Fish oil

About: Fish oil is a research topic. Over the lifetime, 9887 publications have been published within this topic receiving 367953 citations. The topic is also known as: fish oils & Fish oil.

Fatty acids as biocompounds: their role in human metabolism, health and disease - a review. part 2: fatty acid physiological roles and applications in human health and disease

Abstract: Background: This is the second of two review parts aiming at describing the major physiological roles of fatty acids, as well as their applications in specific conditions related to human health. Results: The review included the current literature published in Pubmed up to March 2011. In humans, fatty acids are a principle energy substrate and structural components of cell membranes (phospholipids) and second messengers. Fatty acids are also ligands of nuclear receptors affecting gene expression. Longer-chain (LC) polyunsaturated fatty acids (PUFA), including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid are precursors of lipid mediators such as eicosanoids (prostaglandins, leukotrienes, thromboxanes), resolvins and neuroprotectins. Lipid mediators produced by EPA and DHA (LC n-3 PUFA; mainly found in oily fish) are considered as inflammation-resolving, and thus, fish oil has been characterised as antiinflammatory. Recommendations for EPA plus DHA intake from oily fish vary between 250-450 mg/day. Dietary reference values for fat vary between nutrition bodies, but mainly agree on a low total and saturated fat intake. The existing literature supports the protective effects of LC n-3 PUFA (as opposed to n-6 PUFA and saturated fat) in maternal and offspring health, cardiovascular health, insulin sensitivity, the metabolic syndrome, cancer, critically ill patients, and immune system disorders. Conclusion: Fatty acids are involved in multiple pathways and play a major role in health. Further investigation and a nutrigenomics approach to the effects of these biocompounds on health and disease development are imperative and highlight the importance of environmental modifications on disease outcome.

Long-chain n-3 fatty acids and inflammation: potential application in surgical and trauma patients

Abstract: Lipids used in nutritional support of surgical or critically ill patients have been based on soybean oil, which is rich in the n-6 fatty acid linoleic acid (18:2n-6). Linoleic acid is the precursor of arachidonic acid (20:4n-6). In turn, arachidonic acid in cell membrane phospholipids is the substrate for the synthesis of a range of biologically active compounds (eicosanoids) including prostaglandins, thromboxanes, and leukotrienes. These compounds can act as mediators in their own right and can also act as regulators of other processes, such as platelet aggregation, blood clotting, smooth muscle contraction, leukocyte chemotaxis, inflammatory cytokine production, and immune function. There is a view that an excess of n-6 fatty acids should be avoided since this could contribute to a state where physiological processes become dysregulated. One alternative is the use of fish oil. The rationale of this latter approach is that fish oil contains long chain n-3 fatty acids, such as eicosapentaenoic acid. When fish oil is provided, eicosapentaenoic acid is incorporated into cell membrane phospholipids, partly at the expense of arachidonic acid. Thus, there is less arachidonic acid available for eicosanoid synthesis. Hence, fish oil decreases production of prostaglandins like PGE2 and of leukotrienes like LTB4. Thus, n-3 fatty acids can potentially reduce platelet aggregation, blood clotting, smooth muscle contraction, and leukocyte chemotaxis, and can modulate inflammatory cytokine production and immune function. These effects have been demonstrated in cell culture, animal feeding and healthy volunteer studies. Fish oil decreases the host metabolic response and improves survival to endotoxin in laboratory animals. Recently clinical studies performed in various patient groups have indicated benefit from this approach.

Omega-3 fatty acids improve liver and pancreas function in postoperative cancer patients

Abstract: Epidemiologic studies have indicated that high intake of saturated fat and/or animal fat increases the risk of colon and breast cancer. Omega-3 PUFAs in fish oil (FO) can inhibit the growth of human cancer cells in vitro and in vivo. These effects are related to the uptake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into the cellular substrate pool and their competitive metabolism with arachidonic acid (AA) at the cyclooxygenase and 5-lipoxygenase levels. The metabolites of EPA and DHA have less inflammatory and immunosuppressant potency than the substances derived from AA. Based on previous experimental data, we hypothesized that FO supplementation after major abdominal cancer surgery would improve hepatic and pancreatic function. Ours was a prospective, randomized, double-blinded clinical trial on 44 patients undergoing elective major abdominal surgery, randomly assigned to receive total parenteral nutrition (TPN) supplemented with either soybean oil (SO 1.0 g/kg body weight daily, n = 20) for 5 days or a combination of FO and SO (FO 0.2 + SO 0.8 g/kg body weight daily, n = 24). Compared to pure SO supplementation in the postoperative period, FO significantly reduced ASAT [0.8 +/- 0.1 vs. 0.5 +/- 0.1 mmol/(l. sec)], ALAT [0.9 +/- 0.1 vs. 0.6 +/- 0.1 mmol/(l. sec)], bilirubin (16.1 +/- 5.3 vs. 6.9 +/- 0.6 mmol/l), LDH (7.7 +/- 0.4 vs. 6.7 +/- 0.4 mmol/(l. sec) and lipase (0.6 +/- 0.1 vs. 0.4 +/- 0.1 micromol/(l. sec) in the postoperative course. Moreover, patients with increased risk of sepsis (IL-6/IL-10 ratio >8) showed a tendency to shorter ICU stay (18 hr) under omega-3 PUFA treatment. Weight loss as encountered after the SO emulsion of 1.1 +/- 2.2 kg was absent in the FO group. After major abdominal tumor surgery, FO supplementation improved liver and pancreas function, which might have contributed to the faster recovery of patients.

Docosahexaenoic acid-concentrated fish oil supplementation in subjects with mild cognitive impairment (MCI): a 12-month randomised, double-blind, placebo-controlled trial

Abstract: Epidemiological studies have suggested a beneficial effect of fish oil supplementation in halting the initial progression of Alzheimer’s disease. However, it remains unclear whether fish oil affects cognitive function in older people with mild cognitive impairment (MCI). This study investigated the effects of fish oil supplementation on cognitive function in elderly person with MCI. This was a 12-month, randomised, double-blind, placebo-controlled study using fish oil supplementation with concentrated docosahexaenoic acid (DHA). Thirty six low-socioeconomic-status elderly subjects with MCI were randomly assigned to receive either concentrated DHA fish oil (n = 18) or placebo (n = 18) capsules. The changes of memory, psychomotor speed, executive function and attention, and visual-constructive skills were assessed using cognitive tests. Secondary outcomes were safety and tolerability of the DHA concentrate. The fish oil group showed significant improvement in short-term and working memory (F = 9.890; ηp 2 = 0.254; p < 0.0001), immediate verbal memory (F = 3.715; ηp 2 = 0.114; p < 0.05) and delayed recall capability (F = 3.986; ηp 2 = 0.121; p < 0.05). The 12-month change in memory (p < 0.01) was significantly better in the fish oil group. Fish oil consumption was well tolerated, and the side effects were minimal and self-limiting. This study suggested the potential role of fish oil to improve memory function in MCI subjects. Studies with larger sample sizes, longer intervention periods, different fish oil dosages and genetic determinations should be investigated before definite recommendations can be made.

Fatty acid productive value and β‐oxidation capacity in Atlantic salmon (Salmo salar L.) fed on different lipid sources along the whole growth period

Abstract: The major aim of the current study was to evaluate the effect of substituting fish oil (FO) for a vegetable oil blend (VO) as dietary lipid source on lipid catabolism in Atlantic salmon (Salmo salar L.). The experiment endured from the start of feeding until the salmon reached 2.5 kg. Total and peroxisomal β-oxidation capacities were determined in red and white muscle and liver. In addition, fatty acid productive value (FAPV) was calculated during the four time periods the experiment was divided into. In all the three tissues, an increased β-oxidation capacity was found prior to seawater transfer; however, calculating the difference between the peroxisomal β-oxidation capacity and the total, the peroxisomal β-oxidation increased more than the mitochondrial β-oxidation capacity. Hence, in liver and red muscle, 100%and 70%, respectively, of the total β-oxidation capacity was accounted by peroxisomes prior to seawater transfer, compared with approximately 60% and 3% during the seawater phase. In contrast, white-muscle mitochondria was the main organelle responsible for oxidizing fatty acids during the entire experiment (>90%). However, during the period of high energy demand (parr-smolt transformation), fish fed VO exhibited significantly lower β-oxidation capacity than fish fed FO, coinciding with low FAPV and low specific growth rate (SGR). Further, during periods of high growth rate, fish oxidized even essential fatty acids (18:2n-6, 18:3n-3, 20:5n-3, and 22:6n-3) when given in surplus. Low dietary levels of essential fatty acids gave significantly higher FAPV of these fatty acids in the whole body. However, the FAPV of 22:1n-11 was low, indicating that this fatty acid is highly utilized as a substrate for β-oxidation, irrespective of the dietary levels. There were no differences in whole lipid content between fish fed either FO or VO.