Alternative Sources of Omega 3 Fats: Can We Find a Sustainable Substitute for Fish?

Increasing demand for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) containing fish oils is putting pressure on fish species and numbers. Fisheries provide fish for human consumption, supplement production and fish feeds and are currently supplying fish at a maximum historical rate, suggesting mass scale fishing is no longer sustainable. However, the health properties of EPA and DHA long chain (LC) omega 3 polyunsaturated fatty acids (PUFA) demonstrate the necessity for these oils in our diets. EPA and DHA from fish oils show favourable effects in inflammatory bowel disease, some cancers and cardiovascular complications. The high prevalence of these diseases worldwide indicates the requirement for alternative sources of LC PUFA. Strategies have included plant-based fish diets, although this may compromise the health benefits associated with fish oils. Alternatively, stearidonic acid, the product of alpha linolenic acid desaturation, may act as an EPA enhancing fatty acid. Additionally, algae oils may be a promising omega 3 PUFA source for the future. Algae are beneficial for multiple industries, offering a source of biodiesel and livestock feeds. However, further research is required to develop efficient and sustainable LCPUFA production from algae. This paper summarises the recent research for developing prospective substitutes for omega 3 PUFA and the current limitations that are faced. (Authors abstract)
Fisheries are currently producing the maximum fish stocks per annum in order to supply fish for human consumption, as well as supplying feed for industrial fish farms and fish oil supplements, resulting in a substantial effect on fish levels and the possibility of extinction. However, an expansive literature indicates that omega 3 fish oils are crucial dietary components. In order to protect fish species and the oceans’ ecosystems, alternative sources for long chain polyunsaturated fatty acids (LCPUFA) are required. Currently explored alternatives include plant oils with high omega 3 content, the use of stearidonic acid and algae oils. This review highlights the importance of LC PUFA in our diet, focusing on their role in inflammation and risk and progression of particular diseases. Additionally, possible alternative sources for these LC PUFA are discussed.  Chronic inflammation has shown an association with many of the current, prevalent diseases including cancer and inflammatory bowel disease. As dietary fatty acids show a prominent role in the inflammatory response, researchers have investigated the relationship between consumption of particular fatty acids with inflammatory-related disease, such as cancer. Studies highlight a major contribution of dietary fatty acids in the modulation of inflammatory responses and the implication of this in disease outcome. Plants high in omega 3 PUFA, such as linseed, primrose, echium and hempseed, contain only shorter chain omega 3 PUFA and none, or low levels of EPA and DHA. Omega 3 fatty acids possess highly beneficial effects for modulating risk of prevalent diseases. Due to the decline in fish species and number, alternative sources of these fatty acids are required. Potential substitutes include plant oils, stearidonic acid and algae oils. Plant oils contain low amounts of LC PUFA and the use of plant oils in fish feed has shown mostly disappointing results. SDA has potential as an EPA enhancing fatty acid, although sources of SDA are limited. Lastly, algae offer a promising alternative. The use of algal oils will benefit multiple industries. (Authors abstract)