Dietary Interventions in Autism Spectrum Disorders

This week at work, I ate a sandwich made out of “healthy” granary bread. For a couple of hours afterwards, I felt lethargic, slow and was really unable to concentrate or work effectively.

As visitors to the Asperger Management website will know, I have been taking an increasingly strong interest in the subject of diet of late.

Given this, and my initial findings, I have been trying to find out more and build on the initial, basic knowledge I acquired from reading the Autism Research Unit at Sunderland University’s Autism as a Metabolic Disorder: Guidelines for Gluten and Casein-free Dietary Interventions that I have previously reviewed at:

Dietary Interventions in Autism Spectrum Disorders published recently by Jessica Kingsley Publishers is written by a clinical psychologist, Kenneth Aitken, with a specialist interest in Asperger Syndrome Disorder (ASD).

Before reviewing the book, I would like to add some caveats. Firstly, as Autism as a Metabolic Disorder: Guidelines for Gluten and Casein-free Dietary Interventions also importantly emphasises, the current limited research data into diet and autism, and the fact that everyone is different, means that not the same dietary interventions are always applicable to eevryone. Specialist advice should always been sought therefore before embarking on any diet change programme.

The book is specialised, detailed and contains a lot of technical terminology to explain various issues which I am unable to comment upon as it requires expert knowledge. What follows, therefore, is a précis of some of the general issues and messages from a layman’s perspective into how they may affect a person in a work context.

The book describes a number of different diets that may be relevant and applicable to someone with ASD. It provides insight into how diet can affect the mood and behaviour of someone with ASD, the bases of different dietary approaches and how to identify if a new diet is doing any good. It is not a book about weight loss.

The author makes the point initially that dietary treatment interventions are generally often difficult to understand, complicated to implement and expensive to maintain.

They can, however, have major beneficial effects. Most are safe and can correct a range of physiological differences and should be implemented before adopting any complementary or alternative approaches. Specialist advice is still important however.

Many people with ASD do not have a dietary problem, but some do and success has been reported by those who have adopted certain diets in terms of behaviours, moods and general well-being.

However, as Aitken notes, few dieticians are knowledgeable about ASD and related dietary treatments but, helpfully, interest in the subject is growing.

The text first explores why we eat what we do? Nutrition is usually part of an interaction with at least one other person, so eating is invariably a social activity.

In addition, our diets have undergone huge changes recently. Sugar is absorbed in much greater quantities, as are foods like potatoes which have boosted carbohydrate consumption. Increased glutamate (gluten) has also increased via processed foods

The net effect is that high protein, high fibre, low carbohydrate and low sugar diets have been replaced by largely the opposite. We are now also increasingly exposed to additives, colourings and flavour enhancements. Supplements on the other hand, have largely been ignored, despite them becoming increasingly important.

The effects of this have probably gone largely unnoticed by many. As Sternberg points out, our physical and mental well-being is inextricably linked: diet plays an important role in gene expression and physical and behavioural development.

A problem with ASD related diets to date, is that it is assumed that the same diet is appropriate for every person. Yet having Asperger syndrome probably presents additional issues in respect of diet.

Many believe that there is gastrointestinal (GI) issue with ASD. GI disturbance has been attributed to fatty eating and some food restrictions occur in some cases which can have major developmental consequences. This makes implementing dietary interventions more challenging.

According to the book, research by Erikson (2005) does seem to support the finding that there is an ASD-specific pattern of gastroenterological symptoms which is higher than in the general population. Addressing this can have a significantly positive effect on behaviour and development but, it would seem, people with ASD may have a very different biology.

The book’s preliminary conclusion is that there is no dietary approach will help everyone with an ASD as there is no one, uniform biological cause. However, starting with the premise that a number of approaches may be helpful, and that some may have negative consequences, is a useful starting point.

A number of different diets have been advocated for people with ASD such as the gluten and casein free approach outlined by the Autism Research Unit. However, as Aitken rightly states, much is still unknown about the effects of food, food additives and contaminants.

The chapter on dietary interventions starts by identifying certain behaviours that may suggest a dietary intervention is worth trying for those with ASD: loud noises, the sleep-wake cycle, (unusual body clock), presence of food-related difficulties, an excessive fluid intake, suspected epilepsy, dry skin, overweight/underweight, easily tired or lethargic or evidence of self-injurious behaviour.

If a person demonstrates a number of these then there may be a reasonable case for dietary intervention. The perinent question is: which diet?

Different people will have different susceptibilities to different foods due to their differing “chemical individuality”. The likelihood of any dietary intervention being successful is likely to depend therefore on a person’s biological characteristics.

It is important not to treat everyone as the same, even though we do all require the same dietary intake of essential nutrients. An individually tailored approach to dietary management is needed as our digestions vary also because of what we consume and how our bodies deal with the things we eat.

A clear research finding has been the health benefits that come from carbohydrate reduction, not increased protein intake. I immediately took note of this for the reason I cited at the start of this review: carbohydrates, I have found, slow me down!

There are many genetic differences in the ability of individuals to digest carbohydrates like sugars and starches. Before the Western diet of eating processed foods was widely adopted, which had a high intake of complex carbohydrates, there was a much lower instance of strokes, heart disease and obesity.

As Dietary Interventions in Autism SpectrumDisorders points out, adoption of a Western diet has resulted in a steady rise in the prevalence of these conditions. As food production has been industrialized we have become more dependent on a small number of food crops – a mere 17 which encompass 90% of all human food and which are carbohydrate rich – wheat, maize, rice, barley, potato, sorghum, rye.

This can lead to toxic reactions which are variable and complex. Some people will show major reactions to foods that are well tolerated by others. Gradual insidious exposure can acclimatize the body to a higher toxic load than would normally be tolerated with rapid exposure.

Most humans have adapted to having regular exposure to low level toxins where introduction is insidious but, it is believed, they are affecting the functioning of our brains.

To highlight just how complex the area in general is, the book describes how some substances are highly toxic in excess and need to be avoided in large amounts, even though the same substances may be essential at low levels.

Vitamin A depletion, through a self restricted diet, can result in severe visual loss for example, even though it is biologically essential. Indeed, some commentators believe that high dose supplementation can actually be helpful to people with an ASD.

The book then looks at substances that may assist and what diets may be applicable for someone with ASD. Selenium is thought to be beneficial, yet levels in fruits and vegetables have been falling over the last few decades due to changes in farming methods meaning many people are now selenium deficient.

A range of diets have been suggested for people with ASD, but research is at an early stage and is inconclusive. Much research into diet focuses on why a diet “can’t work” rather than, as the author believes, “this doesn’t work and here is the reasonable evidence to prove why”.

Many of the diets advocated have a limited evidence base, so the author has provided a systematic review of the evidence to date and the theory that underpins the principal dietary approaches advocated so far. I these there appear to be certain common factors. As I am unable to comment professionally, I have explored these only briefly.

The Mackarness (low Carbohydrate, High Protein) Diet was an early attempt to alter body metabolism to address various physical and mental health problems, and is not disimilar to the Atkins Diet which followed recently. Neither has made specific claims in relation to ASD.

Brillat-Severin as long ago as 1825 grasped that bread, cakes, pastas and potatoes caused overweight and suggested a low carbohydrate diet.

The Mackarness Diet asserts that there are different metabolic types which in the case of the “fatty-easily type” individual (someone who readily puts on weight) results in a metabolic defect and lower ability to metabolize carbohydrate. This leads to easy weight gain on high-carbohydrate diets due to our inability as humans to cope sufficiently with a diet of high carbohydrates: cereal and root crops, milk product and refined sugar diet emanating from an agrarian and animal domestication culture. Many of things we have trouble digesting today are because they are not part of our natural diet.

In recent years there has been an increased intake of refined carbohydrates, i.e. white flour and sugar, alongside a drop in protein. There has also been a change in the relative levels of omega-3 and omega-6 oils in the animals and fish being consumed.

I have always enjoyed, and generally felt better, when I have eaten foods like fish and avoided breads, and the book explains how the non-saturated fats found in omega-3 play an important role in ASDs and related conditions (Richardson).

However, the increased use of grains in fattening domestic animals has resulted in a change in the fatty acid balance in red meats and in many farmed fish. This has fundamentally changed the likely benefits from merely adopting a Mackarness or high protein, low carbohydrate type diet. The adoption of a high-protein diet which is also high in saturated fats is, therefore, likely to still be detrimental.

The aim of the Mackarness diet is not just to lose weight, but reduce the likelihood of medical conditions like type-2 diabetes and mental health concerns like anxiety and depression developing. The diet claims to reduce the load on the individual by substituting a more “ecologically relevant” diet based on more digestible foods.

Ketogenic diets are explored next. These induce the body to use fat, rather than carbohydrates, for energy. It is a high fat diet and some success has been reported with ASD. Ketogenic diets are thought to modify metabolism.

The Feingold Diet is an addictive elimination approach developed in the US by Dr Ben Feingold, initially as a treatment for hyperactive behavior. It has been used extensively to help people with ASD, particularly those individuals who have problems with over-activity and concentration.

The focus of the Feingold approach is the removal of three food additives: synthetic colourings, synthetic flavours and preservatives and one group of artificial sweeteners: aspartame.

Proponents of the Feingold diet claim that it can reduce hyperactivity, impulsivity, compulsions, emotional concerns and improve attention and sleep. Actual results are mixed: 55% said they felt better; 45% reported no change, though there are no suspected related problems with the diet per se.

The Specific Carbohydrate Diet, (SCD) has been used in some cases with ASD to repair and restore the gastrointenstinal system by correcting bacterial and yeast imbalances.

The diet is described as complex and prescriptive with no gluten, grains and flours allowed and is often followed if there is no benefit derived from a casein and gluten free diet.

Some carbohydrates are allowed such as simple sugars. Complex sugars such as milk, lactose and sucrose are not permitted, as are starches like grains, corn rice and potatoes.

There are no published studies on the use of SCD. However, there is detailed information on how to implement the approach. A useful website is the Elaine Gottschall www.breakingthe and her books Food and the Gut Reaction (1987) and Breaking the Vicious Cycle (1994) are among the bets known works on the subject.

There is also the autism-specific site and that provide further information. In the UK provides information on a number of issues.

The CF-GF diet is casein/gluten free. Casein is a protein found in milk. This and gluten can be metabolized to produce opiod-like compounds.

Gluten is a protein found in a number grains, particularly wheat, barley and rye and so is found in many types of bread, cakes and biscuits which can trigger gluten sensitivity reactions.

There are various theories concerning possible problems related with ASD and the presence of casein and gluten in a diet. One example is the “Leaky Gut Theory or problems with the passage of opiod compounds into the bloodstream across the lining of the intestine. The absence of milk is thought to be beneficial in reducing this.

A review of the seven published studies on CF-GF dietary interventions in ASD were uniformly supportive. However, though the only study with reasonable vigour (Knivesberg 2002) found significant improvements, the book points out that there is no “gold standard” level of research into casein/gluten free diets.

The Low Oxalate Diet describes how oxalates – salts found as crystals in plants and, therefore, in many foods and drinks – can be highly elevated in some people with Autism.

There are no major positive physiological effects of oxalates in the human body, but biochemically, excess amounts are thought to impair the body’s ability to break down protein. In a low carbohydrate diet this can lead to problems due to lack of glycogen.

It is thought that a low oxalate diet can lead to improvements in certain physiological areas and with behaviours. Most relate to bowel and bladder problems but it can also mean certain previously un-tolerated foods can be accepted.

The Low Glutamate Diet is a non-essential amino acid (glutamate) which some suggest is more prevalent in those with ASD. It is thought that a number of genetic conditions associated with ASD affect the development of the central nervous system receptors and early brain development.

Glutamate is a neuro-transmitter found in the neuro-system. Though, there is limited evidence concerning the possible role of reducing dietary glutamate in ASD, some conditions in ASD are known to result in abnormalities in glutamate metabolism in the brain. Blocking them has shown some apparent improvement in learning, memory and social behaviour.

Phenal is another amino-acid high in certain foodstuffs and a low Phenylaline Diet is thought to possibly address an inherited recessive metabolic defect of phenylaline metabolism (PKU) to cope with a diet that is low in this amino-acid. Some commentators have suggested that before the introduction of dietary treatment for PKU, it was a common cause of both learning disability and ASD.

A Low Phenol Diet restricts the intake of highly phenic foods and associated compounds. Some individuals can show reactions to these and there is some evidence for differences in phenol metabolism in ASD which may be important in the production of oxidative damage to the ASD central nervous system.

The Biology Ecology Diet (BED) draws from a number of approaches. The general theme is low dairy, low carbohydrate and low sugar intake. Adherence to this general diet it is thought, may lead to ketosis, as maintaining protein and fat intake whilst reducing sugar and carbohydrates will encourage the process. There is, however, no evidence as of yet to suggest that the approach will be of particular benefit in ASD.

There are various forms of the Rotation Diet. Here foods are simply rotated to enable calorie intake to be cut and the maintenance of interest in foods generally despite cutting the amount of calories consumed.

A principle rule is separating carbohydrate and protein consumption. Food from the same group should be eaten every second day and specific foods should be eaten only once in any given day. So, if you eat cornflakes for breakfast, you cannot eat any other corn based foods that day.

Dietary Interventions in Autism Spectrum Disorders concludes by evaluating the different approaches and the evidence to date.

To begin with the author reiterates that there are a number of problems in general with the diets presented for people with autism. There are also a number of common features.

Carbohydrate restriction appears to be common and generally helpful. Though most low carbohydrate approaches will result in transient tiredness initially they are likely to be beneficial over time as the body adapts to ketosis and the production of energy from fats.

Though various dietary approaches all have their adherents and appear to have helped people in some capacity, it is suggested that the Simple Restriction Diet is possibly a good way of getting started
Carbohydrate restriction is also common to some of the other, more prominent approaches – Mackarness/Atkins/Ketogenic – and the casein/gluten free diets.

All claim success in improving aspects of behavior and development in ASD. There is also quite strong anecdotal evidence that dairy is, in general, detrimental as is exposure to pesticide and fertilizer residues as outlined in the Feingold approach.

The book then outlines some important caveats with any of the diets and a chnage in diet in general. One important factor is to ensure that there are no undue nutritional restrictions resulting from any diet. Unless there is appropriate supplementation, and adequate nutritional intake is ensured on a low-carbohydrate diet, essential nutrients may be deficient.

As the book rightly continually re-enforces, professional assistance should always be sought. Before starting on the Simple Restriction – or an other – Diet, a proper baseline evaluation should also be undertaken covering required medical considerations.

The next conclusion resonates strongly with my own experience. Namely, that a high protein diet, lower carbohydrate diet typically diminishes hunger and often leaves one un-sated. It may, as the author points out, also mean that an appropriate level of nutritional intake is absent. I am not sure perosnally that I have yet to locate the answer to this.

As important as organizing and getting a dietary regime up and running is to work out whether it is actually making a difference.

This comes back to the point about an individualized, effective dietary approach which can take time to realise and which should be also be evaluated systematically. A baseline period of recording its outcomes is suggested as it gives an idea of possible problem foods or food groups, dietary efficiencies and key behaviors or lack of them.

The book then states that there is no magic answer as to what should or should not be eaten. Ideally, a person should try to adopt a diet high in animal proteins from fish, crustaceans, good quality eggs, most cheeses and organically reared meat. These categories need be explored closely howeve because, as the book lists, there are exceptions in each category.

It is advised that olive oil should used with cooking and that drinks should be sugar free and water drank from a glass, (no more plastic cups from the water tank at work for me!). All milk high in carbohydrate should be avoided.

The book then describes how any changes should be gradually introduced so that carbohydrate intake can be steadily reduced and ketosis is induced. This may take several weeks for people with ASD to achieve.

How long any effect takes to coem to pass is largely dependent on the nature of the problem and on what is being tried. 16 weeks is thought to be a required minimum, though, again, it will depend on the diet adopted.

I can relate strongly to this principle. Over time I have taken positive steps in relation to my diet, but they have taken time to realize. I have learnt that the benefits do not appear immediately and that it is a slow, incremental process.

In conclusion, the book sensibly stresses again the need to seek specialist advice before embarking on any diet and that a number of factors need to be carefully monitored before any diet introduced. As stated, this should be done gradually whilst ensuring that nutritional intake is always maintained.

The key conclusion of Dietary Interventions in Autism Spectrum Disorders is the same as I personally have arrived at: that the evidence, though incipient, makes further investigation highly worthwhile, even though proper assessments and clinical trials are urgently further needed.

I enjoyed Dietary Interventions in Autism Spectrum Disorders. The book contains numerous reference sources for readers to investigate further and is well written.

Though the detail and much of the terminology was to a degree beyond my understanding, it did re-enforce, and has stimulated further, my interest and motivation as a person with Asperger syndrome find out more about diet and how changes could benefit me.

I will be refraining from eating granary sandwiches at work from here on in!

Dietary Interventions in Autism Spectrum Disorders: Why They Work and Why They Don’t When They Don’t, Kenneth J. Aitken, Jessica Kingsley Publishers, 2009.

ISBN: 978 1 84310 939 6

Managing with Asperger Syndrome