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Food for Thought: Are processed soy protein products bad for you?

Answer: Soy is the richest source of legume protein and is very versatile. It is enjoyed in many forms, including edamame, tofu, milk, nuts, tempeh, flour, textured vegetable protein and protein powder.

The most solid evidence on soy and health pertains to soy’s cholesterol-lowering effects, which have earned foods containing soy protein a health claim that they may reduce risk of heart disease. Eating around 25–40 grams (g) of soy protein per day has been found to lower LDL cholesterol in studies. Reaching 25 g can be achieved by eating two to three servings of soy daily. This is equivalent to 1 cup of soymilk, a half cup of tofu and one-third of a cup of soy nuts.

Soybeans and food made from them are high in B vitamins, polyunsaturated fats and isoflavones, phytochemicals that may prevent certain types of cancer and that are known to lower total and LDL cholesterol.

Soy is found in many processed foods today—either hidden or as the major ingredient in patties, hot dogs, cheese, ice cream and textured vegetable protein. Soy protein isolate is the form most widely used in food production. Generally, processed soy products are not as healthy as whole, unprocessed soy, as they contain fewer isoflavones and little, if any, fiber. Search product labels for isoflavones and fiber content.

Concerns surrounding potential health implications of soy appear to relate largely to processing methods and to the isoflavone (phytoestrogen) content. If processed soy foods are a major part of your diet, look for products that carry the USDA organic seal and are labeled “Made with organic soy.” Phytoestrogens in soy act as weak estrogens. Since refined soy protein isolate contains lower levels of isoflavones than whole soy foods, there should not be a concern. Still, individuals with a hormone-sensitive cancer should consult their primary health professional because the effects of high soy intake are still unknown.

Based on available evidence, consuming two to three servings of soy foods daily, including processed products, is safe for healthy individuals. But make more room for whole soy foods as an excellent plant-based protein.

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Jennie McCary, MS, RD, LD

IDEA Author/Presenter
You can pose your own question to our contributing editor Jennie McCary, MS, RD, LD, a registered di... more less
February 2012

© 2012 by IDEA Health & Fitness Inc. All rights reserved. Reproduction without permission is strictly prohibited.

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