Hypothyroidism (under-active thyroid) can remain undetected for years. People commonly have the symptoms of hypothyroidism even though their blood tests indicate that their thyroid function is ‘normal’. This is because standard pathology tests for thyroid function can have difficulty detecting ‘sub clinical’ cases of hypothyroidism. The most common symptoms of hypothyroidism are chronic tiredness, constipation, feeling the cold and dry skin. If you are in a high risk category for thyroid dysfunction - have a family member with a thyroid condition (especially your mother); are at the menopausal age; have experienced lots of stress in the past two-three years; or have hormonal imbalances - then it’s important that you support your thyroid, even if the tests tell that your thyroid is ‘normal’. One of the best ways to support thyroid function is with diet.

Certain foods improve hypothyroidism by supplying the essential minerals that the thyroid needs to function and produce hormones.
These include:

  • Tyrosine-rich foods. The amino acid tyrosine combines with iodine to make the hormone thyroxine. These foods include meat, fish, turkey and chicken breast, low fat milk and yogurt, almonds, avocado, bananas, lima beans, pumpkin seeds, sesame seeds, lentils. Supplements of tyrosine should be taken on an empty stomach or with other carbohydrate foods so that it doesn’t have to compete with other amino acids.

  • Iodine-rich foods. Iodine is needed to make thyroid hormones. Ideal food sources include Celtic sea salt, seaweed (sushi, nori rolls), salt water fish and sea food. Iodized salt is available but should be used in small amounts once or twice a week along with a good quality Celtic sea salt. Iodine supplements are usually in the form of kelp tablets. Consult your health practitioner before using these, because the wrong dose can unbalance your thyroid.

  • High quality protein. All of our body’s glands and hormones are made from protein. Try to eat high quality lean protein at every meal.

  • Selenium-rich foods – meat, chicken, salmon, tuna, seafood, whole unrefined grains, brazil nuts, brewer’s yeast, broccoli, dairy products, garlic, onions and black strap molasses.

  • Supplements of Vitamin B complex and essential fatty acids because they help to balance the entire hormonal system.

  • Sunlight – while not a food, its important to get a daily dose of safe sun. Light stimulates the pineal gland, which in turn positively affects the thyroid as well as all the other endocrine glands.

    Certain foods are detrimental for hypothyroidism because they can
    inhibit the production of thyroid hormones.
    These include:

  • Soy products. Isoflavones are hormone-like substances found in soy products. High consumption of soy products have been found to suppress thyroid function in some people and can even cause or worsen hypothyroidism. In particular, an isoflavone called genistein, appears to reduce thyroid hormone output by blocking the activity of an enzyme called thyroid peroxidase. This enzyme is responsible for adding iodine onto the thyroid hormones.

    How much is too much soy? Each person can tolerate a different amount and unfortunately soy is hidden in many processed and refined foods. If you have a family history of thyroid disease or a diet low in the minerals iodine and selenium, you need to be careful of your soy intake. Reduce your consumption of soy products (soy milk, tofu, tempeh, miso, soy sauce) to a maximum of two or three times per week. If you have already been diagnosed with hypothyroidism, or you display the common symptoms, then reduce your intake to less than twice in a week.

  • Cruciferous vegetables – broccoli, cauliflower, Brussels sprouts, cabbage, mustard, rutabagas, kohlrabi, and turnips. Isothiocyanates are the category of substances in cruciferous vegetables that have been associated with decreased thyroid function. They appear to reduce thyroid function by blocking thyroid peroxidase, and also by disrupting messages that are sent across the membranes of thyroid cells. Cooking these vegetables does make the isothiocyanates less available. Also, because they are so good for us in other ways, only restrict this group if you have been actually diagnosed with hypothyroidism or have strong symptoms.

  • Low progesterone goes hand in hand with low thyroid, so avoid foods that promote oestrogen dominance. This includes any animal product that has not been produced organically (chicken, eggs, dairy, beef, lamb, pork, etc.). All of these foods are available organic.

  • It is believed by some researchers that chlorine and fluoride (found in most tap water) block iodine receptors in the thyroid gland, eventually leading to hypothyroidism.

  • Gluten is linked to thyroid dysfunction (both hyper and hypo thyroid) so if you have any digestive problems or any one in your family with a gluten sensitivity, it would be worth dramatically reducing your gluten intake.

    Please note: The information in this article is not intended to take the place of a personal relationship with a qualified health practitioner nor is it intended as medical advice.

    About the Author:


    Alison Cassar is a naturopathic practitioner and nutritionist and runs a busy clinic in Sydney, Australia. Her particular interest is chronic tiredness as it’s a very common presenting symptom in clinic. Her website and e-book