Thyroid problems and diet

Proper thyroid functioning is essential. Can diet help to prevent and treat an over- or underactive thyroid? Read more.

Step 1: Understanding the relationship between thyroid problems and diet
The thyroid gland is one gland we cannot do without. We need the trace element iodine to regulate thyroid metabolism. Without iodine the thyroid gland is not able to make thyroid hormones.

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

When people eat foods that are deficient in iodine they develop hypothyroidism (underactive thyroid) or common goitre. Another condition, hyperthyroidism (overactive thyroid) is not so closely linked to iodine consumption.

In South Africa, common table salt has been iodised for the past three or so 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".

Step 2: Adopting healthy habits

• 1. If you suspect that you have a thyroid problem, consult your doctor first. Have thyroid function tests done and let the doctor decide if you have an overactive or underactive or normal thyroid gland.
• 2. Make sure that the table salt you use contains potassium iodate.
• 3. Don’t take iodine supplements unless advised to do so by your doctor. Although adults need about 150 micrograms of iodine a day, taking more in the form of kelp tablets, see weed extract and iodine drops, can have a toxic effect on the body and should be avoided.

Step 3: Understanding the dietary principles

How much iodine do we need?
Scientists have not yet agreed exactly how much iodine people need to remain healthy, but in South Africa, the Recommended Dietary Allowance (RDA) is as follows:

• 50 microgram/day for infants younger than one year
• 70 micrograms/day for children between the ages of one and three years
• 150 micrograms/day for persons older than four
• 200 micrograms/day for pregnant and lactating women.

The South African RDAs for iodine are very similar to those in America.

Sources of iodine in the diet
Top of the list is seafood - fish, fresh and canned; oysters, prawns, shrimps, crayfish, mussels, and seaweed (the latter is not so popular in our country, but provides people in Japan and the East with plenty of iodine).

The iodine content of other foods, such as cereals, fruits, vegetables, meat, milk and eggs always depends on the iodine of the soil and water in the area where these foods have been produced. So food products produced along our coastline will contain more iodine than foods from inland farms.

Finally there is iodised table salt, which is now available, in fact compulsory, in our country.

The best way of making quite sure that you are getting enough iodine, is to eat fish three times a week. One portion of haddock, for example, contains up to 600 micrograms of iodine.

- (Health24, updated August 2011)