Soy & Hypothyroidism

Soy is an edible crop that is classed under the plant family Leguminosae. It is a unique source of vegetable protein with all essential amino acids. Soy has gained popularity due to its possible health benefits. However, soy can have antithyroid effects and inhibit the production of thyroid hormones. If you want to use soy, talk to your doctor first.

Soybean Composition

The chief components of soy include complete protein, vegetable oils, mucilage fiber, essential fatty acids, vitamins, salts and minerals. Soybean oil is a pale yellow liquid that contains two essential fatty acids, namely linoleic and linolenic acids, which aren't produced in your body. Soy also contains substances called isoflavones, a form of the steroidal human estrogen. These plant molecules may provide protection against cancer and heart disease, notes the University of Maryland Medical Center.

Hypothyroidism

Hypothyroidism is a chronic disease that is characterized by deficient activity of the thyroid gland. Your risk of developing hypothyroidism increases with age. In fact, more than half of new hypothyroidism cases are found in middle-aged and elderly women. A deficiency of thyroid hormones causes fatigue, lethargy, sleepiness, constipation, weight gain, poor memory and goiter.

Soy and Hypothyroidism

Soy may cause a decrease in thyroid function. In cell culture and animal studies, the isoflavonoid compounds in soy have been found to block the thyroid peroxidase activity, according to the Linus Pauling Institute. The enzyme thyroid peroxidase facilitates the uptake of sodium iodide by the thyroid gland. Your body needs iodine to make thyroid hormones.

Side Effects

You should avoid soy, especially raw soybeans, if you have a known food allergy. Soy allergy appears more frequently among children. However, a child may experience soy allergy symptoms differently. Symptoms may include itching and swelling of the skin, breathing difficulty, dizziness, wheezing, vomiting, diarrhea and low pulse. Soy is high in purines, a major base of DNA and RNA. High serum purine levels can lead to uric acid crystals precipitating in joint spaces. This is called gout. Soy sufferers should not consume large amounts of soy.