Children's IQ and Reading Ability Affected by Mother's Milk Consumption During Pregnancy

Pregnant women or women who are planning to have children should ensure they consume enough iodine, which is found in milk and fish, or risk their child having a low IQ and reading ability, according to a new study.

A study published in the British Journal of Nutrition looked at 1,000 pregnant women and 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.

The study showed that iodine deficiency was common - affecting two-thirds of women. Overall, children born to women with the least iodine had a 60 per cent higher risk of lower scores in the tests, a report published in The Lancet medical journal revealed. 

Study leader Margaret Rayman of the University of Surrey and colleagues at the University of Bristol analyzed mother/child pairs from the Avon Longitudinal Study of Parents and Children study by measuring urinary iodine concentration -- and creatinine to correct for urine volume -- in stored samples from 1,040 first-trimester pregnant women.

Previous research has shown that conventional milk is better for pregnant women than organic milk. The study also noted that organic milk contains 42 per cent less iodine than the regular variety.

"Our results show the importance of adequate iodine status during early gestation and emphasize the risk that iodine deficiency could pose to the developing infant, even in a country classified as only mildly iodine deficient," the researchers concluded. "Iodine deficiency in pregnant women in Britain should be treated as an important public health issue that needs attention."

Co-author Dr Sarah Bath said those planning a pregnancy and breastfeeding mothers should make sure their diets contained a good natural supply of iodine. Although salt contains iodine in many other countries, it is not routinely added in the UK.

Their advice, published on the British Dietetic Association website, recommends that pregnant and breastfeeding women need 250 micrograms per day and other adults need 150mcg.