Composition differences between organic and conventional meat: a systematic literature review and meta-analysis

Abstract Demand for organic meat is partially driven by consumer perceptions that organic foods are more nutritious than non-organic foods. However, there have been no systematic reviews comparing specifically the nutrient content of organic and conventionally produced meat. In this study, we report results of a meta-analysis based on sixty-seven published studies comparing the composition of organic and non-organic meat products. For many nutritionally relevant compounds (e.g. minerals, antioxidants and most individual fatty acids (FA)), the evidence base was too weak for meaningful meta-analyses. However, significant differences in FA profiles were detected when data from all livestock species were pooled. Concentrations of SFA and MUFA were similar or slightly lower, respectively, in organic compared with conventional meat. Larger differences were detected for total PUFA and n-3 PUFA, which were an estimated 23 (95 % CI 11, 35) % and 47 (95 % CI 10, 84) % higher in organic meat, respectively. However, for these and many other composition parameters, for which meta-analyses found significant differences, heterogeneity was high, and this could be explained by differences between animal species/meat types. Evidence from controlled experimental studies indicates that the high grazing/forage-based diets prescribed under organic farming standards may be the main reason for differences in FA profiles. Further studies are required to enable meta-analyses for a wider range of parameters (e.g. antioxidant, vitamin and mineral concentrations) and to improve both precision and consistency of results for FA profiles for all species. Potential impacts of composition differences on human health are discussed.

[1]  P. Calder.  Marine omega-3 fatty acids and inflammatory processes: Effects, mechanisms and clinical relevance. , 2015, Biochimica et biophysica acta.

[2]  Wolfgang Viechtbauer,et al.  Conducting Meta-Analyses in R with the metafor Package , 2010 .

[3]  S. Cunnane,et al.  alpha-Linolenic acid supplementation and conversion to n-3 long-chain polyunsaturated fatty acids in humans. , 2009, Prostaglandins, leukotrienes, and essential fatty acids.

[4]  Jessica Gurevitch,et al.  STATISTICAL ISSUES IN ECOLOGICAL META‐ANALYSES , 1999 .

[5]  Minou Yussefi-Menzler,et al.  The World of Organic Agriculture , 2014 .

[6]  J. Silverstein,et al.  Issues of Fish Consumption for Cardiovascular Disease Risk Reduction , 2013, Nutrients.

[7]  Bas Eickhout,et al.  Exploring changes in world ruminant production systems , 2005 .

[8]  R. Sanderson,et al.  Conjugated linoleic acid isomer concentrations in milk from high- and low-input management dairy systems , 2009 .

[9]  Gavin B. Stewart,et al.  Meta-analysis in applied ecology , 2010, Biology Letters.

[10]  C. Pugliese,et al.  Performance of Cinta Senese pigs and their crosses with Large White. 1 Muscle and subcutaneous fat characteristics. , 2005, Meat science.

[11]  L. Frewer,et al.  Food consumers and organic agriculture. , 2007 .

[12]  J. Manson,et al.  Types of Dietary Fat and Risk of Coronary Heart Disease: A Critical Review , 2001, Journal of the American College of Nutrition.

[13]  F. Hu,et al.  Plasma and erythrocyte biomarkers of dairy fat intake and risk of ischemic heart disease. , 2007, The American journal of clinical nutrition.

[14]  R. Krauss,et al.  A reappraisal of the impact of dairy foods and milk fat on cardiovascular disease risk , 2009, European journal of nutrition.

[15]  J. Bruinsma.  World Agriculture: Towards 2015/2030: An Fao Perspective , 2002 .

[16]  Gillian Butler,et al.  Manipulating dietary PUFA in animal feed: implications for human health , 2013, Proceedings of the Nutrition Society.

[17]  K. Hayes,et al.  Dietary n-6 and n-3 fatty acid balance and cardiovascular health. , 2004, Annual review of nutrition.

[18]  Xiao-Hua Zhou,et al.  Statistical Methods for Meta‐Analysis , 2008 .

[19]  C. Benbrook,et al.  Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses , 2015 .

[20]  P. Calder,et al.  Is there a role for fatty acids in early life programming of the immune system? , 2010, Proceedings of the Nutrition Society.

[21]  J. McGlone,et al.  Intensive indoor versus outdoor swine production systems: genotype and supplemental iron effects on blood hemoglobin and selected immune measures in young pigs. , 1999, Journal of animal science.

[22]  Ingram Olkin,et al.  Are Organic Foods Safer or Healthier Than Conventional Alternatives? , 2012, Annals of Internal Medicine.

[23]  Paula Pereira,et al.  Meat nutritional composition and nutritive role in the human diet. , 2013, Meat science.

[24]  P. Williams,et al.  Nutritional composition of red meat , 2007 .

[25]  Niels Skovgaard,et al.  Handbook of organic food safety and quality , 2008 .

[26]  P. Calder,et al.  Gender differences in the n-3 fatty acid content of tissues , 2008, Proceedings of the Nutrition Society.

[27]  Mark W. Lipsey,et al.  Practical Meta-Analysis , 2000 .

[28]  Jessica Gurevitch,et al.  THE META‐ANALYSIS OF RESPONSE RATIOS IN EXPERIMENTAL ECOLOGY , 1999 .

[29]  P. A. van den Brandt,et al.  Consumption of organic foods and risk of atopic disease during the first 2 years of life in the Netherlands , 2008, British Journal of Nutrition.

[30]  V. Muchenje,et al.  Atherogenicity index and health-related fatty acids in different stages of lactation from Friesian, Jersey and Friesian×Jersey cross cow milk under a pasture-based dairy system. , 2014, Food chemistry.

[31]  T. Ulbricht,et al.  Coronary heart disease: seven dietary factors , 1991, The Lancet.

[32]  A. Fisher,et al.  Fatty acid composition and eating quality of lamb types derived from four diverse breed × production systems. , 2000, Meat science.

[33]  An Pan,et al.  Red meat consumption and mortality: results from 2 prospective cohort studies. , 2012, Archives of internal medicine.

[34]  Beate Huber,et al.  The World of Organic Agriculture – Statistics and Emerging Trends (Session at the BIOFACH 2015) , 2015 .

[35]  Robert B. Gramacy,et al.  amei: An R Package for the Adaptive Management of Epidemiological Interventions , 2010 .

[36]  Rashmi Sinha,et al.  Trends in meat consumption in the USA , 2010, Public Health Nutrition.

[37]  Methods for comparing data across differently designed agronomic studies: examples of different meta-analysis methods used to compare relative composition of plant foods grown using organic or conventional production methods and a protocol for a systematic review. , 2013, Journal of agricultural and food chemistry.

[38]  E. Emken,et al.  Dietary linoleic acid influences desaturation and acylation of deuterium-labeled linoleic and linolenic acids in young adult males. , 1994, Biochimica et biophysica acta.

[39]  Jessica Gurevitch,et al.  1. Place of Meta-analysis among Other Methods of Research Synthesis , 2013 .

[40]  R. Pardini,et al.  Docosahexaenoic Acid (DHA), a Primary Tumor Suppressive Omega-3 Fatty Acid, Inhibits Growth of Colorectal Cancer Independent of p53 Mutational Status , 2007, Nutrition and cancer.

[41]  G. Guyatt,et al.  GRADE: an emerging consensus on rating quality of evidence and strength of recommendations , 2008, BMJ : British Medical Journal.

[42]  Albert Sundrum,et al.  Quality in organic, low-input and conventional pig production , 2007 .

[43]  P. Parodi.  Has the association between saturated fatty acids, serum cholesterol and coronary heart disease been over emphasized? , 2009 .

[44]  Kerrie Mengersen,et al.  Statistical Models and Approaches to Inference , 2013 .

[45]  Christine M. Williams,et al.  Long-chain n-3 PUFA: plant v. marine sources. , 2006, The Proceedings of the Nutrition Society.

[46]  C. Leifert,et al.  The effects of dairy management and processing on quality characteristics of milk and dairy products , 2011 .

[47]  R. Sanderson,et al.  Effect of organic and conventional crop rotation, fertilization, and crop protection practices on metal contents in wheat (Triticum aestivum). , 2011, Journal of agricultural and food chemistry.

[48]  Efsa Publication,et al.  EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA); Scientific Opinion on Dietary Reference Values for fats, including saturated fatty acids, polyunsaturated fatty acids, monounsaturated fatty acids, trans fatty acids, and cholesterol , 2010 .

[49]  J. Garssen,et al.  Dietary long chain n‐3 polyunsaturated fatty acids prevent allergic sensitization to cow's milk protein in mice , 2013, Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology.

[50]  K. Hunter,et al.  Estimation of cis-9, trans-11 conjugated linoleic acid content in UK foods and assessment of dietary intake in a cohort of healthy adults , 2009, British Journal of Nutrition.

[51]  S. Luquet,et al.  A Western-like fat diet is sufficient to induce a gradual enhancement in fat mass over generations[S] , 2010, Journal of Lipid Research.

[52]  M. Fraser,et al.  Production performance and meat quality of grazing lambs finished on red clover, lucerne or perennial ryegrass swards , 2004 .

[53]  M. Borenstein,et al.  Publication Bias in Meta-Analysis , 2006 .

[54]  M. López-Alonso,et al.  Factors affecting trace element status in calves in NW Spain. , 2009 .

[55]  Kerrie Mengersen,et al.  Handbook of Meta-analysis in Ecology and Evolution , 2013 .

[56]  Emmanuel K. Yiridoe,et al.  Comparison of consumer perceptions and preference toward organic versus conventionally produced foods: A review and update of the literature , 2005, Renewable Agriculture and Food Systems.

[57]  C. Leifert,et al.  Meat quality and health implications of organic and conventional beef production. , 2015, Meat science.

[58]  A. Tedstone,et al.  National Diet and Nutrition Survey , 2010 .

[59]  R. Gibbs,et al.  Current intakes of EPA and DHA in European populations and the potential of animal-derived foods to increase them , 2008, Proceedings of the Nutrition Society.

[60]  F. Q. Ribeiro.  The meta-analysis , 2017, Brazilian journal of otorhinolaryngology.

[61]  R. Uauy,et al.  Nutritional quality of organic foods: a systematic review. , 2009, The American journal of clinical nutrition.

[62]  A. J. McAfee,et al.  Red meat from animals offered a grass diet increases plasma and platelet n-3 PUFA in healthy consumers , 2010, British Journal of Nutrition.

[63]  J. Wood,et al.  Effect of a grass-based and a concentrate feeding system on meat quality characteristics and fatty acid composition of longissimus muscle in different cattle breeds , 2005 .

[64]  E. Zeltner,et al.  Effects of organic husbandry methods and feeding regimes on poultry quality. , 2007 .

[65]  M. Borenstein,et al.  Publication Bias in Meta-Analysis: Prevention, Assessment and Adjustments , 2006 .

[66]  Carlo Leifert,et al.  Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses , 2014, The British journal of nutrition.

[67]  C. Seal,et al.  Agroecosystem Management and Nutritional Quality of Plant Foods: The Case of Organic Fruits and Vegetables , 2011 .

[68]  E. Nelson,et al.  Effects of long-chain polyunsaturated fatty acid supplementation on neurodevelopment in childhood: a review of human studies. , 2010, Prostaglandins, leukotrienes, and essential fatty acids.

[69]  N. Wareham,et al.  Dietary intake and status of n-3 polyunsaturated fatty acids in a population of fish-eating and non-fish-eating meat-eaters, vegetarians, and vegans and the product-precursor ratio [corrected] of α-linolenic acid to long-chain n-3 polyunsaturated fatty acids: results from the EPIC-Norfolk cohort. , 2010, The American journal of clinical nutrition.

[70]  A. W. Kemp,et al.  Randomization, Bootstrap and Monte Carlo Methods in Biology , 1997 .

[71]  D. I. Givens,et al.  Dairy products in the food chain: their impact on health. , 2011, Annual review of food science and technology.

[72]  C. Pugliese,et al.  Performance of Cinta Senese pigs and their crosses with Large White 2. Physical, chemical and technological traits of Tuscan dry-cured ham. , 2007, Meat science.

[73]  J. Hibbeln,et al.  Changes in consumption of omega-3 and omega-6 fatty acids in the United States during the 20th century. , 2011, The American journal of clinical nutrition.

[74]  J. Kahl,et al.  Comparison of nutritional quality between conventional and organic dairy products: a meta-analysis. , 2012, Journal of the science of food and agriculture.

[75]  N. Lundeheim,et al.  Free range rearing of pigs with access to pasture grazing - effect on fatty acid composition and lipid oxidation products. , 2001, Meat science.

[76]  P. Calder,et al.  Conversion of alpha-linolenic acid to longer-chain polyunsaturated fatty acids in human adults. , 2005, Reproduction, nutrition, development.