Can the GAPS Diet Actually Treat Autism and Other Diseases? A Look at the Research
Key takeaways:
The GAPS (gut and psychology syndrome) diet was created to improve gut health. The idea is that improving gut health might lessen inflammation that contributes to certain diseases.
We need more research before we can say if the GAPS diet actually treats health conditions. There are no studies showing that it can reverse autism or other conditions.
The GAPS diet gets rid of many foods and beverages at first. It’s mainly made of fermented foods, organic meat and fish, and large amounts of certain fats.
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Some healthcare professionals recommend the GAPS diet as an alternative treatment for symptoms of certain health conditions. This controversial diet has even been reported to reverse autism in some cases. The diet instructs you to remove foods and drinks that might be irritating the gut lining.
But does it work? The theory is that by healing the gut, the diet can improve behavioral and psychological conditions. We’ll explain exactly what foods are included in the GAPS diet and what the research says about its possible health benefits.
What is the GAPS diet?
The GAPS diet is a restrictive diet that’s promoted as a natural treatment for autism and other behavioral disorders. GAPS stands for “gut and psychology syndrome.” The theory is that gut imbalances play an important role in psychological or neurological conditions. So healing a damaged gut can help treat conditions like autism or fibromyalgia, according to proponents of this diet.
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The GAPS diet involves avoiding foods and drinks that might be irritating the gut lining. Instead, it recommends nutrient-dense, easily digestible foods like bone broth, fermented vegetables, and fats. In fact, the GAPS diet is mainly made of fermented foods, organic meat and fish, and large amounts of certain fats.
Dr. Natasha Campbell-McBride, a neurologist and neurosurgeon, developed the GAPS diet to treat people with various medical and behavioral conditions. The diet gained traction from celebrity endorsements and anecdotal reports of reversals in symptoms. This includes her own son, who she claims was healed from autism using the GAPS protocol.
GAPS protocol
The GAPS nutritional protocol refers to Campbell-McBride’s recommendations that go beyond diet changes. This includes:
Supplements like probiotics and digestive enzymes
Lifestyle strategies like avoiding certain chemicals in cleaning and beauty products
“Detoxification” techniques, such as juicing, enemas, salt lamps, and fresh plants in the home
Gut-brain connection: Your digestion can affect your mood and mental health. Read about how gut health can affect conditions ranging from irritable bowel syndrome to Parkinson’s disease.
Diet and gut health: Learn about the best diet and lifestyle choices to improve the health of your gut.
Fecal transplants: Researchers are studying fecal transplants as a possible treatment for conditions such as autism and multiple sclerosis. Find out what the science says.
Campbell-McBride further advises staying away from electromagnetic radiation, which is emitted from smartphones and Wi-Fi devices. There are various other suggested “detoxification” methods, but the most important part of the protocol is dietary changes.
What conditions is the GAPS diet used for?
The GAPS diet was developed to help treat people with neurological or psychological conditions. But some believe it can help with many different chronic health conditions that stem from an unhealthy gut.
According to their proponents, the GAPS diet is said to help conditions, such as:
Developmental disorders like autism, attention-deficit hyperactivity disorder (ADHD), and learning disabilities
Autoimmune conditions like Hashimoto’s thyroiditis or rheumatoid arthritis
Skin conditions such as eczema and psoriasis
Psychiatric conditions like depression, schizophrenia, or bipolar disorder
Rheumatological conditions like fibromyalgia and chronic fatigue syndrome
Digestive conditions such as irritable bowel syndrome, gastritis, and colitis
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Does the GAPS diet actually work?
There’s no solid evidence that proves the GAPS diet can treat or prevent any of the above conditions. And since it’s so restrictive and individualized, it’s hard to design a good study to research its effectiveness.
One small study of 17 children found that those who followed the GAPS diet or another similarly restrictive diet were more likely to show improvement in their behavior and attention.
But there were several problems with the study. Results were based on parental reports, which can lead to biased reporting. Many people (up to 60%) weren’t able to comply with the restrictive diet. And those who did the GAPS diet were also given supplements of omega-3 fatty acids, probiotics, vitamin C, and vitamin D. Omega-3 fatty acids have been found to lead to improvement in behaviors associated with autism. So the study doesn’t prove that the diet changes led to improvement.
Gut health and autism
While there’s no good evidence that the GAPS diet can help treat conditions like autism, there’s a link between gut health and the brain. This is known as the gut-brain connection.
A large review looked at 25 different studies on the effects of diet and supplements on autism. Researchers found that some supplements — like probiotics and omega-3 fatty acids — may be helpful to manage symptoms of autism. But the research on diet interventions, like gluten-free or ketogenic diets, were inconclusive.
In another study, 18 participants with autism received a fecal transplant to change their gut microbiome. They saw an improvement in digestive and autism-related symptoms for 2 years after getting the fecal transplant.
So it’s possible that dietary changes to improve gut bacteria might help with certain autism symptoms. But there’s no definitive research showing that autism or any other disability can be prevented or treated by diet alone.
What foods do you eat on the GAPS diet?
Not everyone does the GAPS protocol the same way. Some people may go straight into the full GAPS diet. Others start with an introductory diet. This stage is intended to heal gut damage before moving on to the full diet plan.
Introductory diet (elimination phase)
This part of the diet is the most restrictive. It involves eliminating most foods and then slowly adding foods that are considered nourishing to the gut. Foods are introduced in a stepwise fashion:
Step 1: Eat homemade meat or fish stock, soups, and probiotics (from homemade sauerkraut, yogurt, or fermented vegetables). Drink ginger tea with a little honey in between meals.
Step 2: Add raw organic egg yolks, stews, and casseroles with meats and vegetables, fermented fish, and homemade ghee.
Step 3: Add avocado, pancakes, eggs scrambled with ghee, goose fat, or duck fat.
Step 4: Gradually add meats cooked by roasting or grilling. Add cold pressed olive oil and freshly pressed juices. Eat baked bread made from nut and seed flours.
Step 5: Add cooked apple and raw vegetables.
Step 6: Add raw fruit and other baked goods.
Each person will take a different amount of time to move through the steps of the elimination phase. Your stools may become loose during this time. It’s recommended to wait until stools are more solid before moving on to the next step.
Full GAPS diet (maintenance phase)
This is the main meal plan associated with the GAPS diet. You can either start here, or do the introductory diet first. People are instructed to follow this diet for a long time, often 1 to 2 years. Some people are instructed to follow this diet for life, depending on the medical condition they’re trying to treat.
This part of the meal plan incorporates all the foods from the introductory diet, along with a wider range of:
Meat (preferably grass-fed and pasture-raised)
Organic eggs
Fish and shellfish (preferably wild-caught)
Fresh fruits and vegetables
Nuts
Coconut oil
Baked goods made from seed or nut flours
Fermented foods
Unpasteurized organic milk and homemade cheese products
List of foods to avoid on the GAPS diet
While eating the full GAPS diet, it’s recommended to avoid:
Grains
Commercial dairy, aside from hard cheese
Starchy vegetables (like potatoes, parsnips, and yams)
Processed foods, especially processed carbs
Added sugars
Coming off the GAPS diet (reintroduction phase)
The reintroduction phase is when a person transitions away from a GAPS diet and reintroduces most foods. It’s recommended to wait until you’ve had normal digestion and stools for at least 6 months before starting reintroduction.
The GAPS diet doesn’t give precise instructions for which foods to introduce first. But it’s advised to reintroduce foods one at a time and add new foods every 2 to 3 days. It’s also recommended to continue to avoid ultra-processed foods and refined sugars.
What are the benefits of the GAPS diet?
Even though there’s no clear evidence that the GAPS diet treats certain conditions, it may still have some health benefits. Some of the dietary changes associated with the GAPS diet protocol may help to:
Lower diabetes risk: People who stop eating refined carbohydrates and processed foods have a lower risk of obesity and Type 2 diabetes.
Improve gut health: Your digestive system needs good bacteria to function smoothly. The GAPS diet includes fermented foods that help boost this kind of healthy bacteria.
Lower chemical exposure: The GAPS diet recommends avoiding artificial sweeteners, pesticides, and preservatives. Researchers are still trying to understand how these chemicals may be harmful to your body.
Limit alcohol consumption: The GAPS diet mostly gets rid of alcohol. Although moderate alcohol consumption may be beneficial to health, heavy alcohol use is one of the leading causes of preventable deaths in the U.S.
What are the risks of the GAPS diet?
One of the major risks to the GAPS diet is how restrictive it is. Some of the ways it can be harmful include:
Time and stress: People whose children have disabilities or medical conditions are already under a higher amount of stress than other families. The added stress of having to prepare special foods might not be manageable in the long term.
Malnutrition: The restrictive nature of the GAPS diet also makes malnutrition a real concern. Many people have food aversions and sensitivities — especially children with autism or other behavioral conditions. If their only choices are GAPS-approved foods, they may not eat enough. This could lead to malnutrition if they don’t eat enough calories or nutrients.
Food poisoning: The GAPS diet incorporates raw and unpasteurized dairy products. Pasteurization kills bacteria that can cause serious illness. The diet also recommends raw eggs, which can also lead to serious bacterial infections.
Lower fiber intake: The heavy emphasis on fats and protein can lead to lower fiber intake. Fiber is important for many reasons. Eating too much meat at the expense of fiber-rich foods could also raise your risk of colorectal cancer.
Disordered eating: The GAPS diet has a long list of rules to follow. And in some people, it could lead to disordered eating or orthorexia, an unhealthy focus on eating only “healthy” foods. When people become so focused on their diet that they forget about other important parts of life, their mental health can suffer.
Frequently asked questions
If you’re following the GAPS diet, you can eat carbs from fruits and vegetables, though it’s recommended to avoid starchy vegetables like potatoes, parsnips, and yams. You can also get carbs from dairy products, like milk and cheese. Legumes like lentils, lima beans, and split peas can also be enjoyed while on the GAPS diet.
Yes. When you’re on the full GAPS diet, or maintenance phase, you can have coffee. But it’s recommended to drink coffee that’s weak and freshly made. Instant coffee should be avoided while on the GAPS diet.
The low-FODMAP and GAPS diet are both elimination diets. The low-FODMAP diet is intended to help people with digestive problems, while the GAPS diet is intended to help a wide variety of conditions including psychological ones. The low-FODMAP diet recommends avoiding foods high in fermentable sugars, and has less emphasis on fermented foods and meat products. So there are differences in which foods are restricted.
The bottom line
The GAPS diet is a restrictive eating protocol that was created to treat many different medical conditions. But the current research doesn’t offer any convincing evidence that it’s effective.
Also, the diet can be hard to follow and has some health risks. It may be better to focus on eating a well-balanced diet and limiting processed foods. Over time, this could improve your health in a more balanced and sustainable way.
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References
Abele, S., et al. (2021). Specific carbohydrate diet (SCD/GAPS) and dietary supplements for children with autistic spectrum disorder. Proceedings of the Latvian Academy of Sciences.
Campbell-McBride, N. (n.d.). Introduction diet. Gut and Psychology Syndrome.
Delaunay-Vagliasindi, S., et al. (2021). GAPS nutritional protocol: How healing the gut removes the basis for all chronic diseases. Journal of Orthomolecular Medicine.
Doaei, S., et al. (2021). The effect of omega-3 fatty acids supplementation on social and behavioral disorders of children with autism: A randomized clinical trial. Pediatric Endocrinology Diabetes and Metabolism.
Fowlie, G., et al. (2018). The perturbance of microbiome and gut-brain axis in autism spectrum disorders. International Journal of Molecular Sciences.
Frisch, T. (2016). Interview: Dr. Natasha Campbell-Mcbride discusses the science behind GAPS, modern nutrition woes. Eco Farming Daily.
GAPS Diet. (n.d.). Dairy introduction.
GAPS Diet. (n.d.). Full GAPS diet.
GAPS Diet. (n.d.). GAPS outline.
Kang, D., et al. (2019). Long-term benefit of microbiota transfer therapy on autism symptoms and gut microbiota. Scientific Reports.
Maki, K. C., et al. (2023). Dietary substitutions for refined carbohydrate that show promise for reducing risk of Type 2 diabetes in men and women. The Journal of Nutrition.
Marcos, A., et al. (2021). Moderate consumption of beer and its effects on cardiovascular and metabolic health: An updated review of recent scientific evidence. Nutrients.
Pancheva, R., et al. (2024). Therapeutic diets and supplementation: Exploring their impact on autism spectrum disorders in childhood – a narrative review of recent clinical trials. Research in Autism Spectrum Disorders.
Syed, K., et al. (2023). Low-FODMAP diet. StatPearls.
Tuan, J., et al. (2015). Dietary and lifestyle factors associated with colorectal cancer risk and interactions with microbiota: Fiber, red or processed meat and alcoholic drinks. Gastrointestinal Tumors.
Wastyk, H. C., et al. (2021). Gut-microbiota-targeted diets modulate humane immune status. Cell.
