The popularity of dairy free milk alternatives has soared in recent times but a new study, carried out by the University of Surrey and published by the British Journal of Nutrition has reported that they are not a suitable substitute for cows' milk when it comes to iodine content.
Dairy milk is the main source of iodine in our diet, providing 40% of the average daily intake, so switching to plant-based alternatives may impact health.
Milk-alternative drinks contain iodine levels under 2% of that found in cow's milk
The study looked at 44 non-fortified milk-alternative drinks and revealed iodine concentrations of under 2% of that found in cow's milk. Specifically, the milk alternatives analysed were soya, almond, coconut, oat, rice hazelnut and hemp drinks, and they were compared to semi-skimmed milk.
Professor Margaret Rayman, an expert in nutritional medicine at the University of Surrey, said:
"Many people are unaware of the need for this vital dietary mineral and it is important that people who consume milk-alternative drinks realise that they will not be replacing the iodine from cows’ milk which is the main UK source of iodine."
Dr Sarah Bath, lecturer in public health nutrition at Surrey, added:
"If avoiding milk and dairy products, consumers need to ensure that they have iodine from other dietary sources, where possible."
The rise in popularity of dairy free milk alternatives come with a proliferation of ‘clean-eating’ diets that focus on avoiding processed foods and eating raw produce.
Earlier this year the National Osteoporosis Society warned of the consequences of the clean-eating fad sweeping the country after finding that more than a fifth of young adults had severely cut their milk intake.
Nearly three quarters of teenage girls in Britain are iodine deficient
Incredibly an estimated 70% of teenage girls in Britain are iodine-deficient, and doctors are also concerned that pregnant women are not consuming enough of it.
Iodine is required to make thyroid hormones, which help keep cells and the metabolic rate healthy. It is also widely recognised as essential for normal fetal brain development, therefore its particularly important that adequate amounts are consumed during pregnancy.
In fact previous research by the University of Surrey found a link between poor maternal iodine levels and lower IQ and reading scores in their children. Further to this a Norwegian study showed a link between low iodine levels in pregnancy and reduced language and fine motor skills in 3 years olds.
Sources of Iodine
While milk is the main source of iodine in the UK it is not the only place you can find this important mineral - other good sources include white fish and eggs. Seaweed is an extremely reliable and particularly concentrated source of iodine so it's important not to consume too much as excessive iodine intake can cause thyroid
If you are unable to obtain adequate amounts of iodine through diet then iodine supplementation could be an alternative. However, if you are unsure about how much iodine you are currently consuming through your diet then it's important to consult your doctor, especially if you are pregnant.
The Iodine Food Fact Sheet provided by The British Diabetic Association is a particularly useful resource if you wish to find out more about iodine, its food sources and how much you need.