Your Diet Tailored To Your Genes: Preventing Diseases or Misleading Marketing? A report by GeneWatch UK Your Diet Tailored to Your Genes: Preventing Diseases or Misleading Marketing? By Dr Helen Wallace January 2006 The Mill House · Manchester Road · Tideswell · Buxton Derbyshire SK17 8LN · UK Phone: 01298 871898 · Fax: 01298 872531 GeneWatch E-mail: [email protected] UK Website: www.genewatch.org Acknowledgements GeneWatch UK would like to thank Eric Brunner, Dave Curtis, Stuart Hogarth, Tim Lobstein, Tom MacMillan, Erik Millstone, Paolo Vineis and Shefaly Yogendra for their helpful comments on a draft of this report. The content of the final report remains the responsibility of GeneWatch UK. Cover photograph by Xenia Antunes. Www.xenia.com.br GeneWatch UK 2 January 2006 Contents 1 Executive summary..................................................................................................................6 2 Introduction.............................................................................................................................14 3 Nutrigenomics in context.......................................................................................................16 3.1 Our diets and our health...................................................................................................16 3.2 Our diets and the food industry ........................................................................................20 3.3 The supplements industry ................................................................................................23 3.4 The diet industry, diet drinks and low-fat products ...........................................................24 3.5 Techno-foods and health claims for foods........................................................................26 3.6 The pharmaceutical industry ............................................................................................34 3.7 Governments and public health........................................................................................35 3.8 Summary ..........................................................................................................................36 4 'Personalised nutrition' as a health strategy .......................................................................38 4.1 The science of nutrigenomics...........................................................................................38 4.2 Nutrigenetics – diet and genes.........................................................................................40 4.2.1 Tailoring dietary advice to genes...............................................................................41 4.2.2 Food products tailored to your genes .......................................................................43 5 Nutrigenomics: who's involved.............................................................................................44 5.1 Major research projects....................................................................................................44 5.2 The role of the food, pharma and biotech industries in nutrigenomics.............................47 5.3 The role of governments ..................................................................................................52 5.4 Summary ..........................................................................................................................53 6 Role of genes in diet-related disease ...................................................................................54 6.1 Types of evidence ............................................................................................................54 6.2 Genes and diet-related diseases......................................................................................56 6.2.1 Obesity......................................................................................................................56 6.2.2 The metabolic syndrome (Syndrome X) ...................................................................63 6.2.3 Diabetes....................................................................................................................63 6.2.4 Heart disease............................................................................................................65 6.2.4.1 Cholesterol and dietary fats ...........................................................................66 6.2.4.2 Blood pressure and salt .................................................................................68 6.2.4.3 Homocysteine and folate ...............................................................................70 6.2.4.4 Marketing genetic tests for heart disease susceptibility.................................71 6.2.5 Stroke........................................................................................................................71 6.2.6 Cancer ......................................................................................................................72 6.2.7 Food intolerances .....................................................................................................75 6.2.8 Allergies and inflammatory diseases ........................................................................77 6.2.9 Osteoporosis, falls and fractures ..............................................................................78 6.2.10 Brain disease and neurodegenerative disorders ......................................................79 6.2.11 Vitamin and mineral deficiencies and overload.........................................................81 7 Genes, food preferences and mood .....................................................................................83 7.1 Food preferences, appetite and obesity ...........................................................................83 7.2 Taste.................................................................................................................................85 8 Limited scientific evidence for genetically tailored diets ...................................................87 9 The potential negative health and social impacts of nutrigenomics.................................90 9.1 Personalised diets: diverting science ...............................................................................90 9.2 Undermining public health?..............................................................................................92 9.3 Misleading consumers......................................................................................................92 GeneWatch UK January 2006 3 9.3.1 Genetic testing unregulated ......................................................................................93 9.3.2 Confusing advice ......................................................................................................94 9.4 Privacy, stigma and discrimination ...................................................................................94 9.5 Ethnicity and race.............................................................................................................95 9.6 Health inequalities ............................................................................................................95 9.7 Personalised choice – a contradiction?............................................................................97 9.8 Patenting and profiteering ................................................................................................98 9.9 Good for business? ..........................................................................................................98 9.10 Costs and resources ........................................................................................................98 10 Conclusions and recommendations...................................................................................100 11 References ............................................................................................................................102 Tables Table 1. Top ten food manufacturers, 2002/3.................................................................................20 Table 2. Top ten food retailers, 2003/4...........................................................................................21 Table 3. The world's biggest food advertisers, 1999/2000.............................................................21 Table 4. The US diet industry, 2002 ...............................................................................................25 Table 5. The UK techno-foods market in 2001...............................................................................30 Table 6. Conditions considered influential in future functional foods development .......................32 Table 7. Major research projects including diet and genes ............................................................44 Table 8. Personalised medicine and the food industry supply chain..............................................48 Table 9. Genetic testing companies directly involved in nutrigenomics .........................................48 Boxes Box 3.1. Malnutrition and under-nutrition........................................................................................16 Box 3.2. Diet and chronic diseases ................................................................................................16 Box 3.3. Global strategy on diet, physical activity and health.........................................................17 Box 3.4. What people eat