Mum-to-be's junk food lower baby's IQ? Diet can have direct impact on development of child's brain Study found a link between unhealthy eating and depression which can affect a child's IQ scores Researchers are urging pregnant women to use 'a window of opportunity' to eat healthily and prevent the long-term damage of poor nuitrition Damaging: The research shows that processed foods such as pizza can damage a baby's cognitive develoment Pregnant women who are depressed often turn to junk food for comfort but they could be damaging their children's brain power in later life, warn researchers. A new study found a link between unhealthy eating in pregnancy and depression which can affect a child's IQ scores at the age of eight. Experts say a poor diet during pregnancy has a direct impact on the baby's developing brain. But there is a "window of opportunity" to prevent longer-term problems triggered by poor nutrition, say researchers from King's College London and Canada. They are urging mothers-to-be who are suffering depression to seek help and eat healthier foods to offset the potential harm to their offspring. The research team studied 6,979 women and their children who were part of the Avon Longitudinal Study of Parents and Children in the UK (also known as the "Children of the 90s" study). The women were assessed for symptoms of depression five times between the period when they were 18 weeks pregnant and when their child was 33 months old. They were asked to complete a food questionnaire to assess their eating habits when they were 32 weeks pregnant and again when their child was 47 months old. The children's cognitive function was assessed when they were eight years old by using tests of performance IQ and verbal IQ. Women who had symptoms of depression were more likely to be eating an unhealthy diet, the study found. This meant they were mostly eating processed food such as chips, crisps, meat pies or pasties and junk food, defined as chocolate bars, cakes, or buns, and biscuits, which are high in unhealthy trans fats. The researchers found women who were depressed during pregnancy were more likely to have unhealthy diets, with these factors linked to their eight-year-olds having less good brain power than those whose mothers ate more healthily. Even depressed women classified as eating healthy foods - such as fish, nuts and vegetables - were more at risk of their children having worse IQ scores if they ate a "lower" healthy diet. The research team took into account factors affecting the rate of depression including teenage mother, low maternal education, substance use and criminal lifestyle. The study led by Dr Edward Barker of the Institute of Psychiatry, King's College London was published online by the British Journal of Psychiatry. Danger: The study also found that women who are depressed during pregnancy are also more likely to have bad diets as they seek comfort in fatty food Dr Barker said "Our study provides evidence that prenatal maternal depression symptoms relate to both increased unhealthy and decreased healthy prenatal diets which, in turn, is associated with reduced child cognitive function. During pregnancy, the diet of the mother directly influences the nutritional environment of the foetus, which presumably will affect the development of the foetal nervous system including the brain. The researchers point out their research does not show prenatal depression causes damage to children's cognitive functioning - only a correlation. It is possible that depression is a sign of stress that could be affecting brain development, partly because it affects the way the body processes certain beneficial vitamins. Poor diet at different times in pregnancy can affect different aspects of the maturing brain, says the study. The findings show the importance of encouraging women who are depressed during pregnancy to eat more healthily during a "promising window of opportunity" for changing the outcome for their children, said Dr Barker. He said "Helping women adopt a healthier diet during pregnancy could be highly effective in reducing the association between reduced cognitive functions in children and prenatal maternal depression."