Overview

Autism, also known as autism spectrum disorder (ASD) or autism spectrum condition (ASC), is a lifelong form of neurodivergence where people interact, communicate, process information, and behave differently. Some studies suggest that a gluten-free diet might have a helpful effect on the behaviour and traits of ASD that others can find challenging, but this is still uncertain.

The World Health Organization (WHO) reports that about 1 in 100 children are affected by autism, while the Centers for Disease Control and Prevention (CDC) suggests a higher prevalence of 1 in 36. Some reports suggest that avoiding gluten might help improve behaviour, cognitive function, and traits associated with ASD that people can find challenging. Some people believe that it could even support brain development in autistic children. However, studies to date have been ambiguous.^1,2

This article discusses autism, how it typically presents, and whether avoiding gluten might benefit autistic people.

What is autism?

ASD is a neurodevelopmental difference that influences how individuals develop and learn. People with autism are born with it, and their traits are often observed in infancy or early childhood, although some may not be diagnosed until adulthood.

Autism comes under the umbrella term of neurodivergence, along with other diagnoses such as ADHD, dyslexia, dyspraxia, dyscalculia, and Tourette’s. Genetic predispositions and environmental influences may contribute to why a person is neurodivergent. 

Using inclusive and respectful language when talking about autism

Some people prefer to talk about autism using person-first language, where they describe themself as a person with autism. Other people prefer identity-first language, where they describe themselves as an autistic person. Similarly, some people dislike the term ASD (even if it is the official diagnostic term used) because they feel that the word “disorder” implies that there is something wrong with them.

According to the WHO, ASD manifests through difficulties in social interactions, communication skills, and behaviours, as well as through unique interests and differences in sensory perception. Autistic people often feel that traits such as having a strong ability to focus closely on tasks, or a good memory for certain details, are positive aspects of autism. Other traits may mean that an autistic person needs support around particular tasks, or in their workplace (or school).

Rather than being a problem to be fixed, it is simply a different way of how someone’s brain can work. We can all embrace the idea that everyone's brain functions uniquely, promoting acceptance of neurological diversity (known as neurodiversity).³

What are the signs and traits of autism?

Autism presents a wide range of signs and traits that vary from person to person. These characteristics may include differences in communication, social interaction, and behaviour, and often appear in early childhood. Recognising these signs can help in understanding and supporting individuals on the autism spectrum.

Autism in young children

In young children, signs of autism can vary but often include a range of behaviours and responses that may be different from their peers. These signs may include:^3,4

• Not responding to their name: Children with autism may not react when called by name, even though they may hear it
• Avoiding eye contact: They might avoid making eye contact with others or may seem uninterested in interacting socially
• Sensitivity to sensory stimuli: Certain tastes, smells, or sounds might cause distress, leading them to become very upset or agitated
• Lack of social smiles: They might not smile when someone smiles at them, which is a typical social response for many young children
• Repetitive movements: Repetitive actions such as hand flapping, finger flicking, or rocking back and forth are common traits in young children with autism
• Delayed speech: Speech may be delayed, and they may speak less frequently than other children of the same age
• Limited interest in pretend play: Children with autism often show less interest in imaginative or pretend play, which is an important aspect of social development
• Echolalia: Repeating words or phrases they have heard, often without understanding their meaning, is another sign
• Behavioural overwhelm: In certain situations, such as changes in routine or sensory overload, they may become overwhelmed, often expressing this through challenging behaviours or frequent crying

Autism in older children

As children grow older, signs of autism may evolve, though many traits remain consistent. In older children, you may notice:^3,4

• Difficulty understanding others' emotions or thoughts: They might struggle to grasp what others are feeling or thinking, making social interactions more challenging
• Unusual speech patterns: Speech may include repeating specific words or phrases (known as echolalia), or they may talk at length about a topic without pausing to allow others to speak, which can make conversations difficult
• Resistance to changes in routine: Any disruption to their daily schedule may cause significant distress, and they might become very upset by changes, even if they are minor
• Intense focus on specific interests: They may have a strong enthusiasm for particular subjects or activities, often dedicating a lot of time and energy to them
• Difficulty with requests or instructions: They might become agitated or frustrated when asked to complete tasks, especially if they find the request unclear or overwhelming
• Challenges with making friends: They may have difficulty initiating or maintaining friendships, or they might prefer spending time alone rather than engaging with peers
• Literal interpretation of language: Understanding idiomatic expressions or figurative speech can be challenging. For example, they may struggle to understand phrases like "break a leg" or "it's raining cats and dogs"
• Difficulty expressing emotions: They may find it hard to express how they feel, sometimes leading to emotional outbursts or withdrawal
• Sensory overload and exhaustion: After spending time in busy or social environments, they may become easily overwhelmed or exhausted, needing time alone to recharge

How autism affects different genders

Autism can present differently in individuals, and it is often diagnosed more frequently in those assigned male at birth than in those assigned female at birth.⁴  However, individuals assigned female at birth on the autism spectrum may:

• Mask some signs of autism by imitating the behaviour and play of others
• Withdraw or become more reserved in situations they find challenging
• Appear to manage social situations with more ease
• Display fewer repetitive behaviours

As a result, autism may be more difficult to identify in individuals assigned female at birth.

What is gluten and what is a gluten-free diet?

Gluten is a protein found in wheat and several other grains such as rye, spelt, and barley. Gluten can also sometimes be present in oats. A gluten-free diet is a diet that excludes any foods that contain gluten.

At the molecular level, gluten consists of two proteins (chains of repeating units called amino acids) called gliadin and glutenin. While an amino acid chain is a linear polymer, it has the ability to coil and fold on itself to form a three-dimensional shape.

Gliadin tends to fold into a compact spherical shape, while glutenin often adopts a more elongated rope-like shape. Amino acids present in both these proteins help the formation of hydrogen bonds between them. Gliadin and glutenin form a network within the dough that resembles the support poles found in a tent frame.  This network gives dough its structure and preserves its shape throughout the baking process (in a similar way to how the tent support poles hold up the tent).

Is there a connection between ASD and gluten?

In a study published in 2021, researchers looked at existing literature and found a correlation between autism spectrum disorder (ASD) and coeliac disease (CD). However, they suggested that more research is needed to determine if consuming gluten increases autism traits that people can struggle with.

The researchers suggested that factors like opioid activity from incompletely digested gluten compounds (exorphins) could affect brain function and behaviour. Exorphins are like natural opioids in our body and can attach to opioid receptors in the brain, affecting its function.

Additionally, inflammation from oxidative stress or anti-gluten antibodies could influence why ASD and coeliac disease occur together in some children. This may be particularly so when there are shared genetic factors. Furthermore, the researchers suggested that gluten might increase stress in individuals with ASD who do not have coeliac disease.²

Although this is just one study, and therefore not a firm basis for drawing firm conclusions, it raises interesting questions about gluten and autism that future studies should seek to explore.

Summary

Autism, or ASD/ASC, is a lifelong neuro-difference marked by atypical ways of socialising, communicating, processing information, and behaving. Its prevalence varies, with estimates ranging from 1 in 100 children according to the World Health Organization (WHO) to 1 in 36 according to the Centers for Disease Control and Prevention (CDC).

ASD is not a disorder; it reflects neurological diversity, with traits presenting differently across individuals and age groups. For instance, younger children might display signs such as avoidance of eye contact, while older children may have different communication styles and patterns compared to their peers.

Gender differences in autism are also observed, with girls or individuals assigned female at birth often hiding their symptoms. This can result in them not being diagnosed or being misdiagnosed. Scientists are exploring potential dietary links to autism, with gluten being studied as a possible trigger for some symptoms.

Certain studies suggest that following a gluten-free diet may improve behavioural and cognitive difficulties associated with ASD, but more research is needed to confirm these findings. The connection between ASD and gluten involves various theories, such as the relationship between poorly digested gluten, brain function, inflammation, and genetics. However, more research is required to fully understand this connection.