Differentiating prescription omega-3-acid ethyl esters (P-OM3) from dietary-supplement omega-3 fatty acids

Omega-3 Fatty Acids in Cardiovascular Disease and Diabetes: a Review of Recent Evidence

PURPOSE OF REVIEW

Omega-3 fatty acids (n-3 FA) lower triglycerides, have anti-inflammatory properties, and improve metabolism. Clinical evidence of cardiovascular benefit with omega-3 fatty acids is mixed. We discuss mechanisms providing biological plausibility of benefit of omega-3 fatty acids in cardiovascular risk reduction and review clinical trials investigating the benefits of prescription omega-3 fatty acids in dyslipidemia, atherosclerotic cardiovascular disease (ASCVD), and diabetes.

RECENT FINDINGS

Although early trials showed no benefit of omega-3 fatty acids in ASCVD, the REDUCE-IT trial noted significant risk reduction in ASCVD events with highly purified EPA (icosapent ethyl) use which has changed the landscape for currently available therapeutic options. However, other large trials like STRENGTH and VITAL, which used different formulations of prescription omega-3 fatty acids, did not note significant cardiovascular risk reduction. Thus the effectiveness of omega-3 fatty acids for cardiovascular disease prevention is an ongoing topic of debate. A relative paucity of studies examining benefits for glycemic outcomes in persons with diabetes exists; however, few studies have suggested lack of benefit to date. Significant residual cardiovascular risk exists for individuals with hypertriglyceridemia. Prescription omega-3 fatty acids are more commonly used for CV risk reduction in these patients. Clinical guideline statements now recommend icosapent ethyl use for selected individuals with hypertriglyceridemia to reduce cardiovascular events given recent evidence from the REDUCE-IT trial. Nonetheless, data from other large scale trials has been mixed, and future research is needed to better understand how different preparations of omega-3 may differ in their cardiovascular and metabolic effects, and the mechanisms for their benefit.

Algae-induced taste and odour problems at low temperatures and the cold stress response hypothesis

The existence of taste and odour (T&O) in drinking water is one of the principal causes of consumer complaints and is commonly related to algae growth. Numerous studies have confirmed the existence of algal blooms emerging specifically in low-temperature periods, herein referred to as "cold algae"; these include chrysophytes, cryptophytes, dinoflagellates and diatoms. In addition, the adaption mechanisms of these "cold algae" involve high flexibility in their nutrient intake and to the hydrological characteristics of the waters and their high contents of intracellular polyunsaturated fatty acids (PUFAs). Like algae proliferating in higher temperature waters, cold algae can also produce offensive odours. The potential dominant T&O compounds of low-temperature algae probably include saturated/unsaturated aldehydes and even some terpenoids. Among these, the polyunsaturated aldehydes (PUAs), the derivatives of polyunsaturated fatty acids, are the dominant T&O compounds and are probably synthesized during cell rupture. It was found that, for cold algae, low temperature may have a favourable effect on the generation of algae-induced T&O compounds. Furthermore, to better understand the internal mechanisms of algal T&O production, the stress response theory is introduced, which provides ideas for T&O control in raw water and in water treatment. Finally, implications for T&O management are given based on this review. KEY POINTS: • Like algae proliferating in higher temperature waters, cold algae can produce offensive odours. • Low temperatures may have a favourable effect on the generation of algae-induced T&O compounds. • The stress response theory can help to better understand the internal mechanisms of algal T&O production.

Monoacylglycerol Form of Omega-3s Improves Its Bioavailability in Humans Compared to Other Forms

Numerous benefits are attributed to omega-3 fatty acids (OM3) especially in cardiovascular health. However, bioavailability and clinical efficacy depend on numerous factors, including OM3 form, food matrix effects (especially the lipid content of the diet), and metabolic capacity. Here, we show in humans that a "pre-digested" OM3-sn-1(3)-monoacylglycerol lipid structure (OM3-MAG) has a significantly greater absorption at high therapeutic doses (2.9 g/day) than the most commonly OM3-ethyl ester (3.1 g/day) form (used for the treatment of hypertriglyceridemia), and a comparable profile to other pre-digested OM3 free fatty acids (OM3-FFA) structure (3.2 g/day). Nutritional supplement doses of MAG resulted in similar increases in OM3 blood level, compared to OM3 triacylglycerols (OM3-TAG) supplements in obese subjects (1.2 g/day) under low fat diet, and in children with cystic fibrosis (1.0 g/day). These results suggest that both forms of pre-digested OM3-MAG and OM3-FFA are effectively absorbed and re-incorporated effectively into triacylglycerols inside the enterocytes, before being exported into the chylomicrons lipid transport system. The pre-digested OM3-MAG might provide a more effective therapy in severe cardiovascular conditions where high doses of OM3 are required and a low-fat diet is indicated, which limited digestive lipase activity.

Is There Something Fishy About Fish Oil?

BACKGROUND

Fish is consumed as food worldwide and is considered as a rich source of essential nutrients required for a healthy life. Supplementation with fish oil has been adopted as a solution to prevent or cure many pathophysiological states and diseases by both the professionals and the civil population. The beneficial effects are, however, being questioned, as some controversial results were obtained in clinical and population studies.

METHODS

Critical evaluation of studies regarding known effects of fish oil, both in favour of its consumption and related controversies.

RESULTS

From the literature review, contradictory allegations about the positive action of the fish oil on human health emerged, so that a clear line about its beneficial effect cannot be withdrawn.

CONCLUSION

Scientific results on the application of fish oil should be taken with caution as there is still no standardised approach in testing its effects and there are significantly different baselines in respect to nutritional and other lifestyle habits of different populations.

Lyophilized apples on flax oil and ethyl esters of flax oil - stability and antioxidant evaluation

The research aimed to assess the effect of whole lyophilized apples added to flax oil or flax ethyl esters for oxidation processes and fatty acid profiles. The samples were washed with nitrogen and sealed in PE pouches. The analyses were performed on day 0 and afterwards on 7th, 14th, 28th, 56th and 84th day of storage. The antioxidant capacity was determined by stating in the samples DPPH, ABTS•+, and FRAP. Fatty acid profiles of the test samples were analyzed using GC-MS. The addition of lyophilized apples did not limit the decrease in C18: 3, n-3 after storage. The reduction of free radicals (ABTS, DPPH) was the lowest in samples with ethyl esters mixed with lyophilized apples rather than in the case of specimens that were a mixture of flax oil and lyophilized apples. The addition of lyophilized apples limited the decrease of IV and PV in ethyl esters, and in the case of flax oil AV. Obtained data show the possibility of wider usage of apple for the improvement of stability of the ethyl esters or flax oils and at the same time there are the real possibilities of the development of such kinds of preparations for the feeding industry.

Safety and tolerability of prescription omega-3 fatty acids: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Omega-3 fatty acids [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] are widely recommended for health promotion. Over the last decade, prescription omega-3 fatty acid products (RxOME3FAs) have been approved for medical indications. Nonetheless, there is no comprehensive analysis of safety and tolerability of RxOME3FAs so far.

METHODS

A systematic review of randomized controlled trials (RCTs) was carried out based on searches in six electronic databases. The studies involving marketed RxOME3FA products were included, and adverse-effect data were extracted for meta-analysis. Subgroup analysis and meta-regression were conducted to explore the sources of potential heterogeneity.

RESULTS

Among the 21 included RCTs (total 24,460 participants; 12,750 from RxOME3FA treatment cohort and 11,710 from control cohort), there was no definite evidence of any RxOME3FA-emerging serious adverse event. Compared with the control group, RxOME3FAs were associated with more treatment-related dysgeusia (fishy taste; p = 0.011) and skin abnormalities (eruption, itching, exanthema, or eczema; p < 0.001). Besides, RxOME3FAs had mild adverse effects upon some non-lipid laboratory measurements [elevated fasting blood sugar (p = 0.005); elevated alanine transaminase (p = 0.022); elevated blood urea nitrogen (p = 0.047); decreased hemoglobin (p = 0.002); decreased hematocrit (p = 0.009)]. Subgroup analysis revealed that EPA/DHA combination products were associated with more treatment-related gastrointestinal adverse events [eructation (belching; p = 0.010); nausea (p = 0.044)] and low-density lipoprotein cholesterol elevation (p = 0.009; difference in means = 4.106mg/dL).

CONCLUSION

RxOME3FAs are generally safe and well tolerated but not free of adverse effects. Post-marketing surveillance and observational studies are still necessary to identify long-term adverse effects and to confirm the safety and tolerability profiles of RxOME3FAs.

Why Prodrugs and Propesticides Succeed

What are the advantages of bioactivation in optimizing drugs and pesticides? Why are there so many prodrugs and propesticides? These questions are examined here by considering compounds selected on the basis of economic value or market success in 2015. The 100 major drugs and 90 major pesticides are divided into ones acting directly and those definitely or possibly requiring bioactivation. Established or candidate prodrugs accounted for 19% of the total drug sales, with corresponding values of 20, 37, and 17% for proinsecticides, proherbicides, and profungicides. The 19 prodrugs acting in humans generally had better pharmacodynamic/pharmacokinetic properties for target enzyme, receptor, tissue, or organ specificity due to their physical properties (lipophilicity and stabilization). Bioactivation usually involved hydrolases or cytochrome P450 oxidation or reduction. Prodrugs considered are neuroactive aripiprazole, eletriptan, desvenlafaxin, lisdexamfetamine, quetiapine, and fesoterodine; cholesterol-lowering atorvastatin, ezetimibe, and fenofibrate; various prodrugs activated by esterases or sulfatases, ciclesonide, oseltamivir, dabigatran; omega-3 fatty acid ethyl esters and esterone sulfate; and five others with various targets (sofosbuvir, fingolimod, clopidogrel, dapsone, and sildenafil). The proinsecticides are the neuroactive chlorpyrifos, thiamethoxam, and indoxacarb, two spiro enol ester inhibitors of acetyl CoA carboxylase (ACCase), and the bacterial protein delta-endotoxin. The proherbicides considered are five ACCase inhibitors including pinoxaden and clethodim, three protox inhibitors (saflufenacil, flumioxazin, and canfentrazone-ethyl), and three with various targets (fluroxypyr, isoxaflutole, and clomazone). The profungicides are prothioconazole, mancozeb, thiophanate-methyl, dazomet, and fosetyl-aluminum. The prodrug and propesticide concept is broadly applicable and has created some of the most selective pharmaceutical and pest control agents, illustrated here by major compounds that partially overcome pharmacokinetic limitations of potency and selectivity in the corresponding direct-acting compounds. The challenges of molecular design extend beyond the target site fit to the bioactivatable precursor and the fascinating chemistry and biology matched against the complexity of life processes.

Essential fatty acids as functional components of foods- a review

During the recent decades, awareness towards the role of essential fatty acids in human health and disease prevention has been unremittingly increasing among people. Fish, fish oils and some vegetable oils are rich sources of essential fatty acids. Many studies have positively correlated essential fatty acids with reduction of cardiovascular morbidity and mortality, infant development, cancer prevention, optimal brain and vision functioning, arthritis, hypertension, diabetes mellitus and neurological/neuropsychiatric disorders. Beneficial effects may be mediated through several different mechanisms, including alteration in cell membrane composition, gene expression or eicosanoid production. However, the mechanisms whereby essential fatty acids affect gene expression are complex and involve multiple processes. Further understanding of the molecular aspects of essential fatty acids will be the key to devising novel approaches to the treatment and prevention of many diseases.

Basal omega-3 fatty acid status affects fatty acid and oxylipin responses to high-dose n3-HUFA in healthy volunteers

A subject's baseline FA composition may influence the ability of dietary highly unsaturated omega-3 FAs (n3-HUFA) to change circulating profiles of esterified FAs and their oxygenated metabolites. This study evaluates the influence of basal n3-HUFA and n3-oxylipin status on the magnitude of response to n3-HUFA consumption. Blood was collected from fasting subjects (n = 30) before and after treatment (4 weeks; 11 ± 2 mg/kg/day n3-HUFA ethyl esters). Esterified FAs were quantified in erythrocytes, platelets, and plasma by GC-MS. Esterified oxylipins were quantified in plasma by LC-MS/MS. Treatment with n3-HUFAs increased n3-HUFAs and decreased n6-HUFAs in all reservoirs and increased plasma n3-oxylipins without significantly changing n6-oxylipin concentrations. As subject basal n3-HUFAs increased, treatment-associated changes decreased, and this behavior was reflected in the percentage of 20:5n3 + 22:6n3 in red blood cell membrane FAs (i.e., the omega-3 index). To maintain an omega-3 index of 8% and thus reduce cardiovascular disease risk, our analyses suggest a maintenance dose of 7 mg/kg/day n3-HUFA ethyl esters for a 70-kg individual. These results suggest that the basal n3 index may have clinical utility to establish efficacious therapeutic experimental feeding regimens and to evaluate the USDA Dietary Guidelines recommendations for n3-HUFA consumption.

Reductions of acetylcholine release and nerve growth factor expression are correlated with memory impairment induced by interleukin-1beta administrations: effects of omega-3 fatty acid EPA treatment

Interleukin (IL)-1beta may play an important role in Alzheimer's disease. However, the relationships between glucocorticoids and acetylcholine (ACh), and between neurotrophins and ACh in IL-1-induced memory deficits are unknown. While ethyl-eicosapentaenoate (E-EPA) has recently been reported to reduce inflammation and improve memory, cholinergic and neurotrophic mechanisms by which E-EPA improves memory is unclear. This study evaluated: (i) the correlation between ACh release and memory impairment; (ii) the effect of glucocorticoids on ACh release; (iii) the relationship between nerve growth factor (NGF) and inflammation; and (iv) the effects of E-EPA treatment on IL-1beta-induced changes. Intracerebroventricular IL-1beta administrations produced a significant reduction in hippocampal ACh release in rats fed control diet, which was partially attenuated by mifepristone (RU 486) and completely blocked by IL-1 receptor antagonist. In eight-arm radial maze, significantly less ACh release was correlated with the memory deficits after IL-1beta administrations. mRNA expression of hippocampal NGF was lower, whereas IL-1beta was higher when compared with controls. E-EPA treatment significantly improved the memory, which was correlated with normalizing ACh release, and expressions of NGF and IL-1beta. This study revealed important mechanisms by which IL-1beta impairs, while E-EPA improves memory through IL-1-glucocorticoid-ACh release and IL-1-NGF-ACh release pathways.

Prescription omega-3-acid ethyl esters for the treatment of very high triglycerides

Triglyceride (TG) levels can increase for numerous reasons, including a sedentary lifestyle, an unhealthy diet, especially one rich in refined carbohydrates, and comorbidities. According to the National Cholesterol Education Program (NCEP), the normal TG level is < 150 mg/dL. Patients with very high TG (VHTG) levels (> or = 500 mg/dL) should be promptly managed and treated to reach lipid treatment goals, as determined by the NCEP. Lowering TG levels is the primary management goal in these patients, while lowering low-density lipoprotein cholesterol and non-high-density lipoprotein cholesterol levels are secondary goals. Therapeutic lifestyle changes are often recommended initially for patients with elevated TGs; however, concomitant drug therapy is often required. Data show that intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can significantly decrease serum TGs, along with plasma concentrations of certain lipoproteins. Omega-3-acid ethyl esters are available by prescription or as dietary supplements. Clinical trials in adult patients with VHTGs show that four 1 g capsules of prescription omega-3 fatty acids, which contain 465 mg of EPA and 375 mg of DHA per capsule, can effectively decrease TG levels by up to 45%, and is generally well tolerated.

Dispelling the myths about omega-3 fatty acids

Although there is an enormous amount of information available on omega-3 fatty acids, it is sometimes misleading, contradictory, and unsupported by scientific fact. Consumers and medical professionals may be confused regarding the potential value of omega-3 fatty acid supplements, despite having either read or heard about fi sh oil consumption and/or omega-3 fatty acid benefits and risks. The availability of a prescription formulation of omega-3-acid ethyl esters (P-OM3) has provided important new information that helps to dispel the myths and alleviate concerns surrounding the use of omega-3 fatty acids in clinical practice. The safety and efficacy of P-OM3, but not dietary-supplement omega-3 fatty acids, are documented in placebo-controlled trials. In general, studies using Food and Drug Administration-approved dosages of P-OM3 have not substantiated various myths surrounding the negative effects of omega-3 fatty acids. Thus, there are now evidence-based clinical guidelines for the use of omega-3 fatty acids in clinical practice.

Omega-3 fatty acids for cardioprotection

The most compelling evidence for the cardiovascular benefit provided by omega-3 fatty acids comes from 3 large controlled trials of 32,000 participants randomized to receive omega-3 fatty acid supplements containing docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) or to act as controls. These trials showed reductions in cardiovascular events of 19% to 45%. These findings suggest that intake of omega-3 fatty acids, whether from dietary sources or fish oil supplements, should be increased, especially in those with or at risk for coronary artery disease. Patients should consume both DHA and EPA. The target DHA and EPA consumption levels are about 1 g/d for those with known coronary artery disease and at least 500 mg/d for those without disease. Patients with hypertriglyceridemia benefit from treatment with 3 to 4 g/d of DHA and EPA, a dosage that lowers triglyceride levels by 20% to 50%. Although 2 meals of oily fish per week can provide 400 to 500 mg/d of DHA and EPA, secondary prevention patients and those with hypertriglyceridemia must use fish oil supplements if they are to reach 1 g/d and 3 to 4 g/d of DHA and EPA, respectively. Combination therapy with omega-3 fatty acids and a statin is a safe and effective way to improve lipid levels and cardiovascular prognosis beyond the benefits provided by statin therapy alone. Blood DHA and EPA levels could one day be used to identify patients with deficient levels and to individualize therapeutic recommendations.