A recent review published in the Journal of Endocrinological Investigation examines how nutrition and dietary patterns influence thyroid function and autoimmune thyroid diseases, according to an article released on Apr. 7.
Thyroid disorders affect many people worldwide, with autoimmune thyroid diseases being particularly common. The review highlights that while iodine is essential for producing thyroid hormones, a broader range of nutrients—including selenium, iron, zinc, vitamin D, and vitamin B12—also play important roles in supporting healthy thyroid function.
Researchers conducted a structured literature review using studies from January 2005 to June 2025. They found that both deficiency and excess of iodine can disrupt thyroid health. "The U-shaped relationship between iodine intake and thyroid disorders" means that inadequate intake can lead to conditions like goiter or hypothyroidism, while too much may trigger hyperthyroidism or autoimmune issues in those genetically predisposed.
The study also points out that selenium helps protect the thyroid from damage by free radicals but notes that supplementation is not recommended unless there is a proven deficiency. Other nutrients such as zinc and iron are crucial for enzyme regulation related to hormone production; deficiencies increase the risk of hypothyroidism or autoimmune disease.
Dietary patterns were found to be just as significant as individual nutrients. A Mediterranean diet—rich in fruits, vegetables, whole grains, fish, and olive oil—was associated with better outcomes for the thyroid due to its antioxidants and anti-inflammatory properties. In contrast, Western diets high in saturated fats and processed foods were linked with chronic inflammation and higher rates of autoimmune disease.
Restrictive diets like gluten-free or lactose-free regimens showed no clear benefit for those without specific intolerances; some even led to nutritional deficiencies. Similarly, moderate consumption of soy-based foods or cruciferous vegetables was generally safe if iodine intake was sufficient.
The findings suggest nutrition plays a complex role in maintaining thyroid health beyond just iodine intake alone. The authors conclude that evidence-based dietary guidance—particularly encouraging nutrient-rich eating patterns such as the Mediterranean diet—can help improve individual outcomes while addressing the global burden of thyroid diseases.
