Protecting the Next Generation
Iodine deficiency: Is Australia experiencing a brain drain with our children ?



Bread manufacturers will next year be required to add iodine to bread because of concerns among health authorities of a re-emergence of iodine deficiency diseases (IDD).

The demands for iodine increase markedly during pregnancy and lactation. Worldwide IDD is the single greatest cause of preventable mental retardation. Severe deficiency causes cretinism, stillbirth and miscarriage, but even mild deficiency can significantly affect the learning ability of children by up to 10-15 IQ points. Iodine is a chemical element which is an essential micronutrient necessary for the production of the thyroid hormones that regulate growth -normal brain and physical development, and energy expenditure. An adult only requires about a teaspoon of iodine over a lifetime, but it is not stored in the body and requires constant renewal.

It occurs naturally in many vegetables but eastern and southern Australian soils are poor in iodine. The most potent sources of iodine are fish and sea-weeds, dairy foods and eggs. In the past, milk became enriched with iodine because the dairy industry used iodine-based disinfectants to clean milk bottles.

Interventions to address iodine deficiency in Australia have been instigated before. In the 1920s iodised household salt was introduced and in 1947 tablets were provided free of charge as part of a goitre prevention programme. Public education was also part of these initiatives. Today some table salt is iodised, but reduction in salt consumption for health reasons and greater use of commercial salt, sea salt and rock salt which do not contain added iodine mean that only 10% of salt consumed is fortified with
iodine. Changing habits have given rise to the hidden phenomenon of the re-emergence of IDD.

Science has alerted us to the need to treat not only the visible disease of goitre but the far more insidious outcome of brain damage in the next generation. Most recently health authorities wanted to add iodine to a range of products but dieticians objected to the plan on the grounds that it would encourage consumption of some foods that were high in fats and salt. As a result it was decided to limit iodine fortification to bread but use a heavier concentration than would otherwise have been the case.

For some people who suffer from an over-active thyroid gland, iodine may need to be limited. Ingredients listed on packaged bread must identify the presence of iodised salt. .Organic bread will not be required to contain iodised salt. Australian health ministers agreed in March that the iodine deficiency was serious enough to justify mandatory fortification but left the final decision to the board of Food Standards Australia New Zealand (FSANZ).

The timing of the change in October 2009 will coincide with the introduction of folic acid into bread. The addition of this B complex vitamin is expected to prevent between 14 and 49 neural tube defects in pregnancies annually. The -dual introduction of these additives will require bread labels to be changed only once. In the meantime it is important to ensure that we are all ingesting enough iodine by using iodised table salt and
eating fish regularly. Pregnant women, lactating women and children may need to take
supplements. Education remains an important part of this public health measure.

Reprinted from House Call, Newsletter of the Community Consultative Committee, Vo19,Issue 3, Sept.2008 in Madeleine Strong Cincotta, editor Scleroderma Outlook Newsletter No. 170 February 2009