Brain damage. Breast disease. Cardiovascular risk. All of these mental and physical health problems can have an association with iodine deficiency. Yet if you’re reading this in the UK and many other European countries, it’s likely that you are at least slightly iodine deficient.
Most of us have no idea of how potentially serious a health issue this could be.
Iodine deficiency is not only responsible for thyroid health. It could be an underlying factor in a wide range of mental and physical health conditions, from breast cancer to low IQ. Yet there is relatively little awareness of this issue, even within the wider medical community.
The UK is the 7th most iodine deficient country in the world
• Europe has the highest percentage of iodine deficiency in the world, according to World Health Organisation (WHO) research, despite the fact that iodine deficiency is generally presented as a problem of the developing world.
• The UK is the 7th most iodine deficient country in the world, rated between Angola and Mozambique.
• In the 1990s, more than 90% of the population of Denmark was found to be at least mildly deficient in iodine. This led to a high rate of goitre and nodular hyperthyroidism. In 2000 a mandatory programme of iodising household and bread salt was introduced, which reduced the incidence of iodine deficiency and thyroid disease in Denmark.
According to the World Health Organisation, iodine deficiency is the world’s most prevalent, yet easily preventable cause of brain damage.
Severe iodine deficiency can lead to goitre, a swelling of the neck caused by enlargement of the thyroid gland. It can also caus cretinism, a condition of mental and physical retardation.
In the days before the function of iodine in the body was understood, goitre and cretinism were widespread throughout Europe and the world.
Essential for body and mind
Iodine is essential for physical and mental development. It has a direct association with the thyroid as it is needed to produce thyroid hormones, but thyroid hormones act throughout the body, controlling:
• brain development
• basal metabolic rate
• growth and development
• temperature regulation
• fat production
• blood vessels
• bone marrow
Research conducted on 1,040 pregnant women at the University of Bristol in the UK and published in 2013 showed that low iodine status in early pregnancy was significantly associated with the child being in the bottom quartile of scores for verbal IQ at age eight and for reading accuracy and reading comprehension at age nine.
Ideally iodine supplementation should start before conception in order to build up iodine levels in the body. WHO recommendations are for pregnant and lactating women to take 250mcg of iodine every day, and women of childbearing age to take 150mcg of iodine daily.
Iodine and breast health
According to David Brownstein, MD, in his book “Iodine: Why You Need It; Why You Can’t Live Without It”, iodine is essential for breast health. Iodine concentrates in and is secreted by the mammary glands, Brownstein says. Adequate iodine is essential for the maintenance of healthy breasts – insufficient supplies can lead to fibrocystic breast disease, or lumpy breasts.
Brownstein also points out that the therapeutic use of iodine in treating breast cancer was first mentioned in medical literature in 1896.
There is a direct relationship between breast cancer and goitre, and regions of the world where iodine deficiency is prevalent.
Type 2 diabetes and cardiovascular health risks
Studies have indicated links between thyroid problems, cardiovascular issues and Type 2 diabetes. Research conducted in March 2016 found an association between low urinary iodine levels and dyslipidemia, a condition of abnormalities associated with serum lipid metabolism. This is one of the risk factors for cardiovascular disease and a main component of metabolic syndrome.
A 2009 study found that iodine treatment given to children with moderate iodine deficiency improved their lipid profile and reduced their insulin levels compared to a control group.
A 1996 German study of teenage girls with endemic goitre found that iodine therapy reduced plasma cholesterol.
Testing for iodine deficiency
There is no medically accepted way to test for iodine deficiency in an individual. Skin patch tests are commonly discussed online, but are generally considered unreliable. I did a skin patch test using tincture of iodine (or you can use Lugol’s – see box) to assess my own condition, and the iodine was absorbed into my skin so rapidly – within an hour – that I felt this was enough, together with other health factors, to indicate that I had an iodine deficiency problem.
Urinary iodine tests are generally used for population research purposes, but are not considered reliable enough for individual assessment. However, the late Dr Guy Abraham, who pioneered the high dose iodine protocol, developed an individual assessment known as the iodine-loading test whereby 50mg of iodine is taken with a glass of water, and then urine samples are collected over the next 24 hours for lab analysis.
The iodine skin patch test
To do the test, apply tincture of iodine or Lugol’s iodine to the surface of the skin on the inside of your arm or your thigh, or onto your stomach, in roughly a three-inch square, just before you go to bed.
The theory is that the faster the iodine colour disappears from the skin, the more iodine deficient is the person tested. This is because if you are deficient in iodine, your body will quickly absorb the iodine that it needs, but that if you have sufficient iodine in your system, the iodine will remain on your skin.
In general, if the yellow iodine colour has faded after eight hours, or when you get up the next morning, you are considered to have an iodine deficiency. If the colour is still there 24 hours later, you probably have nothing to worry about.
When I did the test, I painted iodine onto my arm and my stomach, and both patches disappeared within an hour – which suggested to me that even given the inaccuracy of the test, my iodine reserves were probably pretty low.
Taking iodine supplements
The recommended daily supplementation dose for iodine is 150mcg, or 250mcg for pregnant and breastfeeding women. Iodine supplements are often taken in the form of kelp tablets, available from chemists, health shops or online.
Most health practitioners do not advise taking more than 500mcg of iodine per day. However increasing numbers of people are taking high dose iodine, sometimes more than ten times the recommended daily dose. This practice is not without health risks, although many people are claiming great success with it. Read more about it in this post.
Why does the UK have such high levels of iodine deficiency?
In the 19th century iodine deficiency caused health problems throughout the world. But as scientists learned more about the importance of iodine, iodised salt was introduced in many industrialised countries – sometimes by law, sometimes on a voluntary basis.
For some reason, the UK was not one of these countries, even though several UK regions were known to have a prevalence of goitre among the population.
However, from the 1920s on, UK dairy farmers have been giving their herds iodine-fortified cattle feed and salt licks. Interestingly, this is done to improve their reproductive performance. The use of iodophor disinfectants has been introduced to clean teats and milk tankers, and iodinated casein is given to cows to increase lactation.
The iodine then finds its way into the milk supply, especially during the winter months when cattle are more dependent on artificial feed.
The general increase in milk consumption from the 1940s, following campaigns by the Milk Marketing Board, is believed to be the reason why estimated dietary iodine intakes in the UK increased from 80mcg to 255mcg between 1952 and 1982.
But over the last couple of decades the consumption of milk and dairy products has declined. Also, an increasing trend to replace iodine compounds used in the dairy and baking industries with non-iodine alternatives may have reduced iodine intake in the population.
A survey published in 2011, the first national survey of iodine status in the UK for more than 60 years, found average urinary iodine levels to be just 80mcg/L, indicating mild iodine deficiency.
In April 2015 news headlines trumpeted research findings that organic milk contained significantly less iodine than conventionally-produced milk. This was because organic herds were not being given mineral supplementation in their feed. However, according to the Organic Milk Suppliers Cooperative (OMSCo), this practice has now changed.
“By early 2015 we announced that we’d achieved comparable results with those in the conventional market,” said Richard Hampton, managing director of OMSCo.
But if – like me – you have an intolerance to all cow’s milk, whether organic or not, you may need to take iodine supplements. WHO recommends a daily dose of 150mcg per day, but some people are taking ten times that amount. Find out more here.