Organic milk could contain a third less iodine than normal milk, scientists claim - but the organic milk industry has issued a swift rebuttal (file picture) Pregnant women and breastfeeding mothers who drink organic milk may be putting their child’s health at risk, scientists claim. They say it contains a third less iodine than normal milk – which could affect infant brain growth and intelligence later in life. UHT longlife milk was also found to have similarly low levels of the mineral, academics from Reading University found. Because milk is the main source of iodine in the British diet – providing 40 per cent of the average daily intake – switching to organic may have a significant impact on health, they warn. The organic milk industry last night issued a swift rebuttal. Organic milk is often drunk for its supposed health benefits, with claims that it contains omega-3 fatty acids that are good for the heart. And in response to environmental and animal welfare concerns, the sector is growing. One in every 20 pints of milk bought is now organic and more than 300 million pints were sold in the UK last year, worth £160million. But researchers said that because organic farmers do not give their cows as many artificial supplements the milk lacks iodine, which is important for the healthy development of babies in the womb and in their first months of life. The mineral is thought to have a major impact on the formation of the brain, with repercussions for IQ and school success later in life. Study author Professor Ian Givens said the findings could have ‘serious implications for public health’. He stressed that organic milk was not ‘bad’ for health, and said Britons could get the same amount of iodine as in a pint of normal milk by drinking an extra half-pint of the organic variety. But he warned that without careful monitoring, the country risks ‘sleepwalking’ into a new health crisis in the 21st century. Iodine deficiency was once endemic in parts of the UK, with thousands in the 1930s and 1940s suffering from the thyroid condition goitre. The latest findings, published in the journal Food Chemistry, were based on skimmed, semi-skimmed and full-fat milk purchased at four unnamed supermarkets. But the organic milk industry last night said the research – conducted in January last year – was out of date. Pregnant women and breastfeeding mothers who drink organic milk may be putting their child’s health at risk due to the smaller amount of iodine in the product. Iodine is essential for brain growth . OMSCo, which provides two-thirds of Britain’s organic milk, said procedures had been changed over the past 18 months to ensure more iodine is fed to dairy herds. Peter Melchett, of the Soil Association, also dismissed the findings, saying organic milk had ‘scientifically proven’ health benefits. Research in 2013 by experts in Bristol and Surrey found that children born to women deficient in iodine have a 60 per cent risk of lower IQ scores at the age of nine. Professor Jean Golding, one of the authors of that study, last night welcomed the new findings, saying: ‘Milk is a major source of iodine, but it is important to know which sort of milk is most appropriate.’
Milk is main source of iodine in British diet, providing 40% of daily intake.
Academics say switching to organic milk could significantly impact health.
UHT longlife milk was also found to have similarly low levels of the mineral.