Classed as a legume, soy is a wild plant of southeast Asia, where it has been cultivated for thousands of years. It is a major source of plant protein and edible oils. Soy protein is of excellent quality and can be used as an alternatives to a range of meat and dairy products. Currently, scientists are also looking to soy as an approach for treating a variety of diseases, including diabetes and cancer, according to the University of Maryland Medical Center (UMMC). Nevertheless, you must consume soy-based products with care, under the supervision of a doctor, specifically if you have certain health problems or concerns, including an impaired thyroid function.
Soybean Composition
Soy contains a good amount of protein, oils, soluble fiber, essential fatty acids, vitamins, salts and minerals. It provides all essential amino acids that humans require and thus is a "complete protein." Soy oil, a pale yellow liquid, is the richest source of two polyunsaturated fatty acids, linoleic and linolenic acids. These fatty acids are essential for human nutrition. The non-nutritive compounds in soy, such as resveratrol, phytosterols and isoflavones, are thought to produce most of the health benefits linked to soy, according to UMMC.
Thyroid Disorders
Thyroid disorders result when the thyroid gland, a butterfly-shaped gland lying at the front of your neck, does not produce appropriate amounts of thyroid hormones. Thyroid diseases affects both sexes and all ages, although the majority of cases are found in women over age 50. Because thyroid hormones are essential to the normal functioning of metabolism, decreased levels of circulating thyroid hormones can cause your body to slow down. Symptoms are usually very subtle and gradual. They can be hard to diagnose, if the symptoms are mild. Thyroid disorders, if left untreated, can cause serious health complications, such as goiter.
Soy and Thyroid Disorders
People with an underactive thyroid gland should generally avoid soy-based products, because soy can interfere with thyroid hormone synthesis. In cell culture and animal studies, soy isoflavones, a group of chemicals with estrogenic activity, have been reported to diminish substantial amounts of thyroid peroxidase activity, according to the book "The Anti-Estrogenic Diet: How Estrogenic Foods and Chemicals Are Making You Fat and Sick" by Ori Hofmekler and Rick Osborn. Thyroid peroxidase is the key enzyme for the production of thyroid stimulating hormone by the anterior pituitary gland.
Other Side Effects
Other major side effects of soy are linked to soy allergic reactions. A small number of people have allergies to soy because of a genetic sensitivity to the protein found in soy. Some common soy allergy symptoms include harmless skin reactions, itching and swelling of the mouth and throat, hives, trouble breathing, difficulty in swallowing, low blood pressure and gastrointestinal problems, according to Alfonso Tirado of the University of Hawaii at Manoa. Soy contains purines, a crystalline base. High intakes of soy can raise your blood levels of uric acid, a breakdown product of purine. When uric acid crystals deposit in joint spaces, it can set the stage for intense inflammation, pain and swelling. This is called gout. Thus, people with purine-related health problems must keep their soy intake at low levels.
References
- University of Maryland Medical Center: Soy
- Ohio State University, Department of Food Science & Technology: Soybeans Proteins
- Florida Agency for Health Care Administration: Soy
- University of Hawaii at Manoa: Food Allergies; Alfonso Tirado; 2005
- "The Anti-Estrogenic Diet: How Estrogenic Foods and Chemicals Are Making You Fat and Sick"; Ori Hofmekler and Rick Osborn; 2007
- University of Maryland Medical Center: Gout
