Iodine

What is Iodine?

Iodine is an essential trace element which is important for hormone development in the body. Our bodies normally contain 20-30g of iodine, with more than 75% of that amount found in the thyroid gland and the rest distributed throughout the body. Iodine is important in our diet as it is required to make hormones which are produced by the thyroid gland. The thyroid gland helps to regulate many metabolic processes in the body, such as promoting growth and development of the body including the brain. Iodine deficiencies in children can lead to poor cognition and mental retardation. Inadequate iodine intake may also lead to an enlarged thyroid gland, known as a goitre. Long term deficiency can lead to hypothyroidism with symptoms including dry skin, hair loss, fatigue and slowed reflexes.

New iodine fortification in bread

Since October 2009 it is mandatory for manufacturers to fortify bread with iodine (from iodised salt). Mandatory fortification involves adding a certain vitamin or mineral to a specified food. Food Standards Australia New Zealand (FSANZ) developed mandatory iodine fortification to help combat the re-emergence of iodine deficiency in the population. The only exceptions to this regulation are organic bread and bread mixes, which will not be required to contain iodised salt. To verify whether iodised salt has been added to these products, check the ingredient list on the product or ask the baker. Manufacturers must list the added mineral on the label of food containing the mineral.

Why might iodine intake be low in Australia?

• People are adding less salt to their cooking these days, therefore the iodised salt consumption has dropped.
• People are eating more processed foods, which are not required to be made with iodised salt.
• There is less iodine in milk due to changes in processing techniques.
• There is a lack of iodine in Australian soils, meaning it is not absorbed into our fresh produce?

Where is iodine found in our food supply?

Iodine is found in a variety of foods as it mainly originates in the ocean and the soil. The amount contained in plants depends on the iodine level of the soil in which the plants are grown.

The richest natural food sources of iodine are saltwater seafood such as clams, lobsters, oysters, sardines etc.

Some salts are iodised to help combat the low intake of iodine in Australia. The iodine in these salts is derived from mined mineral sources and does not come from animal or plant sources. Iodine also comes from iodophors which are a disinfectant used in processing, coloring agents, and dough conditioners. Diluted iodophor is used in the dairy industry and often by homebrewers and home wine makers to sanitize equipment and bottles.

How much iodine do we need?

Did you know?

Goitrogens are substances that suppress the function of the thyroid gland by interfering with iodine uptake. These include some drugs and chemicals but some raw foods also contain goitrogens, which can be deactivated by heating/cooking. Some examples include cabbage, turnips, peanuts, cassava, and soybeans.

Selenium plays an important role in forming the active form of the thyroid hormone T3, therefore it is ideal to include selenium rich foods in the diet. These include cereals (corn, wheat, and rice), nuts (brazil nuts and walnuts), legumes (soybeans), meat, seafood, eggs and dairy.

Tips to get enough iodine in your diet

A more natural way to get adequate iodine levels in your diet, compared to using processed iodised salt and manufactured breads, is by adding kelp (seaweed ) to your rock salt. You can use your Thermomix to grind your own rock salt and kelp together to your desired consistency. You can then add your iodine enriched salt to meals, homemade breads etc.
Include seafood in your diet regularly; aim for 2-3 meals per week. Try out some recipes from the Thermomix seafood cookbook 'A seafood bounty'.