n-3 fatty acids and acute-phase proteins

The aim of this study was to determine the effects of n-3 fatty acids on acute-phase proteins and response. Healthy male volunteers were submitted to standard bicycle ergometry once without supplementation and a second time after 3-weeks supplementation with highly purified n-3 fatty acids (1.75 g eicosapentaenoic acid and 1.05 g docosahexaenoic acid per day). Acute-phase proteins (immunoglobulin M, complement C4, haptoglobin, C-reactive protein, alpha 2-macroglobulin, coerulopasmin, fibrinogen, alpha 1-glycoprotein) were measured before, immediately after, 24 and 72 h after exercise. There were significantly lower values of immunoglobulin M (pre-exercise and at 72 h) and alpha 2-macroglobulin (pre-exercise) when cross-sectionally comparing the baseline data with and without n-3 supplementation. Longitudinal comparisons show that the ergometric test induced a discrete acute-phase reaction, which is evident with and without n-3 fatty acids. Yet the kinetics of the response seem to be altered by n-3 supplementation. The relative increase of most acute-phase proteins is numerically larger and the rise persists longer, which is particularly evident for fibrinogen and alpha 1-glycoprotein. The findings suggest that n-3 fatty acids lower acute-phase proteins at baseline and alter the pattern of change following acute exercise.     

Distal procto-colitis and n-3 polyunsaturated fatty acids: the mechanism(s) of natural cytotoxicity inhibition

BACKGROUND: Altered natural killer (NK) and lymphokine-activated killer (LAK) cell activities have been reported with ulcerative colitis (UC). Previously, we have shown that in patients with UC, the n-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), specifically inhibit natural cytotoxicity with clinical improvement in disease activity. The aim of this study therefore was to evaluate the possible mechanism(s) involved in this inhibition, and in particular the alteration of production of interleukin 2 (IL2) and the arachidonic acid metabolite leukotriene B4 (LTB4), both known to modulate NK cell activity. MATERIALS AND METHODS: Each patient with procto-colitis received either fish oil extract (EPA 3.2 g, DHA 2.4 g; n = 9) or placebo (n = 9) daily for 6 months. Monthly assessment included disease activity using clinical and sigmoidoscopic scores. Peripheral blood mononuclear (PBMN) cells were isolated and NK cell cytotoxic activity in vitro was measured. Monthly serum samples were analysed for LTB4, IL2 and soluble IL2 receptors (sIL2R). RESULTS: The n-3 PUFAs group had significantly reduced NK cell activity, compared with the placebo group (P < 0.05, Mann-Whitney U-test). In the n-3 PUFA group, incubation of PBMN cells for 72 h with recombinant interleukin 2 (rIL2) reversed the NK inhibition. In patients with active proctocolitis, serum levels of LTB4 correlated positively with NK cell cytotoxicity (r = 0.873, P < 0.05, Kendall's correlation coefficient). After six months of n-3 PUFAs supplementation, serum levels of LTB4 were undetectable with concurrent significant reduction in NK cell cytotoxic activity. The latter was associated with significant reduction of serum IL2 and sIL2R levels (P < 0.05). CONCLUSION: This study has demonstrated both evidence of suppression of immune reactivity and concurrent reduction in disease activity in patients with proctocolitis receiving n-3 PUFAs supplementation. This may have important implications for therapy in patients with UC.     

Encapsulated fish oil enriched in alpha-tocopherol alters plasma phospholipid and mononuclear cell fatty acid compositions but not mononuclear cell functions

BACKGROUND: Several studies have reported that dietary fish oil (FO) supplementation alters cytokine production and other functional activities of peripheral blood mononuclear cells (PBMC). However, few of these studies have been placebo controlled and few have related the functional changes to alterations in PBMC fatty acid composition PATIENTS AND METHODS: Healthy subjects supplemented their diets with 9 g day-1 of encapsulated placebo oil (3 : 1 mix of coconut and soybean oils), olive oil (OO), safflower oil (SO), evening primrose oil (EPO) or FO [providing 2.1 g eicosapentaenoic acid (EPA) plus 1.1 g docosahexaenoic acid (DHA) per day] for 12 weeks; the capsules also provided 205 mg alpha-tocopherol per day. Blood was sampled at 4-weekly intervals and plasma and PBMC prepared. Plasma phospholipid and PBMC fatty acid composition, plasma alpha-tocopherol and thiobarbituric acid-reactive substance concentrations, plasma total antioxidant capacity, the proportions of different PBMC subsets, the proportions of PBMC expressing the adhesion molecules CD2, CD11b and CD54, and PBMC functions (lymphocyte proliferation, natural killer cell activity, cytokine production) were measured. All measurements were repeated after a 'washout' period of 8 weeks. RESULTS: The placebo, OO and SO capsules had no effect on plasma phospholipid or PBMC fatty acid composition. The proportion of dihomo-gamma-linolenic acid in plasma phospholipids was elevated in subjects taking EPO and was decreased in subjects taking FO. There was no appearance of gamma-linolenic acid in the plasma phospholipids or PBMC in subjects taking EPO. There was a marked increase in the proportion of EPA in the plasma phospholipids (10-fold) and PBMC (four-fold) of subjects taking FO supplements; this increase was maximal after 4 weeks of supplementation. There was an increase in the proportion of DHA in plasma phospholipids and PBMC, and an approximately 20% decrease in the proportion of arachidonic acid in plasma phospholipids and PBMC, during FO supplementation. Plasma concentrations of alpha-tocopherol were significantly elevated during supplementation in all subjects and returned to baseline values after the washout period. There were no effects of supplementation with any of the capsules on total plasma antioxidant activity or plasma thiobarbituric acid-reactive substances or on the proportion of different PBMC subsets, on the proportion of PBMC expressing adhesion molecules, on natural killer cell activity, on the proliferation of mitogen-stimulated whole blood cultures or PBMC, or on the ex vivo production of a range of cytokines by whole blood cultures or PBMC cultures stimulated by either concanavalin A or lipopolysaccharide. CONCLUSION: Supplementation of the diet with 3.2 g EPA plus DHA per day markedly alters plasma phospholipid and PBMC fatty acid compositions. The lack of effect of FO upon PBMC functions may relate to the level of alpha-tocopherol included in the supplements.     

Influence of intravenous n-3 lipid supplementation on fatty acid profiles and lipid mediator generation in a patient with severe ulcerative colitis

Abstract. N-3 fatty acids were supplied to a 36-year-old female patient suffering from ulcerative colitis and severe steroid side-effects, in a sequence of parenteral and enteral administration. During a moderately active period of disease, 200 ml d^-1 fish oil-derived lipid emulsion (eicosapentaenoic acid [EPA], 4–2 g; docosahexaenoic acid [DHA], 4.2 g) was infused for 9 days, in parallel with rapid tapering of the steroid dose. Disease activity declined rapidly, and the patient was subsequently provided with 16 fish oil capsules per day (EPA, 2.9 g; DHA, 1.9 g) for 2 months. At the end of this period of therapy, severe colitis recurred with intestinal and extraintestinal manifestations. The n-3 lipid emulsion was then used for intravenous alimentation (29 days, maximum dose 300 ml per day); during this time, marked improvement of the inflammatory bowel disease was noted. During both periods of parenteral n-3 lipid administration, total plasma EPA and DHA contents increased several-fold, surpassing that of arachidonic acid; this plasma n-3 fatty acid enrichment was only maintained to a minor extent during the intermediate period of dietary fish oil supplementation. The intravenously administered EPA-containing triglycerides were rapidly hydrolyzed, as evidenced by the appearance of substantial quantities of EPA in the plasma free fatty acid fraction. Platelet and neutrophil total membrane content of EPA and DHA as well as n-3 fatty acid/AA membrane ratios similarly increased during the periods of intravenous n-3 lipid administration and declined during oral fish oil uptake. In contrast, erythrocyte membrane enrichment in EPA and DHA occurred only after the prolonged (2 month) period of dietary n-3 lipid supplementation. Ex vivo stimulation of neutrophils with A23187 showed progressive increase in 5-series leukotriene- and 5-HEPE-generation during both periods of n-3 lipid infusion, in parallel with the rise of plasma EPA contents. Maximum 5-series/4-series leukotriene ratios surpassed 0.25. Similarly, ratios of thromboxane B₃/B₂ liberated from ex vivo stimulated platelets surpassed 0.4 during ongoing n-3 lipid infusion. The profound changes in fatty acid profiles and lipid mediator generation may be related to the reduction in colitis activity observed during the periods of intravenous n-3 lipid supplementation.     

Bariatric surgery reduces fasting total fatty acids and increases n-3 polyunsaturated fatty acids in morbidly obese individuals

Background: Obesity is a global pandemic leading to increased mortality and increased risk of cardiovascular disease. Bariatric surgery is an established treatment of obesity leading to weight loss and reduction of mortality. To further elucidate how bariatric surgery improves metabolic control, we explored the fatty acid (FA) profiles in morbidly obese subjects treated with lifestyle intervention and subsequent bariatric surgery.

Methods: The intervention group consisted of 34 morbidly obese patients scheduled for bariatric surgery and the control group of 17 non-obese patients scheduled for elective laparoscopic procedures. The intervention group had to undergo lifestyle changes preoperatively. Fasting blood samples were drawn at admission, after lifestyle intervention and 1 year after bariatric surgery.

Results: At admission, the morbidly obese patients had significantly higher levels of monounsaturated FAs (MUFAs) and lower levels of n-6 polyunsaturated FAs (PUFAs) and n-3 PUFAs than healthy controls (all p-values <.05). In the intervention group, there was a significantly lower level of total FAs after lifestyle intervention, and from admission to 1 year after surgical intervention (both, p?<?.05), primarily reflecting a lower proportion of saturated FAs (SFAs). Following bariatric surgery, but not after lifestyle changes, there was an increase in the proportion of n-3 PUFA (p?<?.05) reaching levels not significantly different from healthy controls.

Conclusions: Our findings suggest that a reduced proportion of the proposed anti-atherogenic n-3 PUFAs characterizes morbidly obese individuals, and that this FA profile is reversed by bariatric surgery, but not by lifestyle intervention.     

Failure of omega-3 polyunsaturated fatty acids in prevention of migraine: a double-blind study versus placebo

Omega-3 polyunsaturated fatty acids (OPFA) have beneficial effects on inflammatory reactions and production of cytokines. They decrease the release of 5HT by platelets and possess vasorelaxant activity. This led them to be tried in the prophylactic treatment of migraine. After 4 weeks of a single-blind placebo run-in period, patients were randomized and treated in double-blind condition by placebo or OPFA 6 g a day for 16 weeks, followed by a 4-week placebo run-out period. The intention to treat population included 196 patients. Those who received all four treatment periods included 96 patients taking OPFA and 87 taking placebo. The primary efficacy analysis was the number of migraine attacks during the last 4 weeks of treatment. During this period, the mean number of attacks was 1.20 +/- 1.40 in the OPFA group and 1.26 +/- 1.11 in the placebo group (NS). The total number of attacks during the 4-month period of the study was significantly different between groups: 7.05 in the placebo group, 5.95 in the OPFA group (P = 0.036). Mean intensity, mean duration of the attacks and rescue medication use, were not significantly different between the two groups. Except for a significant difference against OPFA for eructations, the tolerance was satisfying. Despite a run-in placebo period of 1 month, a very strong placebo effect was observed in this trial: 45% reduction of the attacks between run-in and 4-month treatment period (55% in the OPFA group, P = 0.058). Finally, this large study did not confirm two previous studies based on a small number of patients.     

Positive zinc intake and a Japanese diet rich in n-3 fatty acids induces clinical remission in patients with mild active ulcerative colitis: a randomized interventional pilot study

Zinc intake has reduced hospitalizations in patients with ulcerative colitis (UC), highlighting the need to maintain blood zinc levels. This prospective study investigated whether the promotion of zinc intake and a Japanese diet (high in n-3 fatty acids) could induce clinical remission in patients with mild active UC. Patients with mild active UC were randomly assigned to either (1) continue an unrestricted diet or (2) receive nutritional guidance promoting zinc intake and a Japanese diet. The primary endpoint was clinical remission at 24 weeks. Secondary endpoints were the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) scores, Clinical Activity Index (CAI), Geboes Histopathology Score (GHS), and biomarkers, including zinc levels, measured at 12 and 24 weeks. Nutritional assessments were performed using the Food Frequency Questionnaire. The CAI, UCEIS, and GHS scores were significantly lower in the intervention group than in the control group, with a significantly higher proportion of patients achieving clinical remission. Furthermore, the intervention group exhibited weight gain and significantly increased blood zinc levels. The combination of promoting dietary zinc intake and a Japanese diet rich in n-3 fatty acids can induce clinical remission in patients with mild active UC.     

Dietary supplementation with very long-chain n-3 fatty acids in man decreases expression of the interleukin-2 receptor (CD25) on mitogen-stimulated lymphocytes from patients with inflammatory skin diseases

Abstract T-cell activation and cytokine production play an important role in several chronic inflammatory diseases. Because n-3 fatty acids exert beneficial effects on the clinical state of some of these diseases, we examined the effect of dietary supplementation of n-3 fatty acids on T-cell proliferation, expression of CD25 (interleukin-2 receptor alpha-chain), secretion of interleukin-2, interleukin-6 and tumour necrosis factor from T-cells from patients with psoriasis and atopic dermatitis. During 4 months, 21 patients supplied 6 g of highly concentrated ethyl esters of EPA and DHA in gelatin capsules daily to their diet. In the control group 20 patients supplied 6 g per day of corn oil in gelatin capsules to their diet. Eicosapentaenoic acid (20:5, n-3) of serum phospholipids increased from 14 (min 4-max 42) to 81 (min 59-max 144) mg l^-1 (P < 0·01) in patients with atopic dermatitis receiving n-3 fatty acids, and from 25 (min 7-max 66) to 74 (min 46-max 142) mg l^-1 (P < 0·01) in patients with psoriasis, whereas docosahexaenoic acid (22:6, n-3) increased from 65 (min 46-max 120) to 92 (min 54-max 121) mg l^-1 (P < 0·05) and from 81 (min 38-max 122) to 92 (min 63-max 169) mg l^-1 (NS) in atopic and psoriatic patients, respectively. The changes in the serum phospholipid fatty acid profile in the groups receiving n-3 fatty acids, correlate to the dietary intake of corresponding fatty acids. There was no significant change in the fatty acid pattern of serum phospholipids in the corn oil group before and after supplementation. Mitogen-induced secretion of interleukin-6 was significantly higher in patients with psoriasis compared to patients with atopic dermatitis, whereas the secretion of interleukin-2, tumour necrosis factor, PHA-induced T-cell proliferation and expression of CD25 on lymphocytes were similar in the two groups of patients. Patients receiving supplementation of n-3 fatty acids decreased significantly the percentage of CD25 positive lymphocytes from 40·5 before start to 35·5 (P < 0·05) after the trial. The patients who received corn oil increased the level of tumour necrosis factor from 1095 pg ml^-1 before start to 1536 pg ml^-1 after the trial (P < 0·05). In conclusion, dietary intake of very long-chain n-3 fatty acids may suppress the expression of CD25 positive lymphocytes, which may partly account for the anti-inflammatory effect exerted by these fatty acids.     

Effects of n-3 polyunsaturated fatty acid supplementation on quadriceps weakness immediately after total knee arthroplasty: a pilot,randomized, open-label clinical trial

[Purpose] Severe quadriceps weakness immediately after total knee arthroplasty can be problematic. The n-3 long-chain polyunsaturated fatty acids have antioxidant and anti-inflammatory effects against ischemia–reperfusion injury, whereas n-6 long-chain polyunsaturated fatty acids exert pro-inflammatory effects, thereby promoting ischemia–reperfusion injury. [Participants and Methods] We explored the efficacy of preoperative n-3 long-chain polyunsaturated fatty acid supplementation against early quadriceps weakness among 20 patients scheduled for total knee arthroplasty (intervention group, n=10; control group, n=10). The intervention group received 645 mg of eicosapentaenoic acid) and 215 mg of docosahexaenoic acid daily for 30 days preoperatively. Serum eicosapentaenoic acid, docosahexaenoic acid, and arachidonic acid levels were measured preoperatively. We compared serum derivatives of reactive oxygen metabolites as oxidative stress biomarkers, knee circumference, thigh volume, knee pain during the quadriceps strength test, and quadriceps strength preoperatively and 4 days postoperatively to quantify the change. [Results] Preoperative n-3 long-chain polyunsaturated fatty acid supplementation significantly increased the (eicosapentaenoic acid+docosahexaenoic acid)/arachidonic acid ratio in the intervention group. A significantly lower increase in quadriceps weakness was exhibited in the intervention group than in the control group. However, changes in oxidative stress, knee/thigh swelling, and knee pain during strength testing did not significantly differ between the two groups. [Conclusion] Preoperative n-3 long-chain polyunsaturated fatty acid supplementation exhibited beneficial effects on quadriceps weakness immediately after total knee arthroplasty.     

Pharmacology and therapeutics of omega-3 polyunsaturated fatty acids in chronic inflammatory disease

Omega-3 (n−3) polyunsaturated fatty acids (n−3 PUFAs) have well documented anti-inflammatory properties, and consequently therapeutic potential in chronic inflammatory diseases. Here we discuss the effects of n−3 PUFAs on various inflammatory pathways and how this leads to alterations in the function of inflammatory cells, most importantly endothelial cells and leukocytes. Strong evidence indicates n−3 PUFAs are beneficial as a dietary supplement in certain diseases such as rheumatoid arthritis; however for other conditions such as asthma, the data are less robust. A clearer understanding of the pharmacology of n−3 PUFAs will help to establish targets to modulate chronic inflammatory diseases.     

多不饱和脂肪酸与产后抑郁的相关性研究

目的该文探讨产前和产后妇女体内的多不饱和脂肪酸(PUFAs)水平高低是否影响产后抑郁的发生率。方法选取102例足月顺产符合条件并自愿参与的产妇,留取产前及产后3、42d的血清进行PUFAs水平检测,填写围产期抑郁相关因素调查量表和爱丁堡产后抑郁量表(EPDS)进行评分,分析产后抑郁的发生率。结果在102例孕产妇中,出现产后抑郁者28例,阳性率为27.5%,二十碳五烯酸(EPA)低值组、二十二碳六烯酸(DHA)低值组和中值组的产后抑郁发生率高于高值组;花生四烯酸(AA)高值组的产后抑郁发生率高于低值组。结论 EPA和DHA水平越低,越容易发生抑郁。     

Prevention of sudden cardiac death by n-3 polyunsaturated fatty acids

There were already several epidemiologic studies that showed eating fish frequently seemed to reduce deaths from coronary heart disease. There were also observational and clinical trials, which more specifically showed that the reduction in cardiovascular deaths from eating fish were largely the result of n-3 polyunsaturated fatty acids in fish oil for the prevention of sudden cardiac death (SCD). This led me to perform a clinical trial in which all subjects had an implanted cardioverter-defibrillator and were at very high risk of SCD. The results of this study and the mechanisms by which the n-3 fish oil fatty acids prevent fatal cardiac arrhythmias will be the subject of this review.     

The effects of n-3 polyunsaturated fatty acid-rich total parenteral nutrition on neutrophil apoptosis in a rat endotoxemia

Although recruited neutrophils function as first-line defense to remove bacteria, delayed apoptosis is implicated in persistent inflammation leading to organ injury. Leukotrien B₄, n-6 polyunsaturated fatty acids (PUFAs) product, is one of the mediators that delay neutrophil apoptosis. The mechanism of the beneficial effects of supplementation of fish oil-based long-chain n-3 PUFAs in parenteral nutrition for critically ill patients has not been fully understood. One possible mechanism is the less inflammatory n-3 PUFAs products can compete with proinflammatory n-6 PUFAs products for access to the enzymes. The aim of this study was to determine whether n-3 PUFA rich parenteral nutrition may alter the composition of fatty acids in the neutrophil membrane and restore delay of neutrophil apoptosis during endotoxin-induced systemic inflammation in rats. The animals in group 1 were treated with 20% Hicaliq NC-N in Neoparen-2 for three days. The animals in group 2 (referred to as n-6 PUFA-rich parenteral nutrition) were given parenteral nutrition solutions containing 20% soybean oil in Neoparen-2 (n-6/n-3 = 10). The animals in group 3 (referred to as n-3 PUFA-rich parenteral nutrition) were administered parenteral nutrition consisting of 10% soybean oil and 10% fish oil emulsion (n-6/n-3 = 1.3). The n-3/n-6 ratio of the neutrophil membrane was significantly increased in group 3 and was associated with restored lipopolysaccharide-delayed-apoptosis of neutrophils in bone marrow cells and increased production of leukotriene B₅ from peritoneal neutrophils stimulated by lipopolysaccharide. Our preliminary results showed that n-3 PUFA-rich parenteral nutrition regulated neutrophil apoptosis and prevented synthesis of pro-inflammatory eicosanoids, explaining the protective effects seen in the clinical setting.     

Resolvins and omega three polyunsaturated fatty acids: Clinical implications in inflammatory diseases and cancer

Inflammation is a central process in several disorders and contributes to cancer progression. Inflammation involves a complex cascade of pro-inflammatory and anti-inflammatory signaling events with protein and lipid mediators. Recent advances in lipid detection have revealed the importance of lipid mediators in inflammation. Omega three polyunsaturated fatty acids (ω-3 PUFA) are found naturally in fish oil and have been extensively studied in multiple inflammatory diseases with improved outcomes. Resolvins are thought to be the active metabolites of ω-3 PUFA, and are responsible for facilitating the resolving phase of acute inflammation. Clinically, resolvins have been associated with resolution of acute kidney injury and acute lung injury, micro and macro vascular response to injury, and inhibition of microglia-activated inflammation in neurodegenerative disorders. In addition to inflammatory diseases, ω-3 PUFA and resolvins appear to modulate cancer progression. ω-3 PUFA intake has been associated with reduced inflammation in colorectal cancer, and favorable phenotype in breast cancer. Resolvins offer promising therapeutic potential as they may modulate inflammation with minimal side-effects, in contrast to currently available anti-inflammatory medications. This review describes the roles of ω-3 PUFA and resolvins in the inflammatory cascade, various inflammatory diseases, and specific cancers. Additionally, it will discuss the clinical therapeutic potential of resolvins as targets in inflammatory diseases and cancers.     

Effect of omega-3 fatty acids supplementation on anthropometric indices in children and adolescents: A systematic review and meta-analysis of randomized controlled trials

• •Background Childhood obesity is a major public health problem with a global prevalence greater than 23 %. Omega-3 polyunsaturated fatty acids (omega-3 FAs) supplementation may improve anthropometric indices by increased energy expenditure, attenuated appetite, elevated adiponectin levels, though current evidence is still inconclusive.
• •Objective The aim of this systematic review was to conduct the first comprehensive meta-analysis of randomized controlled trials on the association between omega-3 FAs supplementation and anthropometric indices in children and adolescents.
• •Methods We performed an extensive online database search of the published literature using the SCOPUS, Web of Science, PubMed, EMBASE, and Cochrane library databases from the index date through April 2019. Six studies met inclusion criteria. Changes in anthropometric indices (weight, BMI and waist circumference) were extracted from each article. Statistical heterogeneity was assessed by calculating the I² statistic. We used the standardized mean difference (SMD) with 95 % confidence interval. The meta-analysis was performed based on a random effects model.
• •Results This meta-analysis demonstrated that omega-3 FAs supplementation had no effect on reducing body weight (SMD = -0.00, 95 % CI -0.26 to 0.25), BMI (SMD = -0.07, 95 % CI -0.32 to 0.17) and waist circumference (SMD = -0.16, 95 % CI -0.51 to 0.19).
• •Conclusions Omega-3 FAs supplementation did not change anthropometric indices in children and adolescents. Further large-scale studies with larger sample sizes in children and adolescents are needed to clarify the effects of omega-3 FAs.

     

Effects of diet and/or n-3 fatty acid supplementation on components of the interleukin-6 trans-signalling system in elderly men

Background. It has previously been shown that both very long chain omega-3 polyunsaturated fatty acids (n-3 PUFA) and a Mediterranean-like diet (Md), are able to reduce the risk of cardiovascular (CV) mortality and morbidity. The exact mechanisms behind this effect are yet to be established. To date, there exist no data on the effect of n-3 PUFA supplementation and Md on components of the interleukin-6 (IL-6) trans-signalling (ts) system that plays a central role in the family of pro-atherosclerotic inflammatory markers. Methods. A total of 563 men were included in the DOIT study, a randomised factorial-designed trial comparing the effect of 36 months of dietary counseling, n-3 PUFA supplementation (2.4 g/d), or both on different circulating biomarkers of atherosclerosis in elderly high-risk men. We used commercially available ELISA methods to analyse circulating levels of soluble glycoprotein 130 (sGP130), soluble IL-6 receptor (sIL-6r), and IL-6. Results. There was no significant effect of either of the intervention principles on circulating levels of sGP130 or sIL-6r. We have shown previously that there is no effect on IL-6 concentrations either. Conclusions. This is the largest trial analysing possible effects of Md or n-3 PUFA supplementation on the IL-6ts system. Although the reduction of CV risk through dietary intervention or n-3 PUFA supplementation has previously been linked to anti-inflammatory effects, we could not find an effect of these interventions on the IL-6ts system. This indicates that the beneficial effects of Md or n-3 PUFA observed in previous studies seem to be independent of the IL-6ts system.     

ω3多不饱和脂肪酸的作用机制及应用研究进展

介绍了ω3多不饱和脂肪酸在免疫及抗感染、保护血管、抗肿瘤、促进生长发育方面的作用机制及应用研究进展。     

Omega-3 polyunsaturated fatty acids and cardiovascular disease: an emphasis on omega-3-acid ethyl esters 90 for the treatment of hypertriglyceridemia

A number of epidemiological/observational studies, as well as large-scale randomized intervention studies, have been conducted to provide evidence for the efficacy of ω-3 fatty acids against atherosclerotic diseases. Currently, ω-3 fatty acids are commercially available in many parts of the world containing the same active ingredients as Lotriga^® (ω-3-acid ethyl esters 90 [O3AE highly concentrated ω-3 fatty acid ethyl esters, consisting of eicosapentaenoic acid-ethyl ester and docosahexaenoic acid-ethyl ester [EPA-E/DHA-E]). A recent head-to-head comparative study of O3AEE90 versus EPA-E demonstrated that O3AEE90 4g/day led to a significantly greater reduction in triglycerides (TG) than EPA-E 1.8g/day and that O3AEE90 2g/day produced comparable effects on TG to those with EPA-E 1.8g/day. While both agents were shown to be useful in lowering TG, the hallmark feature of O3AEE90, that is, the presence of the DHA-E component versus its absence in EPA-E, needs to be further examined for its clinical implications.     

The effects of omega-3 polyunsaturated fatty acids on cardiac rhythm: A critical reassessment

Although epidemiological studies provide strong evidence for an inverse relationship between omega-3 polyunsaturated fatty acids (n−3 PUFAs) and cardiac mortality, inconsistent and often conflicting results have been obtained from both animal studies and clinical prevention trials. Despite these heterogeneous results, some general conclusions can be drawn from these studies: 1) n-PUFAs have potent effects on ion channels and calcium regulatory proteins that vary depending on the route of administration. Circulating (acute administration) n−3 PUFAs affect ion channels directly while incorporation (long-term supplementation) of these lipids into cell membranes indirectly alter cardiac electrical activity via alteration of membrane properties. 2) n−3 PUFAs reduce baseline HR and increase HRV via alterations in intrinsic pacemaker rate rather than from changes in cardiac autonomic neural regulation. 3) n−3 PUFAs may be only effective if given before electrophysiological or structural remodeling has begun and have no efficacy against atrial fibrillation. 5) Despite initial encouraging results, more recent clinical prevention and animal studies have not only failed to reduce sudden cardiac death but actually increased mortality in angina patients and increased rather than decreased malignant arrhythmias in animal models of regional ischemia. 6) Given the inconsistent benefits reported in clinical and experimental studies and the potential adverse actions on cardiac rhythm noted during myocardial ischemia, n−3 PUFA must be prescribed with caution and generalized recommendations to increase fish intake or to take n−3 PUFA supplements need to be reconsidered.