Not just genetics, lifestyle, diet contribute to thyroid disorders

Heavy metal and pesticide exposure, poor gut health, chronic stress and food intolerance can all worsen the condition

MOSTLY AUTO-IMMUNE in nature with underlying genetic predisposition, thyroid disorders may have something to do with the way you eat and live. Some of the common causes could be heavy metal and pesticide exposure, poor gut health, chronic stress and food intolerance.

Foods traditionally thought to impact thyroid function, also called goitrogens, include soy, turnips, cabbage, cauliflower, broccoli, brussel sprouts rutabaga (Swedish turnip), kale (form of cabbage) and kohlrabi (German turnip or knol kohl).

Goitrogens are known to suppress the function of thyroid gland by interfering with iodine uptake, which can, as a result, cause an enlargement of the thyroid gland, known as goiter. In other words, goitrogens inhibit thyroid hormone synthesis. However, the goitrogenic effect of these foods is mostly destroyed on cooking. Also, their effect is only relevant if goitrogenic foods are taken in large amounts as staple foods. Several studies done on goitrogenic foods have demonstrated insignificant effects on metabolism.

However, a recent study (2010) reported that catechins (flavonoids) in green tea extracts are goitrogenic and had an antithyroid effect, when consumed in high doses. Dietary sources of iodine include sea water, iodised salt, seaweed and shellfish like shrimps, clams, oysters, marine fish. Breast milk contains iodine to provide for the infant’s requirements and lactating women require extra iodide in their diets.

A relatively newer association is seen between auto-immune thyroid disorders (both Hashimoto’s and Graves’) and food intolerance. This happens when the body reacts to certain foods negatively which can then cause an abnormal immune response. This response can lead to a cascade of events, including inflammation, difficulty in absorbing nutrients, fatigue, mood disturbances, hormonal imbalance and even auto-immune disorders. Food intolerance can disturb thyroid function and is often related to auto-immune thyroid disorders. Indeed, a strong association has been reported among those having gluten related disorders and celiac disease.

Several scientific studies confirm an increased prevalence of autoimmune thyroid disorders in celiac populations. The converse also appears to be true, ie celiac disease is seen in higher percentage of individuals with autoimmune thyroid disorders than the general population.

A recent scientific study published in the Journal of Pediatrics in 2009, conducted on about 325 children reported that auto-immune thyroiditis is strongly associated with celiac disease. It is suggested that individuals with auto-immune thyroid disorders be screened for gluten intolerance and those with gluten intolerance to be screened for auto-immune thyroid disorders. A study published in 2001, in the American Journal of Gastroenterology reported that following a gluten-free diet helped in the improvement and recovery of autoimmune thyroid disease in some cases. Certain micronutrients have also been associated with thyroid health. These include iron, folic acid, selenium, zinc, magnesium, manganese, vitamin B12 & vitamin D.

Minimising exposure to heavy metals through environmental pollution and contamination, taking care of your digestion and managing stress through yoga and meditation can all be useful in managing your thyroid health. There is a word of caution, treatment or diet should not be modified without consultation with your physician.

Author is a clinical nutritionist and founder of www.theweightmonitor.com and Whole Foods India