ADHD and Western Diet Link in Adolescents

A Western style diet, which typically consists of processed, fried, and sugary foods, has been linked to attention deficit hyperactivity disorder (ADHD) in adolescents by researchers in Australia. This study is a significant step in determining what role diet may play in ADHD.

The exact number of children and adolescents who have ADHD is not known, but according to the Centers for Disease Control and Prevention, 3 to 7 percent of school-age children have the mental health condition, with some studies stating higher rates in some communities. Boys are nearly twice as likely as girls to have ADHD.

Previous studies have linked various environmental factors as possible causes or contributors to ADHD. Lead exposure, for example, has been named as a possible culprit, as have chemicals found in common household products, such as phthalates and polyfluoroalkyl chemicals (PFCs). A recent study has also named organophosphates, which are used to treat pests on fruits and vegetables, as a factor in ADHD.

In the new Australian study, researchers evaluated the dietary patterns of 1,800 adolescents who had participated in the Raine Study, a long-term study that examines diet, exercise, and other measures from birth up to twenty years. The researchers compared the dietary data with the number of adolescents who had been diagnosed with ADHD by age 14 years.

Wendy Oddy, associate professor and leader of nutrition studies at Perth’s Telethon Institute for Child Health Research, said “We found a diet high in the Western pattern of foods was associated with more than double the risk of having an ADHD diagnosed compared with a diet low in the Western pattern,” even after they made allowances for social and family factors. Overall, 115 adolescents had been diagnosed with ADHD, 91 boys and 24 girls.

The researchers looked at specific foods and found that a diagnosis of ADHD was associated with processed meats, red meat, fast foods, high-fat dairy products, and sugary foods. A healthy diet is high in fresh fruits and vegetables, whole grains, and fish, an approach that is high in nutrients, fiber, and omega-3 fatty acids.

Although the investigators are not certain what the relationship between a Western diet and ADHD is, one suggestion is that a Western diet is low in omega-3 fatty acids, which are associated with improved mental health and brain function. Another idea is that the Western diet offers little in the way of essential micronutrients, such as iron, which are critical for brain health, or that the artificial colors, flavors and other additives have a role.

On the flip side, another suggestion is that the impulsive nature of children who have ADHD may lead them to make poor dietary choices and experience cravings for comfort foods. For now, the results of this study suggest that a Western diet may have an important role in ADHD and support further research into the matter.

SOURCES:
Centers for Disease Control and Prevention
Howard AL et al. Journal of Attention Disorders 2010 Jul 14