Soy Protein and Soy Isoflavones

Soy foods are popular because of the many health benefits they provide.
Photo credit: Mc559, Flickr User, Creative Commons

Photo credit: Mc559, Flickr User, Creative Commons

Nutrition Information

Soybeans are a low-cost source of protein with a rich-nutrient profile. The popularity of soy foods has increased because of the health benefits they provide. Soybeans are 40 percent protein, 20 percent fat (mainly polyunsaturated), 35 percent carbohydrate, and 5 percent minerals, such as calcium. They are also a good source of fiber.

Processing breaks the soybean into two parts: oil and solids. The solids consist mainly of protein and carbohydrate.

Soy protein products are a good substitute for meat, poultry, and other animal-based foods because of their high quality protein.

Consuming 25 grams of soy protein per day from foods has been shown to lower LDL cholesterol levels.

Soy isoflavones are special substances found in soybeans that work in combination with the soy protein to provide health benefits. These isoflavones include genistein, daidzein, glycitein, also known as phytoestrogens.

Incorporating highquality food sources of soy protein, rather than taking soy or soy isoflavone supplements, is recommended as the best way to obtain health benefits.

Shopping Tips

On the label, look for foods with 6¼ grams of soy protein per serving. Foods providing this amount of soy protein per serving can state that “a diet low in saturated fat and cholesterol that includes 25 grams of soy protein a day may reduce the risk for heart disease.”

Try new soy products like soy sausage or soyrizo, garden or soy burgers, soy nuts as a salad topper or snack, or soy nut butter in place of peanut butter.

Motivational Tip Excellent sources of soy protein include soy milk, tofu, tempeh, miso, and edame. Give them a try!

Ways to Add Soy

Replace some or all of the meat in your favorite recipes with tofu or texturized vegetable protein (TVP). For example, in spaghetti sauce, replace half of the ground beef with TVP; for stir-fry or fajitas, replace the chicken or beef with cubed tofu; or make tacos with TVP.

Use silken tofu to replace sour cream, yogurt, or cheese in recipes:

  • Vegetable dip for vegetables with half silken tofu and half sour cream
  • Morning smoothie with silken tofu instead of yogurt
  • Lasagna with half ricotta cheese and half pureed firm tofu
  • Topping of half sour cream and half silken tofu on baked potatoes

Tips Affecting Different Age Groups

Young women who eat soy foods appear to have a lower risk of developing breast cancer later in life. For postmenopausal women, eating soy products may increase risk. Check with your physician if you are concerned about your risk. Soy protein may decrease the risk for prostate cancer if men consume it throughout their lives.

Regular consumption may also reduce the risk of type 2 diabetes and help manage symptoms for those that have the disease. There has been some evidence that regular consumption may also help in obesity prevention, but further research is needed.


Messina, V. “Soyfoods and Heart Disease.” Today’s Dietitian 18, no. 4 (April 2016): 18–22.

Nguyen, L., F. Steinberg, S. Cherr, “Nutrition and Health Info Sheet: Soy.” University of California Davis Department of Nutrition, January 2016.

Reviewed and revised by Sharon McDonald, senior extension educator.

Examine Your Choices

What I buy now
What I plan to try
Example: Stir-fry
Beef cubes
Tofu to replace beef cubes

My Goal:




Serving Size: Makes 10 servings


  • 1 pound lasagna noodles
  • ½ pound mushrooms, sliced
  • 1 Tablespoon vegetable oil
  • 10 ounces tofu, drained
  • ½ cup grated Parmesan cheese
  • 1 to 2 cloves garlic, crushed
  • ¼ cup chopped fresh parsley, or 1 Tablespoon dried
  • 2 to 2½ cups canned tomato sauce
  • 2 cups grated part-skim mozzarella cheese


Boil the lasagna noodles until just tender. Do not overcook. Drain. Sauté the mushrooms in the oil until tender. Mash the tofu in a bowl and mix with the Parmesan cheese and garlic. Preheat oven to 350°F. Lightly oil an 8½-by-11-inch baking pan. Line bottom of pan with a layer of noodles. Spread with half the tofu mixture, then add half the mushrooms, half the parsley, about half the sauce, and one-third the grated cheese. Add another layer of noodles and repeat the process. Place noodles on top. Sprinkle with the rest of the grated cheese. Top with remaining tomato sauce. Bake 45 minutes or until nicely browned. Refrigerate leftovers.
Nutrient Information: One serving: 350 calories, 19 g protein, 49 g carbohydrate, 4 g fiber, 9 g fat, 3.5 g saturated fat, 580 mg sodium, and 30% DRI for calcium.

Tip: Not sure you’re ready for tofu? Use half tofu and half lean ground beef in the recipe as a way to introduce soy to your family.

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Soy Protein and Soy Isoflavones


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Contact Information

Phone: 814-863-3973
Lynn James, M.S., R.D., L.D.N.
  • Nutrition, Food Safety & Health Senior Educator
Phone: 570-556-4744
Sharon McDonald, MEd, RD, LDN
  • Extension Educator, Food Safety & Quality
Phone: 814-865-6953