GM plants for omega-3
Genetically modified (GM) plant crops will replace fish oil as a more sustainable source of long-chain omega-3 in the next decade, scientists working on the EU-funded Lipgene project have predicted.
The project is exploring the relationship between diet, genes, obesity and related diseases.
Currently, the only plant-sourced omega-3 is alpha-linolenic acid, a shorter-chain omega-3 derived from plants like linseed.Fish oil and algae remain the primary sources of the more beneficial eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) omega-3 oils.
With fish stocks in "perilous decline", more sustainable sources of EPA and DHA were needed, claimed professor Johnathan Napier, plant biotechnologist at Rothamsted Research, who is trying to develop transgenic plants containing EPA and DHA. "Aquaculture is projected to consume 97% of the current production of fish oils. We therefore need an alternative, both for human and animal nutrition, and for aquaculture."
While several companies were producing DHA from harvesting the microalgae that fish eat in order to accumulate long chain PUFAs, this was a costly process with a large environmental footprint, claimed Napier. A more sustainable option was to introduce the genes regulating the production of EPA and DHA in algae into plants such as rapeseed.
However, producing rapeseed with useful quantities of these polyunsaturated fatty acids (PUFAs) was impossible using conventional breeding, he said. GM plants offered the way forward.
Other strands of the Lipgene project exploring how to enrich chicken meat with EPA and DHA through changes to poultry feed, were also progressing well, said Dr Caroline Rymer, senior research fellow at the University of Reading.
"You can achieve useful quantities [150mg of long chain PUFAs per 100g of fresh meat] by feeding chickens 40g of fish oil per 1kg of chicken feed." Quality and taste over the shelf-life of the product was maintained by adding vitamin E [an antioxidant] to the chicken feed, she added.
