Autism affects how the body functions in a variety of ways, including how a person responds to certain foods. Depending on the severity of the diagnosis, people with autism may struggle with full allergies to certain foods, intolerances to others, or a combination of both.

How do allergies manifest differently in people with autism?

True food allergies occur when a specific food triggers an strong immune response within body. These responses can be anything from hives to full anaphylactic shock, resulting in death if no medical intervention is given. With autism, some foods seem to cause a delayed reaction response-- which is not characteristic of true allergy symptoms. One of the most common reactions is eosinophilic esophagitis. Certain foods will cause a delayed inflammatory reaction in the esophagus and digestive tract. The inflammation can damage the cells of the soft tissue lining these passages.

This condition can be harder to diagnose than a true allergy, simply because delayed food reactions are not as easy to track. It may be unclear at first which food is causing the problem. An allergy specialist will have to preform a number of tests in order to narrow down the cause from a number of possible allergens. Because some autistic children and adults have trouble with verbally communicating discomfort, this problem can go undiagnosed. However, it is important to see an allergy specialist simply because the pain from inflammation can make other autism symptoms, like acting out or difficulty staying on task, worse.

What about food intolerances?

Autism affects cognitive function, but it also has some affect on the body's ability to efficiently process food through the digestive tract. One the reasons that digestion is more difficult for individuals with autism is that they:

  • may have less healthy gut flora that normal. 
  • have underdeveloped chemical pathways for eliminating heavy metals 
  • have slowed digestive response
  • may not have normal detox functions for the by-products of some foods, like sugar and fat.

Most individuals on the spectrum do struggle with constipation, bloating, and other common upsets of the GI tract. Usually, these struggles are made worse when eating certain foods. Because nutritional uptake from the digestive tract is affect, neurological symptoms of autism, such as trouble speaking or difficulty concentrating, may be made worse. Symptoms of food intolerance are most often caused by dairy, wheat, and soy. An allergy specialist can help affected individuals get to the bottom of which foods cause the trouble.

Digestion problems for people with autism can be helped by choosing foods that aid digestion and improve the health of the gut. For most people on the spectrum, it's best to include:

  • foods rich in omega-3 fatty acids. The standard American diet has an overabundance of omega-6 fatty acids, with not enough omega-3s. The imbalance promotes inflammation in the body and upsets the digestive system. It's best to include foods rich in omega-3 fats like walnuts and fish,
  • probiotics. A lack of healthy gut flora is what can lead to bloating and yeast growth in the digestive tract. The best probiotics are live and raw. Living probiotics can be found in fermented foods like sauerkraut and kefir. Kefir can be made from coconut milk or other liquids if dairy is a trigger food.  
  • pre-biotics. Unlike probiotics, pre-biotics help to nourish bacteria that are already in the digestive tract. Foods that are nourishing to gut flora include onions, berries, mushrooms, bananas, and legumes. 

The food that feeds the body is key to preventing disease and improving digestion. This fact does not change when it comes to autism. In order to rule out slow-acting allergies and harmful food intolerances, people with autism should consult with their doctor and may need to see an immunologist or visit an allergy clinic in order to achieve the best physical health possible for them.