Eicosapentaenoic acid (EPA) reduces cardiovascular events: relationship with the EPA/arachidonic acid ratio

Engineering Fatty Acid Biosynthesis in Microalgae: Recent Progress and Perspectives

Microalgal lipids hold significant potential for the production of biodiesel and dietary supplements. To enhance their cost-effectiveness and commercial competitiveness, it is imperative to improve microalgal lipid productivity. Metabolic engineering that targets the key enzymes of the fatty acid synthesis pathway, along with transcription factor engineering, are effective strategies for improving lipid productivity in microalgae. This review provides a summary of the advancements made in the past 5 years in engineering the fatty acid biosynthetic pathway in eukaryotic microalgae. Furthermore, this review offers insights into transcriptional regulatory mechanisms and transcription factor engineering aimed at enhancing lipid production in eukaryotic microalgae. Finally, the review discusses the challenges and future perspectives associated with utilizing microalgae for the efficient production of lipids.

Habitual fish consumption and healthy lifestyle behaviours may be associated with higher total serum bilirubin level and anti-inflammatory activity: a cross-sectional study

Habitual fish consumption and a healthy lifestyle are associated with lower atherosclerotic CVD (ASCVD) risk. Mildly elevated bilirubin, an end product of Hb metabolism, may be associated with anti-inflammatory effects, suppressing ASCVD risk. No data exist on the relationship between fish consumption, total serum bilirubin (TSB) and inflammation in clinical settings. We conducted a cross-sectional study between April 2019 and March 2020 in a cohort of 8292 participants (average age, 46·7 (sd 12·9) years and 58·9 % men) with no history of ASCVD and TSB concentrations < 2·0 mg/dl. Multiple stepwise regression analysis showed Hb concentrations were a solid positive determinant of TSB concentrations (β = 0·302, P< 0·0001). Fish consumption (β = 0·025, P= 0·019) and aerobic exercise (β = 0·021, P= 0·043) were statistically weak but significantly positive determinants of TSB concentrations. Cigarette smoking negatively affected TSB concentrations (β = −0·104, P< 0·0001). Moreover, with increasing fish consumption, the proportion of participants with a habit of cigarette smoking decreased, and that of participants who engaged in aerobic exercises increased (P< 0·0001 for both). Furthermore, as TSB concentrations increased, the leukocyte counts and C-reactive protein concentrations decreased (P< 0·0001 for both). In conclusion, despite the lesser relevance given to TSB concentrations than Hb concentrations, higher fish consumption and healthier lifestyle behaviours related to fish consumption habits may be additively or synergistically associated with higher TSB concentrations and anti-inflammatory activity, leading to attenuated ASCVD risk. Further investigations are needed to clarify the causal relationships between these factors.

Association and Implications of Blood and Plaque n-3 Polyunsaturated Fatty Acid Composition in Patients Treated with Oral Eicosapentaenoic Acid before Carotid Endarterectomy

Long-chain n-3 polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA), have been shown to prevent atherosclerosis-related cardiovascular disease, including stroke. Recently, the ratio of serum EPA to arachidonic acid (AA; EPA/AA ratio) has been reported to be a biomarker to prevent cardiovascular disease. In this study, we evaluate whether the serum EPA/AA ratio would be a useful biomarker for determining the efficacy of orally administered EPA in preventing stroke by investigating tissue and serum EPA/AA ratios, serum inflammatory markers, and carotid artery intimamedia thickness (IMT). Patients with dyslipidemia, as the primary illness scheduled for carotid endarterectomy (CEA), were included and randomly assigned to the EPA group (EPA: 1,800 mg/day plus statin; 10 patients) or non-EPA group (statin only; 15 patients). PUFA fraction was evaluated in the tissue (post-CEA) and serum (pre-CEA and 6 months thereafter). As for the tissue PUFA fraction in the plaque, the EPA group had a significantly higher EPA/AA ratio (EPA group, 0.46; non-EPA group, 0.28; p  = 0.01). At 6 months postoperatively, the EPA group had a significantly higher serum EPA/AA ratio (baseline, 0.83; follow-up, 1.60; p  = 0.05). No significant differences were found for inflammatory markers and IMT. Both serum and tissue EPA/AA ratios were higher in patients treated with oral EPA. Serum EPA/AA ratio might be a useful biomarker for the efficacy of orally administered EPA.

Placental AA/EPA Ratio Is Associated with Obesity Risk Parameters in the Offspring at 6 Years of Age

During pregnancy, maternal polyunsaturated fatty acids (PUFA) are transferred to the fetus through the placenta by specific FA transporters (FATP). A higher perinatal exposure to n-6 over n-3 PUFA could be linked to excess fat mass and obesity development later in life. In this context, we aimed to assess the associations between long chain PUFAs (LC-PUFAs) (n-6, n-3, and n-6/n-3 ratios) measured in the placenta at term birth with obesity-related parameters in the offspring at 6 years of age and assess whether these associations are dependent on the placental relative expression of fatty acid transporters. As results, the PUFAn-6/PUFAn-3 ratio was 4/1, which scaled up to 15/1 when considering only the arachidonic acid/eicosapentaenoic acid ratio (AA/EPA ratio). Positive associations between the AA/EPA ratio and offspring's obesity risk parameters were found with weight-SDS, BMI-SDS, percent fat mass-SDS, visceral fat, and HOMA-IR (r from 0.204 to 0.375; all p < 0.05). These associations were more noticeable in those subjects with higher expression of fatty acid transporters. Therefore, in conclusion, a higher placental AA/EPA ratio is positively associated with offspring's visceral adiposity and obesity risk parameters, which become more apparent in subjects with higher expressions of placental FATPs. Our results support the potential role of n-6 and n-3 LC-PUFA in the fetal programming of obesity risk in childhood. For the present study, 113 healthy pregnant women were recruited during the first trimester of pregnancy and their offspring were followed up at 6 years of age. The fatty acid profiles and the expression of fatty acid transporters (FATP1 and FATP4) were analyzed from placental samples at birth. Associations between LC-PUFA (n-6, n-3, and n-6/n-3 ratios) and obesity risk parameters (weight, body mass index (BMI), percent fat mass, visceral fat, and homeostatic model assessment of insulin resistance (HOMA-IR)) in the offspring at 6 years of age were examined.

Fatty acids act on vascular endothelial cells and influence the development of cardiovascular disease

Endothelial cells (ECs) maintain the health of blood vessels and prevent the development of cardiovascular disease (CVD). Free saturated fatty acids (FAs) induce EC damage and increase the risk of CVD by promoting arteriosclerosis. Conversely, polyunsaturated FAs (PUFAs), such as docosahexaenoic acid, are thought to suppress EC damage induced during the early stages of CVD. This review describes the effects of multiple dietary FAs on EC disorders involved in the development of CVD. The roles of FAs in atherosclerosis and CVD were analyzed by evaluating articles published in PubMed, Science Direct, and Web of Science. Saturated FAs were found to induce EC damage by reducing the production and action of EC-derived nitric oxide. Oxidative stress, inflammation, and the renin-angiotensin system were found to be involved in EC disorder. Furthermore, n-3 PUFAs were found to reduce EC dysfunction and prevent the development of EC disorder. These results indicate that FAs may affect EC failure induced during the early stages of CVD and reduce the risk of developing the disease.

Promising Sources of Plant-Derived Polyunsaturated Fatty Acids: A Narrative Review

(1) Background: Polyunsaturated fatty acids (PUFAs) are known for their ability to protect against numerous metabolic disorders. The consumption of oily fish is the main source of PUFAs in human nutrition and is commonly used for supplement production. However, seafood is an overexploited source that cannot be guaranteed to cover the global demands. Furthermore, it is not consumed by everyone for ecological, economic, ethical, geographical and taste reasons. The growing demand for natural dietary sources of PUFAs suggests that current nutritional sources are insufficient to meet global needs, and less and less will be. Therefore, it is crucial to find sustainable sources that are acceptable to all, meeting the world population's needs. (2) Scope: This review aims to evaluate the recent evidence about alternative plant sources of essential fatty acids, focusing on long-chain omega-3 (n-3) PUFAs. (3) Method: A structured search was performed on the PubMed search engine to select available human data from interventional studies using omega-3 fatty acids of non-animal origin. (4) Results: Several promising sources have emerged from the literature, such as algae, microorganisms, plants rich in stearidonic acid and GM plants. However, the costs, acceptance and adequate formulation deserve further investigation.

Abnormal erythrocyte fatty acid composition in first-diagnosed, drug-naïve patients with depression

BACKGROUND & AIMS

The correlation between fatty acids (FAs) and depression is not yet conclusive. This study examined the relationship of FAs composition with the presence and clinical characteristics of first-diagnosed, drug-naïve patients with depression.

METHODS

A total of 139 first-diagnosed, drug-naïve patients with depression and 55 healthy controls (HCs) were included in the cross-sectional study. The levels of erythrocyte membrane FAs were compared and then the correlation between clinical symptoms and fatty acid levels in depression was investigated.

RESULTS

Compared to HCs, patients with depression had higher C18:1n9t (z = -2.033, p = 0.042), C20:4n6 (z = -2.104, p = 0.035), C20:3n6 (z = -2.104, p = 0.035) and n-6 polyunsaturated fatty acids (PUFAs) (z = -2.127, p = 0.033), whereas the levels of C18:1n9c (z = -3.348, p = 0.001) were significantly lower. Higher C20:3n6, C20:4n6, C18:1n9t and n-6 PUFAs levels were associated with higher severity of depressive and anxiety symptoms in patients with depression, and the correlation remained after adjusting for the related confounding factors (p < 0.05).

CONCLUSIONS

Patients with first-diagnosed, drug-naïve depression show abnormal erythrocyte fatty acid composition. Trans fatty acids (TFAs) and n-6 PUFAs levels are closely related to clinical characteristics of depression. This study indicated that increased n-6 PUFAs and TFAs are characteristic changes of first-diagnosed, drug-naïve depression.

To Explore the Key Active Compounds and Therapeutic Mechanism of Guizhi Gancao Decoction in Coronary Heart Disease by Network Pharmacology and Molecular Docking

Objective. Coronary heart disease (CHD) is the leading cause of death from cardiovascular disease and has become an important public health problem worldwide. Guizhi Gancao Decoction (GGD) has been shown to be used in the treatment of CHD with good efficacy, but its specific therapeutic mechanism and active ingredients have not been fully clarified. This study aims to identify the active compounds and key targets of GGD in the treatment of CHD, explore the therapeutic mechanism of GGD, and provide candidate compounds for anti-CHD drug development. Methods. The main compounds of GGD were determined by UPLC-MS/MS analysis and screened by SwissADME. The corresponding targets of GGD compounds were obtained from SwissTargetPrediction, and the targets of CHD were obtained from the HERB and GeneCards databases. The STRING 11.5 database was used to analyze the PPI (Protein-Protein Interactions) network of potential therapeutic targets of GGD compounds. Cytoscape 3.7.2 was used to construct target-related networks and find core targets. The GEO database was used to validate the differential expression of core targets. The PANTHER Classification System was used to functionally classify potential therapeutic targets for GGD. The GO biological process analysis and KEGG pathway analysis of targets were completed by DAVID 6.8 database. AutoDockTools 1.5.6 and PyMol 2.5.2 were used to perform molecular docking of core targets with the active GGD compounds. Results. 7 active GGD compounds were obtained based on UPLC-MS/MS and pharmacological parameter evaluation, which corresponded to 131 CHD-related targets. Among them, EGFR, MAPK3, RELA, CCND1, ESR1, PTGS2, NR3C1, CYP3A4, MMP9, and PTPN11 were considered core targets. According to the targets related to CHD, glycyrrhetinic acid, liquiritigenin, and schisandrin are considered key active ingredients. GO biological process and KEGG analysis indicated that the potential targets of GGD in the treatment of CHD involve a variety of biological processes and therapeutic mechanisms. Molecular docking results showed that both the core targets and the corresponding compounds had the good binding ability. Conclusions. This study contributes to a more comprehensive understanding of the therapeutic mechanism and active ingredients of GGD for CHD and provides candidate compounds for drug development of CHD.

Changes in the Eicosapentaenoic Acid to Arachidonic Acid Ratio in Serum over 10 Years in a Japanese Community: The Hisayama Study

AIM

Circulating omega-3 and omega-6 polyunsaturated fatty acids may to contribute to cardiovascular health at the population level. Over a decade, we investigated changes in the serum eicosapentaenoic acid (EPA) to arachidonic acid (AA) ratio, and in serum concentrations of the individual fatty acids, in a Japanese community.

METHODS

Community surveys took place in 2002-2003 and 2012-2013 in a rural area of Japan. The community surveys included 3,194 and 3,220 community dwellers aged ≥ 40 years who did not take EPA medication in 2002-2003 and 2012-2013, respectively. Fatty acid fractionations in serum were measured using a gas chromatography method. Changes in the serum EPA/AA ratio over time were examined using linear mixed models.

RESULTS

Overall, the average serum EPA/AA ratio decreased over the 10 years. A decreasing trend in the serum EPA/AA ratio occurred in all age groups except participants aged ≥ 80 years, with larger decreases in the younger age groups. A similar decline in serum EPA/AA ratio occurred in participants with and those without lipid-lowering therapy. Serum EPA concentrations were slightly increased in the whole population but remained stable or even decreased in participants aged 40-69. In contrast, the average serum AA concentrations increased in all age groups.

CONCLUSION

In a Japanese community, the serum EPA/AA ratio decreased over 10 years at the population level, especially in middle-aged participants.

Possibility for Prevention of Type 2 Diabetes Mellitus and Dementia Using Three Kinds of Brown Rice Blends after High-Pressure Treatment

As it has been reported that type 2 diabetes mellitus increases the risk of Alzheimer’s disease, we investigated how to prevent type 2 diabetes and dementia using biofunctional boiled rice. We adopted unpolished super-hard rice (SHBR) for diabetes and wax-free unpolished black rice (WFBBR) for dementia and blended those with ordinary non-polished rice (KBR) (blending ratio 4:4:2), adding 2.5% waxy black rice bran (WBB) and 0.3% rice oil after high-pressure treatment (HPT) (WFBSK) to improve its palatability. This boiled rice is rich in dietary fiber, anthocyanin, free ferulic acid and β-secretase inhibitory activity. A randomized, parallel-group comparison study was conducted for 12 weeks with 24 subjects, using Cognitrax to evaluate their cognitive function primarily. Furthermore, as the secondary purpose, we performed a single-dose test for postprandial blood glucose and insulin secretion at the end of the human intervention test. After 12 weeks, consumers of the WFBSK rice exhibited significant improvement in language memory by cognitive test battery compared with those who consumed the control white rice (p < 0.05). Moreover, subjects who consumed the WFBSK rice had lower insulin secretion levels than those who consumed the control polished rice (p < 0.05).

The Frequency and Amount of Fish Intake Are Correlated with the White Blood Cell Count and Aerobic Exercise Habit: A Cross-sectional Study

Objective We investigated the relationship between the amount and frequency of fish intake, and the white blood cell (WBC) count and aerobic exercise habits. Methods We conducted a cross-sectional study between April 2019 and March 2020 at the Health Planning Center of Nihon University Hospital on a cohort of 8,981 male subjects. Results The average amount and frequency of fish intake were 134±85 g/week and 2.14±1.28 days/week, respectively. The WBC count decreased significantly as the amount of fish intake increased (p<0.0001). According to a multivariate regression analysis, a high fish intake amount (β=-0.082, p<0.0001) and regular aerobic exercise (β=-0.083, p<0.0001) were independent determinants of a low WBC count. The proportion of subjects engaged in regular aerobic exercise increased with an increase in the amount of fish intake (p<0.0001). Furthermore, the amount and frequency of fish intake significantly correlated with the amount of n-3 polyunsaturated fatty acid intake determined using the Japan's National Nutrition Survey results (both r=0.962 and 0.958). Therefore, the amount of fish intake could be substituted by the average number of days of fish intake per week. Conclusion A high fish intake was an independent determinant of a low WBC count and engagement in regular aerobic exercise, regardless of whether the fish intake was defined by the amount or frequency of fish intake. However, since fish intake frequency can be measured more easily, this may be used to measure the fish intake.

Trimester-Specific Reference Ranges for Saturated, Monounsaturated and Polyunsaturated Fatty Acids in Serum of Pregnant Women: A Cohort Study from the ECLIPSES Group

In the course of pregnancy, increasing importance is being placed on maintaining optimal fatty acid (FA) levels and particularly n-3 PUFAs to ensure correct fetal development. However, reference ranges for FA have been reported in only a few studies. Our objective is to provide quantitative reference intervals for SFAs, MUFAs, and PUFAs (n-6 and n-3) in a large population of healthy pregnant women from a developed country. A prospective study of pregnant women (n = 479) was conducted from the first trimester (T1) to the third trimester (T3). A total of 11 fatty acids were analyzed in serum by gas chromatography mass spectrometry and were expressed as absolute (µmol/L) and relative (percentage of total FA) concentration units. Serum concentrations of SFAs, MUFAs, n-6 PUFAs, n-3 PUFAs, various FA ratios, and the EFA index were determined. The reference intervals (2.5/97.5 percentiles) in absolute values from T1 ranged from 1884.32 to 8802.81 µmol/L for SFAs, from 959.91 to 2979.46 µmol/L for MUFAs, from 2325.77 to 7735.74 µmol/L for n-6 PUFAs, and from 129.01 to 495.58 µmol/L for n-3 PUFAs. These intervals mainly include the values of other studies from European populations. However, reference ranges vary according to some maternal factors. The FA levels proposed, obtained from a large sample of pregnant women, will be a useful tool for assessing the degree of adequacy of FAs in pregnant women and will help to carry out dietary interventions based on certain maternal factors.

Omega-3 Polyunsaturated Fatty Acids (PUFAs): Emerging Plant and Microbial Sources, Oxidative Stability, Bioavailability, and Health Benefits-A Review

The omega−3 (n−3) polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic (DHA) acid are well known to protect against numerous metabolic disorders. In view of the alarming increase in the incidence of chronic diseases, consumer interest and demand are rapidly increasing for natural dietary sources of n−3 PUFAs. Among the plant sources, seed oils from chia (Salvia hispanica), flax (Linum usitatissimum), and garden cress (Lepidium sativum) are now widely considered to increase α-linolenic acid (ALA) in the diet. Moreover, seed oil of Echium plantagineum, Buglossoides arvensis, and Ribes sp. are widely explored as a source of stearidonic acid (SDA), a more effective source than is ALA for increasing the EPA and DHA status in the body. Further, the oil from microalgae and thraustochytrids can also directly supply EPA and DHA. Thus, these microbial sources are currently used for the commercial production of vegan EPA and DHA. Considering the nutritional and commercial importance of n−3 PUFAs, this review critically discusses the nutritional aspects of commercially exploited sources of n−3 PUFAs from plants, microalgae, macroalgae, and thraustochytrids. Moreover, we discuss issues related to oxidative stability and bioavailability of n−3 PUFAs and future prospects in these areas.

Placental Angiogenesis in Mammals: A Review of the Regulatory Effects of Signaling Pathways and Functional Nutrients

Normal placental development and proper angiogenesis are essential for fetal growth during pregnancy. Angiogenesis involves the regulatory action of many angiogenic factors and a series of signal transduction processes inside and outside the cell. The obstruction of placental angiogenesis causes fetal growth restriction and serious pregnancy complications, even leading to fetal loss and pregnancy cessation. In this review, the effects of placental angiogenesis on fetal development are described, and several signaling pathways related to placental angiogenesis and their key regulatory mediators are summarized. These factors, which include vascular endothelial growth factor (VEGF)-VEGF receptor, delta-like ligand 4 (DLL-4)-Notch, Wnt, and Hedgehog, may affect the placental angiogenesis process. Moreover, the degree of vascularization depends on cell proliferation, migration, and differentiation, which is affected by the synthesis and secretion of metabolites or intermediates and mutual coordination or inhibition in these pathways. Furthermore, we discuss recent advances regarding the role of functional nutrients (including amino acids and fatty acids) in regulating placental angiogenesis. Understanding the specific mechanism of placental angiogenesis and its influence on fetal development may facilitate the establishment of new therapeutic strategies for the treatment of preterm birth, pre-eclampsia, or intrauterine growth restriction, and provide a theoretical basis for formulating nutritional regulation strategies during pregnancy.

Higher Frequency of Fish Intake May Be Associated with a Lower Neutrophil/Lymphocyte Ratio: Anti-Atherosclerotic Effects of Fish Consumption

BACKGROUND

Higher fish consumption has been reported to be associated with a lower incidence of coronary artery disease (CAD). An elevated neutrophil/lymphocyte ratio (NLR), a marker of systemic inflammation, is reportedly associated with the development of adverse CAD events. We hypothesized that a higher fish intake was associated with a lower NLR.

METHODS AND RESULTS

This cross-sectional study was conducted in a cohort of 8,237 Japanese subjects who had no history of atherosclerotic cardiovascular disease registered at the Health Planning Center of Nihon University Hospital between April 2018 and March 2019. The average weekly frequency of fish intake was 2.32 ± 1.31 days. The NLR decreased significantly as the weekly frequency of fish intake (0 day, 1-2 days, 3-4 days, or 5-7 days) increased (p = 0.001). A multiple stepwise regression analysis identified the weekly frequency of fish intake (β = -0.045, p < 0.0001) and habitual alcohol intake (β = -0.051, p < 0.0001) as significant but weak, negative, and independent determinants of the NLR. Conversely, the presence of metabolic syndrome (β = 0.046, p < 0.0001), the presence of treatment for diabetes mellitus (β = 0.054, p < 0.0001), and the presence of treatment for hypertension (β = 0.043, p < 0.0001) were significant positive and independent determinants of the NLR.

CONCLUSIONS

The present results suggest that a higher frequency of fish intake appears to be associated with a lower NLR, suggesting an anti-systemic inflammation effect. This association may partially explain the preventive effects of a higher fish intake on CAD events.

Al-Dirbashi O, Alkaabi J. Metabolomic Profiling of Lipids and Fatty Acids: 3 Years Postoperative Laparoscopic Sleeve Gastrectomy

Visceral obesity is common in the United Arab Emirates and worldwide. Although laparoscopic sleeve gastrectomy (LSG) leads to effective and sustainable weight loss, its long-term beneficial impact on other risk factors, including blood lipid and fatty acid (FA) profiles, remains unknown. These two profiles were assessed in patients 3 years after undergoing LSG and in LSG candidates (controls). Lipid profiles were measured using the Cobas e411 modular analyzer, and 35 FAs were identified. The age and body mass index were 36.55 ± 8.65 years and 31.49 ± 6.43 kg/m2 in the LSG group and 35.44 ± 9.51 years and 32.29 ± 5.38 kg/m2 in the control group, respectively. The overall lipid profile was more favorable in the LSG group than in the control group. Total saturated, monounsaturated, and polyunsaturated FAs were similar between the groups, but total medium-chain FAs were more abundant in the LSG group. In endogenous FA synthesis, the estimated activity of C16Δ9 desaturase and Δ5 desaturase decreased, whereas that of elongase increased in the LSG group compared with that in the control group. The benefits of LSG on blood lipid and FA profiles in patients with 3-year LSG may be limited. Hence, lifestyle interventions combined with a long-term and strict regular follow-up regime may be warranted for patients undergoing LSG.

Nutraceutical, Dietary, and Lifestyle Options for Prevention and Treatment of Ventricular Hypertrophy and Heart Failure

Although well documented drug therapies are available for the management of ventricular hypertrophy (VH) and heart failure (HF), most patients nonetheless experience a downhill course, and further therapeutic measures are needed. Nutraceutical, dietary, and lifestyle measures may have particular merit in this regard, as they are currently available, relatively safe and inexpensive, and can lend themselves to primary prevention as well. A consideration of the pathogenic mechanisms underlying the VH/HF syndrome suggests that measures which control oxidative and endoplasmic reticulum (ER) stress, that support effective nitric oxide and hydrogen sulfide bioactivity, that prevent a reduction in cardiomyocyte pH, and that boost the production of protective hormones, such as fibroblast growth factor 21 (FGF21), while suppressing fibroblast growth factor 23 (FGF23) and marinobufagenin, may have utility for preventing and controlling this syndrome. Agents considered in this essay include phycocyanobilin, N-acetylcysteine, lipoic acid, ferulic acid, zinc, selenium, ubiquinol, astaxanthin, melatonin, tauroursodeoxycholic acid, berberine, citrulline, high-dose folate, cocoa flavanols, hawthorn extract, dietary nitrate, high-dose biotin, soy isoflavones, taurine, carnitine, magnesium orotate, EPA-rich fish oil, glycine, and copper. The potential advantages of whole-food plant-based diets, moderation in salt intake, avoidance of phosphate additives, and regular exercise training and sauna sessions are also discussed. There should be considerable scope for the development of functional foods and supplements which make it more convenient and affordable for patients to consume complementary combinations of the agents discussed here. Research Strategy: Key word searching of PubMed was employed to locate the research papers whose findings are cited in this essay.

Prevention of Endothelial Dysfunction and Cardiovascular Disease by n-3 Fatty Acids-Inhibiting Action on Oxidative Stress and Inflammation

BACKGROUND

Prospective cohort studies and randomized controlled trials have shown the protective effect of n-3 fatty acids against cardiovascular disease (CVD). The effect of n-3 fatty acids on vascular endothelial cells indicates their possible role in CVD prevention.

OBJECTIVE

Here, we describe the effect of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on endothelial dysfunction-caused by inflammation and oxidative stress-and their role in the development of CVD.

METHODS

We reviewed epidemiological studies done on n-3 fatty acids in CVD. The effect of DHA and EPA on vascular endothelial cells was examined with regard to changes in various markers, such as arteriosclerosis, inflammation, and oxidative stress, using cell and animal models.

RESULTS

Epidemiological studies revealed that dietary intake of EPA and DHA was associated with a reduced risk of various CVDs. EPA and DHA inhibited various events involved in arteriosclerosis development by preventing oxidative stress and inflammation associated with endothelial cell damage. In particular, EPA and DHA prevented endothelial cell dysfunction mediated by inflammatory responses and oxidative stress induced by events related to CVD. DHA and EPA also increased eNOS activity and induced nitric oxide production.

CONCLUSION

The effects of DHA and EPA on vascular endothelial cell damage and dysfunction may involve the induction of nitric oxide, in addition to antioxidant and anti-inflammatory effects. n-3 fatty acids inhibit endothelial dysfunction and prevent arteriosclerosis. Therefore, the intake of n-3 fatty acids may prevent CVDs, like myocardial infarction and stroke.

Association among daily fish intake, white blood cell count, and healthy lifestyle behaviors in an apparently healthy Japanese population: implication for the anti-atherosclerotic effect of fish consumption

Higher fish consumption has been reported to be associated with a lower incidence of coronary artery disease. We hypothesized that a higher frequency of fish intake may be associated with lower peripheral white blood cell (WBC) counts, a marker of chronic inflammation, which is known to be involved in the development of atherosclerotic cardiovascular disease (ASCVD), and a healthy lifestyle. This cross-sectional study was conducted between April 2018 and August 2018 at the Health Planning Center of Nihon University Hospital in a cohort of 4105 apparently healthy subjects. The average frequency of fish intake was 2.3 ± 1.3 days per week. The WBC count decreased significantly as the frequency of fish intake (0-2 days, 3-4 days, or 5-7 days per week) increased (s < 0.0001). Multivariate linear regression analysis identified higher weekly frequency of fish intake as a significant independent determinant of a lower WBC count (β =  - 0.051, p = 0.001). Furthermore, as the weekly frequency of fish intake increased, the proportion of habitual cigarette smokers decreased (p = 0.021), that of subjects engaging in habitual aerobic exercises increased (p < 0.0001), and the weekly alcohol intake frequency increased (p < 0.0001). Moreover, the above-mentioned lifestyle behaviors were also independent determinants of the WBC count. These results suggest that a high frequency of fish intake might be associated with healthier lifestyle behaviors as well as lower WBC counts, and thus may both exert beneficial anti-inflammatory effects and represent a component of healthier lifestyle behaviors associated with a lower risk of ASCVD in Japanese. This association may be partially related to the preventive effects of a higher fish intake on ASCVD events. CLINICAL TRIAL REGISTRATION: UMIN ( http://www.umin.ac.jp/ ) Study ID: UMIN000039197 retrospectively registered 1 February 2020.

Effects of a Japanese Cuisine-Based Antihypertensive Diet and Fish Oil on Blood Pressure and Its Variability in Participants with Untreated Normal High Blood Pressure or Stage I Hypertension: A Feasibility Randomized Controlled Study

Aim: The Dietary Approaches to Stop Hypertension (DASH) diet is recommended for lowering blood pressure (BP). Our previous single-arm trial revealed that the Japanese cuisine-based DASH (J-DASH) diet (supplying NaCl 8.0 g per day) reduced BP and improved cardiometabolic biomarkers. The present study’s primary objective was to test the feasibility of the J-DASH diet based on its effects on the BP and BP variability of subjects with untreated high-normal BP or stage 1 hypertension.

Methods: The 6-month study period was held from December 2015 to August 2016. The participants were recruited through advertisements in local newspapers and our website and from among randomized participants at Yamaguchi University Hospital. The 2-month treatments included the following: the J-DASH-1 diet 1×/day or the J-DASH-2 diet providing a fish hamburger-patty 2×/day (5 days/week respectively). The control group consumed their usual diets. For the subsequent 4 months, all participants consumed their usual diets. The main outcome measure was the feasibility of the J-DASH diet. We also collected the data of clinic BP and home BP (by automatic BP monitor), cardiometabolic biomarkers, and lifestyle and psychosocial parameters during the intervention phase. We examined behavior changes throughout the study period, and the diets’ safety.

Results: Fifty-one participants were recruited; following screening, 48 met the inclusion criteria and were randomized by central allocation. Eight participants were eliminated based on exclusion criteria, and the 40 participants were randomly allocated to the J-DASH 1 and J-DASH 2 groups ( n =13 each) and the usual-diet group ( n =14). The participants’ mean age was 50 years, and 44% were women. The three groups’ clinic BP values were not significantly different, but the home BP values were lower in the J-DASH 1 group and lowest in the J-DASH 2 group compared to the usual-diet group and differed significantly among the three groups throughout the study period ( p ＜0.0001). The home BP variability was significantly lower in the J-DASH groups compared to the usual-diet group throughout the study period ( p ＜0.01). The other indices including fish oil showed little differences among the groups throughout the study period.

Conclusions: The J-DASH diet was feasible to improve home BP and stabilize its variability, and it did so more effectively than the participants’ usual diets.

Administration of eicosapentaenoic acid may alter lipoprotein particle heterogeneity in statin-treated patients with stable coronary artery disease: A pilot 6-month randomized study

BACKGROUND

We hypothesized that the addition of eicosapentaenoic acid (EPA) to ongoing statin therapy could change the particle heterogeneity of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) particles, even in stable coronary artery disease (CAD) patients.

METHODS

We assigned CAD patients already receiving statin therapy to one of two groups: an EPA group (1800 mg/day; n = 30) and a control group (n = 30). A gel permeation high-performance liquid chromatography method was used to measure the particle concentration and number of lipoprotein subclasses.

RESULTS

In the EPA group, significant decreases of both the concentration and number of medium LDL (p = 0.0002 and 0.0001), small LDL (p = 0.0004 and 0.0005) and very small LDL (p = 0.0005 and 0.002) particles were observed. Conversely, the concentration and number of large HDL particles increased significantly (p = 0.024 and 0.048). The concentration of very large HDL particles also increased significantly (p = 0.028). Furthermore, significant correlations between the variables that showed significant changes in the LDL and HDL particle subclasses, and the EPA/arachidonic acid (AA) ratio were found. No other significant associations of lipoprotein particle heterogeneity with the serum EPA/AA ratio were noted in either the control group or the EPA group. Interestingly, univariate and multivariate regression analyses revealed that increased serum lecithin-cholesterol acyltransferase activity, a key enzyme of HDL cholesterol efflux, was a predictor for increased above-mentioned HDL particles subclasses.

CONCLUSIONS

Administration of EPA might alter both LDL and HDL particle heterogeneity, causing decreased concentration and number of smaller LDL particles and increased concentration and number of larger HDL particles. Furthermore, addition of EPA to ongoing statin therapy appears to be capable of increasing the EPA/AA ratio, which might have an anti-atherosclerotic effect on lipoprotein particle heterogeneity, even in stable CAD patients with well-controlled serum lipid levels.

CLINICAL TRIAL REGISTRATION

UMIN (http://www.umin.ac.jp/) Study ID: UMIN000010452.

Differential Effects of Roux-en-Y Gastric Bypass Surgery and Laparoscopic Sleeve Gastrectomy on Fatty Acid Levels

BACKGROUND

Bariatric surgery is associated with improved cardiovascular outcomes and also affects lipid levels, but few studies have compared the effects of Roux-en-Y gastric bypass (RYGB) surgery with those of laparoscopic sleeve gastrectomy (LSG) on serum fatty acid levels. The present study compares the effects of RYGB and LSG surgeries on serum fatty acid levels.

METHODS

The study participants were women who were undergoing either RYGB or LSG and body mass index (BMI)-matched controls. Fasting blood samples to measure glucose, insulin, and fatty acids were drawn at baseline and at 6 and 18 months from baseline.

RESULTS

Serum fatty acid data were available for 57 participants at baseline, of whom 56 had data at 6 months and 41 had data at 18 months from baseline. Compared with baseline, serum non-esterified fatty acids (NEFAs) levels were significantly higher at 6 and 18 months in the LSG group compared with the RYGB group. In the RYGB group, 2 saturated fatty acids (SFAs), 2 monounsaturated fatty acids (MUFAs), and 1 polyunsaturated fatty acid (PUFA) were significantly decreased after surgery, compared with those of the LSG group.

CONCLUSIONS

A significant increase in NEFAs was seen after LSG, compared with RYGB. Compared with the LSG group, several serum fatty acids were significantly reduced after RYGB.

TRIAL REGISTRATION

NCT01228097.

Plant-based stearidonic acid as sustainable source of omega-3 fatty acid with functional outcomes on human health

Dietary omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA) like eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) are known to be potent biological regulators with therapeutic and preventive effects on human health. Many global health organizations have recommended consuming marine based omega-3 sources for neonatal brain development and reducing the risk of various chronic diseases. However, due to concerns regarding the origin, sustainable supply and safety of the marine sources, alternative n-3 PUFA sources are being explored. Recently, plant-based omega-3 sources are gaining much importance because of their sustainable supply and dietary acceptance. α-linolenic acid (ALA, 18:3n-3) rich seed oils are the major omega-3 fatty acid source available for human consumption. But, efficiency of conversion of ALA to n-3 LC-PUFAs in humans is limited due to a rate-limiting step in the n-3 pathway catalyzed by Δ6-desaturase. Botanical stearidonic acid (SDA, 18:4n-3) rich oils are emerging as a sustainable omega-3 source with efficient conversion rate to n-3 LC-PUFA especially to EPA, as it bypasses the Δ6-desaturase rate limiting step. Several recent studies have identified the major plant sources of SDA and explored its potential health benefits and preventive roles in inflammation, cardiovascular disease (CVD) and cancer. This systematic review summarizes the current state of knowledge on the sources, nutraceutical roles, food-based applications and the future perspectives of botanical SDA.

Dietary and Pharmacological Fatty Acids and Cardiovascular Health

CONTEXT

The effects of dietary intake of different fatty acids and pharmacological use of fatty acids, specifically long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs), on cardiovascular health and atherosclerotic cardiovascular disease (ASCVD) prevention have been examined in a large number of observational studies and clinical trials. This review summarizes recent data and discusses potential mechanisms.

EVIDENCE ACQUISITION

The review is based on the authors' knowledge of the field supplemented by a PubMed search using the terms seafood, fish oil, saturated fatty acids, omega-3 fatty acids, eicosapentaenoic acid, docosahexaenoic acid, polyunsaturated fatty acids, monounsaturated fatty acids, and ASCVD.

EVIDENCE SYNTHESIS

We mainly discuss the recent clinical trials that examine the effects of different types of dietary fatty acids and pharmacological use of n-3 PUFA products on ASCVD prevention and the potential mechanisms.

CONCLUSIONS

While replacement of dietary saturated fat with unsaturated fat, polyunsaturated fat in particular, or intake of LC n-3 PUFA-rich seafood has generally shown benefit for ASCVD prevention and is recommended for cardiovascular benefits, data on effects of n-3 PUFA products on ASCVD health are inconsistent. However, recent clinical trials support benefits of prescription EPA in ASCVD prevention. n-3 PUFAs may contribute to ASCVD prevention through multiple mechanisms, including lowering plasma triglyceride levels, anti-inflammatory effects, antithrombotic effects, and effects on endothelial function.

Ratios of serum eicosapentaenoic acid to arachidonic acid and docosahexaenoic acid to arachidonic acid were inversely associated with serum resistin levels: The Hisayama Study

AIMS/INTRODUCTION

Resistin is an adipocyte-derived polypeptide that leads to the progression of insulin resistance and subsequent atherosclerosis. Some studies have reported an association between self-reported intake of n-3 polyunsaturated fatty acids (PUFAs) and serum resistin levels. However, no studies have investigated the association between the ratio of serum levels of n-3 to serum n-6 PUFAs and the serum resistin concentration in the general population.

MATERIALS AND METHODS

We carried out a cross-sectional study of 3,200 community-dwelling Japanese individuals aged ≥40 years in 2002-2003. The ratios of serum eicosapentaenoic acid or docosahexaenoic acid to arachidonic acid (AA) were categorized into quartiles. The associations of serum eicosapentaenoic acid/AA and docosahexaenoic acid/AA with the serum resistin concentration were assessed using linear regression models with adjustment for potential confounding factors.

RESULTS

The geometric mean of serum resistin was 10.3 ng/mL. The age- and sex-adjusted geometric mean of serum resistin decreased significantly with increased levels of serum eicosapentaenoic acid/AA (quartile 1: 11.3 ng/mL; quartile 2: 10.6 ng/mL; quartile 3: 10.3 ng/mL; quartile 4: 9.3 ng/mL; P for trend <0.001). A similar association was observed for serum docosahexaenoic acid/AA (quartile 1: 11.1 ng/mL; quartile 2: 10.6 ng/mL; quartile 3: 10.1 ng/mL; quartile 4: 9.7 ng/mL; P for trend <0.001). An adjustment for potential confounding factors did not change these associations.

CONCLUSIONS

Higher ratios of serum n-3 to n-6 PUFAs were associated with lower serum resistin levels. Consumption of a large amount of n-3 PUFAs might have desirable effects on resistin-mediated diseases.

Association of Platelet Membrane Fatty Acid Composition with Markers of Oxidative Stress in Healthy Men

Background

Platelet membranes are extremely susceptible to peroxidation, forming a variety of lipid peroxides, including malondialdehyde (MDA), which has been implicated in the etiology of cardiovascular diseases. Moreover, platelet-leukocyte aggregates (PLAs) are known to contribute to advanced endothelial injury and atherogenesis.

Material/Methods

Fatty acid (FA) methyl esters of the platelet membranes of 79 apparently healthy men without any acute clinical condition at the time of the study were identified by GC/MS. MDA was measured by HPLC in blood serum, and PLAs were analyzed by whole-blood flow cytometry. Individuals were divided into quartiles according to MDA concentration and percentage of PLAs formation. The composition of platelet membrane FAs was compared to MDA concentration and the percentage of PLAs formation in apparently healthy individuals.

Results

In quartiles (Q) with higher MDA concentration, percentage of C 16: 1ω7 (Q₁vs. Q₃, p=0.021), C 20: 1ω9 (Q₂vs. Q₄, p=0.028) and C 20: 5ω3 (Q₂vs. Q₄, p=0.046) was lower. However, C 22: 5ω3 (Q₁vs. Q₄, p=0.038) and total ω3 (Q₁vs. Q₂, p=0.024) were higher.

Conclusions

MDA and the formation of platelet-monocyte aggregates stimulate the incorporation of monounsaturated fatty acids and polyunsaturated fatty acids in platelet phospholipid membranes, which may be a hallmark for a changed level of biologically active compounds required for the activation of future platelets.

Partitioning of Rumen-Protected n-3 and n-6 Fatty Acids is Organ-Specific in Growing Angus Heifers

Dietary polyunsaturated fatty acids (PUFA), especially n-3 and n-6 fatty acids (FA), play an important role in the regulation of FA metabolism in all mammals. However, FA metabolism differs between different organs, suggesting a distinct partitioning of highly relevant FA. For the present study in cattle, a novel technology was applied to overcome rumen biohydrogenation of dietary unsaturated FA. Angus heifers were fed a straw-based diet supplemented for 8 weeks with 450 g/day of rumen-protected oil, either from fish (FO) or sunflower (SO). The FA composition in blood and five important organs, namely heart, kidney, liver, lung, and spleen, was examined. In blood, proportions of polyunsaturated FA were increased by supplementing FO compared to SO. The largest increase of eicosapentaenoic acid (EPA) proportion was found with FO instead of SO in the kidney, the lowest in the lung. Docosahexaenoic acid (DHA) was increased more in the liver than in kidney, lung, and spleen. The heart incorporated seven times more EPA than DHA, which is more than all other organs and described here for the first time in ruminants. In addition, the heart had the highest proportions of α-linolenic acid (18:3n-3) and linoleic acid (18:2n-6) of all organs. The proportions of polyunsaturated FA in the lung and spleen were exceptionally low compared to heart, liver, and kidney. In conclusion, it was shown that the response to FO in the distribution of dietary n-3 FA was organ-specific while proportions of n-6 FA were quite inert with respect to the type of oil supplemented.

Cardiovascular, electrophysiologic, and hematologic effects of omega-3 fatty acids beyond reducing hypertriglyceridemia: as it pertains to the recently published REDUCE-IT trial

Heart disease continues to affect health outcomes globally, accounting for a quarter of all deaths in the United States. Despite the improvement in the development and implementation of guideline-directed medical therapy, the risk of adverse cardiac events remains substantially high. Historically, it has been debated whether omega-3 polyunsaturated fatty acids provide clinical benefit in cardiac disease. The recently published REDUCE-IT trial demonstrated a statistically significant absolute risk reduction of 4.8% in its primary endpoint (cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or unstable angina) with the use of icosapent ethyl, which is a highly purified eicosapentaenoic acid (EPA) ethyl ester. However, the mechanism of action of omega-3 fatty acids is not commonly discussed. Moreover, the use of EPA was not without risk, as the incidence of atrial fibrillation was increased along with a trend towards increased bleeding risk. Thus, our aim is to help explain the function of purified EPA ethyl ester, especially at the molecular level, which will ultimately lead to a better understanding of their clinically observable effects.

The eicosapentaenoic acid:arachidonic acid ratio and its clinical utility in cardiovascular disease

Eicosapentaenoic acid (EPA) is a key anti-inflammatory/anti-aggregatory long-chain polyunsaturated omega-3 fatty acid. Conversely, the omega-6 fatty acid, arachidonic acid (AA) is a precursor to a number of pro-inflammatory/pro-aggregatory mediators. EPA acts competitively with AA for the key cyclooxygenase and lipoxygenase enzymes to form less inflammatory products. As a result, the EPA:AA ratio may be a marker of chronic inflammation, with a lower ratio corresponding to higher levels of inflammation. It is now well established that inflammation plays an important role in cardiovascular disease. This review examines the role of the EPA:AA ratio as a marker of cardiovascular disease and the relationship between changes in the ratio (mediated by EPA intake) and changes in cardiovascular risk. Epidemiological studies have shown that a lower EPA:AA ratio is associated with an increased risk of coronary artery disease, acute coronary syndrome, myocardial infarction, stroke, chronic heart failure, peripheral artery disease, and vascular disease. Increasing the EPA:AA ratio through treatment with purified EPA has been shown in clinical studies to be effective in primary and secondary prevention of coronary artery disease and reduces the risk of cardiovascular events following percutaneous coronary intervention. The EPA:AA ratio is a valuable predictor of cardiovascular risk. Results from ongoing clinical trials will help to define thresholds for EPA treatment associated with better clinical outcomes.

Icosapent Ethyl Effects on Fatty Acid Profiles in Statin-Treated Patients With High Triglycerides: The Randomized, Placebo-controlled ANCHOR Study

Introduction

Fatty acid content in plasma and red blood cells (RBCs) may provide insight into potential physiologic benefits of omega-3 fatty acids. Icosapent ethyl is a pure prescription form of eicosapentaenoic acid (EPA) ethyl ester approved by the US Food and Drug Administration at a dose of 4 g/day as an adjunct to diet to reduce triglyceride levels in adults with severe (≥ 500 mg/dl) hypertriglyceridemia.

Methods

This was a prespecified exploratory subset analysis of the ANCHOR study, which randomized 702 statin-treated patients at increased cardiovascular risk with triglycerides 200–499 mg/dl and controlled low-density lipoprotein cholesterol (40–99 mg/dl). This analysis examined effects of icosapent ethyl 4 g/day versus placebo on fatty acid levels in plasma and RBCs using a gas chromatograph assay method with flame ionization detector.

Results

In plasma, treatment with icosapent ethyl 4 g/day resulted in significant increases versus placebo in the mean concentrations of EPA (+ 635%; P < 0.0001) and its metabolite, docosapentaenoic acid n-3 (+ 143%; P < 0.0001) with no significant change in docosahexaenoic acid. Treatment with icosapent ethyl 4 g/day versus placebo also resulted in significant decreases in the omega-6 fatty acids linoleic acid (− 25%) and arachidonic acid (AA; − 31%), as well as the AA/EPA ratio (− 91%). Icosapent ethyl 4 g/day also decreased the omega-9 fatty acid oleic acid (− 29%) and the saturated fatty acids palmitic acid (− 23%) and stearic acid (− 16%) (all P < 0.0001). Results were similar for RBCs.

Conclusions

Icosapent ethyl 4 g/day significantly increased EPA and produced other potentially beneficial shifts in fatty acids in plasma and RBCs versus placebo.

Trial Registration

ClinicalTrials.gov Identifier, NCT01047501

Funding

Amarin Pharma Inc.

Plain Language Summary

Plain language summary available for this article.

Variations in the eicosapentaenoic acid-arachidonic acid ratio associated with age in acute myocardial infarction patients undergoing primary percutaneous coronary intervention

Acute myocardial infarction (AMI) is a life-threatening disease, and its incidence has been increasing even in the young population. Although a low eicosapentaenoic acid (EPA)-arachidonic acid (AA) ratio is associated with an increased risk of coronary artery disease, the effect of age on EPA/AA ratios in AMI patients remains unclear. This study aimed to clarify the independent polyunsaturated fatty acid (PUFA)-related determinants of age in younger and older AMI patients. A total of 153 consecutive patients who underwent primary percutaneous coronary interventions (PCIs) for de novo AMIs were enrolled in this study. Patients' background data, including PUFA and lipid profiles during PCI, were evaluated retrospectively. The EPA/AA ratio correlated positively with age (r = 0.21; P = 0.011) and increased markedly from age 60 years. Patients aged < 60 years (n = 35) had a lower mean EPA/AA ratio (0.25 ± 0.16) than patients aged ≥ 60 years (n = 118) (0.38 ± 0.25) (P < 0.001). The AA level was more dependent on age than on EPA level (r = - 0.34, P < 0.001 vs. r = 0.12, P = 0.16). The multivariate analysis revealed that a 0.1 EPA/AA ratio increase (odds ratio 1.50; 95% confidence interval 1.09-2.06), body mass index, triglyceride level, and aspirin administration were independently associated with the age stratification of AMI patients. The EPA/AA ratio was higher in younger AMI patients who have undergone primary PCIs than in older patients. Younger population at risk for AMI should be managed with multiple interventions including PUFA profiling.

A longitudinal study of the association of the eicosapentaenoic acid/arachidonic acid ratio derived from fish consumption with the serum lipid levels: a pilot study

It has been demonstrated that regular fish consumption is associated with a reduced mortality from atherosclerotic cardiovascular disease (ASCVD). However, data are scarce regarding the correlation between the changes in the serum eicosapentaenoic acid/arachidonic acid (EPA/AA) ratio associated with regular fish consumption and the changes in the serum lipid profile variables. This study was designed as a hospital-based longitudinal study to investigate the relationship between the changes in the serum EPA/AA ratio and changes of the serum lipid levels in patients with one or more risk factors for ASCVD. In 475 patients followed-up for at least 1 year, univariable and multivariable regression analyses conducted after adjustments for the risk factors of ASCVD revealed that the absolute change of the EPA/AA ratio (∆EPA/AA ratio) was independently and significantly associated with the changes of the serum levels of low-density lipoprotein cholesterol (LDL-C) (β = - 0.129, p = 0.005), triglyceride (TG) (β = - 0.108, p = 0.019), non-high-density lipoprotein cholesterol (non-HDL-C) (β = - 0.149, p = 0.001), and TG/HDL-C ratio, a marker of the LDL particle size (β = - 0.104, p = 0.02), while not being correlated with any other lipid parameters. On the other hand, while the ∆ docosahexaenoic acid (DHA)/AA ratio was inversely correlated with the changes of the serum HDL-C level and positively correlated with the changes of the TG/HDL-C ratio, possibly serving to promote development of atherosclerosis. The results suggest that an increase of the EPA/AA ratio might be associated with decrease of the serum levels of LDL-C, TG and non-HDL-C levels, as well as with an increase of the TG/HDL-C ratio, which represents increased LDL particle size, all of which play a role in the development of ASCVD. A high EPA/AA ratio, but not DHA/AA ratio, derived from fish consumption might reduce the risk of ASCVD through reducing the risk of development of atherosclerosis.Clinical Trial Registration Information: UMIN ( http://www.umin.ac.jp/ ), Study ID: UMIN000010603.

Eicosapentaenoic Acid and Prevalence of Cardiovascular Disease in Hemodialysis Patients

Eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio showed inverse associations with cardiovascular disease (CVD) in general population. However, this has not been examined enough in dialysis patients. We cross-sectionally investigated the relationship between EPA/AA ratio and prevalence of CVD in 321 chronic hemodialysis patients (64 ± 11 years old; 110 women; dialysis vintage 10 ± 8 years) in an urban area of Tokyo. CVD was defined as a composite of ischemic heart disease, ischemic stroke and hemorrhagic stroke. The frequency of dietary fish intake was also examined. Logistic regression was used to quantify the association of EPA/AA ratio with CVD. EPA/AA ratio was 0.31 ± 0.19 and 154 patients (48%) consumed fish once or less weekly. One hundred and thirty patients (41%) had CVD, including 65 with ischemic heart disease, 70 with ischemic stroke, and 20 with hemorrhagic stroke. Age (odds ratio [OR], 1.04; P = 0.01), hypertension (OR, 2.25; P = 0.002), and dialysis vintage (OR, 1.04; P = 0.02) were associated with CVD; however, EPA/AA was not after adjustment for other risk factors. A similar relationship was observed between fish intake and CVD prevalence. We did not find any significant association between EPA/AA ratio and prevalence of CVD, although traditional risk factors such as age, hypertension and dialysis vintage were associated with CVD. These results might have been influenced by the fact that only a small proportion of our patients showed a high EPA/AA ratio.

Integrated Network Pharmacology and Metabolomics Analysis of the Therapeutic Effects of Zi Dian Fang on Immune Thrombocytopenic Purpura

Current hormone-based treatments for immune thrombocytopenic purpura (ITP) are associated with potentially serious adverse reactions. Zi Dian Fang (ZDF) is a multi-target Traditional Chinese Medicine (TCM) used to treat both the symptoms and root causes of ITP, with fewer side effects than hormone-based treatments. This study analysis of the therapeutic effects of ZDF on ITP from three aspects: platelet proliferation, immunoregulation, and inflammation. After detection of 52 chemical constituents of ZDF by UPLC-Q-TOF/MS, The main targets and pathways affected by ZDF were screened by network pharmacology and verified by Western blot and ELISA. Meanwhile, metabolomics analysis were applied to a mouse model of ITP to identify and screen endogenous terminal metabolites differentially regulated by ZDF. Integrated network pharmacology and metabolomics analysis of the therapeutic effects of ZDF on ITP may be as follows: ZDF counteracts ITP symptoms mainly by inhibiting Ras/MAPKs (Ras/Mitogen-activated protein kinases) pathway, and the expression of upstream protein (Ras) and downstream protein (p-ERK, p-JNK, p-p38) were inhibited, which affects the content of effect index associated with proliferation (Thrombopoietin, TPO; Granulocyte-macrophage colony stimulating factor, GM-CSF), inflammation (Tumor necrosis factor-α, TNF-α; Interleukin-6, IL-6), immune (Interleukin-2, IL-2; Interferon-gamma, IFN-γ; Interleukin-4, IL-4), so that the body’s arginine, Δ¹²-prostaglandin j2 (Δ¹²-PGJ2), 9-cis-Retinoic Acid, sphingosine-1-phosphate (S1P), oleic acid amide and other 12 endogenous metabolites significantly changes. Considering the established safety profile, the present study suggests ZDF may be a useful alternative to hormone-based therapies for the treatment of ITP.

Omega-3 and omega-6 polyunsaturated fatty acids: Dietary sources, metabolism, and significance - A review

Linoleic acid (LA) (n-6) and α-linolenic acid (ALA) (n-3) are essential fatty acids (EFAs) as they cannot be synthesized by humans or other higher animals. In the human body, these fatty acids (FAs) give rise to arachidonic acid (ARA, n-6), eicosapentaenoic acid (EPA, n-3), and docosahexaenoic acid (DHA, n-3) that play key roles in regulating body homeostasis. Locally acting bioactive signaling lipids called eicosanoids derived from these FAs also regulate diverse homeostatic processes. In general, ARA gives rise to pro-inflammatory eicosanoids whereas EPA and DHA give rise to anti-inflammatory eicosanoids. Thus, a proportionally higher consumption of n-3 PUFAs can protect us against inflammatory diseases, cancer, cardiovascular diseases, and other chronic diseases. The present review summarizes major sources, intake, and global consumption of n-3 and n-6 PUFAs. Their metabolism to biosynthesize long-chain PUFAs and eicosanoids and their roles in brain metabolism, cardiovascular disease, obesity, cancer, and bone health are also discussed.

Adaptive thermogenesis by dietary n-3 polyunsaturated fatty acids: Emerging evidence and mechanisms

Brown/beige fat plays a crucial role in maintaining energy homeostasis through non-shivering thermogenesis in response to cold temperature and excess nutrition (adaptive thermogenesis). Although numerous molecular and genetic regulators have been identified, relatively little information is available regarding thermogenic dietary molecules. Recently, a growing body of evidence suggests that high consumption of n-3 polyunsaturated fatty acids (PUFA) or activation of GPR120, a membrane receptor of n-3 PUFA, stimulate adaptive thermogenesis. In this review, we summarize the emerging evidence that n-3 PUFA promote brown/beige fat formation and highlight the potential mechanisms whereby n-3 PUFA require GPR120 as a signaling platform or act independently. Human clinical trials are revisited in the context of energy expenditure. Additionally, we explore some future perspective that n-3 PUFA intake might be a useful strategy to boost or sustain metabolic activities of brown/beige fat at different lifecycle stages of pregnancy and senescence. Given that a high ratio of n-6/n-3 PUFA intake is associated with the development of obesity and type 2 diabetes, understanding the impact of n-6/n-3 ratio on energy expenditure and adaptive thermogenesis will inform the implementation of a novel nutritional strategy for preventing obesity.

Low omega-3 index values and monounsaturated fatty acid levels in early pregnancy: an analysis of maternal erythrocytes fatty acids

Background

It is unanimously recognized that the maternal nutritional status at the pregnancy onset influence both short-term and long-term health of the mother and offspring. Among several nutrients, LCPUFA, particularly from the omega-3 family, are of utmost importance. This study was carried out to determine fatty acids profile of maternal erythrocyte membranes in early pregnancy and to identify potential determinants impacting on this status.

Methods

A cohort of 122 healthy women with a singleton pregnancy was included. Fatty acids were analyzed using gas chromatography. Because of the lack of cutoff values, reference ranges were used to determine fatty acids categories.

Results

Of concern, our data revealed low monounsaturated and long-chain omega-3 fatty acid status in most participants. More than 75% of Belgian pregnant women exhibited Pal, AO and EPA levels as well as IOM3 values below the laboratory reference ranges. Higher DHA concentrations and IOM3 values were found among foreign-nationality participants, non-smokers and physically active women. With regard to dietary factors, omega-3 supplements and diet seem to be complementary since DHA from supplements (but not from diet) and EPA from diet (but not from supplements) were found to be associated with higher concentrations of DHA and EPA, respectively.

Conclusions

Our study presents evidence demonstrating that the fatty acid status of most early pregnant women is far from being optimal based on the admitted general reference values. Clinicians should be advice to carefully evaluate and improve this status to guarantee the best possible outcome for both the mother and the baby.

Electronic supplementary material

The online version of this article (10.1186/s12944-018-0716-6) contains supplementary material, which is available to authorized users.

Effect of Vascepa (icosapent ethyl) on progression of coronary atherosclerosis in patients with elevated triglycerides (200-499 mg/dL) on statin therapy: Rationale and design of the EVAPORATE study

Despite reducing progression and promoting regression of coronary atherosclerosis, statin therapy does not fully address residual cardiovascular (CV) risk. High‐purity eicosapentaenoic acid (EPA) added to a statin has been shown to reduce CV events and induce regression of coronary atherosclerosis in imaging studies; however, data are from Japanese populations without high triglyceride (TG) levels and baseline EPA serum levels greater than those in North American populations. Icosapent ethyl is a high‐purity prescription EPA ethyl ester approved at 4 g/d as an adjunct to diet to reduce TG levels in adults with TG levels >499 mg/dL. The objective of the randomized, double‐blind, placebo‐controlled EVAPORATE study is to evaluate the effects of icosapent ethyl 4 g/d on atherosclerotic plaque in a North American population of statin‐treated patients with coronary atherosclerosis, TG levels of 200 to 499 mg/dL, and low‐density lipoprotein cholesterol levels of 40 to 115 mg/dL. The primary endpoint is change in low‐attenuation plaque volume measured by multidetector computed tomography angiography. Secondary endpoints include incident plaque rates; quantitative changes in different plaque types and morphology; changes in markers of inflammation, lipids, and lipoproteins; and the relationship between these changes and plaque burden and/or plaque vulnerability. Approximately 80 patients will be followed for 9 to 18 months. The clinical implications of icosapent ethyl 4 g/d treatment added to statin therapy on CV endpoints are being evaluated in the large CV outcomes study REDUCE‐IT. EVAPORATE will provide important imaging‐derived data that may add relevance to the clinically derived outcomes from REDUCE‐IT.

Higher Prevalence of "Low T3 Syndrome" in Patients With Chronic Fatigue Syndrome: A Case-Control Study

Chronic fatigue syndrome (CFS) is a heterogeneous disease with unknown cause(s). CFS symptoms resemble a hypothyroid state, possibly secondary to chronic (low-grade) (metabolic) inflammation. We studied 98 CFS patients (21-69 years, 21 males) and 99 age- and sex-matched controls (19-65 years, 23 males). We measured parameters of thyroid function, (metabolic) inflammation, gut wall integrity and nutrients influencing thyroid function and/or inflammation. Most remarkably, CFS patients exhibited similar thyrotropin, but lower free triiodothyronine (FT3) (difference of medians 0.1%), total thyroxine (TT4) (11.9%), total triiodothyronine (TT3) (12.5%), %TT3 (4.7%), sum activity of deiodinases (14.4%), secretory capacity of the thyroid gland (14.9%), 24-h urinary iodine (27.6%), and higher % reverse T3 (rT3) (13.3%). FT3 below the reference range, consistent with the "low T3 syndrome," was found in 16/98 CFS patients vs. 7/99 controls (OR 2.56; 95% confidence interval = 1.00-6.54). Most observations persisted in two sensitivity analyses with more stringent cutoff values for body mass index, high-sensitive C-reactive protein (hsCRP), and WBC. We found possible evidence of (chronic) low-grade metabolic inflammation (ferritin and HDL-C). FT3, TT3, TT4, and rT3 correlated positively with hsCRP in CFS patients and all subjects. TT3 and TT4 were positively related to hsCRP in controls. Low circulating T3 and the apparent shift from T3 to rT3 may reflect more severely depressed tissue T3 levels. The present findings might be in line with recent metabolomic studies pointing at a hypometabolic state. They resemble a mild form of "non-thyroidal illness syndrome" and "low T3 syndrome" experienced by a subgroup of hypothyroid patients receiving T4 monotherapy. Our study needs confirmation and extension by others. If confirmed, trials with, e.g., T3 and iodide supplements might be indicated.

Therapeutic potential of omega-3 fatty acid-derived epoxyeicosanoids in cardiovascular and inflammatory diseases

Numerous benefits have been attributed to dietary long-chain omega-3 polyunsaturated fatty acids (n-3 LC-PUFAs), including protection against cardiac arrhythmia, triglyceride-lowering, amelioration of inflammatory, and neurodegenerative disorders. This review covers recent findings indicating that a variety of these beneficial effects are mediated by "omega-3 epoxyeicosanoids", a class of novel n-3 LC-PUFA-derived lipid mediators, which are generated via the cytochrome P450 (CYP) epoxygenase pathway. CYP enzymes, previously identified as arachidonic acid (20:4n-6; AA) epoxygenases, accept eicosapentaenoic acid (20:5n-3; EPA) and docosahexaenoic acid (22:6n-3; DHA), the major fish oil n-3 LC-PUFAs, as efficient alternative substrates. In humans and rodents, dietary EPA/DHA supplementation causes a profound shift of the endogenous CYP-eicosanoid profile from AA- to EPA- and DHA-derived metabolites, increasing, in particular, the plasma and tissue levels of 17,18-epoxyeicosatetraenoic acid (17,18-EEQ) and 19,20-epoxydocosapentaenoic acid (19,20-EDP). Based on preclinical studies, these omega-3 epoxyeicosanoids display cardioprotective, vasodilatory, anti-inflammatory, and anti-allergic properties that contribute to the beneficial effects of n-3 LC-PUFAs in diverse disease conditions ranging from cardiac disease, bronchial disorders, and intraocular neovascularization, to allergic intestinal inflammation and inflammatory pain. Increasing evidence also suggests that background nutrition as well as genetic and disease state-related factors could limit the response to EPA/DHA-supplementation by reducing the formation and/or enhancing the degradation of omega-3 epoxyeicosanoids. Recently, metabolically robust synthetic analogs mimicking the biological activities of 17,18-EEQ have been developed. These drug candidates may overcome limitations of dietary EPA/DHA supplementation and provide novel options for the treatment of cardiovascular and inflammatory diseases.

The Ratio of Eicosapentaenoic Acid (EPA) to Arachidonic Acid may be a Residual Risk Marker in Stable Coronary Artery Disease Patients Receiving Treatment with Statin Following EPA Therapy

BACKGROUND

We investigated the relationship between the eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio and non-high-density lipoprotein cholesterol (non-HDL-C) level, a major residual risk of coronary artery disease (CAD), in statin-treated CAD patients following EPA therapy.

METHODS

We conducted a 6-month, prospective, randomized clinical trial to investigate the effect of the additional administration of EPA on the EPA/AA ratio and the serum non-HDL-C level in stable CAD patients receiving statin treatment. We assigned CAD patients already receiving statin therapy to an EPA group (1800 mg/day; n = 50) or a control group (n = 50).

RESULTS

A significant reduction in the serum non-HDL-C level was observed in the EPA group, compared with the control group (-9.7 vs. -1.2%, p = 0.01). A multiple-regression analysis with adjustments for coronary risk factors revealed that achieved EPA/AA ratio was more reliable as an independent and significant predictor of a reduction in the non-HDL-C level at a 6-month follow-up examination (β = -0.324, p = 0.033) than the absolute change in the EPA/AA ratio. Interestingly, significant negative correlations were found between the baseline levels and the absolute change values of both non-HDL-C and triglyceride-rich lipoproteins, both markers of residual risk of CAD, indicating that patients with a higher baseline residual risk achieved a greater reduction.

CONCLUSION

The present results suggest that the achieved EPA/AA ratio, but not the absolute change in EPA/AA ratio, following EPA therapy might be a useful marker for the risk stratification of CAD among statin-treated patients with a high non-HDL-C level.

CLINICAL TRIAL REGISTRATION

UMIN ( http://www.umin.ac.jp/ ) Study ID: UMIN000010452.

Therapeutic potential of omega-3 fatty acids supplementation in a mouse model of dry macular degeneration

Purpose

To evaluate the therapeutic effects of omega-3 (ω-3) and omega-6 (ω-6) fatty acids in the CCL2^-/- model of dry age-related macular degeneration (AMD). The blood level of eicosapentaenoic acid (EPA) and arachidonic acid (AA) served to adjust the treatment dosage (AA/EPA=1-1.5).

Methods

Nine-month-old animals were allocated to different groups: (A) C57BL/6 untreated , (B) CCL2^-/- untreated, (C) CCL2^-/- treated with ω-3+ω-6, and (D) CCL2^-/- treated with ω-3. Treatment was daily administered by gavage for 3 months. Fatty acids analysis was performed and retinas were histologically examined. Three-month-old wild type mice were used for comparison purposes. Real-time PCR and Western blot were performed for retinal inflammatory mediators.

Results

Increased EPA and decreased AA levels were observed in both blood and retinas in the treatment groups. The outer nuclear layer thickness was increased in groups C (90.0±7.8 μm) and D (125.6±9.8 μm) [corrected] compared with groups B (65.6±3.0 μm) and A (71.1±4.2 μm), and in young mice, it was 98.0±3.9 μm. A decrease in NF-κB expression was noted in the treatment groups. Interleukin (IL) 18 protein levels demonstrated a significant reduction in the ω-3-treated group only.

Conclusion

Supplementation with ω-3+ω-6 or ω-3 alone (AA/EPA=1-1.5) suggests a protective mechanism in the CCL2^-/- animal model of dry AMD, with a more beneficial effect when ω-3 are used alone. Our findings indicated that inflammation is not the only determining factor; perhaps a regenerative process might be involved following administration of ω-3 fatty acids.

Measurement of red blood cell eicosapentaenoic acid (EPA) levels in a randomised trial of EPA in patients with colorectal cancer liver metastases

We investigated red blood cell (RBC) PUFA profiles, and the predictive value of RBC EPA content for tumour EPA exposure and clinical outcomes, in the EMT study, a randomised trial of EPA in patients awaiting colorectal cancer (CRC) liver metastasis surgery (Cockbain et al., 2014) [8]. There was a significant increase in RBC EPA in the EPA group (n=43; median intervention 30 days; mean absolute 1.26[±0.14]% increase; P<0.001), but not in the placebo arm (n=45). EPA incorporation varied widely in EPA users and was not explained by treatment duration or compliance. There was little evidence of 'contamination' in the placebo group. The EPA level predicted tumour EPA content (r=0.36; P=0.03). Participants with post-treatment EPA≥1.22% (n=49) had improved OS compared with EPA <1.22% (n=29; HR 0.42[95%CI 0.16-0.95]). RBC EPA content should be evaluated as a biomarker of tumour exposure and clinical outcomes in future EPA trials in CRC patients.

Determination of Eicosapentaenoic, Docosahexaenoic, and Arachidonic Acids in Human Plasma by High-Performance Liquid Chromatography with Electrochemical Detection

A high-performance liquid chromatography with electrochemical detection (HPLC-ECD) system was developed for the simultaneous determination of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA) in human plasma. In the present HPLC-ECD system, EPA, DHA, and AA were separated using a reverse-phase C30 column and detected based on the voltammetric reduction of 3,5-di-tert-butyl-1,2-benzoquinone (DBBQ). Chromatographic peak areas were proportional to the concentration of EPA, DHA, and AA from 0.75 μM to 0.1 mM (r > 0.998). The concentrations of EPA, DHA, and AA in plasma from healthy human subjects after overnight fasting were determined, and the ratio of EPA to AA was obtained by the present HPLC-ECD method, which required 40 μL of human plasma and a simple procedure of sample preparation using diethyl ether extraction. Moreover, changes in EPA, DHA, and AA concentrations in a human subject were monitored before and after fish oil supplement administration by the present HPLC-ECD system.