Genetically modified plants are an alternative to oily fish for providing n-3 polyunsaturated fatty acids in the human diet: A summary of the findings of a Biotechnology and Biological Sciences Research Council funded project.

A L West,J A Napier,P C Calder,K A Lillycrop,E A Miles,G C Burdge

doi:10.1111/nbu.12478

Abstract

The n‐3 polyunsaturated fatty acids (PUFA) present primarily in oily fish, namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are important components of cell membranes and that are needed for normal development and cell function. Humans have very limited capacity for EPA and DHA synthesis from α‐linolenic acid and so they must be obtained pre‐formed from the diet. However, perceived unpalatability of oily fish and fish oil concerns about contamination with environmental pollutants, dietary choices that exclude fish and animal products, and price limit the effectiveness of recommendations for EPA and DHA intakes. Moreover, marine sources of EPA and DHA are diminishing in the face of increasing demands. Therefore, an alternative source of EPA and DHA is needed that is broadly acceptable, can be upscaled and is sustainable. This review discusses these challenges and, using findings from recent nutritional trials, explains how they may be overcome by seed oils from transgenic plants engineered to produce EPA and DHA. Trials in healthy men and women assessed the acute uptake and appearance in blood over 8 hours of EPA and DHA from transgenic Camelina sativa compared to fish oil, and the incorporation of these PUFA into blood lipids after dietary supplementation. The findings showed that postprandial EPA and DHA incorporation into blood lipids and accumulation in plasma lipids after dietary supplementation was as good as that achieved with fish oil. The oil derived from this transgenic plant was well tolerated. This review also discusses the implications for human nutrition, marine ecology and agriculture.

Highlights

First double bond is three carbons from the methyl end of the molecule
The four principle n-3 polyunsaturated fatty acids (PUFA) are unevenly distributed between tissues (Arterburn et al 2006), which suggests that their incorporation into cell membranes is related to specific cell functions. aLinolenic acid (18:3n-3, ALA) and eicosapentaenoic acid (20:5n-3, EPA) each account for less than 1% of total membrane fatty acids in human tissues (Arterburn et al 2006)
Increased consumption of SDA, which is only present in significant amounts in members of the genus Echium (Guil-Guerrero et al 2001), is an unsuitable dietary strategy for increasing EPA + docosahexaenoic acid (DHA) levels. These findings show that plant-derived n-3 fatty acids, ALA and SDA, are not effective replacements for pre-formed EPA and DHA in the human diet (Plourde & Cunnane 2007)

Summary

Introduction

First double bond is three carbons from the methyl end of the molecule. In humans, n-3 PUFA in the diet and in cell membranes typically vary in the length of the hydrocarbon chain between 18 and 22 carbons, and in the degree of unsaturation between three and six double bonds, all in the cis configuration (Burdge & Calder 2015). GM oil and n-3 fatty acids in human diet 3 increased intake of ALA does not provide an alternative dietary source of EPA and DHA to consuming these PUFA pre-formed (Burdge & Calder 2006).

Results

Conclusion