What is the autism diet?

There are a couple of different theories as to why children with autism can benefit from a diet free from gluten and casein. One draws a connection between food allergies and behavioral problems. An allergy is essentially an extreme inflammatory response by the immune system to a substance that it sees as an invader. Allergies can manifest in a wide variety of physical symptoms, including diarrhea, vomiting, hives, wheezing and rashes.

Children with autism often have trouble communicating, so they may not be able to tell their parents that they're experiencing painful symptoms like acid reflux and stomach cramps. Instead, they scream, act aggressively and throw temper tantrums. The discomfort, pain and other physical reactions from the allergic response could trigger autistic behaviors.

­Another theory states that many children with autism have a "leaky gut," also known as increased intestinal permeability. This theory suggests that autistic children have tears and holes in their intestinal walls, possibly due to damage from toxins, antibiotic sensitivity or infections (such as an overgrowth of the yeast Candida albicans). In addition, these children may lose healthy digestive bacteria and have damage to the cells that produce enzymes needed to absorb certain proteins (such as gluten) properly.

Both leaky gut and problems with absorbing specific proteins, the theory goes, can cause intestinal contents to enter the bloodstream. This not only includes toxins and bad bacteria, but also protein molecules that haven't been fully digested. The latter may actually lead to food allergies because the immune system treats the molecules as foreign matter. It can also lead to what some autism researchers call the opioid effect.

Proponents of the leaky gut theory believe that the partially digested protein molecules from gluten and casein, also known as peptides, can reach the brain via the bloodstream. Peptides have a molecular structure similar to that of your brain's natural opioids (endorphins), so they're drawn to the brain's opioid receptors. This leads to problems with behavior, speech and social skills. Just as opioid drugs such as heroin are addictive, so are foods high in gluten and casein for children with leaky gut.

Some autism researchers have tested the urine of these children and found high levels of these peptides, which seem to support the leaky gut syndrome theory. Researcher Dr. Paul Shattock has drawn a connection between escalating levels of peptides and the most severely impaired autistic children [aource: McCandless]. However, a March 2008 study published in the Archives of Diseases in Childhood by British researchers found that children with autism didn't have a higher level of peptides than those who did not have the disorder.

Many doctors don't believe that leaky gut syndrome exists. Some children with autism do have food allergies when tested, but not all. But for their parents, some don't mind that there's not science-based evidence to back up the autism diet. What matters is that it worked for their child. We'll look at exactly what a gluten-free/casein-free (GFCF) diet entails, as well as avoiding salicylates and other foods, next.

A 2008 survey conducted by the Autism Research Institute showed that out of the 2,500 cases in which a gluten-free, casein-free (GFCF) diet was used in the treatment of autism, 66 percent of children showed improvement. Fifty-two percent of the more than 6,300 cases in which parents just eliminated casein also got better. However, not all children with autism experience benefits from special diets.

It's pretty challenging to avoid all gluten and casein, and it's important to discuss any dietary changes with a doctor. Most parents begin with removing casein, which is easier to do. Going on the full GFCF diet is generally a slow process that involves eliminating one food at a time, and most believe that the child should be casein-free for about a month to see if there are improvements. Once gluten is removed, the trial period should last at least four months.

Removing all casein and gluten from a child's diet means paying a lot of attention to ingredient lists. The obvious foods containing casein include milk, all forms of cheese, yogurt, ice cream and butter. However, it can also be found in cookies, hot dogs, vitamins, cream soups and salad dressing. If the ingredient list includes casein, caseinate, sodium caseinate, lactose or whey, then it's not allowed on a casein-free diet.

Gluten is even more prevalent. In addition to being in anything made with wheat (bread, crackers, baked goods, pasta), it can also be found in other grains, such as rye, barley and oats. Soy sauce contains gluten, and so do hot dogs, lunch meats, seasonings and spices, licorice, tea (if the tea bags are sealed with wheat paste) and a host of other prepackaged foods. Gluten is even used in nonfood items like toothpaste, lip balm and lotion, so parents must read those labels, too. Those who have gotten positive results from the diet stress the importance of eliminating all casein and gluten and claim that accidental slip-ups have resulted in a return of autism behaviors.

So what do children on GFCF diets eat? There are lots of gluten-free foods available in grocery stores and health-food stores due to the numbers of people with celiac disease, an autoimmune disorder affecting the small intestine that results from a reaction to a specific type of gluten. Most children on these diets eat a lot of lean protein, fruits and vegetables.

Although the GFCF diet is the most common autism diet, some parents take it a step further and remove other foods as well. Those who believe that yeast overgrowth can cause autistic behavior restrict sugar intake because sugar is food for yeast and encourages its growth. The yeast-free diet prohibits any fermented foods (such as vinegar) as well as any foods that may contain molds, like mushrooms.

Other diets may remove artificial colorings, flavorings and preservatives because they can contain salicylates, a plant compound also found in some fruits. The connection between artificial colorings, flavorings and preservatives and behavior disorders isn't new; a similar diet has been used to treat children with ­ADHD since 1979 (and has also been controversial).

For a more in-depth look at autism, related disorders and the issues surrounding it, try the links on the next page.