Food and Thyroid. Diet for a healthy thyroid

The thyroid gland produces, stores and releases essential hormones that regulate metabolism, heart rate and body temperature, as well as playing a key role in growth, fertility and red blood cell formation.

One of the key components that determine thyroid function is genetics. However, there is still a large percentage of variability that is determined by environmental factors, such as: type of diet, alcohol consumption, exposure to pollutants, exercise... But how does this affect your thyroid hormones?

Effect of alcohol and tobacco on the thyroid:

Toxic substances such as tobacco alter the natural balance of thyroid hormones by decreasing thyroid stimulating hormone (TSH) and increasing triiodothyronine (T3) and thyroxine (T4), causing hormonal imbalance. On the other hand, high alcohol consumption also acts as a toxic substance to the body, and has been shown to damage thyroid gland cells, reduce their size and cause hormonal imbalances.

Effect of weight and high BMI:

Another factor that can affect thyroid function is body weight, especially body mass index (BMI), which in turn is related to diet and physical activity. Most studies have found that people with a higher BMI tend to have higher levels of the hormone TSH (you can check your TSH levels with a thyroid test.).

In fact, it is not surprising to find that there is a link between weight and thyroid hormones, as people with hyperthyroidism have generally been found to experience weight loss, while hypothyroidism is often associated with weight gain.

How does diet influence the thyroid?

There are numerous studies that show how diet can influence a healthy thyroid, as well as different nutritional strategies that can be very favourable in the evolution of the main thyroid diseases.

The type of food we eat influences thyroid function, so it's important to eat a balanced and nutritious diet - here are some tips to keep it healthy.

• Consuming enough iodine: Iodine is a mineral essential for the production of thyroid hormones. People who do not get enough iodine in their diet may have an underactive thyroid. Foods rich in iodine include fish, seaweed, dairy products and iodised salt. It is important not to exceed the recommended amount of iodine (150 micrograms per day), as too much can be harmful to the thyroid. If you are iodine deficient, your doctor may recommend an iodine supplement.
• Avoid foods that interfere with iodine absorption: Some foods can disrupt iodine absorption by the thyroid. These include cabbage, cauliflower, broccoli, turnips, radishes and mustard. It is not a matter of avoiding these foods altogether, but of eating them in moderation and in combination with other iodine-rich foods. Especially if you have hypothyroidism or Hashimoto's thyroiditis, you may want to limit your intake.
• Make sure you have enough selenium: Selenium is a mineral that is important for the production and regulation of thyroid hormones. Foods rich in selenium include fish, shellfish, Brazil nuts and sunflower seeds. It is important not to exceed the recommended amount of selenium (55 micrograms per day), as too much can also be harmful to the thyroid.
• Avoid iron deficiency: Iron deficiency may affect the production of thyroid hormones. Iron-rich foods include red meat, cabbage, fish and legumes.
• Eat foods rich in zinc: Zinc is also important for healthy thyroid function. Foods rich in zinc include red meat, nuts, seeds and seafood.
• Avoid excess soya: Soy contains isoflavones that can interfere with thyroid function in people with hypothyroidism or Hashimoto's thyroiditis. If you have a healthy thyroid, there is no need to avoid this food, but if you have a thyroid condition, you may want to limit your intake.
• Hydration: Water makes up more than 60 % of our body weight. Unless you have a medical condition that requires you to limit your fluid intake, such as heart or kidney failure, it is important to make sure you drink enough water throughout the day.

Diet options for hypothyroidism:

There are currently a multitude of possible diets to treat hypothyroidism, the aim is to find the perfect one for each person. Among the most common are the following:

• Elementary diet: Intended for people with severe digestive problems, such as Crohn's disease or eating disorders. This diet involves eliminating solid foods to allow the digestive tract to rest.
• Gastrointestinal and psychological syndrome (GAPS) diet: It is a therapeutic approach that focuses on gut health and its relationship to mental health. It consists of a specific diet that aims to restore the integrity of the intestinal barrier and improve the overall health of the body.
• Gluten-free diet: A gluten-free diet is recommended for people with coeliac disease, which may be more common in people with hyperthyroidism.
• Paleo diet: This diet is based on the dietary patterns of our Paleolithic ancestors. It focuses on eating natural, unprocessed foods that can be hunted or gathered.
• Ketogenic diet: It is a diet low in carbohydrates, moderate in protein and high in healthy fats. The goal is for the body to burn fat instead of carbohydrates for energy.
• Autoimmune Protocol Diet (AIP): It is a food-based approach to reduce inflammation created by autoimmune disorders. It is an elimination diet with slow progressive reintroduction to rule out reactivity.
• Elimination diet: It consists of eliminating any food that contributes to the intolerance, sensitivity or allergy.

It is important to remember that diet is just one of the factors that can affect thyroid health. If you suspect you may have a thyroid problem, it is important to analyse these hormonal parameters to follow a treatment recommended by a health professional.

Bibliographical references:

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