is the green soybeans; they generally boiled in the shell and the shell is discarded and the soy beans inside are eaten. Miso is a fermented soybean product used in cooking. Soy-based foods include soy-based infant formulas and soynut butter, which is a similar to peanut butter but made out of soybeans. Soy ingredients are found in a wide variety of foods. Soy flour is used in food products due to its high protein content (and it’s gluten-free). Soy lecithin is used in food manufacturing in foods that are high in fat or oil. Soybean oil can be used for cooking or in food products. Lastly, soy protein isolate results from highly refined soy and contains about 90% protein; this is often used in some protein supplements. Soybeans, soy flour, and soy protein isolate are commonly used to make alternative meat products such a veggie burgers. With all of the different options to consume soy, due to its high protein content, soy can make a great high protein meat alternative to increase your intake of plant foods and add some variety to your diet!

As you can see, soybeans can be used in a variety of food applications. Some types have minimal processing such as with tofu, tempeh, and soymilk; soy protein isolate is the most processed form of soy. Generally, the types of soy foods that are less processed are healthier options and should be consumed more frequently than heavily processed options. If you are concerned about consuming genetically modified (GMO) soybeans and soy products, purchase organic versions instead and this ensures that the soy is non-GMO. 

The health of soy can be a controversial topic and due to this there has been much research done on soy and health. Of important note, soy is a common allergen. If you have an allergy to soy it must be avoided and the following information regarding soy is not applicable. Some common myths around soy include: 1. that soy increases estrogen levels and cause increase risk of breast cancer and that boys and 2. men shouldn’t consume soy because it causes feminization. Let’s explore the facts around soy. Soy contains isoflavones which are phytoestrogens, or plant chemicals capable of exercising estrogen-like effects. The isoflavones in soy are able to bind the estrogen receptors in the human body. This might sound like a scary thing however, when these isoflavones bind to receptor sites, they can block the more potent human estrogens from binding to the receptor. This action may help protect women from breast cancer; moderate soy consumption does not appear to increase the risk of recurrence of breast cancer either. According to research, isoflavone- rich soy does not affect testosterone or estrogen levels in men when consumed in moderate amounts. Soy foods may also help to lower LDL (“bad” cholesterol) cholesterol levels. Soy foods can affect the thyroid gland in people who have hypothyroid or who have iodine deficiency. For people who have hypothyroidism or iodine deficiency, they should limit soy intake until iodine levels are sufficient and the dosage of thyroid hormone medication is properly adjusted. Then these individuals should work with their healthcare provider to make sure their dosage of thyroid medication stays appropriate if moderate soy intake is part of their regular diet. 

Based on what research has shown and what we know about the nutritional profile of soy, moderate soy consumption as part of an overall healthy diet is either neutral or actually beneficial for our health. What is moderate soy consumption though? Moderate soy consumption is considered one to two servings daily of whole soy foods, such as cooked soybeans, soy milk, tofu, edamame, or tempeh. A serving is considered one cup of soy milk, 3-4 oz or about ½ cup of tofu, or ½ cup of shelled edamame. Each of these standard servings of soy contains about 7 grams of protein and 25 mg of isoflavones. More processed soy foods (such as soy protein supplements and soy meat replacements) can be substituted for these daily servings of whole soy foods but should done less frequently. The health effects of consuming more than 100 mg of isoflavones per day is not known, so for now, stick with moderate soy intake to get the health benefits of soy. 

Most of us have tried soy milk but are less familiar with tofu and other soy products such as soy curls. Cooking with tofu can be intimidating and can take some experimenting to find what you and your family like. Tofu can be purchased in the refrigerated section of grocery stores in a rectangle container packed in water or found in a box in the Asian aisle in shelf-stable packaging. One way to introduce tofu is to add some to a fruit smoothie. Using the shelf stable silken tofu, combine about ¼ to ½ of a block with some frozen bananas and strawberries (or any fruits you like) and maybe some spinach in a blender and blend together until smooth. The tofu adds a great source of protein and makes the smoothie smooth and creamy!

If you’d like to set up an appointment with a registered dietitian for support in your nutrition and health goals or if you have additional questions on soy or would like help with how to incorporate soy into your diet, please give the diabetes program a call at 701-627-7931.