Dietary Interventions in Autism Spectrum Disorders

Why They Work When They Do, Why They Don't When They Don't

Kenneth Aitken

• Publisher: Jessica Kingsley Publishers
• Year: 2008
• ISBN:
  9781846428609
• Topic: Psychology
• Subtopic: Autism Spectrum Disorders
• Index: Psychology

Given the increased interest in the relationship between diet and autism spectrum conditions, this is a timely publication which is both thorough and balanced in content. Parents and professionals alike will find this book of use by virtue of Ken's meticulous reviews of current scientific evidence for a variety of diets combined with practical advice on the application of such interventions.'

- Dr. Paul Whiteley, Autism Research Unit

'Dr. Aitken provides a timely synthesis of diet interventions in autistic spectrum disorders set within a framework of historical and political references. This informative work offers invaluable assistance to the wider clinical team, further enabling effective support and guidance to the ASD community in its quest for a healthy future.'

- Rosemary Kessick, former CEO of AiA (Allergy Induced Autism)

Research in autism increasingly indicates the existence of different forms of the condition, and the possibility of dietary interventions having a positive effect on symptoms and behaviours associated with autism.

The author explores the main dietary approaches that have been advocated in ASD. For each approach, the author explores the potential benefits; evidence for and against the diet and its relation to different genetic conditions; and information, where available, on relevant publications, web resources and support groups. The author proposes an approach, the Simple Restriction Diet (SRD), which he describes in detail, explaining how to implement this approach and how to use it to work out whether a dietary approach is of benefit.

This book will be a valuable resource for families, individuals and professionals wishing to understand and explore the possibilities of dietary interventions and the benefits they can have for those on the autism spectrum.

PART I

DIETS, ASDS AND
DIETARY
INTERVENTIONS

CHAPTER 1

Introduction to Diet and ASDs

I take the view, and always have, that if you cannot say what you are going to say in twenty minutes you ought to go away and write a book about it.

Lord Brabazon of Tara (1884–1964)

First and foremost, this is a book about dietary factors in ASD, how they can affect mood and behaviour, how understanding the bases to different dietary approaches can help to identify whether a particular dietary intervention may be worth trying, and how, if you implement a diet, to tell whether it has done any good. It provides a mixture of theory, evidence and practical advice together with some forays into why some of the evidence base is not as strong as we would ideally like it to be.

This is not a book on how to help obese people with ASD to control their weight. Weight loss may result from some of the approaches we discuss but is not the primary focus. A wide range of diets is advocated for weight loss, and the evidence is often confusing and contradictory (a recent brief overview of 50 of the more popular dietary interventions for weight control can be found in Rodriguez 2007).

Neither is this a book on how to cope with behavioural issues in food avoidance (an introduction to this topic can be found in Ernsperger and Stegen-Hanson 2005). I see many ASD individuals who have problems with weight control, but almost as many are underweight as are overweight. Food refusal and difficulties with the introduction of new foods are common problems in ASD (see Cornish 1998), so in adopting any new dietary intervention, finding strategies to deal with these difficulties is important. Often, however, such difficulties are biological in origin and lessen as dietary management begins to show benefits — for example, zinc depletion is common and severe zinc depletion can markedly affect someone’s sense of taste. As body zinc levels improve, a wider range of foods becomes palatable.

Dietary treatment interventions are often difficult to understand, complicated to implement and expensive to maintain. Despite these hurdles, and the limited clinical expertise and support typically made available, many families try hard to implement a variety of specialized diets and frequently claim that they see improvements as a result.

Dietary approaches to ASD are today being used by many and can have major beneficial effects. Most are largely safe and can correct a range of physiological differences. Diet should be corrected first before considering any detailed biomedical assessments or other complementary or alternative approaches. Investing in tests and supplements as a starting point may be both expensive and wasteful where a change of diet might have achieved the same or a similar effect. Differences in diet can result in findings suggesting a particular metabolic difference is present when it is not or could mask a real difference/ deficiency which is already being addressed.

I am not arguing that every person with an ASD has a dietary problem that requires to be addressed; many people do not. There is now a steadily growing literature written by people with ASDs who appear to fit well in society and use their differences to their own advantage (see, for example, Robison 2007, for an eloquent autobiographical account of a highly successful person with an Asperger syndrome diagnosis).

The evidence to date does, however, suggest that such problems are not uncommon. Here, we review and discuss the literature that suggests that such differences affect many individuals who have an ASD, and suggest a method for starting to address this issue.

The ancient Greek term diaita stood for ‘way of life’ or ‘way of being’ and had far broader connotations than the term diet as used today. We typically use diet as a term for a way of cutting down on food after periods of overindulgence in order to try and lose weight rather than as a lifestyle choice.

The Autism Research Institute (ARI), founded by Bernard Rimland, has for many years collected questionnaire data from families of people with autism on the treatments that have been tried and the families’ perceptions of how useful they have been. From the ARI questionnaire data returned by families to the Institute in San Diego, dietary interventions are consistently reported as showing good results (see www.autism.com).

In their assessment of diet outcomes, the ARI asks families to rate whether the treatments they have tried have made the person worse, had no effect or resulted in an improvement. Their most recent survey data is shown in Table 1.1 with respect to effects of dietary interventions:

Table 1.1 Recent ARI diet outcomes
	Worse	No change	Better	Numbers reporting
Candida diet	1%	41%	58%	71
Sugar-free diet	3%	48%	49%	207
Feingold diet	0%	45%	55%	96
CF-GF diet	3%	27%	70%	237
Rotation diet	3%	37%	60%	65
SCD	3%	33%	64%	33

It has to be remembered that this is not a ‘head-to-head’ comparison of approaches. The different diets are often begun for very different reasons. Benefits found from one might not have been looked for from another that could have proven to have the same or a similar effect. In addition, they are being reported on by families who have enough motivation to complete a detailed record form and return it, so are a relatively highly motivated and self-selected group. Whether similar levels of success would be found for an unselected group of people with ASD, or if the recording forms had been completed by someone independent, is impossible to say. What can be said is that within this group the perception of those completing this information is of a high level of success from adopting dietary interventions. This compares to relatively low levels of reported success for more conventional psychopharmacological treatments.

There are many excellent and well-qualified dieticians and nutritionists who know about the normal metabolism of foods, their calorific values, vitamin and mineral content, and the effects of specific metabolic conditions such as phenylketonurea (PKU). Few however are knowledgeable about the dietary treatments that are advocated for ASDs, about whether they are backed by sensible theories, or about the evidence for their safety and efficacy. Interest among dieticians in ASD is steadily growing (Peregrin 2007).

I am not for a moment trying to minimize the importance of the other food-related issues mentioned above – dietary self-restriction can have severe consequences and can result in blindness (Uyanik et al. 2006), developmental delay (Casella et al. 2005) or worse. In the Uyanik et al. paper cited, the child they discuss developed progressive visual loss due primarily to lack of vitamin A (his serum level was 10 µg/l with a normal range of 360–1200 µg/l). This was as a direct result of keeping to a diet from the age of four to eight years that consisted of nothing except fried potatoes and water. A high proportion of ASD children will self-restrict and, as a consequence, they can become deficient in a range of essential nutrients (Cornish 1998).

The general literature on dietary approaches to weight loss and to a range of other conditions is vast. I have tried, where possible, to draw attention to some of the material from this general literature here, where it is relevant. In contrast, the literature on dietary approaches to ASD is relatively sparse. I hope that the coverage given here deals with the major approaches, which have been advocated to date in a reasonably fair and non-judgemental fashion, and access to the resources which will enable anyone to explore the issues farther.

I hope that, as a minimum, this book will provide an introduction to, and a clearer understanding of, various dietary approaches that are advocated for those with ASD. I hope it can also offer some reassurance that there is a literature on, and a rationale for, many of these approaches and there are clinicians who are both competent in the area of ASD and who believe that biobehavioural approaches such as these can be important. It should also be clear that many of the issues are complex, and that rigid adherence to some of these approaches can lead to difficulties which might not at first be obvious.

I also introduce and discuss methods that in the individual case should help to assess their effects. It is often as important to be able to demonstrate that something has worked as it is to have achieved the desired outcome.

Please bearin mind the various factors raised later in the book that are important to check on before starting – like any other approaches which can have positive effects there is also the possibility of negative ones.

A number of the issues covered here are fairly complex, and have been included to provide a basis for informed discussion with a supportive clinician rather than as definitive information.

Topics such as possible effects of diabetes, phenylalanine metabolism, celiac disease, ketogenics and oxalates will fall in this category for many readers.

A number of the possible difficulties arising from diets that are covered here are not dealt with systematically in other books which have dealt with dietary aspects to ASD, and it is as important to be aware of these as it is of the positive effects.

Why do we eat what we do?

In general, mankind, since the improvement of cookery, eats twice as much as nature requires.

Benjamin Franklin (1706–1790)

Let’s start by raising a theme to which we will return — the history of our present human eating patterns and how our nutrition has changed.

From the beginnings of recorded time, gathering, preparing and eating food have been shared social activities (Jones 2007). For all of us from birth, our nutrition, whether we are breast or bottle fed, is part of an interaction with at least one other person (see Trevarthen and Aitken 2001). Throughout the world, gathering food (whether by harpoon, spade, boomerang, or shopping trolley), food preparation, and food consumption are inherently social activities. The requisite skills are often learnt in groups or passed on from parent to child. Differences in social functioning c...

Table of contents

• Cover
• Half Title
• Of Related Interest
• Title Page
• Copyright
• Dedication
• Epigraph
• Contents
• How to Use This Book
• Part I Diets, Asds and Dietary Interventions
• Part II Diets for People with ASDS
• Part III The Simple Restriction Diet (SRD)
• Resources
• References
• Subject Index
• Author Index