Watching his 5-year-old son participate in a holiday pageant at school last December, Gary Greaves says he was blown away by how much Brandon had changed since first being diagnosed with autism in 2005. “We thought he would have to go to a school for autistic children,” says Greaves, “but Brandon has improved enough that he is able to be in a normal kindergarten class. We wouldn't have dreamed of that a year and a half ago.”

Greaves and his wife tried various treatments for their son, but eliminating dairy, gluten, and soy from Brandon's diet packed the greatest therapeutic punch, the Florida-based father says. “Once we removed those, Brandon was a lot more verbal, and his tantrums were limited. He still has autism, but he is doing much better.”

Behavioral and educational therapies continue to serve on the front lines of autism treatment. But mounting evidence shows that nutritional changes, including the removal of common problem foods, can benefit many autistic children, as well as those with other conditions that affect behavior and learning, such as attention deficit hyperactivity disorder (ADHD). “Many parents have come to realize that diet is an important piece [of the treatment puzzle for these children],” says Dana Laake, RDH, MS, LDN, and co-author of The Kid-Friendly ADHD and Autism Cookbook (Fair Winds, 2006).

Diet and the new childhood epidemics

Brandon Greaves is one of the estimated 1.5 million people in the U.S. living with autism, a complex condition that affects the normal functioning of the brain and inhibits social interactions and communication skills. ADHD — which is characterized by impulsiveness, hyperactivity, and the inability to focus — is another neurological disorder on the rise in young children, affecting an estimated 3 percent to 5 percent of U.S. school-aged kids.

Theories abound on why autism and ADHD cases have jumped dramatically, says Wendy Weber, ND, MPH, PhD, research associate professor at Bastyr University in Kenmore, Washington. Researchers continue to speculate about abnormalities in brain development; diets stripped of essential fatty acids, magnesium, and other crucial nutrients; and increased toxin exposure, which can be particularly detrimental to those children who are genetically built with an impaired ability to detoxify their systems. Researchers don't believe diet alone causes these conditions. But a growing number of physicians and families are adding diet interventions to their treatment plans because evidence shows that many children with autism and ADHD have problems digesting and absorbing nutrients from food, Laake says.

The gut-brain connection

The gut-brain connection in autism and ADHD isn't yet fully understood, Weber says. However an increasing number of experts believe that many children with these conditions have food sensitivities and are unable to digest the proteins such as casein and gluten in specific foods. Signs of food sensitivity include gastrointestinal problems, chronic congestion, frequent ear infections, or cravings for specific problem foods, says Laake. Lab tests can help identify some sensitivities.

Casein (a protein found in dairy products), gluten (a plant protein found in wheat, rye, and other grains), and soy trigger the most problems, Laake says. Many researchers believe that when these foods are not completely digested, residue remains in the digestive tract in the form of peptides — short chains of amino acids. If the intestinal lining becomes too permeable or “leaky” — as is the case, theoretically, in many autistic and ADHD kids — these peptides get absorbed into the bloodstream, creating a morphine-like effect that can affect neurological functions, such as speech and auditory processing, and cause a child to zone out or withdraw from others, says Laake.

In some kids, food sensitivities produce symptoms that mimic signs of ADHD, including hyperactivity and the inability to focus. When kids eliminate trigger foods, their symptoms decrease substantially. “If we can identify and address food sensitivities, it can make a dramatic difference for some children,” Weber says. “The challenge is figuring out which sensitivities they have.”