Role of diet in Thyroid disordersadmin
Thyroid gland is located in the front part of the neck and is an endocrine gland which produces thyroid hormones-T3, T4 and TSH. Iodine is majorly required for this synthesis along with Selenium, Iron, Vitamin A and zinc. Thyroid disease affects almost 10-15% of population. Iodine and goitre have been well connected leading to Universal salt iodination program.
- T3 is the active hormone and T4 converts to form 80% T3.
- Thyroid’s role is in body temperature, tissue growth and metabolic rate.
Dietary micronutrients that play an important role in diet are-
- Iodine can be obtained from iodized salt, multivitamin tablets with Iodine, sea water, seafood, milk products and eggs.
- RDA for adult men and women is 150 micrograms, pregnancy is 220 micrograms and lactation is 290 micrograms.
- Iodine is measured by checking urinary iodine levels. When Iodine concentration is below 50 micrograms there’s a deficiency of Iodine.
- Iodine supplementation using iodized oil and salt has helped the situation.
- Iodine is also decreased in Hypertension when one avoids salt.
- Deficiency of Iodine leads to Hypothyroidism and brain damage.
- In pregnancy, Iodine deficiency causes mental retardation, spasticity, deaf mutism and short stature in the new born. It also leads to Goiter and myalgia.
- There can be miscarriage, still births, early labor in pregnant mothers.
- Excess Iodine causes hyperthyroidism, auto immune disease and nodule formation.
- Safe intake of Iodine is 1.1 mg/day.
- 1 tsp provides around 280 microgram Iodine.
- It is an essential micronutrient for Thyroid hormone synthesis.
- Selenium and Iodine deficiencies both cause Hypothyroidism, Auto immune disease, Goiter and Cretinism.
- A healthy balanced diet provides Selenium.
- Selenium sources are Mushrooms, garlic, onion, eggs, wheat germ, sunflower and seasame seeds.
- Selenium deficiency is more in patients having low GI absorption, parenteral nutrition or where soil content is low. When there’s a combined Selenium and Iodine deficiency both need to be supplemented.
- Iron is essential for Thyroid hormone metabolism.
- Iron and Iodine deficiencies coexist and a double fortified salt approach is used to solve this problem.
Include-Iodine rich food, salt, sea food, etc.
- Moderate Goitrogens-Basically substances in foods of Cruciferous family such as Cauliflower, Cabbage, Broccoli which lower your Thyroid hormones .Mix them with other vegetables in lesser quantities and cook /steam well.
- If the Iodine levels are fine then you can have soya also it should be boiled well.
- Avoid Excess salt and Red meat.
- Include-Thyroid inhibitors like Cauliflower, Cabbage etc, Nutritious food.
- Consume-Fresh meat, vegetables, fruits, rice and Iodine free salt.
- Avoid -Low calorie foods like salads and vegetables.
- Avoid Iodine rich foods-Fish, seafood, artificially coloured foods, cough syrups,
Iodized salt, cheese, milk, milk products, egg yellow.
- Studies have shown that a Vegan diet reduces the risk of Hypothyroidism than Omnivorous diet.
- Goitrogens cause persistent Goiter like Cauliflower, Cabbage, Radish, Broccoli, Turnips and rapeseed.
- All the goitrogens affect thyroid hormone synthesis by inhibiting Iodine uptake.
- Excess Iodine may cause Hypothyroidism. So decrease Iodine uptake.
- Study has shown that dietary modification has lead to normal TSH in children with Hypothyroidism.
Iodine deficiency and smoking are risk factors and Alcohol consumption and oral contraceptives lower the risk.
- Dietary nitrites and nitrates are risk factors.
- Leafy vegetables like spinach, lettuce, beetroot are high in nitrates.
- Cancer risk is more with cruciferous vegetables, butter, cheese, pasta, meat and poultry
and lesser with carrots, green salads, citrus fruits ,iodized salt and fish.
Hypothyroidism leads to obesity .It is caused by fluid retention and less metabolic rate.
So have a healthy balanced diet, take Iodine as per requirement and minimise goitrogens in your diet.
Sharma et al,J Med Nutr Neutraceut,2014
Tonstad et al,Nutrients 2013
Kohrle et al ,Best Pract Res Clin Endocrinol Metab,2009
Verma et al ,Saudi Medi journal 2008.
Peterson et al,PLOS one,2012
Knudsen et al,Thyroid,2002
Anderson et al,Am jour clin nutr,2008
Chandra et al,Indian J Med Res,2004