Adverse Reactions to Food (eBook)

Dr Judy Buttriss, British Nutrition Foundation, UK.

Adverse Reactions to Food 3
Contents 5
Foreword 14
Terms of Reference 15
Task Force Membership 16
1 Introduction and Definitions 19
1.1 Introduction 19
1.2 Food intolerance 20
1.2.1 Allergic reactions 20
1.2.2 Enzymic reactions 21
1.2.3 Pharmacological reactions 21
1.2.4 Other non-defined idiosyncratic responses 22
1.3 Food aversion 22
1.3.1 Food avoidance 22
1.4 Food poisoning 23
1.4.1 Chemical food poisoning 23
1.4.2 Foodborne bacterial gastroenteritis 24
1.4.3 Food vehicles 25
1.4.4 Foodborne viral gastroenteritis 26
1.5 Key points 27
Appendix A Classification of adverse reactions to foods 28
2 The Immune System 29
2.1 Introduction 29
2.2 The immune system 29
2.3 Innate immunity 30
2.4 Adaptive immunity 30
2.4.1 Anatomy and cells of adaptive immunity 30
2.4.2 Clonal expansion of lymphocytes 31
2.4.3 B cells, immunoglobulins and humoral immunity 31
2.4.4 T cells and cell mediated immunity 34
2.4.5 The generation of effector T cells 36
2.4.6 Effector CD4+ T cells 41
2.4.7 Effector mechanisms of Th1 mediated immunity 44
2.4.8 Effector mechanisms of Th2 mediated immunity 45
2.5 Allergy 46
2.5.1 IgE mediated allergy 47
2.5.2 Clinical patterns of IgE mediated allergy 51
2.5.3 Non-IgE/T cell mediated allergy 52
2.6 Why do food antigens fail to produce a detrimental immune response? 52
2.6.1 Oral tolerance/true immunological tolerance 53
2.6.2 Mechanisms of oral tolerance 53
2.6.3 Factors influencing oral tolerance 54
2.6.4 Immunological acceptance 54
2.7 Conclusion 55
3 Nutrition and the Immune System 56
3.1 Introduction 56
3.2 Impact of infection on nutrient status 56
3.2.1 Infection is characterised by anorexia 57
3.2.2 Infection is characterised by nutrient malabsorption and loss 57
3.2.3 Infection is characterised by increased resting energy expenditure 57
3.2.4 Infection is characterised by altered metabolism and redistribution of nutrients 57
3.3 Protein-energy malnutrition and immune function 58
3.4 The influence of individual micronutrients on immune function 58
3.4.1 Vitamin A 58
3.4.2 Carotenoids 59
3.4.3 Vitamin B6 59
3.4.4 Vitamin C 59
3.4.5 Vitamin E 59
3.4.6 Zinc 61
3.4.7 Copper 62
3.4.8 Iron 62
3.4.9 Micronutrient combinations and resistance to infection 62
3.4.10 Micronutrients and HIV infection 63
3.4.11 Micronutrients and asthma 63
3.5 Dietary fat and immune function 64
3.5.1 Fatty acids in the human diet 64
3.5.2 Amount of dietary fat and immune function 64
3.5.3 Eicosaniods: a link between fatty acids and the immune system 64
3.5.4 Linoleic acid and immune function 66
3.5.5 a-Linolenic acid and immune function 66
3.5.6 Fish oil and immune function 67
3.5.7 Dietary fat and Th1 skewed immunological diseases 67
3.5.8 Fatty acids and Th2 skewed immunological diseases 68
3.6 Dietary amino acids and related compounds and immune function 69
3.6.1 Sulphur amino acids and glutathione 69
3.6.2 Arginine 69
3.6.3 Glutamine 70
3.7 Probiotics, immune function and allergy 70
3.7.1 The theoretical basis for the use of probiotics 70
3.7.2 Probiotics and immune function 70
3.7.3 Probiotics and allergy 71
3.8 Breast feeding and immune function 71
3.8.1 The composition of breast milk 71
3.8.2 Breast feeding, immune function and infection 72
3.9 General comments 72
3.10 Key points 74
4 Epidemiology of Food Intolerance and Food Allergy 75
4.1 Introduction 75
4.2 The adequacy of currently available epidemiological data for food intolerance 75
4.2.1 Non-IgE mediated allergy 76
4.3 Infants and children 76
4.3.1 Cows' milk intolerance and allergy 77
4.3.2 Allergy to egg 78
4.3.3 Peanut allergy 78
4.3.4 Intolerance to food additives 79
4.4 Adults 79
4.4.1 Peanut allergy in adults 80
4.4.2 Intolerance to food additives in adults 80
4.5 Time trends and geographic differences 80
4.6 The relationship between IgE mediated food allergy and other IgE mediated allergies 81
4.7 General epidemiology of IgE mediated allergy 82
4.8 Key points 84
5 Pre- and Postnatal Sensitisation to Foods 85
5.1 Introduction and definition of terms 85
5.1.1 IgE mediated allergy 85
5.2 Factors that influence neonatal sensitisation to food 85
5.2.1 Genetic background 85
5.2.2 Prenatal exposure 86
5.2.3 Antibody responses 87
5.3 Assessment of abnormal immune response 87
5.3.1 Cord blood or term IgE concentration 88
5.3.2 CD4+ T cell responses to allergens in cord blood 88
5.3.3 CD4+ T cell responses and IgG antibodies to constituents of food 88
5.4 Trigger foods 88
5.5 Dietary factors in the development of atopy in infants 89
5.6 Maternal diet during pregnancy 89
5.7 Breast feeding 90
5.7.1 Evidence supporting the protective effect of breast milk 90
5.7.2 Evidence against breast feeding 91
5.8 Maternal diet during lactation 92
5.9 Use of protein hydrolysate formula 93
5.10 Introduction of solids 94
5.11 Key points 94
6 Common Food Allergies 95
6.1 Introduction 95
6.2 Allergens involved 95
6.3 Diagnosis 96
6.3.1 Misdiagnoses and misconceptions 97
6.4 Clinical features of atopic disease 98
6.4.1 Clinical features of food allergy 98
6.4,2 Childhood eczema 98
6.4.3 Childhood asthma 98
6.4.4 Clinical features in adults 99
6.4.5 The oral allergy syndrome 99
6.5 Foods that cause allergic reactions 100
6.5.1 Allergic reactions to food in young children 101
6.5.2 Peanut allergy 101
6.5.3 Can genetic modification influence allergenicity? 103
6.6 Management of food allergy in childhood 103
6.7 Difficulties in diagnosis and management 105
6.8 Key points 106
7 Other Manifestations of Food Intolerances 107
7.1 Introduction 107
7.2 Reactions affecting the skin 107
7.2.1 Urticaria and angio-oedema 107
7.3 Reactions affecting the gastrointestinal tract 109
7.3.1 Vomiting 109
7.3.2 Gastro-oesophageal reflux 109
7.3.3 Abdominal pain, distension and flatulence 110
7.3.4 Diarrhoea 110
7.3.5 Bacterial overgrowth 110
7.3.6 Constipation 110
7.4 Enteropathies 110
7.4.1 Allergic eosinophilic gastroenteropathy 110
7.4.2 Infantile colic 111
7.4.3 Irritable bowel syndrome 111
7.5 Respiratory system effects 112
7.5.1 Asthma 112
7.5.2 Rhinitis and conjunctivitis (hay fever) 113
7.5.3 Serous otitis media 113
7.5.4 Milk-induced pulmonary haemosiderosis (Heiner’s syndrome) 113
7.6 The central nervous system and behaviour 113
7.6.1 Migraine and food intolerance 113
7.6.2 Migraine and diet 113
7.6.3 Food allergy and migraine 114
7.6.4 Migraine and non-immunologic effects 114
7.6.5 Foods commonly associated with migraine 115
7.7 Evidence of reactions to food in teenagers and adults with mental disorders 116
7.7.1 Children and adolescents 116
7.8 Hyperactivity and attention deficit hyperactivity disorder (ADHD) 116
7.8.1 Studies on attention deficit hyperactivity disorder 117
7.8.2 Studies on the Feingold diet 117
7.8.3 Clinical studies of wider food exclusions 118
7.8.4 Mental illness and gluten sensitivity: schizophrenia 118
7.8.5 Autism 119
7.8.6 Cot death (sudden infant death syndrome, SIDS) 119
7.9 Other clinical symptoms that may be related to adverse effects of foods 120
7.9.1 Enuresis and cystitis 120
7.9.2 Vaginitis/vaginal discharge 120
7.9.3 Athropathy, arthritis 120
7.10 Key points 121
8 Enzyme Defects and Food Intolerance 122
8.1 Introduction 122
8.2 The nature of lactose intolerance 122
8.3 Types of lactose intolerance 123
8.3.1 Congenital lactase deficiency 123
8.3.2 Late onset lactase deficiency/actase non-persistence 123
8.3.3 Secondary lactose intolerance 124
8.4 Prevalence of lactose intolerance 124
8.5 Clinical features of lactose intolerance 125
8.6 Diagnosis of lactose intolerance 125
8.6.1 Lactose maldigestion - reducing substances in stools 125
8.6.2 Lactose maldigestion - breath test 125
8.6.3 Tissue lactase activity 126
8.6.4 Other tests 126
8.7 Treatment of lactose intolerance 126
8.7.1 Secondary lactose intolerance 126
8.7.2 Late onset lactase deficiency 126
8.7.3 Potential for adaptation 128
8.8 Nutritional adequacy of low lactose diets 128
8.9 Hereditary fructose intolerance 129
8.10 Key points 129
9 Coeliac Disease and other Gluten Sensitive Disorders 130
9.1 Gluten 130
9.2 Manifestations of gluten sensitivity 130
9.3 Gluten sensitive enteropathy 130
9.3.1 Subclinical or silent coeliac disease 131
9.3.2 Latent coeliac disease 131
9.3.3 Transient gluten intolerance 131
9.4 Dermatitis herpetiformis 131
9.5 Prevalence of coeliac disease 132
9.6 Presentation of coeliac disease 132
9.6.1 Infants and children 132
9.6.2 Adults 132
9.7 Diagnosis of coeliac disease 133
9.7.1 Small intestinal biopsy 133
9.7.2 Serum antibody tests 133
9.8 Disease associations 135
9.8.1 Dermatitis herpetiformis 135
9.8.2 Type I (insulin dependent) diabetes and other autoimmune disorders 135
9.8.3 Malignancy 135
9.8.4 Neurological disorders 136
9.8.5 Down’s syndrome 137
9.8.6 Epilepsy 137
9.9 Genetics 137
9.10 Epidemiology of coeliac disease 138
9.11 Pathogenesis of coeliac disease 138
9.12 The immune system and coeliac disease 138
9.12.1 Antibody production in the small intestine 138
9.12.2 Cell mediated immunity 139
9.13 Treatment 140
9.14 Compliance with a gluten-free diet 140
9.15 Legislation relating to gluten-free food 141
9.16 The cereals: taxonomy and chemistry 141
9.16.1 Definition of prolamins 141
9.17 Methods for assessing suitability of cereal proteins for gluten sensitive individuals 142
9.17.1 In vivo gluten challenge 142
9.17.2 In vitro tissue culture 142
9.17.3 Tests based on non-human tissue 143
9.18 Which cereals contain gluten? 143
9.19 Which cereals are gluten-free? 143
9.20 What about oats? 143
9.21 Other problematic substances 143
9.21.1 Malt, malt extract, beer and lager 143
9.21.2 Communion wafers 144
9.21.3 Glutenins 144
9.22 Methods of measurement of gluten in foods 144
9.23 The gluten-free diet and new technologies 145
9.24 Does the possibility of immune therapy for coeliac disease exist? 145
9.25 Conclusion 145
9.26 Key points 146
Appendix A- Cereal chemistry 147
Appendix B Cell mediated immunity and coeliac disease 148
10 Clinically Validated Diagnostic Tests and Non-validated Procedures of Unproven Value 149
10.1 Introduction 149
10.2 Procedures of proven value 149
10.2.1 Double-blind placebo-controlled food challenge 149
10.2.2 Skin prick tests 150
10.2.3 Radioallergosorbent test (RAST) 151
10.2.4 Cross-reactivities 151
10.2.5 Summary 151
10.3 Other procedures of proven value for the diagnosis of adverse reactions to foods 151
10.3.1 Endoscopic studies with and without intestinal biopsy 151
10.3.2 Intestinal permeability test 152
10.4 Other tests applied in the diagnosis of food intolerances 152
10.4.1 Respiratory function tests 152
10.5 Non-validated procedures of unproven value 152
10.5.1 Food specific IgG and IgG subclass antibodies 153
10.5.2 Cytotoxicity tests 153
10.5.3 Sublingual, subcutaneous and intradermal provocation and neutralisation tests 153
10.5.4 Immune complex measurements 153
10.5.5 Electro acupuncture 153
10.5.6 Applied kinesiology and the DRIA test 154
10.5.7 Hair analysis 154
10.5.8 Urine injections 154
10.6 Non-immunologically mediated reactions to foods 154
10.7 Costs of inappropriate treatment to the patient and community 154
10.8 Key points 155
11 Diagnosis and Management of Food Intolerance by Diet 156
11.1 Introduction 156
11.2 History and clinical assessment 156
11.3 Clinical and laboratory tests 156
11.4 Diagnostic diets 156
11.4.1 Exclusion diet 157
11.4.2 Empirical diet 157
11.4.3 Few-foods diet 158
11.4.4 Elemental diet 159
11.4.5 Rotation diets 160
11.5 Food challenges 160
11.5.1 Open challenges 160
11.5.2 Double-blind placebo-controlled food challenge (DBPCFC) tests 161
11.6 Milk-free diets 161
11.6.1 Milk substitutes 162
11.7 Egg-free diets 165
11.8 Peanut-free diet 166
11.9 Nutritional hazards of diet therapies 167
11.10 Other pitfalls and problems of diet therapy 168
11.10.1 Risk of anaphylactic reaction during food challenge 168
11.10.2 Cost of diet therapies 168
11.10.3 Psychosocial effects 168
11.10.4 Munchausen’s syndrome by proxy 168
11.11 Conclusion 168
11.12 Key points 169
12 Food Allergens and the Food Industry 170
12.1 Handling food allergens in manufacturing 170
12.2 Identification of allergens 171
12.3 Good manufacturing practice 171
12.3.1 Allergens and GMP 171
12.3.2 Hazard analysis critical control point studies 172
12.3.3 Cross-contamination 173
12.3.4 Confirmation of the presence of allergens 173
12.3.5 Labelling and communicating the presence of allergens in food 174
12.3.6 Legislation 174
12.4 Food safety legislation 174
12.4.1 Food labelling legislation 174
12.4.2 The 25% rule 175
12.4.3 International trade 175
12.4.4 'May contain' statements 176
12.5 Brand extensions 176
12.6 Promotional activities 176
12.7 Labelling and handling allergens in the catering environment 177
12.8 Additional communication initiatives 177
12.8.1 Food intolerance databanks 179
12.9 Manufacturing foods with reduced levels of allergens 179
12.9.1 Foods inherently free of an allergen 179
12.9.2 Foods manufactured to be free from an allergen 179
12.9.3 Hypoallergenic foods 180
12.10 Summary 181
12.11 Key points 182
13 Immunomodulation of Food Allergies 183
13.1 Background 183
13.2 Immunology 184
13.3 Novel treatment strategies 185
13.3.1 Exploiting cross-reactivity between allergens 185
13.3.2 Monoclonal antibody to IgE 185
13.3.3 Immunomodulatory cytokines 185
13.3.4 DNA vaccines 186
13.3.5 Engineered allergens 186
13.3.6 Peptide vaccines 186
13.4 Conclusions 187
13.5 Key points 187
14 Conclusions of the Task Force 188
14.1 Chapter 1 188
14.2 Chapter 2 189
14.3 Chapter 3 189
14.4 Chapter 4 190
14.5 Chapter 5 190
14.6 Chapter 6 191
14.7 Chapter 7 191
14.8 Chapter 8 191
14.9 Chapter 9 192
14.10 Chapter 10 193
14.11 Chapter 11 193
14.12 Chapter 12 193
14.13 Chapter 13 194
15 Recommendations of the Task Force 195
15.1 General recommendations 195
15.2 Recommendations for research priorities 196
15.2.1 Sensitisation to food allergens and understanding food allergy 196
15.2.2 Epidemiology of food intolerance 196
15.2.3 Coeliac disease 197
15.2.4 Other forms of food intolerance 197
15.2.5 Diagnosis 198
15.2.6 Dietary management of food intolerance 198
16 Questions on Food Allergy and Intolerance 199
Definitions of food allergy and intolerance 199
Prevelance of food allergy and intolerance 201
Common causes of food allergy and food intolerance 202
Diagnosis and treatment 203
Appendix 1 Food Additives 207
Glossary 209
Abbreviations 212
References 213
Index 240

"...some of the most eminent practitioners in the field have
contributed to this book, it is no surprise that it is an excellent
and very exhaustive resume of the topic. Although a different
author wrote each chapter, the skilful editing ensures that all the
chapters are written in the same style." (Isabel Skypala,
Journal of Human Nutrition & Dietetics, August
2002)



"Questions on food allergy and intolerance, plus the answers
(this chapter alone makes the book valuable - the complex questions
are answered in a language that all can understand and
interpret).

A must-read for nutritionists, dieticians, medics and food
scientists/technologists." (Food & Beverage Reporter
2004)