Lifestyle
Cutting out cows' milk? Here's how to keep up your iodine intake
The Guardian · 03 Oct 2017
Cow’s milk seems deeply unfashionable at the moment with sales of soya, almond and other milk substitutes growing year on year. Dairy producers are hitting back with the introduction of a fizzy fruit and milk drink (no, me neither). But a recent study by the University of Surrey found that the majority of milk alternatives do not have adequate levels of the mineral iodine, with concentrations at around 2% of that found in cow’s milk (although some are fortified).
That is a worry because we need iodine to make thyroid hormones that regulate metabolism and are essential for brain development in the womb and early life. Babies born with low levels of these hormones (hypothyroidism) may have learning difficulties in later life. All newborn babies in the UK are currently screened at five days old for the condition and given prompt treatment if diagnosed. But evidence suggests that teenage girls and pregnant women are increasingly likely to have low iodine levels and it is unclear what repercussions this may have on them or their children.
Dairy products and white fish are the important dietary sources of iodine in the UK and the low levels in teenage girls may be due to the trend of cutting out dairy, especially cow’s milk. Many countries add iodine to salt but not in the UK, as excess iodine is also bad for thyroid function. Seaweed such as kelp has lots of iodine, but you can have too much of a good thing so it is best not to eat it more than once a week, especially during pregnancy.
So how do you know how much iodine to eat or drink? Adults need 150mcg a day and pregnant or breastfeeding women need 200mcg a day. One portion of white fish, two cups (400ml cow’s milk) or two yoghurts a day should cover it. Vegans should consider supplements. Everyone else might consider going back to cow’s milk - although maybe not the fizzy type.
That is a worry because we need iodine to make thyroid hormones that regulate metabolism and are essential for brain development in the womb and early life. Babies born with low levels of these hormones (hypothyroidism) may have learning difficulties in later life. All newborn babies in the UK are currently screened at five days old for the condition and given prompt treatment if diagnosed. But evidence suggests that teenage girls and pregnant women are increasingly likely to have low iodine levels and it is unclear what repercussions this may have on them or their children.
Dairy products and white fish are the important dietary sources of iodine in the UK and the low levels in teenage girls may be due to the trend of cutting out dairy, especially cow’s milk. Many countries add iodine to salt but not in the UK, as excess iodine is also bad for thyroid function. Seaweed such as kelp has lots of iodine, but you can have too much of a good thing so it is best not to eat it more than once a week, especially during pregnancy.
So how do you know how much iodine to eat or drink? Adults need 150mcg a day and pregnant or breastfeeding women need 200mcg a day. One portion of white fish, two cups (400ml cow’s milk) or two yoghurts a day should cover it. Vegans should consider supplements. Everyone else might consider going back to cow’s milk - although maybe not the fizzy type.
