Can a Gluten and Dairy Free Diet Help Autism?

Can A Gluten Free Diet Help Children with ASD?

A silhouette of a child with symbolic autism puzzle pieces


Autism Spectrum Disorders (ASD) are developmental disorders that affect a child’s ability to communicate and interact socially with those around them.

Some parents have found that putting their child on a gluten and casein free diet has helped to improve the behavioural problems children on the autism spectrum often have. Although some clinical studies have been done, there is not enough evidence to medically support the claim at the moment. However, going gluten and dairy free does have potential health benefits, so it may be worth a try.

As with any dietary change, we recommend speaking to your doctor or nutritionist beforehand.

What are Gluten and Casein?

Gluten is a protein found in wheat-based products like bread, pastries and other baked goods. Ingredients like barley, rye and oats contain other gluten-like substances that some people will be able to tolerate and others may not. Some people have an autoimmune condition triggered by gluten, known as coeliac disease, but there are also people who have a milder sensitivity to it.

There is another protein called casein found in all mammalian milk and dairy foods, including cows, goats and ewes, which some people are allergic or sensitive to.

assortment of baked bread with wheatWhy Go Gluten Free?

The GFCF (Gluten-Free Casein-Free) diet was originally intended for coeliacs, but there is a theory as to why it could be useful for a child on the autism spectrum.

It’s suggested that the gut lining becomes inflamed due to an unhealthy combination of bacteria within the bowels, known as the microbiome. Factors such as an overuse of antibiotics and a poor diet can contribute to the unhealthy balance within the microbiome.

Due to the inflammation, the gut wall becomes compromised, known as Leaky-Gut. It then allows partially-digested casein and gluten proteins to pass through into the blood stream and so on to the brain. These proteins have a similar chemical structure to opioids (morphine and heroin) and so can bind with opioid receptor sites in the brain, which can then affect brain signals. Disrupted brain signals can interfere with activity, sensory output and behaviour, contributing to typical autism spectrum related behaviours.

In a healthy person who doesn’t have a compromised gut wall, the gluten and casein protein fragments would become fully digested and free safe amino acids.

How to Go About It

The decision of whether to start your child on a GFCF diet should be considered and discussed with a suitably qualified Dietitian or Nutritionist. Many children with ASD have issues around food and therefore an already restricted diet in terms of what they will eat. If you further restrict their diet by removing certain items or food groups, there’s a chance they will miss out on essential nutrients which can affect growth and development. Speak to a dietitian or nutritionist about what foods or supplements you may need to add.

Emma Mills

Emma Mills

Emma Mills is a trained Paediatric Dietitian, who works with a number of children with autism at her Brain & Body Nutrition clinic. We asked for her opinion on why parents should be careful about implementing the GFCF diet

“Many parents focus on what to exclude from their child’s diet and don’t fill the nutritional ‘gap’ very well. Long-term, this can significantly compromise nutrient intake and lead to nutritional deficiencies, including poor growth, scurvy and a worsening of negative behaviours. The GFCF diet can be very effective but it needs to be balanced, so it’s best to get advice from a suitably qualified practitioner.”

Before starting the diet, it can help to write a list of the behavioural and social problems the child has, plus their frequency and strength levels. Over the course of the diet test, keep a diary of these symptoms to see if there are any changes. Ask teachers, therapists, babysitters and wider family members to actively monitor the behavioural traits and report back to you. You can then add this information to your own experiences to see if your child is improving.

A Nutritionist’s View

Sarah Hanratty

Sarah Hanratty

We asked clinical nutritionist Sarah Hanratty her opinion of the diet.

“A gluten and dairy free diet is the one intervention that I recommend every parent of a child with autism considers implementing,” she said. “I have seen this diet improve eye contact, sociability and behavioural issues when followed fully by children on the spectrum.

“One child I worked with over a period of six months became more connected, less ‘spaced out’, calmer and able to sleep better. His diet was restricted to just a handful of foods, but over time he became more accepting of different types of food. He also started to gain weight, most likely due to increased absorption of nutrients, having been underweight for much of his life.”

Implement Changes Gradually

So what advice does Sarah have for the parents of children on the autism spectrum?

“My tip for those who want to try the diet is to plan ahead. Think about how you can change or substitute foods that your child currently eats. Perhaps change one meal at a time. Don’t be alarmed if your child only eats foods that contain gluten and dairy at this point. This is not uncommon – over time your child will accept more and more new foods. If it feels too overwhelming, speak with a nutritionist who can guide you through the process.”

If improvements do occur, they obviously cannot be 100% attributed to the GFCF diet. Behavioural changes may be in part due to overall dietary changes such as the removal of fatty, high sugar processed foods with little nutritional value.

Significant changes may take a period of two-three months to manifest, so it’s worth sticking with it for at least that amount of time.


The information in our blog articles is for personal use only and not a substitute for professional medical advice, diagnosis or treatment plans. We are not medical health practitioners or mental health providers. If you’re worried about a potential medical condition, contact your GP or call an ambulance in an emergency situation.

For more information take a look at the below sources: