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Soy Protein for Weight Control
Soy
Why Do Dieters Use It?*
Some dieters say that soy protein provides a source of low-fat, cholesterol-free protein.
What Do the Advocates Say?*
Protein is necessary for rebuilding tissue, which is especially important for bodybuilders. All types of protein provide the body with amino acids.
From an athletic point of view, soy is just another type of protein. Choosing soy protein over other types of protein adds variety to the protein choices available. However, because soy lowers cholesterol, it is an excellent choice for those also trying to lower their cholesterol levels.
Soy is a common ingredient in many meal replacements that are designed to provide a large amount of nutrients in a minimal amount of calories.
*Dieters and weight-management advocates may claim benefits for this supplement based on their personal or professional experience. These are individual opinions and testimonials that may or may not be supported by controlled clinical studies or published scientific articles.
Also indexed as:
- soy protein,
- weight control,
- weight management
About this treatment
Soy
How Much Is Usually Taken by Dieters?
Animal and human studies have suggested that when soy is used as a source of dietary protein, it may have several biological effects on the body that might help with weight loss. A preliminary study found that people trying to lose weight using a meal-replacement formula containing soy protein lost more weight than a group not using any formula. However, controlled studies comparing soy protein with other protein sources in weight loss diets have not found any advantage of soy. When soy protein is used for other health benefits, typical daily intake is 20 grams per day or more.
Side Effects
Soy products and cooked soybeans are safe at a wide range of intakes. However, a small percentage of people have allergies to soybeans and thus should avoid soy products.
Soy isoflavones have been reported to reduce thyroid function in some people. A preliminary trial of soy supplementation among healthy Japanese, found that 30 grams (about one ounce) per day of soybeans for three months, led to a slight reduction in the hormone that stimulates the thyroid gland. Some participants complained of malaise, constipation, sleepiness, and even goiter. These symptoms resolved within a month of discontinuing soy supplements. However, a variety of soy products have been shown to either cause an increase in thyroid function or produce no change in thyroid function. The clinical importance of interactions between soy and thyroid function remains unclear. However, in infants with congenital hypothyroidism, soy formula must not be added, nor removed from the diet, without consultation with a physician, because ingestion of soy may interfere with the absorption of thyroid medication.
Most research, including animal studies, report anticancer effects of soy extracts, though occasional animal studies have reported cancer-enhancing effects. The findings of several recent studies suggest that consuming soy might, under some circumstances, increase the risk of breast cancer. When ovaries have been removed from animals—a situation related to the condition of women who have had a total hysterectomy—dietary genistein has been reported to increase the proliferation of breast cancer cells. When pregnant rats were given genistein injections, their female offspring were reported to be at greater risk of breast cancer. Although premenopausal women have shown decreases in estrogen levels in response to soy, pro-estrogenic effects have also been reported. When pre-menopausal women were given soy isoflavones, an increase in breast secretions resulted—an effect thought to elevate the risk of breast cancer. In yet another trial, healthy breast cells from women previously given soy supplements containing isoflavones showed an increase in proliferation rates—an effect that might also increase the risk of breast cancer.
Of 154 healthy postmenopausal women who received 150 mg of soy isoflavones per day for five years, 3.9% developed an abnormal proliferation of the tissue that lines the uterus (endometrial hyperplasia). In contrast, none of 144 women who received a placebo developed uterine hyperplasia. Although no case of uterine cancer was diagnosed during the study, endometrial hyperplasia is a potential forerunner of uterine cancer. The amount of isoflavones used in this study is two to three times as much as that used in many other studies. Nevertheless, the possibility exists that long-term use of isoflavones could cause uterine hyperplasia, and women taking isoflavones should be monitored appropriately by their doctor.
Some postmenopausal women taking the soy isoflavone genistein have experienced gastrointestinal side effects (abdominal pain, epigastric pain, dyspepsia, vomiting, or constipation).
Interactions with Supplements, Foods, & Other Compounds
Soy contains a compound called phytic acid, which can interfere with mineral absorption.
Interactions with Medicines
Certain medicines interact with this supplement.
 | Some medicines may increase the need for this supplement. |
|---|---|
 | Some medicines interact with this supplement, so they should not be taken together. |
 | Some interactions between this supplement and certain medicines require more explanation. Click the link to see details. |
Note: The following list only includes the generic or class name of a medicine. To find a specific brand name, use the Medicines Index.
| Dessicated Thyroid |
|---|---|
| Levothyroxine |
| Liothyronine |
| Liotrix |
| Ipratropium Bromide |
| Theophylline |
| Warfarin |
Last Review: 05-11-2011
Copyright © 2011 Aisle7. All rights reserved. www.Aisle7.net
Learn more about Aisle7, the company.
The information presented in Aisle7 is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires June 2011.
© 1995-2011 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated. This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.
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