The gluten-free, casein-free (GFCF) diet has become one of the most popular dietary interventions for a host of conditions, most notably autism and irritable bowel syndrome (IBS). The diet is often implemented by patients or parents of autistic children after discovering its benefits by accident or after hearing positive reports from other patients.
Alternative healthcare practitioners often recommend the gluten-free, casein-free diet to patients, as do a relatively small number of medical doctors who specialize in the treatment of particular conditions. It is uncommon however for conventional doctors to recommend the GFCF diet as a treatment for any condition other than instances where allergies to both gluten and casein are present.
There is a growing body of scientific evidence suggesting that removing gluten and casein from the diet may be beneficial in autism, irritable bowel syndrome, and other chronic illnesses. The research is considered by most to be inconclusive at this time and more extensive research has been called for. We will discuss research into the use of the GFCF diet in specific conditions later to help you make an informed decision about whether it may be beneficial for you, your child, or someone else you know.
It should be pointed out that a trial of the GFCF diet is a relatively risk-free undertaking so long as the diet remains balanced, and the rewards may be well worth the effort. Of course when considering putting your child on the GFCF diet you must weigh up the benefits as it is obviously particularly difficult for a child to be deprived of foods they may particularly like.
As always, it is best to discuss a treatment/diet such as this with your doctor or other healthcare professional such as a dietician or nutritionist. It may also be very helpful to talk to others with similar health problems who have tried the diet, whether it helped them or not.
What are Gluten and Casein?
Gluten and Casein are food proteins. Gluten is found in grains, particularly wheat, and casein is found in milk and dairy products, particularly cheese as the casein is more concentrated than in other dairy products.
Main sources of gluten:
* It is currently not confirmed that oats are a primary source of gluten. Research has suggested that oats may only be a problem when contaminated with gluten from the other grains listed when they are processed in the same facility.
Grains are the only food group that contain gluten.
In the average western diet, wheat is by far the most common gluten-containing grain. Wheat flour is the main ingredient in staples such as bread and pasta. It is also used to make highly desirable foods such as cookies, cakes, and confectionary.
Gluten containing ingredients are used widely in the food industry which means there are many other less obvious sources of gluten on the supermarket shelves and in your kitchen cupboards/refridgerator. Some of these include:
- Processed Meats, eg. Sausages
- Malted Drinks, eg. Hot Chocolate
- Ready-mix Spices and Seasonings
- Stock or bouillon
Food packaging will often state if the product contains gluten. This is not always the case however and there are a number of ingedients that contain hidden gluten. When reading food labels people who are on a gluten-free diet must look out for the following:
- Modified food starch
- Hydrolyzed vegetable protein - HVP
- Hydrolyzed plant protein - HPP
- Texturized vegetable protein - TVP
Main Sources of Casein:
- Ice Cream
Like gluten, ingredients containing casein are used widely in the food industry. Some of the foods that contain casein are obvious but others are a lot less so. Many of these foods are those that also contain gluten. Here are some common foods that may contain casein:
- Chips (UK: crisps) and other savoury snacks
- Bread and anything in breadcrumbs
- Soy Cheeses
- Chewing Gum and Breath Mints
- Fortified Cereals
- Processed Meats
- Nutrition Bars
- Protein Shakes
Again, like gluten, manufacturers will often state on the packaging whether a product contains casein or not but it is not a requirement so those seeking to avoid casein need to look out for certain ingredients. These include:
- Milk Solids
- Sodium Caseinate
- Hydrolyzed vegetable protein - HVP
It is also worth noting that both gluten and casein are commonly used as fillers in medications as well as some nutritional supplements.
Following a Gluten and Casein-free Diet
Initially it may seem an impossible task to avoid gluten and casein since wheat and dairy foods are a mainstay of the typical western diet and so many dishes are based on them. There is no doubt that it is not an easy task to eliminate these foods from the diet but it can certainly be done with some effort and planning.
At Home - As you can see from the previous section gluten and casein can be hidden in all kinds of foods that you simply would not expect. This makes it very important that when shopping in the supermarket you check the ingredients on packaging carefully, looking out for the ingredeints list above. Of course if you buy fresh ingredients and cook yourself there is much less risk than if you buy pre-prepared meals. Preparing food at home allows you to have much more control over what is in your diet.
Eating Out - When eating out in restaurants you have much less information about exactly what is in the food you are eating. Obviously you can make the right choices about where to eat. If you are on a gluten and casein-free diet then you really don't want to go out for Italian food. Gluten and casein may well be hidden in dishes that you don't suspect however. For example, major fast food restaurants have revealed that the humble french fry they serve contains both gluten and wheat in the seasoning. On the positive side it is becoming common for restaurants to add gluten-free and dairy-free symbols next to certain dishes on their menus.
Alternatives to Gluten-containing and Dairy Foods
Once you start looking you will find that there are actually many good alternatives to foods that contain gluten and/or casein. As you become familiar with foods that don't contain these proteins you will realize there are actually a lot of nutritious and tasty foods you can eat.
Important grains that do NOT contain gluten:
The most important of these from a dietary perspective are obviously rice and corn. People avoiding gluten can freely eat these grains which are staples in much of the world. Fans of Asian and Mexican food can therefore breathe a sigh of relief (as long as cheese is avoided). It's not all bad news for all those Italian food fans either as there are many gluten-free pastas available which are often made from rice, corn, or buckwheat. The only concern with these is the price which is considerably more than regular wheat pasta.
If you're concerned about flour for baking there are a large number of gluten-free flours available including almond, amaranth, buckwheat, chickpea/garbanzo, and corn.
There are also a number of good alternatives to dairy, especially when it comes to milk.
Obviously these plant milks do not taste much like cow's milk but you may be surprised at how good some of them taste. Most people can get used to using these on their breakfast cereal or as an ingredient for cooking.
There are a growing number of alternatives to other dairy foods as well. Vegan cheeses are often based on soy beans and can often be found in health stores or even supermarkets. Soy-based ice cream is also becoming increasingly common.
If you have a balanced diet then removing foods that contain gluten and casein should not pose a problem. The main thing to look out for is that enough calcium is being consumed since dairy foods are such a major source in western countries. Good alternative sources of calcium include almonds, parsley, corn, and pumpkin seeds. Gluten-containing graisn don't supply particular nutrients that cannot easily be obtained elsewhere.
Why can Gluten and Casein be a Problem?
There are three main mechanisms through which gluten and casein are thought to cause symptoms in susceptible individuals:
Sensitivities to wheat (gluten) and dairy products (casein) are considered to be among the most common, along with others such as eggs, shellfish, and peanuts. More and more people are suffering from food hypersensitivity with steady increases in prevalence in developed countries during the past few decades.1, 2 The reasons for the increase are unclear at present.
The term 'food hypersensitivity' is a broad heading that includes the classical food allergy caused by IgE antibodies and reactions caused by other immunological mechanisms.
Allergies occur when there is an abnormal immune response to proteins such as gluten and casein in foods. The immune system sees these proteins as threatening so launches an attack against them as it would in the case of an infection. In the case of classical food allergy, the immune system produces IgE-type antibodies which attach to the food proteins before other immune chemicals are sent in to get rid of them. It is the action of these immune chemicals which cause symptoms of allergy. It is thought many of the reactions not caused by IgE are caused rather by IgG antibodies which produce symptoms with a more delayed onset and vagueness than the rapid and specific symptoms produced by IgE type allergy.
Food Intolerance/Non-Allergy Reactions
Along with food hypersensitivity to gluten and casein it is thought that foods which contain these proteins may cause symptoms in ways that do not involve the immune system at all. These non-allergy reactions to food are usually refered to as 'food intolerances'. People may be intolerant to certain foods for various different reasons. These mechanisms include:
- Adverse food reaction due to a non-immunologic mechanism
- Pharmacologic (Eg: caffeine, tyramine etc. Drug-like effect)
- Metabolic (Eg: lactase deficiency etc)
- Toxic (Eg: food poisoning)
- Idiosyncratic (unexplained reaction unique to the individual)
Source: Australasian Society of Clinical Immunology and Allergy (ASCIA)
Gluten is thought to be particularly irritating to the gut which results in various digestive symptoms such as bloating, adbdominal pain, and diarrhea. Casein and dairy foods are proposed to result in exess mucus secretion which could worsen respiratory symptoms (mucus in lungs) and also digestive symptoms. Opinion on whether this is actually the case or not seems to be divided.
During the digestion of gluten and casein a number of peptides are produced which have strong similarities to opiate drugs such as morphine and heroin. It is thought that some people cannot digest gluten and casein properly in which case these opiate-like peptides would build up in the gut. If they are absorbed these peptides could in theory act in a way similar to opiate drugs causing various powerful effects in the brain and nervous system. The theory that incomplete digestion of wheat and dairy foods could cause disease was first proposed in 1966 by F.C.Dohan in relation to schizophrenia3.
More recent research which has mainly focused on the role of gluten and casein derived peptides in autism has identified casomorphins4 (casein) and gluten exorphines and gliadorphin (gluten) as likely to be the most problematic.
Gluten and Celiac Disease
As well as the above, gluten is also the trigger for Celiac disease. In this condition the immune system makes antibodies against gluten as in food allergy but the end result is that the walls of the intestines also get attacked by the patient's immune system causing severe damage.
Visit our Celiac disease page to learn more about this condition.
The Gluten-free, Casein-free Diet in Environmental Illnesses
The GFCF diet gets the most attention by far for its use as a treatment for autism. It is one of the most common interventions that parents of autistic children undertake independently from their family doctor and is recommended by advocacy groups such as the Autism Research Institute (ARI) and doctors who use the DAN! protocol. The diet remains a controversial subject however and is not generally recommended by doctors and other conventional medical professionals.
There is certainly evidence available that demonstrates gluten and casein may play a role in causing or aggravating symptoms in autism. Much of the early indication of a link came from research conducted by Reichelt in the early 1990s in which elevated levels of opiate peptides were found in the urine of autistic children.5 In 2003 after other groups of researchers had also detected raised levels of gluten and casein derived peptides in autistic children4, Reichelt published a review of his and other's findings and proposed a comprehensive theory of the role of dietary peptides from gluten and casein in autism.6 He proposed that elevated opiate peptides from incomplete gluten and casein digestion could be causing autism symptoms and may be due to a genetically based digestive enzyme deficiency and/or because too many of these peptides are being absorbed because of damage to the gut.
Reichelt's theory is backed up by a growing body of research demonstrating the many autistic children also have gastrointestinal conditions. Gluten and casein themselves have actually been implicated in causing damage to the intestines by triggering inappropriate immune responses.7 This obviously provides further reason to consider the GFCF diet.
In terms of medical trials actually testing the GFCF diet in children with autism there have been a number of small trials but the general concensus is that the evidence is so far inconclusive. A review of seven trials of the GFCF diet published last year found that all seven studies suggested improvements in some autism symptoms and the researchers on two of the studies also noted imporvement in 'nonverbal cognition'.8 The review authors however cautioned that all of the trials were small and had design flaws which seriously affects the reliability of their findings. Another much larger review conducted by Millward and colleagues and published in 2004 came to similar conclusions.9 After reviewing all available information on trials of the GFCF diet in autism they found conflicting results and only poor quality studies but nevertheless concluded that there is certainly enough evidence to suggest larger research studies are needed.
Irritable Bowel Syndrome (IBS)
Given that the predominant symptoms of IBS include digestive upset and abdominal discomfort it's not surprising that much attention has focused on dietary interventions in the search for effective treatment and symptom control. Elimination diets are often recommended by healthcare providers and IBS patients often undertake them of their own accord. There is a fair amount of research to validate the use of these diets with wheat and dairy products consistently being identified as triggers of IBS symptoms. A review of seven double-blind placebo-controlled trials of elimination diets in irritable bowel syndrome patients published in 1998 found that, "Milk, wheat, and eggs were most frequently identified to cause symptom exacerbation."10 The authors did however suggest that better designed studies were needed to confirm these findings. More recent research has used laboratory testing and discovered that IBS patients have significantly higher levels of IgG antibodies to certain foods including wheat and dairy products than healthy volunteers.11 This suggests that IBS symptoms could be due to abnormal immune system activity.
The specific role of gluten in IBS has been the subject of a large amount of research. Numerous studies have found elevated levels of antibodies against gluten and some have found antibodies usually only associated with Celiac disease in a substantial number of those suffering from IBS.11,12 It has been suggested that a subgroup of people with IBS may have a latent from of Celiac disease13 and research has shown that IBS patients are 10 times more likely to have or develop Celiac disease than the general population.14
In an article published in the prestigious Lancet Journal in 2003 the authors suggested that Candida albicans may play a role in the development of Celiac disease.15 They note that proteins in the cell wall of Candida albicans cells are almost identical to gluten proteins. Since Candida albicans is a comon resident of the small intestine it is suggested that the immune system may become sensitized to the proteins in the yeast cell wall and then cross-react with gluten proteins. If an individual had increased amounts of Candida colinization the risk for developing Celiac disease would likely be greater. More research is needed to test this theory.
Leaky Gut Syndrome
The theory that opiate-like peptides from gluten and casein can cause effects in the brain depends on them being absorbed from the gut in significant quantities. Increased intestinal permeability (leaky gut syndrome) has been found in autistic children16 and the suggestion that peptides from the diet are causing autistic symptoms has become a serious issue.
Research has demonstrated that high gluten intake can cause leaky gut syndrome in healthy people, not just those suffering from Celiac disease.17 Leaky gut syndrome is associated with an increased risk for allergic and autoimmune conditions as well as increasing the likelihood of symptoms triggered by opiate peptides from partially digested gluten and casein.