Diet in Hashimoto’s disease is a very important element in supporting medical treatment. Its purpose is to suppress auto-inflammatory reactions, which can alleviate the symptoms of the disease. What are the most important diet principles for Hashimoto’s disease? Which products are recommended and which are contraindicated?
Diet in Hashimoto disease
The diet in Hashimoto disease is a diet in which the main goal is to support pharmacotherapy by stimulating the synthesis of thyroid hormones conversion of T4 to T3. Acceleration of metabolism and suppressing inflammatory reactions resulting from auto aggression of the immune system. A properly composed diet can also alleviate the symptoms that accompany the disease, such as constipation, water retention, and elevated cholesterol.
The principles of nutrition for people with Hashimoto disease are based on the general principles of healthy eating. However, special attention should be paid to the supply of certain vitamins and minerals, such as iodine, selenium, iron, zinc and vitamin D, and the reduction of the supply of vegetables and fruits containing anti-nutritional substances (goitrogens). Also, you need to ensure the right proportions of macronutrients - protein, fats and carbohydrates.
How to compose a diet in Hashimoto disease?
The share of energy intake from protein in the diet in Hashimoto disease should be 15-25% of the daily energy demand. Amino acids contained in proteins, especially tyrosine, are necessary for the synthesis of biologically inactive T4, which is then transformed, e.g. in muscles, to active T3.
Tyrosine is also needed for the synthesis of dopamine, adrenaline and noradrenaline, which deficiency may exacerbate mood disorders that are characteristic of hypothyroidism. Although tyrosine is an endogenous amino acid (synthesized by the body), another amino acid - phenylalanine - is required for its production, which must be supplied with the diet. Also, the increased amount of protein in the diet speeds up metabolism.
Recommended sources of wholesome animal protein are lean meat (poultry, beef), fermented dairy products (yoghurt, kefir) and eggs. However, a good source of vegetable protein are soybeans, beans, lentils, and peas. However, due to the high content of anti-nutrients, their amount in the diet in Hashimoto disease should be limited.
Low-calorie and low-protein diets should be avoided as they can inhibit thyroid hormone secretion and reduce metabolic rate.
Diet in Hashimoto’s disease should contain 25-30% fat with limitation of unsaturated fatty acids to 10% daily. Due to the strong anti-inflammatory properties, it is recommended to consume polyunsaturated omega 3 fatty acids.
In addition to anti-inflammatory properties that suppress thyroid inflammation, omega 3 fatty acids support the synthesis of thyroid hormones. The consumption of saturated fatty acids contained in fatty dairy products should be limited, because their excessive amount may inhibit the synthesis of thyroid hormones.
You should also reduce the consumption of trans fats in fast-food products, ready-made confectionery and pastries. Trans fats should constitute less than 1% of the body’s energy requirements.
Carbohydrates and fibre
Good sources of carbohydrates in the Hashimoto’s diet should take over 50% of energy demand. It is recommended to consume products with a low glycemic index that will stabilize blood glucose levels, as patients with Hashimoto disease may have problems with its normal level.
A characteristic symptom of Hashimoto’s disease is constipation, which is why the diet for Hashimoto’s disease should contain an adequate amount of dietary fibre, i.e. 25-30 g/day. Dietary fibre will additionally stabilize cholesterol and blood glucose levels. The recommended source of carbohydrates and dietary fibre in the diet are whole grains and cereals.
The menu should exclude completely or minimize the consumption of products with a high content of simple sugars, which are found in sweeties, cakes, sweetened jams and juices.
Vegetables and fruits are a very important element of the Hashimoto’s diet because they provide antioxidants and dietary fibre, and their daily intake should be at least 0.5 kg. However, some plants contain so-called anti-nutrients such as goitrogens.
Goitrogens interfere with the absorption of iodine, which is necessary for the synthesis of thyroid hormones and can cause thyroid goitre. Heat treatment reduces goitrogens content in the vegetables by about 30%, so the consumption of plants containing these substances is recommended in moderate amounts (preferably after heat treatment), so as not to give up a valuable source of important nutrients and dietary fibre completely.
Green tea may also have an adverse effect on the absorption of iodine, as it contains catechins and flavonoids which may reduce iodine absorption.
Supplements for Hashimoto disease
The synthesis of thyroid hormones is a complex process, requiring cofactors in the form of minerals and vitamins at various stages of their metabolism. Studies have shown that people with Hashimoto disease should consider supplementing selected vitamins and minerals.
Iodine is a key element needed for the synthesis of thyroid hormones because it is building block of them. Iodine deficiency results in lower T3 and T4 level and enlargement of the thyroid gland. The demand for iodine for an adult is 150 mcg/day.
The main source of iodine in the diet are iodized table salt, sea fishes, milk and dairy products.
Studies show that excess iodine in people with Hashimoto’s disease can increase the inflammation of the thyroid gland. Sensitivity to iodine is also conditioned individually, which is why you should consult a doctor or dietitian before starting iodine supplementation.
A deficiency of selenium interferes with the tissue transformation of T4 to T3 and the functioning of glutathione peroxidase, an enzyme that prevents oxidative damage of thyroid. The effects of selenium are dependent on the optimal supply of iodine. Appropriate supplementation has been shown to reduce any TPO and anti-TG levels.
The daily requirement for selenium for an adult is 55 mcg/day. It is enough to consume just 2 brazil nuts to cover the daily demand for selenium. Other sources of selenium are:
- chicken eggs
Selenium may be supplemented (mostly recommended in the form of selenomethionine) in selected clinical cases. However, before introducing supplementation, it is worth consulting a doctor or dietitian, because the excessive supply of selenium can be toxic to the body. An excess of selenium in the body can also increase the excretion of iodine in the urine.
Zinc, like selenium, is a substance with antioxidant and anti-inflammatory properties, therefore it will suppress reactions resulting from an autoimmune system of the thyroid. Zinc deficiency results in lower thyroid hormones levels and an increase in the level of anti-TPO and anti-TG antibodies in the blood.
Daily recommended for zinc intake is 8-11 mg/day. Food sources of zinc include
- wheat germ
- pumpkin seeds
In the event of a deficiency of this element, supplementation at a dose of 10 mg/day in the form of zinc citrate may be considered.
Iron is necessary for changing thyroglobulin into T4 and T3 by thyroid peroxidase. Therefore, its deficiency reduces the synthesis of thyroid hormones. Iron deficiency occurs even in 60% of people with hypothyroidism, and its symptom may be anaemia. Women are particularly vulnerable to iron deficiency because they may have heavy periods.
The diet of people with Hashimoto disease should include easily digestible sources of iron, such as liver, beef and eggs. To improve iron absorption, you should consume foods rich in this element together with foods rich in vitamin C for example red peppers or parsley.
Vitamin D, in addition to participating in the regulation of calcium metabolism, participates in immune processes. Studies have shown that vitamin D levels are lower for people with Hashimoto disease than in healthy people.
Therefore, according to the recommendations from 2018 Hashimoto disease is a risk factor for vitamin D deficiency. That’s why in such case, supplementation of Vitamin D is recommended.
According to the current guidelines for the Central European population, adults are recommended to take 800-2000 IU vitamin D daily in the autumn and winter, depending on body weight. In people diagnosed with vitamin D deficiency, it should be higher (up to 10,000 UI/day) and used until the optimal vitamin D concentration in the serum is reached.