DHA-Containing Oilseed: A Timely Solution for the Sustainability Issues Surrounding Fish Oil Sources of the Health-Benefitting Long-Chain Omega-3 Oils

Abstract

Benefits of long-chain (≥C20) omega-3 oils (LC omega-3 oils) for reduction of the risk of a range of disorders are well documented. The benefits result from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); optimal intake levels of these bioactive fatty acids for maintenance of normal health and prevention of diseases have been developed and adopted by national and international health agencies and science bodies. These developments have led to increased consumer demand for LC omega-3 oils and, coupled with increasing global population, will impact on future sustainable supply of fish. Seafood supply from aquaculture has risen over the past decades and it relies on harvest of wild catch fisheries also for its fish oil needs. Alternate sources of LC omega-3 oils are being pursued, including genetically modified soybean rich in shorter-chain stearidonic acid (SDA, 18:4ω3). However, neither oils from traditional oilseeds such as linseed, nor the SDA soybean oil have shown efficient conversion to DHA. A recent breakthrough has seen the demonstration of a land plant-based oil enriched in DHA, and with omega-6 PUFA levels close to that occurring in marine sources of EPA and DHA. We review alternative sources of DHA supply with emphasis on the need for land plant oils containing EPA and DHA.

Enhancing LC-PUFA production in Thalassiosira pseudonana by overexpressing the endogenous fatty acid elongase genes

“…Numerous studies in human health show that the omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) play fundamental roles in the development and function of the human body (reviewed in Ruxton et al 2004;Turchini et al 2012;Kitessa et al 2014). Among their various roles, n-3 LC-PUFAs are essential to neurodevelopment in infants and children and affect brain development and function (Rombaldi Bernardi et al 2012) and visual and cognitive development during the first year of life (Molloy et al 2012) and have beneficial effects in treating depression, ADHD, and Alzheimer's disease and reducing violence (Sinn et al 2010), as well as in prevention and treatment of chronic diseases such as coronary heart disease, elevated triglyceride levels, cancer, and asthma (Simopoulos 2008).…”

Role and Progress of DHA Dietary Supply in Brain Development of Maternal and Golden Periods

“…Tissue DHA is ultimately acquired from the diet either as DHA itself or any of some ω3 PUFA which can be metabolically converted into DHA 48 .…”

Algal oils

“…As an example, the combined EPA and DHA content of farmed Atlantic salmon from Tasmania was around 1750 mg/100 g wet weight with a fish oil diet in winter 2002, but had fallen to around 1050 mg/100 g in autumn 2013 as increasing amounts of chicken fat were added to the fish oil feed (Kitessa et al, 2014). Many diets around the world, including the westernized diet, have minimal consumption of oily fish and are awash with omega-6 fatty acids derived from vegetable oils.…”

“…Around 4.5 kg of wet fish is required to generate 1 kg of fish meal and fish oil (Kitessa et al, 2014). Around 4.5 kg of wet fish is required to generate 1 kg of fish meal and fish oil (Kitessa et al, 2014).…”