Lipid Modification by Enzymes and Engineered Microbes by Uwe T. Bornscheuer

Author:Uwe T. Bornscheuer
Language: eng
Format: epub
ISBN: 9780128131688
Publisher: Elsevier Ltd.

Omega-3 Fatty Acid-Enriched Oils for Improved Nutrition and Health

It is now generally accepted that dietary ω-3 long-chain polyunsaturated fatty acids (LC-PUFAs), such as EPA and its derivative DHA, possess added benefits for human nutrition and health. Studies have reported on the potential of their antithrombogenic, hypotriglyceridemic, and antiinflammatory effects toward the reduction of cardiovascular disease (CVD), as well as on their effects on the reduction of related ailments, such as the growth of atherosclerotic plaque (Kris-Etherton etal.,2002). In agreement with these findings, various reviews report that ω-3 fatty acids are effective in preventing cardiovascular and coronary events, as well as cardiac death, especially in persons with high cardiovascular risk (Delgado-Lista etal.,2012; Wang etal.,2006). Besides their role in CVD reduction, these LC-PUFAs have been of recent interest because of their role in basic brain function. DHA (but not EPA) has been found to comprise approximately 10% of the total fatty acids within brain PLs, and it is believed to have antineuroinflammatory effects. However, it is not clear whether the effects of DHA arise from its PL, unesterified form in vivo, or mediators after its in vivo conversion (Bazinet and Layé,2014). Also related to brain function and development is the fact that since half way of gestation to approximately 2 years of age, DHA is intensively accumulated in the human brain (Brenna and Carlson,2014), evidencing its important role on human development. The antiinflammatory effects of DHA and its precursor EPA are also investigated in diverse ailments, such as asthma, rheumatoid arthritis, and inflammatory bowel disease (Yates etal.,2014), as well as in gastrointestinal cancers, such as pancreatic and colon cancer (Eltweri etal.,2017).

Although it is evident that EPA and DHA are important components for proper human development and potential disease prevention, the human body has limited ability to synthesize EPA and DHA (Eltweri etal.,2017). Therefore, these LC-PUFAs must be sourced from the diet. Unlike diets based on fish consumption, the “Western Diet” is usually based on high fat, cholesterol, protein, sugar, and excess salt intake, which promotes obesity, metabolic syndrome, and CVD (Manzel etal.,2014). EPA and DHA are commonly found in fish, but most commonly found at higher concentrations in fatty fish such as salmon, rainbow trout, mackerel, tuna, and herring (Koski,2008). In order to increase the dietary consumption of these LC-PUFAs within the Western diet, several approaches have been proposed. One of them is that of increasing dietary consumption of α-linoleic acid (ALA, 18:3 ω-3) with the objective of its in vivo conversion to EPA and DHA (see Fig.9.2). However, the Δ6-desaturase enzyme involved in this conversion introduces a rate limiting step for which conversion is poor (Koski,2008; Whelan,2009). Furthermore, ALA must also be acquired from the diet, since unlike plants, animals do not have the plant-based Δ12- and Δ15-desaturase enzymes to metabolize oleic acid (18:1ω-9) into EPA or DHA (Venegas-Calerón etal.,2010). Increasing dietary fish consumption has also been proposed, but overfishing in the past decades has reduced and stressed the fish population, leading to the fishing of species lower in the food chain.

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