High-fat diets may cause attention deficit disorder in kids

High-fat diets may lead to anxiety and attention deficit hyperactivity disorder (ADHD) in children, a new study has claimed. "We found that a high-fat diet rapidly affected dopamine metabolism in the brains of juvenile mice, triggering anxious behaviours and learning deficiencies. Interestingly, when methylphenidate (Ritalin) was administered, the learning and memory problems went away," said Gregory Freund, a professor in the University of Illinois College of Medicine. Freund said that altered dopamine signalling in the brain is common to both ADHD and the overweight or obese state, according to the study published in Psychoneuroendocrinology. "And an increase in the number of dopamine metabolites is associated with anxiety behaviours in children," he added. Freund's team examined the short-term effects of a high-fat (60 per cent calories from fat) versus a low-fat (10 per cent calories from fat) diet on the behaviour of two groups of four-week-old mice. "After only one week of the high-fat diet, even before we were able to see any weight gain, the behaviour of the mice in the first group began to change," he said. Evidence of anxiety included increased burrowing and wheel running as well a reluctance to explore open spaces. The mice also developed learning and memory deficits, including decreased ability to negotiate a maze and impaired object recognition. Switching mice from a high-fat to a low-fat diet restored memory in one week, he noted. In mice that continued on the high-fat diet, impaired object recognition remained three weeks after the onset of symptoms. "Although the mice grow out of these anxious behaviours and learning deficiencies, the study suggests to me that a high-fat diet could trigger anxiety and memory disorders in a child who is genetically or environmentally susceptible to them," he said. Because the animals adapt to the high-fat fare, the scientists also hypothesised that abruptly removing fat from the diet might negatively affect anxiety, learning, and memory.