I am currently researching diet strategies used in the management of different gut issues. This has come about because I have been asked to present at the NZ Society of Naturopaths and Naturopaths of NZ combined annual conference in Auckland in September. My presentation title is “Demystifying diets for functional gut problems” so here I am reviewing diets relating to gut problems!
Recently I wrote a blog on low FODMAPs diet for irritable bowel syndrome (IBS) Low FODMAP foods for IBS. In this blog I am going to focus on the Gut and Psychology Syndromes (GAPS) diet which claims to provide a natural treatment for Autism, ADHD, Dyslexia, Depression, and Schizophrenia.
What is GAPS?
Gut and Psychology Syndromes (GAPS) is a condition that is based on the connection between the function of the digestive system and the brain. It was coined by Dr Natasha Campbell-McBride in 2004 after her own child was diagnosed with learning difficulties. She believes “all diseases begin in the gut” and that the state of the digestive system links all the above mentioned conditions. She also believes that conditions such as asthma, eczema, allergies, eating disorders, and obsessive compulsive disorder can be vastly improved by following the GAPS diet.1
Healthy gut bacteria provide a physical barrier along the length of our intestines. These bacteria protect us from dangerous bacteria (pathogenic bacteria), viruses and fungi. They neutralise toxins, modify the immune system, ferment carbohydrates, produce vitamin K and B vitamins and even provide energy to the cells that line the intestines.1
If beneficial bacteria are weakened then the gut wall is considered open to invasion by various bacteria, parasites and yeast (Candida albicans). This can lead to chronic gut inflammation and malnourished intestinal cells. Intestinal cells are no longer able to function effectively and this results in impaired digestion and absorption “leaky gut”.1
In her book “Gut and Psychology Syndrome: Natural Treatment for Autism, ADD/ADHD, Dyslexia, Dyspraxia, Depression, Schizophrenia” Dr Campbell-McBride claims that once the intestinal lining is damaged, wheat and milk proteins are unable to be broken down by enzymes lining the gut wall and instead are absorbed intact. She explains that these proteins; gluteomorphines (wheat proteins) and casomorphines (milk proteins) can interfere with brain and immune system function.1
She also claims that abnormal gut flora can produce neurotoxins and cause the body to produce antibodies against its own cells in the brain and spinal cord.1 She explains that Candida albicans use glucose to form ethanol and acetaldehyde and that Candida overgrowth during pregnancy can affect child development (as the foetus accumulates toxins), and the infant then produces alcohol in their own gut. Dr Campbell-McBride links aldehyde production in the gut with altered myelin structure, which manifests as multiple sclerosis. She thinks this aldehyde production may be a cause of the neurologic picture of autistic and dyspraxic children. Aldehyde production binds to vitamin B6, preventing its use as a co-factor for neurotransmitters and fatty acid metabolism. She claims that mothers of GAPS children always have gut dysbiosis (imbalance).1
Diet and GAPS
Dr Campbell-McBride claims that sugar and processed carbohydrates increase Candida, Staphylococci, Streptococci, Clostridia and Bacteroids, and predisposes an individual to worms and parasites. She also claims that a high amount of grain intake predisposes individuals to IBS and bowel cancer. She even states that there were no cases of schizophrenia or coeliac disease documented in Ireland until post potato famine when grains became an integral part of the Irish diet! She explains in her book that diet plus other factors such as antibiotic use, surgery, chemotherapy, stress, pollution and oral contraceptive pills have a collective negative effective on beneficial bacteria.1
What does the GAPS diet entail?
The GAPS diet eliminates all complex carbohydrates and only allows smaller sized carbohydrates called monosaccharides (glucose, fructose and galactose) in the diet as these are relatively easy to absorb. This means avoidance of all grains (wheat, millet, spelt, quinoa, and cous-cous etc), starchy vegetables and beans (potatoes, yams, parsnip, soybeans, mungbeans, bean sprouts, chick peas, and fava beans). All fresh fruit, honey and non-starchy vegetables (Table 1) are allowed. Homemade fermented yoghurt is allowed as the fermentation process breaks the carbohydrates into small sugars and the proteins into amino acids that can then be easily absorbed.1
Table 1: Non starchy fresh veg and beans/ lentils allowed in the GAPS diet
The GAPS diet involves the avoidance of proteins in wheat and dairy but allows easy to digest unprocessed proteins such as eggs, fish, and meat. There is an emphasis on liver, meat, bone and fish stock. She recommends avoidance of lean meats because she believes that we can only use meat fibers when they come with fat, collagen and other substances. She recommends eating meat that has a good covering of fat and to eat the skin of poultry and fish.1
Shelled/freshly shelled nuts and seeds are allowed but they should not be roasted, salted, coated or processed in any way. Seeds can be soaked in salty water for 12 hours to improve their digestibility. Fats are tolerated as they are not dependent on brush border enzymes (enzymes on the gut wall that help digest food). She recommends ghee made from organic butter, cold pressed oils and no processed oils.1
The GAPS diet starts off with an introduction diet which can last from a few weeks to a year, depending on the individual. This stage allows for gut healing and recovering. There are six stages and Table 2 includes some aspects of each stage.
Table 2: Six stages of the Introduction diet
After the introduction diet is completed the full GAPS diet then should be followed for 2 years. The full gaps diet includes 85% meat, eggs, fish eggs, fermented dairy and vegetables. There needs to be 6 months normal digestion before including non-GAPS foods.
Is there evidence to support this diet?
There are no studies or published papers on the GAPS diet. Dr Campbell-McBride makes a lot of sweeping statements (she has never met a healthy vegetarian!) and even advises against vaccination in infants born to mothers with fibromyalgia, digestive problems, asthma, eczema, severe allergies, and autoimmune disorders because she claims that viruses from vaccines may survive and persist in GAPS individuals.1
However it is recognised that 70% of our immune system is localised in the intestines (gut associated lymphoid tissue) and that gut microbiota can alter brain function.2 We know that poor diets can negatively alter bacteria in the gut, which can then affect our brain and cognitive function. The exact mechanism is still unknown but it may be via regulating immunity or hormonal and neural messages.2
Many gastrointestinal diseases are associated with neurological affects e.g. migraines/headaches, brain fog, fatique and fainting. Untreated coeliac disease is associated with autistic and psychotic behaviours and neurological conditions. There is also an association with IBS and depression and anxiety.3
The GAPS diet is a traditional diet in many ways with the use of bone broths as a major part of the diet. When I was growing up there was always meat and vegetables in a saucepan together left on the stove which cooked for hours at low heat. This low heat cooking helped liberate nutrients from the bones. This is something I no longer practice but I have started keeping the bones from my roast chicken and lamb dinners to make soups and stews!
I think personally, because I truly believe nutrition can have profound effects on health that I would give this diet a try if I had a GAPS condition. However, I think the diet itself may be challenging, particularly because you need to be able to ferment all your own dairy products and some vegetables. I fermented cabbage before (saukerkraut) but I have not fermented my own dairy products; although I hear it is relatively simple and many people make their own kefir (fermented yoghurt). Fermenting food was not a major tradition in Ireland; apart from breads but bacteria/yeast are killed by the heat. Mead, the oldest alcoholic drink was made from fermented honey, water, herbs and spices! You would also need to get used of making your own breads with nut flours as otherwise it becomes quite expensive buying these breads. It may be extremely challenging for a parent to introduce these foods to a child with learning disabilities and it would require a lot of patience and perseverance. Likewise someone with a mental health condition may not feel motivated to make these changes and they would require a lot of support, and even with support unless they understand the value and are on board with the diet then compliance may be low.
Dr Campbell-McBride often uses indirect evidence as ways to give plausible explanations to her yet to be proven theories. I say yet because a lot of what she is saying may be true and in the future her diet may be recognised as a dietary management option for those suffering from learning disabilities and psychological disturbances. I also wonder if there could be some benefit of including some aspects of the GAPS diet (so it not as extreme) over the long-term e.g. reducing fermentable carbohydrates, including more bone broths and adding small amounts of fermented vegetable into the diet?
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- Campbell-McBride, N. Gut and Psychology Syndrome: Natural Treatment for Autism, ADD/ADHD, Dyslexia, Dyspraxia, Depression, Schizophrenia. 2015, (2nd edition) United Kingdom: Medinform Publishing.
- Holzer, P., Farz, A. Neuropeptides and the Microbiota-gut-brain-axis. Adv Exp Med Biol. 2014; 817:195-219
- De Magistris L, Siniscalco D, Bully C, Loguercio C. Gut-brain axis. A new revolution to understand the pathogenesis of autism and other severe neurological diseases. In Human Nutrition from the gastronenterologists perspective, 2016, pp49-65. E. Grossi, F. Pace (eds) Springer International Publishing Switzerland. DOI 10.1007/978-3-319-30361-1