The thyroid gland needs an adequate supply of iodine in order to make its hormones and function efficiently. Up to 72% of the world’s population is iodine deficient. Several factors contribute to this including depletion of iodine in the soil, diets without ocean fish or sea vegetables, inadequate use of iodized salt, diets high in pasta and breads which contain bromide (bromide binds to iodine receptors), fluoride use and vegan and vegetarian diets. If you use thyroid hormone without first correcting the iodine deficiency, you will exacerbate the body’s deficit of iodine. As an aside, consider that areas of the world with a high iodine intake like Japan have a low rate of breast cancer.
A diet rich in soy may inhibit thyroid function. This subject is controversial in the medical literature. A study of 37 adults who ate a high soy diet for three months revealed that almost 1/2 of the people developed symptoms of low thyroid function. The symptoms resolved one month after stopping the diet. Soy in the US is mostly genetically engineered! Selenium can normalize thyroid function and zinc helps thyroid metabolism.
Diseases associated with hypothyroidism include ADHD, Cardiovascular disease, congestive heart failure, depression, chronic fatigue syndrome, fibromyalgia, ankylosing spondylitis and insulin resistance. Studies have shown ADHD is common among individuals with generalized resistance to thyroid hormone. Studies have also shown that ADHD is improved with thyroid replacement in people with documented hypothyroidism. Hypothyroidism is a risk factor for cardiovascular disease. A low ratio of T3/rT3 is actually a predictor of mortality in congestive heart failure and low T3 is a strong predictor of death in cardiac patients.
Thyroid hormone, specifically T3, improves depression when added to SSRIs in post traumatic stress disorder. Both chronic fatigue syndrome and fibromyalgia are associated with low levels of T3. Finally, lower TSH and higher T4 are associated with improved insulin sensitivity.
Optimal thyroid function requires adequate nutritional intake. It is also related to toxin exposure, other hormone function and medications. Most patients require replacement of both T3 and T4 to optimize function. treatment of thyroid dysfunction should be individualized and customized to each patient.