Introduction
This article dives deep into the potential of the ketogenic diet as a metabolic intervention for autism. We explore the challenges faced by people with autism and their families, highlight the limitations of current treatments, and introduce a new perspective through metabolic psychiatry. With evidence from small-scale studies and surveys pointing to improvements in social interactions, cognitive function, and overall quality of life, the ketogenic diet stands out as a promising avenue to try.
Adults with a form of autism generally report a lower quality of life, particularly in the areas of relationships, living arrangements, and health. At the same time, many of them do not view their neurological differences as a defect, but as part of their identity within the neurodiversity perspective. For this reason, we present the ketogenic diet here as an option to help alleviate specific symptoms, not as a universal “cure.” Clear information about both the benefits and limitations of this option can support autistic individuals, their loved ones, and healthcare professionals in making a well-informed decision together.
Author: Jaap Versfelt
Scientific reviewers
Dr. Eline Dekeyster, Associate professor Leiden University, leader of the research group Lifestyle Brain Interaction
Drs Alexa Schrickel, researcher Universiteit Leiden
Key messages
Reading time 16 minutes
- The prevalence of measured autism is rising, affecting 1-2% of the population in the Netherlands.
- Current treatments for autism, including behavioral therapy and medication, often have limited effectiveness and can have considerable side effects.
- The connection between brain health and body metabolism means that addressing metabolic dysfunction may improve symptoms of neurological conditions like autism.
- The ketogenic diet, already used for epilepsy, shows promise in improving energy availability, neurotransmitter balance and reduced oxidative stress.
- Evidence from studies and surveys indicates that the diet may improve social behavior, cognitive function, and comorbidities like epilepsy and depression.
- Implementing the diet can pose challenges, particularly for individuals with autism, due to sensory sensitivities and the effort required to maintain this dietary regimen.
- Successful adoption of the diet relies on educating supportive companions, personalized coaching and monitoring.
1. Autism spectrum disorder
Autism Spectrum Disorder (autism) is a lifelong condition that affects how the brain processes information. People with autism often have challenges with social interactions, communication, and behavior, as well as unique ways of moving and sensing the world around them. In addition to these challenges, many people with autism also experience other health issues like epilepsy, stomach problems, and mental health conditions such as anxiety and depression. Most people with autism have average to high intelligence. An estimated 30% have an intellectual disability. (NVA).
2. Prevalence of autism
Approximately 1 to 2 percent of people in the Netherlands, more than 200,000 individuals, have autism. The number of people affected by autism — such as parents, siblings, partners, teachers, and caregivers — is many times larger. (Autisme.nl).
Autism prevalence in the Netherlands seem to have increased over recent decades. In the 1980s, the estimated prevalence was lower, around 0.5% (Van der Gaag, 2018). However, the rise in prevalence might be due to changes in definitions or autism-diagnosis tools (Zeidan et al., 2022).
3. Reduced quality of life and societal implications
People with autism often experience a lower quality of life compared to others, as shown by differences in areas like social relationships, independence, and access to work opportunities. They may have fewer friendships, struggle with maintaining jobs, or face difficulties in everyday tasks like managing finances or accessing services.
The quality of life for people with autism does not improve as they age. While some may see modest improvements in specific areas, such as sensory issues or behavior, the overall trajectory often includes challenges in independence, employment, and social relationships (van Heijst, 2015). For example, only 25% of the adults with autism currently have paid work (Holwerda, 2012).
Meanwhile, relatives of individuals with autism often face emotional, social, and financial challenges. They may experience stress and anxiety due to caregiving responsibilities, concerns about their future, and difficulties accessing adequate support or services.
4. Current treatment of autism
The classic treatment approaches to autism focus on behavioral interventions and medical treatment. Their efficacy is limited:
Behavioral therapy targets the core symptoms of autism, and speech and language therapy to improve articulation and communication. Its effect is highest when applied early during development (Hyman et al., 2020).
Pharmacological treatment has been focused on symptom reduction and management of comorbidities rather than targeting causes of autism. Moreover, they come with side effects, many of which are metabolic such as weight gain, increased appetite and gastrointestinal issues (Aishworiya et al., 2022).
5. An alternative approach for autism: metabolic psychiatry
Given that the current treatment options provide insufficient impact on the quality of life of people with autism, it might be timely to explore a different approach: metabolic psychiatry.
5.1 What is metabolic psychiatry?
Metabolic psychiatry is a new paradigm within psychiatry that focuses on the interplay of metabolic processes and brain function for psychiatric conditions. The core idea is that metabolic disruptions – such as insulin resistance, mitochondrial dysfunction, and inflammation – may contribute to psychiatric conditions like depression, bipolar disorder, and schizophrenia. By improving metabolism – through nutrition, exercise, and lifestyle interventions – mental health can potentially be improved.
The word metabolic refers to metabolism, which is the process by which the body generates and utilizes energy. This includes the breakdown of sugars and fats, the regulation of hormones like insulin, and the function of mitochondria (the energy powerhouses of cells).
5.2 Why could this work?
- Brain conditions are linked to metabolic dysfunction. There is abundant evidence that many psychiatric and neurological conditions are associated with metabolic disorder. Autism is one such condition where this relation has been suggested.
- Treatment of metabolic disease. Metabolic disorders can be treated effectively with lifestyle, especially changing food intake from the current western diet (high on ultra processed food and refined carbohydrates) to a diet based on natural food and with reduced carbohydrate intake.
This relationship does not prove that improving a patient’s metabolism leads to improved outcomes of brain conditions. To get to that evidence we need to dive deeper into the evidence.
Boeken over metabole psychiatrie
6. Metabolic disfunction
Our metabolism consists of processes that convert nutrients such as carbohydrates, fats, and proteins into the energy and building blocks our body needs. When metabolic dysfunction occurs, normal metabolic processes are disrupted. This can lead to conditions like type 2 diabetes, cardiovascular diseases, and obesity. For instance, the 2004 Interheart study showed that 90% of heart attacks are caused by lifestyle factors such as abnormal lipid-levels in the blood, smoking, hypertension, diabetes, abdominal obesity, psychosocial factors, consumption of fruits, vegetables, and alcohol, and regular physical activity (Yusuf, 2004).
Metabolic dysfunction can result from insulin resistance and chronic low-grade inflammation. Insulin resistance is a reduced sensitivity of body cells to the hormone insulin, which hinders its ability to regulate blood sugar levels effectively. In chronic low-grade inflammation, the immune system remains slightly activated without noticeable symptoms (Asensi, 2023).
Insulin resistance and low-grade inflammation are partly caused by the Western diet. This diet predominantly consists of ultra-processed foods (accounting for 61% of adult calories and even 75% of children’s calories) combined with fast-digesting carbohydrates. Examples of ultra-processed foods include soft drinks, cookies, sauces, and ready-made meals—in short, almost anything sold in supermarkets with branded packaging. Fast-digesting carbohydrates are found in white bread, pasta, white rice, and fruit juices.
7. Metabolic psychiatry for autism
The brain uses a significant amount of energy. Although it makes up only 2% of our body weight, it consumes 20% of our energy. In other words, metabolism is crucial for brain function. This is why “metabolic psychiatry” is gaining attention—a field that explores the interplay of metabolic processes and brain function, aiming to address psychiatric and brain disorders by improving metabolic function (both in brain and body). Why might metabolic psychiatry also be promising for treating autism? There are several reasons:
7.1 Various brain disorders often occur together
Research shows that having a mental health issue increases the likelihood of having another mental health condition by 2 to 48 times, depending on the type of disorder and the time since the onset of the first condition (Plana-Ripoll, 2019).
For example, people with epilepsy have a three to six times higher chance of developing anxiety disorders (Kanner, 2011), and individuals with depression are twice as likely to develop Alzheimer’s (Ownby, 2006). This interconnectedness between different brain disorders is also seen in autism, where individuals are more likely to experience epilepsy and psychiatric conditions such as depression.
7.2 Brain disorders that often co-occur may have a shared cause
When scientists observe that two conditions frequently occur together, they may suspect a shared cause. Consider a runny nose and a sore throat: these are not separate illnesses but symptoms of a common cause, such as a cold virus. In the case of brain disorders, when multiple conditions co-occur, researchers consider the possibility that they might share a common cause, such as genetic factors or environmental factors or metabolic dysfunctions.
Identifying the underlying cause of a condition allows for more effective treatments, and this principle also applies to brain disorders. However, it is important to remember that just because two conditions co-occur doesn’t necessarily mean they share a single cause – sometimes they may be linked in more complex ways. What might this shared cause be?
7.3 Brain disorders are often linked to metabolic health issues
Brain disorders are not only interconnected with each other but also potentially with metabolic health. The brain, like the heart or liver, is an organ, and metabolic dysfunction disrupts its function as well. Examples of such associations between brain disorders and metabolic dysfunction are manyfold. For instance, individuals with obesity, have a 60–70% higher risk of developing epilepsy (Gao, 2008), and people with diabetes are two to three times more likely to experience depression (Semenkovich, 2015). However, correlation does not imply causation, and the underlying mechanisms linking metabolic dysfunction and brain disorders remain an area of active research.
7.4 Autism is linked to metabolic disturbances in the brain
Research has demonstrated that individuals with autism frequently exhibit metabolic abnormalities, including impaired energy uptake and oxidative stress. Insulin resistance, a core part of metabolic dysfunction, plays an important role in this process:
- Impaired energy uptake. Energy for the brain is produced in mitochondria. When insulin resistance occurs, it can disrupt normal mitochondrial function, leading to impaired energy production. Efficient uptake of glucose is required for neural function and connectivity. Mitochondrial dysfunction and symptoms of autism – like repetitive behaviors, social deficits, and hyperactivity – has been associated in mice, however the specific role of mitochondrial dysfunction and ASD has to be further defined (Rossignol, 2012).
- Oxidative stress. Oxidative stress occurs when there is an imbalance between harmful molecules (reactive oxygen species) and antioxidants. This imbalance can cause damage to the cells. In autism, the production of reactive oxygen species is increased due to mitochondrial dysfunction.
8.Metabolic interventions for autism: the ketogenic diet
A promising approach to tackle autism by improving brain metabolism is the ketogenic diet. This diet has been in use for 100 years for children with epilepsy and can be used as an approach for seizure control for some people with drug-resistant epilepsy. The ketogenic diet tackles many of the mechanisms observed in the brain of people with autism and there are studies (though on small scale) that show its effect.
8.1 Het ketogenic diet
On a regular western diet, rich in carbohydrates (sugar and starches) the brain use glucose for energy. The ketogenic diet provides an alternative energy source for the brain. This diet consists of high-fat, low-carbohydrate foods. For example, meat, eggs, fatty fish, avocado, olive oil, dairy products (like full fat yoghurt), nuts and seeds and vegetables such as broccoli, spinach, and cauliflower.
The ketogenic diet is designed to induce ketosis. Ketosis is a metabolic state defined by increased blood ketone levels. Ketones are molecules produced in the liver by burning fat. The brain takes up ketones and the mitochondria in the brain uses these ketones to produce energy. When ketones are available, such as during fasting or a ketogenic diet, the brain even prefers burning ketones to using glucose for energy production.
8.2 Mechanisms in which the ketogenic diet might help
There are a number of ways in which the ketogenic diet might help people autism:
- More energy uptake. In people with autism energy uptake is impaired. Ketones provide an alternative energy source for the brain.
- Neurotransmitter balance. In people with autism an imbalance between two prominent neurotransmitters, GABA and glutamate, can be seen (Zhao, 2022). The ketogenic diet can inhibit glutamate transporters, thereby counteracting this neurotransmitter imbalance (Romano, 2017).
- Oxidative stress reduction. The ketogenic diet can help reduce oxidative stress by boosting the production of antioxidants and overall lowering the levels of reactive oxygen species.
- Tackling comordities. Many people with autism suffer from comorbidities such as depression and epilepsy. The ketogenic diet is proven to be effective for children with epilsepsy and shows promise to tackle depression.
8.3 Evidence for the effect of the ketogenic diet in autism
A survey, individual case reports and small-scale studies show that a ketogenic diet may improve symptoms of autism, including social behaviour and cognitive function.
- Survey outcome. A survey people trying different diets for autism showed that the ketogenic diet has the largest effect of all diets surveyed on anxiety, attention, cognition, constipation, depression, communication, lethargy, seizures, social interactions and understanding. However, ketogenic diet also had the highest reported adverse risk score compared to all other diets and the number of people on the diet ewas small (21). Importantly, all diets surveyed had higher impact and lower side effects than psychiatric/seizure medications (Matthews, 2023).
- Experimental studies. Next to this survey, several experimental studies with children on a ketogenic diet have been conducted. Examples are El-Rashidy, 2017 which showed improved cognition and sociability in children. Lee, 2018 demonstrated children improve social and communication skills on a ketogenic diet. Mu, 2020 showed better social communication and interaction skills, and less fear or nervousness. These experimental studies had small sample sizes (15 to 45 people), which is likely due to the difficulty of setting up randomized trials in children.
8.4 Safety of the ketogenic diet
We will distinguish between children and adults:
Children
Internationally, the ketogenic diet has been established as a conventional therapeutic approach for drug-resistant epilepsy for over 100 years. In the Netherlands, the ketogenic diet is an accepted treatment for children with epilepsy (Federation of Medical Specialists, 2024). A treatment duration of two years is generally observed, though a shorter period is preferred if seizures stop. In children who followed the diet for very long periods (six to twelve years), complications such as growth delays or kidney stones were found.
Adults
For adults, the ketogenic diet is generally considered safe when monitored by a nutritionist to prevent nutritional deficiencies. However, several important contra-indications should be noted. Individuals with certain metabolic disorders, such as rare genetic conditions that impair fat metabolism, should avoid this diet.
Additionally, careful supervision is necessary for those on specific medications. The ketogenic diet can significantly interact with medications, including but not limited to insulin for diabetes management and lithium for bipolar disorder. Therefore, it’s crucial to involve the treating physician in the dietary planning process, especially for individuals with psychological vulnerabilities or other medical conditions.
Finally, some people embarking on the ketogenic diet could see a marked increase in LDL-cholesterol levels. An increased level of LDL-cholesterol is associated with a higher risk of cardiovascular disease. Therefore, it is advisable to follow-up on lipid levels in the blood.
Ketosis vs Ketoacidosis
People following the ketogenic diet are sometimes warned about ketoacidosis, as ketosis and ketoacidosis are occasionally confused. However, they are two distinct metabolic states:
Ketosis is a metabolic state achieved when the body uses fat as its primary energy source due to a low intake of carbohydrates. This leads to the production of ketones, which the body uses as fuel.
Ketoacidosis, on the other hand, is a dangerous and potentially life-threatening condition that occurs when the body produces an excessive amount of ketones. This happens in the absence of insulin. Without insulin, blood glucose levels rise, and simultaneously, the body attempts to burn fat for energy. This results in high concentrations of ketones in the blood, causing acidification, which is harmful to organs.
A ketogenic diet induces a state of ketosis but does not cause ketoacidosis in individuals with a normally functioning pancreas. However, people with undiagnosed type 1 diabetes or poorly controlled insulin levels are at risk of ketoacidosis (Westerberg, 2013). These individuals should be cautious with the ketogenic diet and always consult a healthcare provider before making significant dietary changes.
9. Starting with the ketogenic diet
t is beyond the scope of this article to describe what the ketogenic diet is and how to start it. To that end, we would kindly refer you to this source: ‘De ultieme keto-gids voor beginners‘. This keto-gids will provide you with:
- A description of the diet
- Further information of the effect of the ketogenic diet
- An explanation of ketosis and ketones and measuring these ketones
- Information on nutrients
- Food types fitting a ketogenic diet
- Recipes
10. Conclusion
The ketogenic diet emerges as a promising approach for improving symptoms and quality of life for individuals with autism. By targeting the metabolic dysfunctions linked to autism, such as impaired energy metabolism and oxidative stress, this diet offers a pathway to address core and associated challenges like social interactions, cognitive impairments, and comorbid conditions such as epilepsy and depression.
Successful adoption of the ketogenic diet requires careful, personalized implementation. Key factors include educating supportive companions, tailoring the diet to individual sensory preferences, and leveraging tools like ketone-level monitors to ensure adherence.
Help advance autism research!
Do you…
Have a diagnosis of autism?
Have at least 3 months of experience with the ketogenic diet?
Are you at least 18 years old?
…and would you like to contribute to science?
For a study within our LBI research group at Leiden University, we are looking for people with autism who want to share their experiences with the ketogenic diet.
Do you know someone, or are you that person? Contact me via LinkedIn or at [email protected] for more information.
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