Linking nutrition and autism

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).

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.”

The GCFC diet

For Brandon Greaves, a gluten- and casein-free (GFCF) diet improved his gastrointestinal and behavioral symptoms and even led to increased language and social function. Nixing soy — another common problem food — helped, too. Kenneth Bock, MD, a family practice doctor in Rhinebeck, New York, and author of Healing the New Childhood Epidemics (Ballantine, 2007), says that although no dietary treatment works for every child, he cuts out gluten and casein for nearly all of his ADHD and autistic patients, for at least a period of time. The GFCF diet “turns lives around,” Bock says. But, despite rising popularity among parents and doctors, the GFCF diet remains controversial.

Current anecdotal evidence suggests that elimination diets may help a surprising number of these kids. “Two-thirds of autistic children and around half of children with ADHD will benefit from a gluten- and casein-free diet,” Laake says. But other experts say better research on the subject is needed. The few studies published to date each had design flaws and results contradict one another. Stay tuned, however: The results from a randomized, double-blind, placebo-controlled study sponsored by the National Institute of Mental Health are expected out this year.

Laake advises an “elimination and challenge” approach, where one food is removed at a time and the child is monitored for symptoms. If no improvement is seen within one month, the food is reintroduced. “The best test is the child's own body,” Laake says. Because gluten and casein are among the most common intolerances, Laake recommends eliminating foods that contain these first, followed by soy, corn, yeast, and other commonly reactive foods, if necessary.

Solving nutrient deficiencies

Fixing nutrient deficiencies can also have positive effects for kids with autism or ADHD. Because of their inability to properly digest food and absorb nutrients, many children with these disorders may be low in zinc, magnesium, B vitamins, iron, essential fatty acids, and other nutrients. These deficiencies, Laake says, can affect everything from behavior to what a carrot tastes like. She advises working with a nutritionist or other knowledgeable health care provider to run tests to pinpoint the exact nutrients lacking in a child's diet and devise a food and supplement program aimed at filling in the gaps.

Lack of magnesium, for instance, can cause hyperactive-like behavior, sound sensitivity, and irritability. Zinc deficiency — a result of a defect in zinc metabolism that's common in autistic children and can be exacerbated by diets high in white flour and other high-glycemic foods — can change a child's sense of taste and smell. This helps explain why autistic children are notoriously picky eaters, often willing to eat only macaroni and cheese, yogurt, and other bland food, Laake says. “For these children, many foods have either no taste or a foul taste.” Poor taste perception won't improve until zinc levels rise. Feeding zinc-rich foods such as seafood, whole grains, beans, and cashews can help, but diet may not be sufficient to meet all of the child's zinc needs. Supplementation is usually the quickest way to get zinc into picky eaters, Laake says (see “Supplements for Autism and ADHD,” page 30).

Because autistic and ADHD kids are often very finicky eaters, Weber says improving and diversifying their diets may help. For her patients, she focuses first on protein-rich breakfasts, replacing foods made with refined flour and sugar with whole grains and fruits and vegetables, and serving water in place of soda or juice. By making these diet changes, Weber says, kids get crucial nutrients and balance their blood sugar levels — which is especially important for those prone to hyperactivity, inattentiveness, and mood swings.

Although Brandon Greaves' father admits that the diet changes aimed at helping a child with autism or ADHD aren't always easy to implement, he says such changes can actually benefit the entire family. “None of us eats fast food anymore,” Greaves says. “It takes a little more time and effort, but we're all eating and feeling better.”

Carlotta Mast is a frequent contributor to Delicious Living.


Supplements for autism and ADHD


Vitamin C reduces harmful oxidants in the body and helps even out levels of dopamine, a neurotransmitter commonly out of balance in children with autism and ADHD. Vitamin E boosts immunity and prevents oxidation of EFAs, which benefit neurological function.

Daily recommended dose: vitamin C, 250-2,000 mg; vitamin E, 100-400 IU


Malabsorption and special dairy-free diets can cause calcium deficiency.

Daily recommended dose: 400-1,000 mg

Essential fatty acids (EFAs)

The omega-3 fats docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) boost brain development and function, and are often low in children with autism and ADHD. Gamma-linolenic acid (GLA), an important omega-6 fat found in evening primrose and borage oils, may also benefit kids with these disorders.

Daily recommended dose: 1,000 mg DHA; 1,000 mg EPA; 80-240 mg GLA


Crucial to protecting the body from heavy-metal overload, magnesium is often low in children with behavioral, cognitive, and mood disorders. Deficiency can cause depression, poor appetite, and muscle spasms.

Daily recommended dose: 100-500 mg


Intake of healthy bacteria increases immunity and helps heal bowel disorders and other gastrointestinal problems associated with autism and ADHD.

Daily recommended dose: 10-30 billion organisms, in capsule or powder form


Vital for proper cognitive function, zinc is typically deficient in autistic children. Supplementation boosts immunity and improves taste perception.

Daily recommended dose: 20-60 mg

Source: Kenneth Bock, MD, author of Healing the New Childhood Epidemics (Ballantine, 2007).

Other diet recommendations for autism and ADHD

Avoid additives, preservatives, and artificial colors

Nitrites and nitrates (preservatives found in bacon, hot dogs, and lunch meats), sorbic acid (found in cheese, frosting, and dried fruits), dyes (especially yellow dye #5), MSG (found most commonly in some Chinese restaurant food, chicken broth or flavoring, and bouillon), and aspartame (an artificial sweetener) can exacerbate symptoms for some children with ADHD and autism. A 2007 Lancet study found that artificial colors and preservatives increase hyperactivity in young children.

Eliminate trans fats

Beyond their negative cardiovascular and neurological health effects, the hydrogenated fats found in processed and fried foods intensify toxic accumulation and cell function problems for children with autism and ADHD.

Go organic

Limit a child's toxic load — which is especially important for kids, such as those with autism or ADHD, who have a decreased ability to handle toxins — by choosing foods free of pesticides and other chemical residues.

Sources: Kenneth Bock, MD, author of Healing the New Childhood Epidemics (Ballantine, 2007), and Dana Laake, RDH, MS, LDN, co-author of The Kid-Friendly ADHD and Autism Cookbook (Fair Winds, 2006).

Parent resources is a parent-support website created by Gary Greaves that includes a national database so parents can locate others in their area living with autism., the website of the Autism Research Institute, offers detailed summaries of the major biomedical treatments currently used to help autistic children, including the gluten- and casein-free diet and vitamin/mineral supplementation.

The Kid-Friendly ADHD and Autism Cookbook (Fair Winds, 2006) by Pamela J. Compart and Dana Laake includes hundreds of recipes and tips for eliminating gluten, casein, and other common allergens.

Healing the New Childhood Epidemics (Ballantine, 2007) by Kenneth Bock helps parents learn more about important nutritional changes and supplements for children with ADHD and autism, and the benefits of heavy-metal detoxification.

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