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

Dominika Średnicka-Tober,Sokratis Stergiadis,Gillian Butler,Ewa Rembiałkowska,Eleni Chatzidimitriou,Smaragda Sotiraki,Chris Seal,Graham C Burdge,Roy Sanderson,Philip C Calder,Halil Yolcu,Charles Benbrook,Teresa Jordon,Carlo Leifert,Marcin Barański,Giulio Cozzi,Gavin Stewart,Joanna Gromadzka-Ostrowska,Håvard Steinshamn,Krogh Larsen M ,M D Eyre ,T Sakowski ,Krystyna Skwarlo‐Sońta ,U Niggli ,Alexandros Stefanakis

doi:10.1017/s0007114515005073

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.

Highlights

Composition of organic meat products differences, heterogeneity was high, and this could be explained by differences between animal species/meat types
This includes linoleic acid (LA; the main n-6 PUFA found in meat), α-linolenic acid (ALA, the main n-3 PUFA found in meat) and, in particular, the very long-chain (VLC, ≥C20) n-3 PUFA EPA, docosapentaenoic acid (DPA) and
Most of the eligible studies were from Europe, mainly from Spain, UK, Italy, Sweden, Poland and Germany, with most of the others coming from the USA and Brazil

Summary

Introduction

Composition of organic meat products differences, heterogeneity was high, and this could be explained by differences between animal species/meat types. Over the last 20 years, an increasing number of scientific studies have compared concentrations of nutritionally relevant compounds in meat from organic and conventional livestock production systems. A range of PUFA found in meat are thought to reduce the risk of CVD[14] This includes linoleic acid (LA; the main n-6 PUFA found in meat), α-linolenic acid (ALA, the main n-3 PUFA found in meat) and, in particular, the very long-chain (VLC, ≥C20) n-3 PUFA EPA, docosapentaenoic acid (DPA) and DHA. Both LA and ALA are known to reduce LDL production and to enhance its clearance[14], whereas VLC n-3 PUFA are shown to reduce arrhythmias, blood pressure, platelet sensitivity, inflammation and serum TAG concentrations[15,16]. There is evidence of other health benefits from increasing

Methods

Results

Conclusion