What foods does the thyroid gland not like: an endocrinologist explains

The thyroid gland rarely "complains" immediately – more often, it silently works at its limit while we attribute fatigue, mood, and weight to stress or age. Many common foods don't cause direct harm, but with regular consumption, they create a constant overload for the hormonal system. Where are the myths, and where are the real health risks?Together with endocrinologist Tetiana Bukhta, we'll explore which foods the thyroid gland "dislikes," what hinders hormone absorption, and where the line between benefit and harm in nutrition lies.Which foods does the thyroid gland "dislike" the most?The thyroid gland reacts worst not to individual products, but to the regular consumption of food that overloads the body and forces it to work in a state of stress. This primarily concerns ultra-processed foods – fast food, snacks, sugary dry breakfasts, carbonated drinks, sausages, and ready-made frozen meals, explains Tetiana Bukhta, an endocrinologist at the "Likuyu" clinic network.Such food usually contains a lot of sugar, salt, and unhealthy fats, but provides almost no nutrients. If it makes up a significant part of the diet, a chronic inflammatory background is formed in the body, in which it is more difficult for hormones to act effectively, and for the thyroid gland to maintain balance.Alcohol plays a separate role: it has a toxic effect on cells, interferes with hormone processing, and enhances inflammatory processes. At the same time, the doctor emphasizes, an occasional burger or a glass of wine is not a problem – regularity and overall eating style are what is crucial.What foods interfere with iodine absorption?Some foods contain goitrogens – biologically active substances that can affect the synthesis of thyroid hormones, in particular by hindering iodine absorption, explains the endocrinologist.The most well-known of these are vegetables from the cabbage family (cruciferous): all types of cabbage, broccoli, cauliflower, turnip, rutabaga, and radish.The key point is that these foods do not need to be excluded from the diet, as the risk to the thyroid gland primarily concerns a large amount of raw cruciferous vegetables, especially if the diet is generally low in iodine.However, after heat treatment (boiling, stewing, or steaming), most goitrogenic compounds are deactivated. At the same time, vegetables retain fiber, vitamins, and antioxidants, which makes them a useful part of a balanced diet.Is it true that some foods reduce the effectiveness of medications for treating the thyroid gland?Some foods and drinks can indeed reduce the effectiveness of thyroid hormone medications if consumed at the same time as the medication. This most often applies to coffee, as well as foods or supplements high in calcium and iron – these can impair the absorption of the hormone in the intestines. That is why such medications are recommended to be taken on an empty stomach, with only water, with a break of at least 30-60 minutes before breakfast and drinks.Soy can also affect hormone absorption, so it's important for people on hormone therapy to separate the timing of medication and soy product intake, and not overindulge. At the same time, soy itself is not dangerous for healthy people and does not cause thyroid diseases. Gluten and dairy products only need to be restricted in the presence of celiac disease, confirmed gluten sensitivity, or lactose intolerance.Can excessive consumption of foods high in iodine be as harmful as a deficiency?Iodine is a critical trace element for the synthesis of thyroid hormones, but in everyday life, it is quite difficult to create an excess of iodine solely through diet, says Tetiana Bukhta.The daily requirement for iodine depends on age and physiological state:for children under 6 years of age – approximately 90 mcg per day,for children aged 6–12 years – approximately 120 mcg,for teenagers and adults – about 150 mcg,For pregnant and breastfeeding women – up to 250 mcg per day.Even foods with a high iodine content, such as seaweed or seafood, rarely lead to an overdose when consumed in moderation and irregularly. Therefore, for most healthy people, the fear of "too much iodine from food" is exaggerated.However, what truly creates a risk of overdose is the independent use of iodine-containing dietary supplements or medications without proper indications and monitoring of test results."Therefore, we recommend a varied diet to our patients, which may include seaweed, fish, mussels, shrimp, as well as plant-based foods containing iodine – beets, dark grapes, lettuce leaves, apples, and walnuts," the doctor adds.How sugar, ultra-processed foods, and trans fats affect hormonal balanceSugar, ultra-processed foods, and trans fats are not a direct cause of thyroid diseases, but they create a metabolic and inflammatory background in which the endocrine system is forced to work under constant overload, explains the endocrinologist:– An excess of sugar in the diet leads to frequent and sharp fluctuations in blood glucose and insulin levels. Over time, this can contribute to the development of insulin resistance – a condition in which cells respond less effectively to hormonal signals. In such an environment, the effectiveness of many hormones, including thyroid hormones, decreases, even if their blood levels formally remain within the normal range.Ultra-processed foods and trans fats are linked to chronic low-grade inflammation, which may not have pronounced symptoms for years but gradually affects the immune system. In the presence of a genetic predisposition, such an inflammatory background can contribute to the development or exacerbation of autoimmune diseases, including autoimmune thyroiditis.In addition, a diet high in ultra-processed foods is usually nutritionally poor: there may be enough calories, but the body is deficient in iodine, selenium, zinc, iron, and B vitamins – all key for the synthesis and action of thyroid hormones.At the same time, hypothyroidism or autoimmune disorders do not arise solely from sweets or fast food. The risks increase in combination with a sedentary lifestyle, excess body weight, chronic stress, and bad habits, which generally disrupt hormonal balance.Does the way you cook food matter for your thyroid health?The method of cooking matters, and not only for the thyroid gland but also for the entire endocrine system in general. During frying, especially at high temperatures and with a lot of fat, so-called advanced glycation end products are formed. These are compounds that can enhance inflammatory processes in the body, negatively affect tissue sensitivity to hormones, and eventually disrupt metabolic balance. For the endocrine system, which works very sensitively, such a chronic inflammatory background is undesirable.At the same time, steaming, stewing, boiling, and baking at moderate temperatures allow you to preserve significantly more vitamins, trace elements, and biologically active substances in the product. In addition, such food is easier to digest and does not create an additional burden on the metabolism.In everyday life, the concept of a "healthy eating plate" can serve as a useful guide, helping you avoid getting bogged down in minor restrictions and instead see your diet as a whole:Approximately half of the plate should be made up of vegetables and fruits – as a source of fiber, vitamins, and antioxidants.a quarter of the plate should be whole grains (oatmeal, buckwheat, brown rice, whole-grain bread), which provide stable, "slow" energy;Another quarter is sources of protein: fish, poultry, legumes, nuts.At the same time, it is worth limiting the consumption of red and processed meat, avoiding an excess of fried foods, using vegetable oils in moderation, and not forgetting about sufficient water balance.What are the most common dietary mistakes people make when trying to "heal" their thyroid gland?The most common mistake is trying to treat the thyroid gland on your own without understanding your own hormonal status. This leads to the uncontrolled use of dietary supplements, because it seems that a "natural" supplement is safe a priori. But this is not the case, as biologically active supplements can contain high doses of trace elements, which, when in excess, are no less harmful than their deficiency.A classic example is selenium. It is indeed necessary for the normal functioning of the thyroid gland, but excessive consumption (in particular, through regular consumption of large quantities of Brazil nuts or selenium supplements) can lead to toxic effects: hair loss, brittle nails, and nervous system disorders.Another common mistake is:Self-prescribing iodine. Iodine is mistakenly perceived as a universal "pill for the thyroid gland," although an excess of iodine can provoke or exacerbate autoimmune thyroid diseases, particularly autoimmune thyroiditis. Taking iodine preparations without prior tests and a doctor's recommendations is especially risky.People also often go to extremes with so-called "superfoods," trying to eat them daily and in large quantities, expecting a quick "recovery." In reality, no single product can "cure" the thyroid gland, and an excess of even beneficial substances disrupts the balance.– I also see a problem with restrictive diets that eliminate gluten, dairy products, cruciferous vegetables, or entire food groups from the diet without any valid reason. Such restrictions often lack medical indications and can lead to deficiencies in protein, calcium, iron, B vitamins, and other important nutrients, which only worsens the overall condition of the body.The thyroid gland doesn't need extremes, as it's sensitive to nutritional balance, micronutrients, lifestyle, and stress levels. That's why any changes to your diet, taking supplements, or "preventative" regimens only make sense after consulting a doctor and understanding the actual state of your hormonal system, the endocrinologist explained.Read alsoWhen it seems like everything is under control, but in reality it's not: how stress breaks the thyroid gland