Women who are pregnant or planning to have children should ensure they consume the right amount of iodine, which is found in milk, or risk their child having a low IQ, according to researchers.
A study of more than 1,000 pregnant women found those who consumed lower amounts of iodine, which is absorbed from food and found in milk, dairy products and fish, were more likely to have children with lower IQs and reading abilities.
Iodine is essential for producing hormones made by the thyroid gland, which has a direct effect on the development of the foetal brain.
Previous research has shown that conventional milk is better for pregnant women than organic milk. A study published in the British Journal of Nutrition discovered that organic milk contains 42 per cent less iodine than the regular variety.
The study by researchers at Bristol and Surrey universities found two thirds of the 1,040 pregnant women they tested were iodine deficient. These women were more likely to have children with lower IQs, and it was found the lower the iodine the lower the IQ and reading ability.