The thyroid gland is an essential gland in our body that control all body functions, and healthy thyroid means a healthy body. The principal function ofthe thyroid gland is to produce T3 (triiodothyronine) and T4 (thyroxine). The hypothalamus and pituitary glands release thyrotropin- releasing hormone (TRH) and thyroid – stimulating hormone (TSH) respectively, and this stimulates the release of T3 and T4 directly from the thyroid gland. The hypothalamic-pituitary- thyroid axis is regulated by negative feedback. Thus, sufficient production or overproduction of T3 and T4 lead to reduced secretion of TRH and TSH. Thyroid hormones play a role in the regulation of metabolism, body temperature, digestion, cognition, muscle strength and cardiac contractility.
Primarily thyroid disease develops when thyroid gland produces too little or too much T3 and /or T4. BUT there is no specific food or dietary supplements that are helpful in treating thyroid disorder. There is no magic diet for a thyroid disorder, as claimed by some social media nutritionist. However, there are certain areas where our diet may be of relevance in the management of throid disease.
Micronutrients essential for healthy Thyroid
Iodine : Iodine is essential for the synthesis of T4 and particularly important in women who are pregnant as it is needed to ensure the development of a baby’s brain during pregnancy and early life. Iodine deficency results in enlarged goitre (thyroid swelling) and an underactive thyroid. However, in UK and other developed countries iodine deficiency is very rare. Sources of dietary iodine are fish, milk, seaweed and iodized salt. excessive intake also results in hypo or hyperthyroidism
If you are taking levothyroxine for hypothyroidism or for a goitre, there is no need to take iodine supplements
selenium: selenium is essential for a healthy thyroid, DNA synthesis, and also protect against infections and oxadative stress. Selenium is required for the enzyme which causes activation and deactivation of thyroid gland. In adults, the thyroid gland has the heighest concentration of selenium in the body. Adding food rich in selenium like Brazilian nuts, tuna, sardines, eggs, and legumes boots your selenium levels. The majority of data on selenium and throid disease are regardring chronic autoimmune throditis, and some studies suggested thast selenium supplement may be beneficial in this autoimmune thyroditis, however, still we ned lareg randomized trials to conclude this.
Zinc: Zinc is essential for activation of thyroid galand also regulate TSH production. Zinc deficiency is very rare in developed countries as it is abundant in many foofds like seafood, eggs, beans, poultry, nuts ( cashew and almonds).
Vitamin D : Vitamin D is required to activate thyroid hormone receptors, and insuffient Vitamin D impairs thyroid function . There are no large scale randomized trials showing VItamin D directly influence thyroid hormone level. Graves` disease is known to cause bone loss, which is cpmounded by Vitamin D deficiency. This bone loss can be regained by treatment and vitamin D supplementation before and after treatment.
Vitamin A : Vitamin A has been shown to regulate throid hormones metabolism and inhibit thyroid stimulating hormone via down regulation . Vitamin A deficency increases TSH secretion from pituitary gland and reduces iodine uptake by thyroid gland. Vitamin deficency is rare due to being in so many foods Animal source (Rertinol) is more potent as compared to plant derived form Carotenes.
Food to avoid
There is no food to avoid completely, eating balanced diet is important for a healthy thyroid. However there are some foods that should be eaten in moderation like
Brassicas (cabbage, cauliflower, kale etc) may contribute to the formation of goitre in some cases, but consumption would need to be very high before this is a real concern. In the UK, under normal dietary conditions, this is not normally a problem and the risk is very low.
Soya interferes with thyroxine absorption, therefore if you are taking thyroxine you should try to avoid soya, but numerous studied have found that consuming soya doesnot cause hypothyroidism in people with adequate iodine stores. If you wish to take soya, there should be as long a time interval as possible between eating the soya and taking the thyroxine.
Avoid products such as kelp, as they may interfere with thyroid function and wellbeing. Kelp is derived from seaweed and is naturally high in iodine. Because of this it is sometimes marketed as a ‘thyroid booster’ and can be purchased in dry preparations and tablets. As with iodine itself, it is of no health benefit to those with thyroid disease.
TAKE- HOME -MESSAGE
A heart healthy diet that includes vegetables, fruits, lean protein, fibre, and omega 3 is paramount. If you still don’t feel well despite your medication, improving your diet and starting an exercise program may help.
Always consult your doctor, or pharmcist before taking any supplements or vitamins, as some can interfere with your throid function or your thyroid blood test.