Nutrition, Health and Disease

Simon Langley-Evans is Deputy Head of School of Biosciences & Professor of Human Nutrition, Faculty of Science, University of Nottingham, Nottingham, UK.

Preface xii Acknowledgements xiii About the companion website xvi Abbreviations xvii Glossary of terms used in this book xviii 1 Introduction to lifespan nutrition 1 1.1 The lifespan approach to nutrition 1 1.2 The concept of balance 2 1.2.1 A supply and demand model 2 1.2.2 Overnutrition 2 1.2.3 Undernutrition 4 1.2.3.1 Increased demand 4 1.2.3.2 The metabolic response to trauma 4 1.2.3.3 Compromised supply and deficiency 6 1.2.3.4 Malnutrition 6 1.2.4 Classical balance studies 8 1.2.5 Overall nutritional status 9 1.3 The individual response to nutrition 10 1.3.1 Stage of the lifespan 10 1.3.2 Genetics 12 1.4 Assessment of nutritional status 13 1.4.1 Anthropometric measures 14 1.4.2 Estimating dietary intakes 14 1.4.2.1 Indirect measures 14 1.4.2.2 Direct measures 16 1.4.2.2.1 Dietary recall methods 16 1.4.2.2.2 Food record methods 17 1.4.2.2.3 Food frequency questionnaire methods 17 1.4.3 Biomarkers of nutritional status 18 1.4.4 Clinical examination 20 1.5 Nutritional epidemiology: Understanding diet disease relationships 20 1.5.1 Cause and effect 20 1.5.2 Bias and confounding 21 1.5.3 Quantifying the relationship between diet and disease 22 1.5.4 Study designs in nutritional epidemiology 24 1.5.4.1 Ecological studies 25 1.5.4.2 Cross ]sectional studies 25 1.5.4.3 Case control studies 26 1.5.4.4 Cohort studies 26 1.5.4.5 RCTs 26 1.5.4.6 Systematic review and meta ]analysis 27 1.6 Dietary reference values 28 1.6.1 The UK DRV system 28 1.6.2 DRVs in other countries 31 2 Before life begins 35 2.1 Introduction 35 2.2 Nutrition and female fertility 36 2.2.1 Determinants of fertility and infertility 36 2.2.1.1 The endocrine control of female reproduction 36 2.2.1.2 Disordered reproductive cycling 37 2.2.1.3 PCOS 38 2.2.2 Importance of body fat 39 2.2.3 Role of leptin 39 2.2.4 Antioxidant nutrients 41 2.2.5 Caffeine and alcohol 43 2.3 Nutrition and male fertility 44 2.3.1 Determinants of fertility and infertility 44 2.3.2 Obesity 46 2.3.3 Alcohol 47 2.3.4 Zinc 48 2.3.5 Antioxidant nutrients 48 2.3.6 Selenium 49 2.3.7 Phytoestrogens and environmental oestrogens 49 2.3.7.1 Phthalates 50 2.3.7.2 Phytoestrogens 50 2.3.7.3 Pesticides 51 2.4 Preparation for pregnancy 52 2.4.1 Why prepare for pregnancy? 52 2.4.2 Maternal weight management 52 2.4.3 Vitamin A and liver 52 2.4.4 Folic acid and neural tube defects 54 2.4.4.1 Supplementation with folic acid 55 2.4.4.2 Fortification with folic acid 55 3 Pregnancy 61 3.1 Introduction 61 3.2 Physiological demands of pregnancy 62 3.2.1 Maternal weight gain and body composition changes 63 3.2.2 Blood volume expansion and cardiovascular changes 63 3.2.3 Renal changes 64 3.2.4 Respiratory changes 64 3.2.5 Gastrointestinal changes 65 3.2.6 Metabolic adaptations 65 3.3 Nutrient requirements in pregnancy 66 3.3.1 Energy protein and lipids 66 3.3.2 Micronutrients 68 3.3.2.1 Iron 68 3.3.2.2 Calcium and other minerals 69 3.3.2.3 Vitamin D 70 3.4 Diet in relation to pregnancy outcomes 71 3.4.1 Miscarriage and stillbirth 71 3.4.2 Premature labour 72 3.4.2.1 Pre ]pregnancy BMI and pregnancy weight gain 72 3.4.2.2 Alcohol and caffeine consumption 73 3.4.2.3 Oral health 74 3.4.3 Hypertensive disorders of pregnancy 76 3.4.3.1 The aetiology of PE 77 3.4.3.2 Nutrition ]related factors and PE 77 3.4.4 Abnormal labour 79 3.5 Nausea and vomiting of pregnancy 79 3.5.1 Nausea and vomiting of pregnancy as a normal physiological process 79 3.5.2 Hyperemesis gravidarum 81 3.6 Cravings and aversions 82 3.6.1 Pica 83 3.7 Gastrointestinal disturbances in pregnancy 84 3.8 High ]risk pregnancies 84 3.8.1 Gestational diabetes 84 3.8.2 Multiple pregnancies 86 3.8.3 Foetal alcohol spectrum disorders 87 4 Fetal nutrition and disease in later life 94 4.1 Introduction 94 4.2 The developmental origins of adult disease 94 4.2.1 The concept of programming 94 4.2.2 Fetal programming and human disease 95 4.2.2.1 Fetal growth 95 4.2.2.2 Nutrition and the constraint of growth 96 4.2.2.3 Fetal growth health and disease 97 4.3 Evidence linking maternal nutrition to disease in later life 99 4.3.1 Epidemiology 99 4.3.2 Criticisms of the programming hypothesis 102 4.3.3 Experimental studies 103 4.3.3.1 Global undernutrition 104 4.3.3.2 Micronutrients 104 4.3.3.3 Macronutrients 105 4.4 Mechanistic basis of fetal programming 106 4.4.1 Thrifty phenotypes and genotypes 106 4.4.2 Mismatched environments 108 4.4.3 Tissue remodelling 108 4.4.4 Endocrine imbalance 109 4.4.5 Nutrient gene interactions 111 4.4.5.1 Polymorphisms in humans 111 4.4.5.2 Gene expression in animals 112 4.4.6 Epigenetic regulation 113 4.5 Implications of the programming hypothesis 115 4.5.1 Public health interventions 115 4.5.2 Trans ]generational transmission of disease risk 117 5 Lactation and infant feeding 123 5.1 Introduction 123 5.2 The physiology of lactation 123 5.2.1 Anatomy of the breast 123 5.2.1.1 The nipple and areola 123 5.2.1.2 The lactiferous ducts 124 5.2.1.3 The lactiferous sinuses 124 5.2.1.4 The alveolar cells 124 5.2.1.5 The rooting reflex 124 5.2.2 Synthesis of milk 124 5.2.2.1 Foremilk and hindmilk 125 5.2.2.2 Time of day 125 5.2.2.3 Course of lactation 125 5.2.2.4 Synthesis of carbohydrates 125 5.2.2.5 Origins of milk fats 126 5.2.2.6 Milk proteins 126 5.2.3 Endocrine control of lactation 127 5.2.3.1 The breast during pregnancy 127 5.2.3.2 Established lactation 128 5.2.3.3 The breast after weaning 128 5.2.4 Maintenance of lactation 129 5.2.5 Nutritional demands of lactation 129 5.3 The advantages of breastfeeding 130 5.3.1 Advantages for the mother 130 5.3.2 Advantages for the infant 132 5.3.3 Recommendation to feed to 6 months 135 5.4 Trends in breastfeeding behaviour 136 5.4.1 Reasons why women do not breastfeed 138 5.4.2 Promoting breastfeeding 140 5.5 Situations in which breastfeeding is not advised 141 5.6 Alternatives to breastfeeding 143 5.6.1 Cow s milk formulas 143 5.6.1.1 Milk stages and follow ]on milk 144 5.6.2 Preterm formulas 145 5.6.3 Soy formulas 146 5.6.4 Hydrolysed protein and amino acid ]based formulas 146 5.6.5 Other formulas 146 6 Nutrition and childhood 150 6.1 Introduction 150 6.2 Infancy (birth to five) 150 6.2.1 The key developmental milestones 150 6.2.2 Nutrient requirements 151 6.2.2.1 Macronutrients and energy 152 6.2.2.2 Micronutrients 154 6.2.3 Nutrient intakes and infants 154 6.2.4 Transition to an adult pattern of food intake 156 6.2.4.1 Complementary feeding 156 6.2.4.2 Nutrition ]related problems 159 6.2.4.2.1 Zinc deficiency 160 6.2.4.2.2 Vitamin D deficiency 160 6.2.4.2.3 Iron deficiency 161 6.2.4.2.4 Food additives and hyperactivity 161 6.2.4.3 Barriers to healthy nutrition 162 6.2.4.3.1 Faddy eating 162 6.2.4.3.2 Poverty 163 6.2.4.3.3 The impact of advertising 165 6.2.4.3.4 Restrictive dietary practices 167 6.3 Childhood (5 13) 167 6.3.1 Nutrient requirements of the older child 167 6.3.2 School meals and the promotion of healthy eating 168 6.3.3 The importance of breakfast 169 6.4 Obesity in children 170 6.4.1 The rising prevalence of obesity 170 6.4.2 The causes of obesity in childhood 171 6.4.2.1 Physical activity 172 6.4.2.2 Food intake 173 6.4.2.3 Genetic disorders 175 6.4.3 The consequences of childhood obesity 176 6.4.3.1 Immediate health consequences 176 6.4.3.2 Tracking of obesity: Consequences for the future 176 6.4.4 Treatment of childhood obesity 178 6.4.5 Prevention of childhood obesity 180 7 Nutrition and adolescence 189 7.1 Introduction 189 7.2 Physical development 189 7.2.1 Growth rate 189 7.2.2 Body composition 190 7.2.3 Puberty and sexual maturation 191 7.2.4 Bone growth 193 7.3 Psychosocial development 196 7.4 Nutritional requirements in adolescence 197 7.4.1 Macronutrients and energy 197 7.4.2 Micronutrients 198 7.5 Nutritional intakes in adolescence 199 7.5.1 Factors that influence food choice 200 7.5.2 Food consumed out of the home 201 7.5.3 Meal skipping and snacking 202 7.6 Potential problems with nutrition 203 7.6.1 Dieting and weight control 203 7.6.2 The vegetarian teenager 204 7.6.3 Sport and physical activity 204 7.6.4 Eating disorders 206 7.6.4.1 AN 206 7.6.4.2 BN 208 7.6.5 The pregnant teenager 209 7.6.6 Alcohol 210 7.6.7 Tobacco smoking 212 7.6.8 Drug abuse 213 8 The adult years 219 8.1 Introduction 219 8.2 Changing needs for nutrients 219 8.3 Guidelines for healthy nutrition 220 8.4 Disease states associated with unhealthy nutrition and lifestyle 223 8.4.1 Obesity 223 8.4.1.1 Classification of overweight and obesity 223 8.4.1.2 Prevalence and trends in obesity 223 8.4.1.3 Causes of obesity in adulthood 224 8.4.1.4 Treatment of obesity 224 8.4.2 Type 2 diabetes 226 8.4.3 The metabolic syndrome 229 8.4.4 Cardiovascular disease 230 8.4.4.1 What is CVD? 230 8.4.4.1.1 Atherosclerosis 230 8.4.4.1.2 CHD 232 8.4.4.1.3 Cerebrovascular disease 232 8.4.4.1.4 Peripheral artery disease 232 8.4.4.1.5 Hypertension 232 8.4.4.2 Risk factors for CVD 233 8.4.4.3 Nutrition ]related factors and risk of CVD 233 8.4.4.3.1 Obesity 233 8.4.4.3.2 Diabetes 234 8.4.4.3.3 Dietary fat and cholesterol transport 235 8.4.4.3.4 Folic acid and plasma homocysteine 237 8.4.4.3.5 Antioxidant nutrients 239 8.4.4.3.6 Sodium and blood pressure 240 8.4.5 Cancer 242 8.4.5.1 What is cancer? 242 8.4.5.2 Diet is a modifiable determinant of cancer risk 244 8.4.5.3 Nutritional epidemiology and cancer 245 8.4.5.3.1 Ecological studies 245 8.4.5.3.2 Migrant studies 246 8.4.5.3.3 Studies of populations with unique characteristics 247 8.4.5.3.4 Case control studies 247 8.4.5.3.5 Cohort studies 248 8.4.5.3.6 Intervention studies 248 8.4.5.3.7 Cancer risk is a product of the whole diet 248 8.4.5.4 Dietary factors that may promote cancer 249 8.4.5.4.1 Obesity 249 8.4.5.4.2 Fat intake 251 8.4.5.4.3 Meat 252 8.4.5.4.4 Alcohol 253 8.4.5.4.5 Specific carcinogens in food 253 8.4.5.5 Dietary factors that may reduce cancer risk 255 8.4.5.5.1 Complex carbohydrates 255 8.4.5.5.2 Milk and dairy produce 257 8.4.5.5.3 Antioxidant nutrients 257 8.4.5.5.4 Folic acid 259 8.4.5.5.5 Non ]nutrient components of plant foodstuffs 260 9 Nutrition ageing and the elderly 268 9.1 Introduction 268 9.2 The ageing population 268 9.3 The ageing process 269 9.3.1 Impact on physiological systems 269 9.3.2 Mechanisms of cellular senescence 270 9.3.2.1 Oxidative senescence 271 9.3.2.2 The role of p53 activation 271 9.3.2.3 Telomere shortening 272 9.3.2.4 The INK4a/ARF axis 273 9.3.3 Nutritional modulation of the ageing process 273 9.3.3.1 CR and lifespan 273 9.3.3.2 Fetal programming of lifespan 275 9.3.3.3 Supplementary antioxidants 275 9.4 Nutrient requirements of the elderly 276 9.4.1 Macronutrients and energy 276 9.4.2 Micronutrients 276 9.4.3 Specific guidelines for the elderly 276 9.5 Barriers to healthy nutrition in the elderly 277 9.5.1 Malnutrition and the elderly 277 9.5.2 Poverty 278 9.5.3 Social isolation 278 9.5.4 Education 279 9.5.5 Physical changes 279 9.5.6 Combating malnutrition in the elderly 279 9.6 Common nutrition ]related health problems 281 9.6.1 Bone disorders 281 9.6.1.1 Bone mineralization and remodelling 281 9.6.1.2 Osteoporosis pathology and prevalence 282 9.6.1.3 Risk factors for osteoporosis 283 9.6.1.4 Dietary interventions for osteoporosis prevention 284 9.6.1.4.1 Calcium and vitamin D 284 9.6.1.4.2 Minerals and protein 285 9.6.1.4.3 Phytoestrogens 286 9.6.1.4.4 Caffeine 286 9.6.1.5 Paget s disease of bone 286 9.6.2 Immunity and infection 286 9.6.3 Digestive tract disorders 289 9.6.3.1 Mouth and oesophagus 289 9.6.3.2 Stomach 289 9.6.3.3 Small intestine 289 9.6.3.4 Large intestine 289 9.6.4 Anaemia 290 9.6.4.1 Iron deficiency anaemia 292 9.6.4.2 Vitamin B12 deficiency 292 9.6.4.3 Folic acid deficiency 293 9.6.4.4 Cognitive impairment and anaemia 293 Appendix An introduction to the nutrients 300 A.1 Classification of nutrients 300 A.2 Carbohydrates 300 A.2.1 Major roles 300 A.2.2 Structure and classification of carbohydrates 300 A.2.3 Digestion and absorption of carbohydrates 301 A.3 Lipids 302 A.3.1 Major roles 302 A.3.2 Structure and classification of lipids 302 A.3.2.1 Fatty acids 302 A.3.2.2 Phospholipids and triglycerides 303 A.3.3 Digestion and absorption of lipids 303 A.4 Proteins 304 A.4.1 Major roles 304 A.4.2 Amino acids 304 A.4.3 Structure of proteins 305 A.4.4 Digestion and absorption of proteins 306 A.5 Micronutients 306 A.5.1 Minerals 306 A.5.2 Vitamins 308 Index 309