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Thyroid-friendly diet

Find out how a thyroid-friendly diet could help you to both minimise thyroid symptoms and maintain a healthy weight.

Could your diet affect your thyroid health? We look at whether a thyroid-friendly diet could help you to minimise thyroid symptoms and maintain a healthy weight.

What is a thyroid-friendly diet?

Diet plays a significant role in our overall health. Although scientific research is ongoing to understand the exact impact of foods and nutrients on thyroid health, there is some evidence for how some foods affect thyroid function.

We spoke to nutritionist Effie Parnell-Hopkinson to see if any foods can help thyroid function and keep it healthy.

Nutritionist, Effie Parnell-Hopkinson said:

“There are no specific diets or food groups that are proven to eliminate thyroid disease or hypothyroidism, but by following a thyroid-friendly diet you can help minimise your symptoms and help you maintain a healthy weight as it encourages eating whole, unprocessed foods and lean protein.

“There are several nutrients that are important to optimise and maintain a healthy and functional thyroid. The top three nutrients include iodine, selenium, and zinc, and these can all be obtained through consuming a varied and balanced diet.

“The best way to optimise your diet for healthy thyroid function is to eat a varied and balanced diet rich in meat, seafood, dairy, eggs, vegetables, fruits and gluten-free grains.

“Foods that should be eaten in moderation include foods that contain gluten, soy products, cruciferous vegetables (cooking further lowers the risk) and caffeinated beverages. If you are taking thyroid medication, please always speak to your doctor before supplementing iodine, selenium or zinc."

So, let’s have a look at how different diets, minerals and vitamins could impact thyroid health.

A gluten-free diet

Having one autoimmune disorder increases the risk of developing other autoimmune conditions. Because of this, the risk of developing coeliac disease is higher in people with autoimmune thyroid disease.

With coeliac disease, the immune system mistakes gliadin, one of the substances that make up gluten, as a threat to the body. Gluten is the protein found in wheat and some other grains. And the molecular structure of gliadin is like the molecular structure of the thyroid gland [2].

When gliadin passes the protective barrier of the gut and enters the bloodstream, the immune system of people with a gluten sensitivity or coeliac disease tags it with antibodies for destruction. Because of the similar structures, the immune system can mistake the thyroid for gluten, causing it to also come under attack.

Not everyone with a thyroid condition is sensitive to gluten, but gluten may act as a trigger for an immune response against the thyroid in people who are already sensitive to gluten.

If you are concerned or think this may affect you, speak to your doctor before making any major dietary changes.

Thyroid-friendly vitamins and minerals

Iodine and thyroid function

Iodine is an essential nutrient that is needed to make thyroid hormones and an iodine deficiency increases the risk of developing hypothyroidism [3]. Iodine supplements are not necessary as it is possible to get enough iodine from your diet alone. Although, if you are you do not consume many iodine-rich foods, supplements may be a convenient method to top your levels up [4].

By eating seaweed, white fish, dairy, and eggs, you can provide your body with enough iodine for normal thyroid function [5]. Adding iodised table salt to your food will also help to meet your iodine requirements, however, as government recommendations are to reduce salt intake for health reasons, you should not rely on iodised table salt as a means of increasing your iodine intake.

If you have thyroid disease, are taking other medication, or have experienced iodine deficiency over many years, you should speak to your GP before taking additional iodine. The recommended daily amounts of iodine are 150 mcg/d for adults and 200 mcg/d for pregnant and breastfeeding women (based on the European Food Safety Authority (EFSA) recommendations).

Too little iodine can have negative effects on thyroid health and function and lead to thyroid swelling (a goitre). There have been foods identified as goitrogenic, meaning they can interfere with iodine uptake in the thyroid gland and interfere with the synthesis of thyroid hormones.

Goitrogenic foods include:

  • Cruciferous vegetables such as bok choy, broccoli, brussels sprouts, cabbage, cauliflower, Chinese cabbage, collard greens, kale and turnips.
  • The rosacea family of fruits, including almonds, apricots, cherries, peaches, pears, plums, raspberries, and strawberries.

Steaming or boiling can reduce the goitrogen content of foods.

Selenium and thyroid function

Selenium is another essential nutrient that the body uses to regulate thyroid hormones. Foods that contain selenium include brazil nuts, fish, eggs, and meat. The Dietary Reference Values (DRV) for selenium is 60 mcg/d for women and 70 mcg/d for men, aged 19-64 [6].

Like iodine, the amount of selenium available through a varied and balanced diet is sufficient, so there’s no need to supplement. Low levels of selenium have been linked with an increased risk of hypothyroidism, goitre, and Hashimoto's thyroiditis [7]. Experts recommend no more than 400 mcg/d of selenium to avoid toxicity, including all sources of food, vitamins, and supplements. Speak to your GP before taking any additional selenium.

Zinc and thyroid function

Zinc is an essential nutrient, meaning that the body cannot produce or store zinc alone and needs to consume it daily through diet. Zinc is needed for metabolic function, to produce thyroid hormones and to regulate TSH [8]. Zinc can increase the levels of thyroid hormone in people with goitres [9].

The recommended daily values for zinc are 9.5 mg and 7.0 mg for men and women, respectively. Zinc is widely available through a varied diet. Good sources of zinc include meat such as chicken and beef, shellfish, bread, dairy, and cereal products.

Please speak to your GP first if you are considering taking any supplements.

Types of thyroid blood tests

  1. Thyroid Function Blood Test - a comprehensive test that looks for TSH, FT4 and FT3 - the more biologically active form of FT4. This test helps you to take a more in-depth look at your thyroid hormones.
  2. Thyroid Function with Antibodies Blood Test - with this test, you can tell if your thyroid hormones are functioning within the healthy range. You can also detect any abnormalities caused by an autoimmune disease. Even if your thyroid function is currently normal, elevated antibodies may increase your risk of developing a thyroid disorder in the future.
  3. Advanced Thyroid Function Blood Test - this test includes the thyroid hormones, thyroid antibodies, and nutritional markers that can support thyroid function. If your nutritional markers are low, this can cause symptoms like a thyroid disorder. For example, low iron (ferritin), low vitamin D and low B vitamins can cause fatigue and low energy.

Unsure which blood test is right for you? Head over to our thyroid buying guide. 

 


References

  1. British Thyroid Foundation. 2022. What we do. [online] Available at: <http://www.btf-thyroid.org/8-general/2-thyroid-disorders-affect-one-in-twenty-people-in-the-uk-could-you-be-one-of-them> [Accessed 4 March 2022].
  2. Vojdani, A., O'Bryan, T. and Kellermann, G., 2008. The Immunology of Gluten Sensitivity beyond the Intestinal Tract. European Journal of Inflammation, 6(2), pp.49-57.
  3. Zimmermann, M. and Boelaert, K., 2015. Iodine deficiency and thyroid disorders. The Lancet Diabetes & Endocrinology, 3(4), pp.286-295.
  4. nhs.uk. 2022. Vitamins and minerals - Iodine. [online] Available at: <https://www.nhs.uk/conditions/vitamins-and-minerals/iodine/> [Accessed 4 March 2022].
  5. Bda.uk.com. 2022. Iodine Food fact Sheet. [online] Available at: <https://www.bda.uk.com/resource/iodine.html> [Accessed 4 March 2022].
  6. Assets.publishing.service.gov.uk. 2022. [online] Available at: <https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/618167/government_dietary_recommendations.pdf> [Accessed 4 March 2022].
  7. Ventura, M., Melo, M. and Carrilho, F., 2017. Selenium and Thyroid Disease: From Pathophysiology to Treatment. International Journal of Endocrinology, 2017, pp.1-9.
  8. Maxwell, C. and Volpe, S., 2007. Effect of Zinc Supplementation on Thyroid Hormone Function. Annals of Nutrition and Metabolism, 51(2), pp.188-194.
  9. Kandhro, G., Kazi, T., Afridi, H., Kazi, N., Baig, J., Arain, M., Sirajuddin, Shah, A., Sarfraz, R., Jamali, M. and Syed, N., 2009. Effect of zinc supplementation on the zinc level in serum and urine and their relation to thyroid hormone profile in male and female goitrous patients. Clinical Nutrition, 28(2), pp.162-168.