Diet in thyroid diseases

The thyroid gland is responsible for the synthesis of certain hormones that regulate metabolism and other functions. These contain iodine in their composition. Both the excess and defect of iodine in the diet can cause problems at the level of this gland. In addition, there are people who for reasons other than food have alterations in the secretion of these hormones by the thyroid gland.

In the human diet there are various foods and drugs that can modify iodine levels, and therefore should be taken into account, especially in people with thyroid conditions. In Spain, iodine deficiency disorders are less common since commercial salts usually have iodine added to them. However, whenever the specialist recommends it for any of these reasons, the following dietary factors should be taken into account:

Some foods very rich in iodine

• Iodized salt
• Fish (Cod; Mullet; Hake; Canned fish; Mackerel; Herring; Horse mackerel)
• Seafood (Cockles; Mussels; Bivalves and Oysters)
• Crustaceans (Shrimp; Lobster; Lobster)
• Soya shoots; Garlic; Lettuce; Seaweed

Some foods with medium iodine content

• Whole fruit yogurt; Condensed milk
• Chard; Spinach
• Lamb’s lettuce; Spinach
• Mushrooms; Mushrooms; Milk mushrooms
• Carrots
• Apple
• Peanuts and cashews

Some foods with medium-low iodine content

• White bread; Potatoes
• Scarole
• Endives
• Peas
• Orange; Figs; Walnuts

Food substances that decrease the uptake of iodine by the thyroid (Important to take into account in people treated pharmacologically for hypothyroidism), also called “Bozyogenic Foods”.

• Thioglucosides (found in kale and in foods from the Brassicae group such as cabbage; Brussels sprouts; cauliflower; green cabbage; broccoli and nabicol, mustard, as well as all those foods or derivatives of the same family).
• Cyanogenic glycosides (found mainly in cassava)

The heat of cooking can favour the destruction of these compounds.