07 June 2011

Iodine and the thyroid gland

Overweight? You've probably wondered whether this is due to a thyroid problem. Find out more about the important role played by iodine in regulating thyroid metabolism.


If you struggle with weight problems you have probably wondered if this is because you have a thyroid problem. In this article we have a look at thyroid functions and the important role played by the trace element iodine in regulating thyroid metabolism.

A long history
Physicians in ancient Greece and Egypt already knew that they could treat patients with grossly swollen necks, or goitre, by prescribing burnt, ground sea sponges. The essential ingredient in these sponges was of course iodine and the patients were cured because the condition “common goitre”, or “hypothyroidism” (underactive thyroid), responds to iodine supplementation.

In 1820, a Dr Coindet from Geneva started to analyse the iodine content of foods and drinking water and discovered a striking relationship between iodine deficiency in soil, water and plants and the occurrence of goitre in parts of Europe.

The first attempts to supplement the diets of school children and so prevent goitre in France in 1860 failed miserably because the dose of iodine that was prescribed was so high that the children developed symptoms of iodine poisoning.

It took 60 years before the Americans were able to prove that, when given at the right dose, iodine supplements prevent endemic goitre in young and old. Despite these advances in the use of iodine to prevent goitre, large scale iodine supplementation was not common, especially in developing countries.

Only in recent years have governments all over the world made iodine supplementation of staple foods or food products mandatory in an attempt to stamp out this wide spread deficiency disease.

Iodised table salt in South Africa
In South Africa, common table salt has been iodised for the past few years. If you were not aware of this, check all the commercial table salt products on the shelves of your supermarket and you will see that every label states: "Contains potassium iodate."

What this means is the following:

  • Anyone who uses table salt in South Africa should theoretically not be prone to developing goitre or hypothyroidism (having said this, always remember to use table salt in moderate quantities and not to overdo your salt intake, which can lead to problems like kidney damage and high blood pressure)
  • Anyone who is allergic to iodine (and there are quite a few people who suffer from an iodine allergy), should ask their chemist for table salt that is not iodised (this may seem unfair to those people who now have to pay extra for their table salt, but the reasoning behind the blanket supplementation of table salt is that the majority of people in South Africa will benefit)

Why do we need iodine?
The answer to this question is that without iodine the thyroid gland is not able to make thyroid hormones. The thyroid gland has rightly been called the "Conductor of the Orchestra of the Body" because it contributes so greatly to our health and wellbeing.

For example, thyroid hormones…

  • stimulate oxygen consumption. This function is also called the calorigenic action which immediately indicates that this hormone increases the use of oxygen in practically all body tissues and helps to burn fuel stores and release energy
  • help to maintain body temperature and prevent us from feeling cold
  • stimulate the heart to beat faster
  • help convert beta-carotene to vitamin A in the body
  • stimulate milk production during breastfeeding
  • help to ensure that nerve impulses are transmitted through the nervous system quickly and efficiently
  • have a dramatic effect on the normal development of the brain while in the foetus is still in womb, and on children during childhood.
  • are essential for normal menstrual cycles and fertility
  • increase the rate of carbohydrate absorption out of the digestive system
  • lower cholesterol levels in the blood
  • play an essential role in normal growth and development of infants and children

The list just goes on and on - proof that the thyroid is one gland we cannot do without. At the same time, we need iodine to make sure that our thyroid glands are functioning in peak condition. - (Dr I.V. van Heerden, DietDoc)

Any questions? Ask DietDoc

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