Blood pressure response to fish oil supplementation: metaregression analysis of randomized trials

Blue Food Consumption and Its Relation to Nutrient Intake among Koreans

(1) Background: "Blue food" is a recently coined term referring to seafood, emphasizing health benefits and sustainability. This study compares nutrient intake levels between Koreans who consume fish and shellfish and those who do not. (2) Methods: Data from the eighth Korea National Health and Nutrition Examination Survey (2019-2020) were used. A total of 9442 individuals were analyzed (≥1 year old). A complex sample design was applied. (3) Results: Younger individuals aged 9 to 29 consumed less fish and shellfish, while those with higher education and income levels consumed more. Compared with the non-consumption group, individuals in the fish and shellfish consumption group exhibited a higher nutrient density in their diets, excluding total fat, saturated fatty acids, monounsaturated fatty acids, and riboflavin (p < 0.01). They also had a higher proportion of nutrient intakes relative to the Recommended Nutrient Intake level for all nutrients than the non-consumption group (p < 0.001), particularly in eicosapentaenoic acid and docosahexaenoic acid intakes. Conversely, the non-consumption group had a higher proportion of nutrient intakes below the Estimated Average Requirement compared with the consumption group. (p < 0.001). (4) Conclusions: Individuals consuming blue food exhibited higher levels of nutrient intake. Developing strategies to promote the consumption of blue food, considering factors such as age, education, and income, is essential.

Neuroprotective and antioxidant effects of docosahexaenoic acid (DHA) in an experimental model of multiple sclerosis

Multiple sclerosis (MS) is a chronic demyelinating disease, whose etiology is not yet fully understood, although there are several factors that can increase the chances of suffering from it. These factors include nutrition, which may be involved in the pathogenesis of the disease. In relation to nutrition, docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid (n-3 PUFA), has emerged as an important player in the regulation of neuroinflammation, being considered a pleiotropic molecule. This study aimed to evaluate the effect of DHA supplementation on clinical state and oxidative stress produced by experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Twenty-five Dark Agouti rats which were used divided into Control Group, Control+Vehicle Group, Control+DHA Group, EAE Group, and EAE+DHA Group. DHA was administered for 51 days by intraperitoneal (i.p.) injection at a dose of 40 mg/kg, once a day, 5 days a week. DHA supplementation produced a decrease in oxidative stress, as well as an improvement in the clinical score of the disease. DHA could exert a beneficial effect on the clinic of MS, through the activation of the antioxidant factor Nrf2.

The effect of omega-3 polyunsaturated fatty acid intake on blood levels of omega-3s in people with chronic atherosclerotic disease: a systematic review

CONTEXT

Atherosclerosis is a systemic pro-inflammatory and pro-oxidative disease, accounting for approximately a third of deaths globally. It has been proposed that omega-3s, through their antioxidant and anti-inflammatory properties, mitigate atherosclerotic disease progression. However, due to the systemic pro-inflammatory and pro-oxidative state of atherosclerosis, it is proposed that patients with atherosclerotic disease may have higher omega-3 requirements than the average requirement, due to increased nutrient utilization in anti-inflammatory and anti-oxidant processes.

OBJECTIVE

The aim of this review was to determine what dose and duration of omega-3 supplementation is required to reach a therapeutic blood level of omega-3s (eicosapentaenoic acid ≥150 µg/mL or omega-3 index ≥8%) in people with chronic atherosclerotic disease.

DATA SOURCES

This systematic review comprehensively searched MEDLINE, Emcare, Scopus, and CINAHL using key search terms for atherosclerotic disease, omega-3, supplementation, and blood levels of omega-3s.

DATA EXTRACTION

Two reviewers independently screened 529 randomized controlled trials (RCTs) supplementing omega-3s in patients with chronic atherosclerotic disease.

DATA ANALYSIS

In total, 25 journal articles from 17 original RCTs were included and assessed quantitatively. Supplementation at 1.8 g to 3.4 g per day for a 3-month-6-month duration, and at 4.4 g and above for as little as 1 month-6 months were identified as the most effective dosage ranges for increasing blood levels of omega-3s to therapeutic levels in people with atherosclerotic disease.

CONCLUSIONS

Consideration should be given to routine omega-3 supplementation and to increasing the omega-3 dietary recommendations and upper limits of daily intake to improve clinical outcomes and reduce the risk of cardiac mortality in this population.

Omega-3 Fatty Acids in Arterial Hypertension: Is There Any Good News?

Omega-3 polyunsaturated fatty acids (ω-3 PUFAs), including alpha-linolenic acid (ALA) and its derivatives eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are "essential" fatty acids mainly obtained from diet sources comprising plant oils, marine blue fish, and commercially available fish oil supplements. Many epidemiological and retrospective studies suggested that ω-3 PUFA consumption decreases the risk of cardiovascular disease, but results of early intervention trials have not consistently confirmed this effect. In recent years, some large-scale randomized controlled trials have shed new light on the potential role of ω-3 PUFAs, particularly high-dose EPA-only formulations, in cardiovascular prevention, making them an attractive tool for the treatment of "residual" cardiovascular risk. ω-3 PUFAs' beneficial effects on cardiovascular outcomes go far beyond the reduction in triglyceride levels and are thought to be mediated by their broadly documented "pleiotropic" actions, most of which are directed to vascular protection. A considerable number of clinical studies and meta-analyses suggest the beneficial effects of ω-3 PUFAs in the regulation of blood pressure in hypertensive and normotensive subjects. These effects occur mostly through regulation of the vascular tone that could be mediated by both endothelium-dependent and independent mechanisms. In this narrative review, we summarize the results of both experimental and clinical studies that evaluated the effect of ω-3 PUFAs on blood pressure, highlighting the mechanisms of their action on the vascular system and their possible impact on hypertension, hypertension-related vascular damage, and, ultimately, cardiovascular outcomes.

Associations between mercury exposure with blood pressure and lipid levels: A cross-sectional study of dental professionals

Mercury (Hg) exposure is a public health problem worldwide that is now being addressed through the Minamata Convention on Mercury. Fish containing methylmercury and dental amalgam containing elemental Hg are the major sources of exposure for most populations. There is some evidence that methylmercury impacts cardiovascular and metabolic health, primarily in populations with high exposure levels. Studies of elemental Hg and these outcomes are relatively rare. We aimed to examine associations between Hg exposure (both elemental and methylmercury) and blood pressure, as well as cholesterol and triglyceride levels. In 2012, we recruited dental professionals attending the Health Screening Program at the American Dental Association (ADA) Annual Session in California. Total Hg levels in hair and blood samples were analyzed as indicators of methylmercury exposure and in urine as an indicator of primarily elemental Hg exposure (n = 386; mean ± sd age 55 ± 11 years). We measured blood pressure (systolic and diastolic) and lipid profiles (total cholesterol, high-density lipoprotein cholesterol [HDL], low-density lipoprotein cholesterol [LDL] and triglycerides). The geometric means (geometric standard deviations) for blood, hair, and urine Hg were 3.64 (2.39) μg/L, 0.60 (2.91) μg/g, and 1.30 (2.44) μg/L, respectively. For every one μg/L increase in specific gravity-adjusted urine Hg, LDL increased by 2.31 mg/dL (95% CI = 0.09, 4.54), in linear regression adjusting for BMI, race, sex, polyunsaturated fatty acid intake from fish consumption, smoking status, and use of cholesterol-lowering medication. No significant associations between Hg biomarkers and blood pressure or hair or blood Hg with lipid levels were observed. Results suggest that elemental Hg exposure may influence LDL concentrations in adults with low-level exposure, and this relationship merits further study in other populations.

Serum Fatty Acids Are Associated with a Higher Risk of Ischemic Stroke

Stroke prevention, a significant public-health concern, begins with recognizing and addressing risk factors. Interventions targeted at modifiable risk factors can effectively prevent ischemic stroke, while Omega-3 fatty acids have been shown to improve stroke outcomes. Our study aimed to investigate the relationship between ischemic-stroke risk factors and fatty acids using a prospective observational study with 274 patients. We collected clinical data on risk factors and measured fatty-acid levels using high-performance liquid chromatography coupled with mass spectrometry. We found that several risk factors, including age, sex, smoking, atrial fibrillation, dyslipidemia, and previous stroke history, had a direct relationship with fatty acids. Of these, smoking had the most significant impact, negatively impacting levels of docosahexaenoic and eicosapentaenoic acid. Conversely, dyslipidemia and atrial fibrillation positively correlated with fatty acids, particularly in female patients and those with recurrent strokes. Age was found to directly correlate with other risk factors and variations in fatty-acid ratios. The stroke rate was higher in males than females before the age of 70, but this trend reversed. Our findings suggest that better management of risk factors, particularly modifiable lifestyle factors, could improve fatty-acid profiles and the balance of Omega-3 and Omega-6 in patients with ischemic stroke.

Effect of Docosahexaenoic Acid (DHA) Supplementation of Preterm Infants on Growth, Body Composition, and Blood Pressure at 7-Years Corrected Age: Follow-Up of a Randomized Controlled Trial

Aim: To determine if supplementation of infants born <33 weeks’ gestation with higher dose docosahexaenoic acid (DHA) affects growth, body composition, and blood pressure at 7 y corrected age (CA) and if treatment effects differed by infant sex at birth and birth weight strata (<1250 and ≥1250 g). Methods: Seven-year follow-up of an Australian multicenter randomized controlled trial in which 657 infants were fed high-DHA (≈1% total fatty acids) enteral feeds or standard-DHA (≈0.3% total fatty acids) from age 2−4 d until term CA. Seven-year CA outcomes were growth (weight, height), body composition (lean body mass, fat mass, waist, and hip circumference), and blood pressure. Results: There was no effect of high-DHA enteral feeds compared with standard-DHA on growth, body composition, and blood pressure at 7-year CA either overall or in subgroup analysis by sex. There was a significant interaction between high-DHA and birthweight strata on height at 7-y CA (p = 0.03). However, the post-hoc analyses by birthweight strata did not reach significance (p > 0.1). High-DHA group infants were more likely to be classified as obese (relative risk 1.6 (95% CI 1.0, 2.6); p = 0.05). Conclusions: DHA supplementation of premature infants did not affect growth, body composition, or blood pressure at 7-year CA overall by sex and birthweight strata. The finding of a higher risk of obesity in children who receive high-DHA needs to be interpreted with caution due to the small number of children classified as obese.

Associations of baseline use of fish oil with progression of cardiometabolic multimorbidity and mortality among patients with hypertension: a prospective study of UK Biobank

PURPOSE

The role of fish oil in the prognosis of hypertensive patients is unknown. This study investigated the associations of fish oil supplementation with the progression of cardiometabolic multimorbidity (CMM) and mortality among patients with hypertension.

METHODS

Based on UK Biobank, we enrolled participants with hypertension and free of other cardiometabolic diseases. The exposure was baseline use of fish oil derived from questionnaires at baseline. The primary outcomes were the incidence of CMM and all-cause mortality. Competing risk models and flexible parametric proportion-hazards models were fitted to assess the adjusted hazard ratios (HRs) for the risk of CMM and mortality outcomes, respectively.

RESULTS

Among 81,579 participants involved [50.37%, men; mean age, 59.38 years (standard deviation, 7.23 years)], 15,990 CMM events and 6456 all-cause deaths were reported (median follow-up, 12.23 years). In multivariable-adjusted models, baseline use of fish oil was associated with 8% lower risk of CMM [95% confidence interval (95% CI) 0.89-0.96, P < 0.001] and 10% lower risk of all-cause mortality (95% CI 0.85-0.95, P < 0.001).

CONCLUSION

In individuals with hypertension, baseline use of fish oil was associated with a reduced risk of CMM and all-cause mortality, and further clinical trials are needed to prove this hypothesis.

Big Fish or No Fish; Eicosapentaenoic Acid and Cardiovascular Disease

Benefits of omega 3 fatty acids for cardiovascular and other diseases have been touted for more than 50 years. The one clear clinical benefit of these lipids is the reduction of circulating levels of triglycerides, making them a useful approach for the prevention of pancreatitis in severely hypertriglyceridemic patients. After a series of spectacularly failed clinical trials that were criticized for the choice of subjects and doses of omega 3 fatty acids used, Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT) using a high dose of icosapent ethyl (IPE) reported a reduction in cardiovascular disease (CVD) events. However, this trial has generated controversy due to the use of mineral oil in the control group and the associated side effects of the IPA. This review will focus on the following topics: What are the epidemiologic data suggesting a benefit of omega 3 fatty acids? What might be the mechanisms for these benefits? Why have the clinical trials failed to resolve whether these fatty acids provide benefit? What choices should a clinician consider?

Omega-3 Polyunsaturated Fatty Acids Intake and Blood Pressure: A Dose-Response Meta-Analysis of Randomized Controlled Trials

Background Current evidence might support the use of omega-3 fatty acids (preferably docosahexaenoic acid and eicosapentaenoic acid) for lowering blood pressure (BP), but the strength and shape of the dose-response relationship remains unclear. Methods and Results This study included randomized controlled trials published before May 7, 2021, that involved participants aged ≥18 years, and examined an association between omega-3 fatty acids (docosahexaenoic acid, eicosapentaenoic acid, or both) and BP. A random-effects 1-stage cubic spline regression model was used to predict the average dose-response association between daily omega-3 fatty acid intake and changes in BP. We also conducted stratified analyses to examine differences by prespecified subgroups. Seventy-one trials were included, involving 4973 individuals with a combined docosahexaenoic acid+eicosapentaenoic acid dose of 2.8 g/d (interquartile range, 1.3 g/d to 3.6 g/d). A nonlinear association was found overall or in most subgroups, depicted as J-shaped dose-response curves. The optimal intake in both systolic BP and diastolic BP reductions (mm Hg) were obtained by moderate doses between 2 g/d (systolic BP, -2.61 [95% CI, -3.57 to -1.65]; diastolic BP, -1.64 [95% CI, -2.29 to -0.99]) and 3 g/d (systolic BP, -2.61 [95% CI, -3.52 to -1.69]; diastolic BP, -1.80 [95% CI, -2.38 to -1.23]). Subgroup studies revealed stronger and approximately linear dose-response relations among hypertensive, hyperlipidemic, and older populations. Conclusions This dose-response meta-analysis demonstrates that the optimal combined intake of omega-3 fatty acids for BP lowering is likely between 2 g/d and 3 g/d. Doses of omega-3 fatty acid intake above the recommended 3 g/d may be associated with additional benefits in lowering BP among groups at high risk for cardiovascular diseases.

The effects of sesame, canola, and sesame-canola oils on cardiometabolic markers in patients with type 2 diabetes: a triple-blind three-way randomized crossover clinical trial

AIMS

To compare the effects of replacing regular dietary oils intake with sesame (SO), canola (CO), and sesame-canola (SCO) oils (a novel blend), on cardiometabolic markers in adults with type 2 diabetes mellitus (T2DM), in a triple-blind, three-way, randomized, crossover clinical trial.

METHODS

Participants were assigned to receive SO, CO, and SCO in three 9-week phases (4 weeks apart). Cardiometabolic makers (serum lipids, Apolipoprotein, cardiovascular risk scores, kidney markers, and blood pressure) were considered at the beginning and the end of intervention phases.

RESULTS

Ninety-two, ninety-five, and ninety-five participants completed the SO, SCO, and CO periods, respectively. After CO consumption, serum Apo A-1 concentrations were significantly higher compared with the SCO period in the whole population (p < 0.05). A considerable reduction in visceral adiposity index values was seen in the CO compared with the SO period in males (p < 0.05). Serum high-density lipoprotein concentration was also significantly higher after the SO intake compared with SCO in females (p < 0.05). The between-period analysis showed a substantial reduction in diastolic blood pressure in the SCO period compared with the CO and SO periods and lower systolic blood pressure after SCO versus CO intake in males (p < 0.05).

CONCLUSIONS

Canola oil might protect CVD through improving Apo A-1 levels in patients with T2DM (particularly in females) and visceral adiposity index in male patients. However, the blend oil might beneficially affect blood pressure in men. Future sex-specific studies might warrant the current findings.

REGISTRY OF CLINICAL TRIALS

This trial was registered in the Iranian Registry of Clinical Trials (IRCT, registration ID: IRCT2016091312571N6).

Hypertension and Dyslipidemia Combined Therapeutic Approaches

Treating blood pressure (BP) alone may provide only limited benefits while it is recommendable to manage the total cardiovascular risk. To date, several studies have shown that concomitant treatment of hypertension and dyslipidemia with non-pharmacological approaches and/or metabolically neutral antihypertensive drugs and statins produce a significantly greater reduction of the risk of developing cardiovascular disease. Thus, in this review article, we summarize the available evidence regarding non-pharmacological and pharmacological approaches with a favourable effect on both BP and lipids.

Atherogenic Index of Plasma and Its Association with Risk Factors of Coronary Artery Disease and Nutrient Intake in Korean Adult Men: The 2013-2014 KNHANES

Coronary artery disease (CAD) has been linked to one of the highest death rates globally. The atherogenic index of plasma (AIP) may be an important predictor of atherosclerosis and cardiovascular disease, superior to the standard atherosclerotic lipid profile. This study investigated the relationship between AIP and obesity indices, blood glucose, lipid profile, and nutrient intake status in Korean adult men. The study included 1292 males aged ≥19 years old who participated in the Korea National Health and Nutrition Examination Survey, 2013-2014. Participants were divided into four groups according to AIP quartiles, calculated as log (triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C)). Body mass index, waist circumference, fasting blood glucose, hemoglobin A1c, total cholesterol, TG, and low-density lipoprotein cholesterol levels increased as AIP levels increased, whereas HDL-C level declined. As the level of AIP increased, intake of saturated fatty acid, calcium, phosphorus, riboflavin, milk, and dairy product decreased significantly, and the contribution rate of milk and dairy products to fat intake decreased. AIP was linked to obesity indices, blood glucose, and blood lipid profile in Korean men, suggesting that it could predict CAD.

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.

Dietary Omega-3 Fatty Acid Intake and Mortality in CKD Population: A 1999-2014 NHANES Analysis

INTRODUCTION

High risk of early death, especially contributed to cardiovascular disease, exists in patients who have chronic kidney disease (CKD). And the burden of cardiovascular disease is able to be lightened by an increase in omega-3 polyunsaturated fatty acid (omega-3 PUFA). A diet high in omega-3 PUFA in the general population is protective, although it is inconclusive about its beneficial role in the CKD population.

METHODS

From the 1999 to 2014 National Health and Nutrition Examination Surveys (NHANES), we can collect 2,990 participants who suffered from CKD, who were classified into 4 groups: <0.86, 0.87-1.30, 1.31-1.92, and 1.93-9.65 g/day based on NHANES 24-h dietary recall questionnaire dietary omega-3 PUFA. Moreover, their mortality details were available to be obtained by linking NHANES to the National Death Index. The associations between dietary omega-3 PUFA and mortality were evaluated by constructing multivariable Cox proportional hazards models.

RESULTS

Over 8 years of a median follow-up, 864 deaths were recorded. The adjusted hazard ratios (95% confidence interval) for all-cause mortality of the diseased people with CKD in the 2nd (0.87-1.30 g/day), 3rd (0.87-1.30 g/day), and 4th (1.93-9.65 g/day) quartiles of dietary omega-3 PUFA were 0.94 (0.72, 1.23), 0.74 (0.54, 1.02), and 0.67 (0.48, 0.93), respectively, versus those with the lowest quartile of dietary omega-3 PUFA intake (<0.86 g/day) (p for trend = 0.011).

CONCLUSION

There may be a inverse relation of dietary omega-3 PUFA intake and all-cause mortality in patients with CKD. Therefore, an increase of dietary omega-3 PUFA may be encouraged to be used clinically in patients with CKD.

Exploring the effects of oily fish consumption on measures of acute and long-term stress in healthy 8-9-year-old children: the FiSK Junior randomised trial

Long-chain n-3 PUFA (n-3 LCPUFA) are known to reduce blood pressure (BP), heart rate and vagal tone, but potential stress-mitigating effects of n-3 LCPUFA are not well investigated. We explored the effects of oily fish consumption on long-term stress and the stress response in schoolchildren. Healthy 8-9-year-old children were randomised to receive about 300 g/week of oily fish or poultry for 12 weeks (199 randomised, 197 completing). At baseline and endpoint, we measured erythrocyte n-3 LCPUFA, hair cortisol and the response to a 1-min cold pressor test (CPT) on saliva cortisol, BP and continuous electrocardiogram recordings. Post-intervention hair cortisol did not differ between the groups, but sex-specificity was indicated (Psex × group = 0·074, boys: -0·9 (95 % CI -2·9, 1·0) ng/g, girls: 0·7 (95 % CI -0·2, 1·6) ng/g). Children in the fish group tended to be less prone to terminate CPT prematurely (OR 0·20 (95 % CI 0·02, 1·04)). Mean heart beat interval during CPT was 18·2 (95 % CI 0·3, 36·6) ms longer and high frequency power increased (159 (95 % CI 29, 289) ms2) in the fish v. poultry group. The cardiac autonomic response in the 10 min following CPT was characterised by a sympathetic peak followed by a parasympathetic peak, which was most pronounced in the fish group. This exploratory study does not support a strong effect of oily fish consumption on stress but indicates that oily fish consumption may increase vagal cardiac tone during the physiological response to CPT. These results warrant further investigation.

Biomarkers of high salt intake

High salt intake is associated with hypertension, which is a leading modifiable risk factor for cardiovascular disease (CVD) and chronic kidney disease (CKD). International Guidelines recommend a large reduction in the consumption of sodium to reduce blood pressure, organ damage, and mortality. In its early stages, the symptoms of CKD are generally not apparent. CKD proceeds in a "silent" manner, necessitating the need for urinary biomarkers to detect kidney damage at an early stage. Since traditional renal biomarkers, such as serum creatinine, are not sufficiently sensitive, difficulties are associated with detecting kidney damage induced by a high salt intake, particularly in normotensive individuals. Several new biomarkers for renal tubular damage, such as neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), vanin-1, liver-type fatty acid-binding protein (L-FABP), and monocyte chemotactic protein-1 (MCP-1), have recently been identified. However, few studies have investigated early biomarkers for CKD progression associated with a high salt diet. This chapter provides insights into novel biomarkers for CKD in normo- and hypertensive individuals with a high salt intake. Recent studies using spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) fed a high salt diet identified urinary vanin-1 and NGAL as early biomarkers for renal tubular damage in SHR and WKY, whereas urinary KIM-1 was a useful biomarker for salt-induced renal injury in SHR only. Clinical studies are needed to confirm these findings.

Health benefits of docosahexaenoic acid and its bioavailability: A review

Docosahexaenoic acid (DHA) is the predominant omega-3 long-chain polyunsaturated fatty acid found in human brain and eyes. There are a number of studies in the literature showing the health benefits of DHA. It is critical throughout all life stages from the need for fetal development, the prevention of preterm birth, and the prevention of cardiovascular disease to the improvements in the cognitive function and the eye health of adults and elderly. These benefits might be related to the modulation of gut microbiota by DHA. In addition, there are some discrepancies in the literature regarding certain health benefits of DHA, and this review is intended to explore and understand these discrepancies. Besides the variations in the DHA contents of different supplement sources, bioavailability is crucial for the efficacy of DHA supplements, which depends on several factors. For example, DHA in phospholipid and triglyceride forms are more readily to be absorbed by the body than that in ethyl ester form. In addition, dietary lipids in meals and emulsification of DHA oil can increase the bioavailability of DHA. Estrogens stimulated the biosynthesis of DHA, whereas testosterone stimulus induced a decrease in DHA. The roles of DHA through human lifespan, the sources, and its recommended daily intake in different countries are also discussed to provide a better understanding of the importance of this review.

Effect of essential fatty acid blend on circadian variations of ambulatory blood pressure in patients with essential hypertension and coronary artery disease risk markers

Flaxseed oil is an excellent source of alpha-linolenic acid ALA known for its antihypertensive action. Flaxseed oil is unstable and its dose is not achievable in our conventional diet hence blending of natural flaxseed oil with palm oil, containing high flavonoids may be a better strategy, to stabilize the blend and provide proper balance of essential fatty acids and potential antioxidant effects. Aim of this study was to access the effect of blended flaxseed oil on 24 h 7-day circadian variations of blood pressure in subjects with essential hypertension. Assessment of CHAT (circadian hyper amplitude tension) using ABPM is the best marker for cardiovascular function. We registered 50 subjects with CAD (Group 1) and 50 subjects with Essential hypertension HT (Group 2) and 52 control subjects with CAD/Hypertension. Group 1 and 2 participant was supplemented with blended flaxseed oil (BFO) (30 ml/day) for the period of 24 weeks, while control group administered available oils sunflower in identical containers, for a follow-up period of 24 weeks. Twenty four hour seven days continuous ambulatory blood pressure monitoring was done initially and after six months of BFO supplementation. There were significant changes noted in lipid profile along with Ambulatory blood pressure parameters like MESOR, ACROPHASE, Hyperbaric Indexes, and CHAT. Circadian hyper amplitude tension (CHAT) incidence decreased after BFO supplementation. Study results suggest that blended flaxseed oil administration can be a potent natural vegetarian antihypertensive supplement which helps in synchronization of cardiac rhythms, and can be used as a preventive treatment of hypertension and as effective vegetarian source of maintaining Omega 3 and omega 6 ratios of essential fatty acids in the body.

DHA 12-LOX-derived oxylipins regulate platelet activation and thrombus formation through a PKA-dependent signaling pathway

BACKGROUND

The effects of docosahexaenoic acid (DHA) on cardiovascular disease are controversial and a mechanistic understanding of how this omega-3 polyunsaturated fatty acid (ω-3 PUFA) regulates platelet reactivity and the subsequent risk of a thrombotic event is warranted. In platelets, DHA is oxidized by 12-lipoxygenase (12-LOX) producing the oxidized lipids (oxylipins) 11-HDHA and 14-HDHA. We hypothesized that 12-LOX DHA-oxylipins may be involved in the beneficial effects observed in dietary supplemental treatment with ω-3 PUFAs or DHA itself.

OBJECTIVES

To determine the effects of DHA, 11-HDHA, and 14-HDHA on platelet function and thrombus formation, and to elucidate the mechanism by which these ω-3 PUFAs regulate platelet activation.

METHODS AND RESULTS

DHA, 11-HDHA, and 14-HDHA attenuated collagen-induced human platelet aggregation, but only the oxylipins inhibited ⍺IIbβ3 activation and decreased ⍺-granule secretion. Furthermore, treatment of whole blood with DHA and its oxylipins impaired platelet adhesion and accumulation to a collagen-coated surface. Interestingly, thrombus formation was only diminished in mice treated with 11-HDHA or 14-HDHA, and mouse platelet activation was inhibited following acute treatment with these oxylipins or chronic treatment with DHA, suggesting that under physiologic conditions, the effects of DHA are mediated through its oxylipins. Finally, the protective mechanism of DHA oxylipins was shown to be mediated via activation of protein kinase A.

CONCLUSIONS

This study provides the first mechanistic evidence of how DHA and its 12-LOX oxylipins inhibit platelet activity and thrombus formation. These findings support the beneficial effects of DHA as therapeutic intervention in atherothrombotic diseases.

Can N-3 polyunsaturated fatty acids be considered a potential adjuvant therapy for COVID-19-associated cardiovascular complications?

Coronavirus disease 2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has currently led to a global pandemic with millions of confirmed and increasing cases around the world. The novel SARS-CoV-2 not only affects the lungs causing severe acute respiratory dysfunction but also leads to significant dysfunction in multiple organs and physiological systems including the cardiovascular system. A plethora of studies have shown the viral infection triggers an exaggerated immune response, hypercoagulation and oxidative stress, which contribute significantly to poor cardiovascular outcomes observed in COVID-19 patients. To date, there are no approved vaccines or therapies for COVID-19. Accordingly, cardiovascular protective and supportive therapies are urgent and necessary to the overall prognosis of COVID-19 patients. Accumulating literature has demonstrated the beneficial effects of n-3 polyunsaturated fatty acids (n-3 PUFA) toward the cardiovascular system, which include ameliorating uncontrolled inflammatory reactions, reduced oxidative stress and mitigating coagulopathy. Moreover, it has been demonstrated the n-3 PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are precursors to a group of potent bioactive lipid mediators, generated endogenously, which mediate many of the beneficial effects attributed to their parent compounds. Considering the favorable safety profile for n-3 PUFAs and their metabolites, it is reasonable to consider n-3 PUFAs as potential adjuvant therapies for the clinical management of COVID-19 patients. In this article, we provide an overview of the pathogenesis of cardiovascular complications secondary to COVID-19 and focus on the mechanisms that may contribute to the likely benefits of n-3 PUFAs and their metabolites.

Role of CaMKII in the regulation of fatty acids and lipid metabolism

BACKGROUND & AIMS

Previous studies have reported the beneficial roles of the activation of calmodulin-dependent protein kinase (CaMK)II to many cellular functions associated with human health. This review aims at discussing its activation by exercise as well as its roles in the regulation of unsaturated, saturated, omega 3 fatty acids, and lipid metabolism.

METHODS

A wide literature search was conducted using online database such as 'PubMed', 'Google Scholar', 'Researcher', 'Scopus' and the website of World Health Organization (WHO) as well as Control Disease and Prevention (CDC). The criteria for the search were mainly lipid and fatty acid metabolism, diabetes, and metabolic syndrome (MetS). A total of ninety-seven articles were included in the review.

RESULTS

Calmodulin-dependent protein kinase activation by exercise is helpful in controlling membrane lipids related with type 2 diabetes and obesity. CaMKII regulates many health beneficial cellular functions in individuals who exercise compared with those who do not exercise. Regulation of lipid metabolism and fatty acids are crucial in the improvement of metabolic syndrome.

CONCLUSIONS

Approaches that involve CaMKII could be a new avenue for designing novel and effective therapeutic modalities in the treatment or better management of metabolic diseases such as type 2 diabetes and obesity.

Cardiovascular Impact of Nutritional Supplementation With Omega-3 Fatty Acids: JACC Focus Seminar

Omega-3 polyunsaturated fatty acids (PUFAs) are a key component of a heart-healthy diet. For patients without clinical atherosclerotic cardiovascular disease, 2 or more servings of fatty fish per week is recommended to obtain adequate intake of omega-3 PUFAs. If this not possible, dietary supplementation with an appropriate fish oil may be reasonable. Supplementation with omega-3 PUFA capsules serves 2 distinct but overlapping roles: treatment of hypertriglyceridemia and prevention of cardiovascular events. Marine-derived omega-3 PUFAs reduce triglycerides and have pleiotropic effects including decreasing inflammation, improving plaque composition and stability, and altering cellular membranes. Clinical trial data have shown inconsistent results with omega-3 PUFAs improving cardiovascular outcomes. In this paper, the authors provide an overview of PUFAs and a summary of key clinical trial data. Recent trial data suggest the use of prescription eicosapentaenoic acid ethyl ester for atherosclerotic cardiovascular disease event reduction in selected populations.

Association of plasma polyunsaturated fatty acids with arterial blood pressure: A Mendelian randomization study

High polyunsaturated fatty acids (PUFAs) intake is recommended for primary and secondary prevention of cardiovascular disease (CVD). However, the association of PUFAs with blood pressure (BP) is still controversial. In the present study, two-sample Mendelian randomization (MR) analysis was performed to investigate the causal relationship of PUFAs with BP, including systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure (PP).Genetic instruments and summary statistics for two-sample MR analysis were obtained from 3 large-scale genome-wide association studies (GWASs). Eight single nucleotide polymorphisms (SNPs) significantly (P < 5 × 10-8) related to 6 PUFAs were used as instrumental variables. Conventional inverse-variance weighted method was adopted to evaluate the causality of PUFAs with BP; the Weighted Median, MR-egger, and Leave-one-out method were used for sensitivity analyses.As a result, there was no evidence of a causal association between all PUFAs and SBP. In addition, arachidonic acid (AA, β = -0.04, P < .001) and eicosapentaenoic acid (EPA, β = -0.47, P = .02) were negatively associated with DBP, while linoleic acid (LA, β = 0.03, P = .005) and α-linolenic acid (ALA, β = 3.83, P < .001) were positively associated with DBP. There was no evidence of a causal relationship between either docosapentaenoic acid (DPA) or docosahexaenoic acid (DHA) with DBP.In conclusion, a genetic predisposition to plasma polyunsaturated fatty acid (PUFA) had a divergent effect on DBP, independent of SBP. It suggested that it is helpful for lower DBP level to supplemental intake of AA and EPA or promote the conversion of LA and ALA to AA and EPA respectively, which need to be further validated with randomized controlled studies.

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.

Omega-3 polyunsaturated fatty acids focusing on eicosapentaenoic acid and docosahexaenoic acid in the prevention of cardiovascular diseases: a review of the state-of-the-art

INTRODUCTION

: An epidemiological study of Greenlandic Inuit suggested the importance of omega-3 polyunsaturated fatty acids (PUFAs) in preventing ischemic heart disease. After this landmark study, large-scale epidemiological studies have examined the benefits of omega-3 PUFAs in the prevention of cardiovascular diseases.

AREAS COVERED

: This article reviews studies on omega-3 PUFAs, and identifies issues relevant to cardiovascular risk.

EXPERT OPINION

: Recent studies have focused on the anti-inflammatory effects of omega-3 PUFAs and specialized pro-resolving mediators. High-purity eicosapentaenoic acid (EPA) ethyl ester and EPA/docosahexaenoic acid (DHA) preparations have been developed primarily for the treatment of hypertriglyceridemia. Various trials on the cardiovascular protective effects of omega-3 PUFAs have been reported, but the results have not been consistent. Some issues of the trials have been suggested, such as using low-dose omega-3 PUFAs and not including hypertriglyceridemia in subject selection criteria. REDUCE-IT study that used a high dose of high-purity EPA preparation showed a relative reduction in cardiovascular events, but, the STRENGTH study that used a high dose of EPA/DHA preparation did not support this benefit. This article reviews the roles of omega-3 PUFAs in cardiovascular diseases, including progress in understanding the molecular mechanisms and recent large-scale clinical trials.

A Whole-Diet Approach Affects Not Only Fasting but Also Postprandial Cardiometabolic Risk Markers in Overweight and Obese Adults: A Randomized Controlled Trial

BACKGROUND

Current dietary recommendations for cardiovascular disease (CVD) prevention focus more on dietary patterns than on single nutrients. However, randomized controlled trials using whole-diet approaches to study effects on both fasting and postprandial CVD risk markers are limited.

OBJECTIVE

This randomized parallel trial compared the effects of a healthy diet (HD) with those of a typical Western diet (WD) on fasting and postprandial CVD risk markers in overweight and obese adults.

METHODS

After a 2-wk run-in period, 40 men and women (50-70 y; BMI: 25-35 kg/m2) consumed the HD (high in fruit and vegetables, pulses, fibers, nuts, fatty fish, polyunsaturated fatty acids; low in salt and high-glycemic carbohydrates; n = 19) or the WD (less fruit, vegetables, and fibers; no nuts and fatty fish; and more saturated fatty acids and simple carbohydrates; n = 21) for 6 wk. Fasting and postprandial cardiometabolic risk markers were assessed as secondary outcome parameters during a 5-h mixed-meal challenge, and a per protocol analysis was performed using 1-factor ANCOVA or linear mixed models.

RESULTS

Differences in diet-induced changes are expressed relative to the HD group. Changes in fasting plasma total cholesterol (-0.57 ± 0.12 mmol/L, P < 0.001), LDL cholesterol (-0.41 ± 0.12 mmol/L, P < 0.01), apolipoprotein B100 (-0.09 ± 0.03 g/L, P < 0.01), and apolipoprotein A1 (-0.06 ± 0.03 g/L, P = 0.05) were significantly different between the diet groups. Changes in postprandial plasma triacylglycerol (diet × time, P < 0.001) and apolipoprotein B48 (P < 0.01) differed significantly between the groups with clear improvements on the HD, although fasting triacylglycerols (-0.24 ± 0.13 mmol/L, P = 0.06) and apolipoprotein B48 (1.04 ± 0.67 mg/L, P = 0.40) did not. Significant differences between the diets were also detected in fasting systolic (-6.9 ± 3.1 mmHg, P < 0.05) and 24-h systolic (-5.0 ± 1.7 mmHg, P < 0.01) and diastolic (-3.3 ± 1.1 mmHg, P < 0.01) blood pressure.

CONCLUSION

A whole-diet approach targeted multiple fasting and postprandial CVD risk markers in overweight and obese adults. In fact, the postprandial measurements provided important additional information to estimate CVD risk. This trial is registered at clinicaltrials.gov as NCT02519127.

Novel Approaches for Omega-3 Fatty Acid Therapeutics: Chronic Versus Acute Administration to Protect Heart, Brain, and Spinal Cord

This article reviews novel approaches for omega-3 fatty acid (FA) therapeutics and the linked molecular mechanisms in cardiovascular and central nervous system (CNS) diseases. In vitro and in vivo research studies indicate that omega-3 FAs affect synergic mechanisms that include modulation of cell membrane fluidity, regulation of intracellular signaling pathways, and production of bioactive mediators. We compare how chronic and acute treatments with omega-3 FAs differentially trigger pathways of protection in heart, brain, and spinal cord injuries. We also summarize recent omega-3 FA randomized clinical trials and meta-analyses and discuss possible reasons for controversial results, with suggestions on improving the study design for future clinical trials. Acute treatment with omega-3 FAs offers a novel approach for preserving cardiac and neurological functions, and the combinations of acute treatment with chronic administration of omega-3 FAs might represent an additional therapeutic strategy for ameliorating adverse cardiovascular and CNS outcomes.

Fish and omega-3 fatty acid consumption and risk of hypertension

BACKGROUND

Experimental studies suggest that omega-3 fatty acid have favorable effects on blood pressure (BP). However, data on the association of long-term dietary intake of omega-3 fatty acid or fish with risk of hypertension in healthy subjects are sparse. We examined whether fish or omega-3 fatty acid consumption was associated with incident hypertension in the Physicians' Health Study (PHS).

METHODS

In a prospective cohort study, we analyzed data on 12 279 PHS participants (mean age: 53.0 ± 8.7 years) free of hypertension at baseline. Fish and omega-3 fatty acid consumption were assessed from a baseline semiquantitative food-frequency questionnaire. Incident hypertension was ascertained via self-reports on annual follow-up questionnaires.

RESULTS

During a mean follow-up of 15.8 years, 6299 men (51.3%) developed hypertension. In a multivariable model controlling for established risk factors for hypertension, fish and omega-3 fatty acid consumption was not significantly associated with incident hypertension. The hazard ratio (95% CI) of hypertension was 1.10 (0.93-1.30) for men who consumed at least five servings per week of fish compared with those who did not consume any fish (P for trend = 0.29). For the highest versus lowest quintile of omega-3 fatty acid intake, the hazard ratio of hypertension was 1.02 (0.94-1.11) (P for trend = 0.34). The associations did not vary by type of fish. There was also no evidence of effect modification by baseline BP, BMI, or history of hypercholesterolemia.

CONCLUSION

Overall, long-term dietary intake of fish and omega-3 fatty acid was not associated with incident hypertension in a cohort of middle-aged and older US men.

Analysis of changes in cardiac circadian rhythms of RR and QT induced by a 60-day head-down bed rest with and without nutritional countermeasure

PURPOSE

Prolonged weightlessness exposure generates cardiovascular deconditioning, with potential implications on ECG circadian rhythms. Head-down (- 6°) tilt (HDT) bed rest is a ground-based analogue model for simulating the effects of reduced motor activity and fluids redistribution occurring during spaceflight. Our aim was to evaluate the impact of 60-day HDT on the circadianity of RR and ventricular repolarization (QTend) intervals extracted from 24-h Holter ECG recordings, scheduled 9 days before HDT (BDC-9), the 5th (HDT5), 21st (HDT21) and 58th (HDT58) day of HDT, the 1st (R + 0) and 8th (R + 7) day after HDT. Also, the effectiveness of a nutritional countermeasure (CM) in mitigating the HDT-related changes was tested.

METHODS

RR and QTend circadian rhythms were evaluated by Cosinor analysis, resulting in maximum and minimum values, MESOR (a rhythm-adjusted mean), oscillation amplitude (OA, half variation within a night-day cycle), and acrophase (φ, the time at which the fitting sinusoid's amplitude is maximal) values.

RESULTS

RR and QTend MESOR increased at HDT5, and the OA was reduced along the HDT period, mainly due to the increase of the minima. At R + 0, QTend OA increased, particularly in the control group. The φ slightly anticipated during HDT and was delayed at R + 0.

CONCLUSION

60-Day HDT affects the characteristics of cardiac circadian rhythm by altering the physiological daily cycle of RR and QTend intervals. Scheduled day-night cycle and feeding time were maintained during the experiment, thus inferring the role of changes in the gravitational stimulus to determine these variations. The applied nutritional countermeasure did not show effectiveness in preventing such changes.

Lipids and Lipid Mediators Associated with the Risk and Pathology of Ischemic Stroke

Stroke is a severe neurological disorder in humans that results from an interruption of the blood supply to the brain. Worldwide, stoke affects over 100 million people each year and is the second largest contributor to disability. Dyslipidemia is a modifiable risk factor for stroke that is associated with an increased risk of the disease. Traditional and non-traditional lipid measures are proposed as biomarkers for the better detection of subclinical disease. In the central nervous system, lipids and lipid mediators are essential to sustain the normal brain tissue structure and function. Pathways leading to post-stroke brain deterioration include the metabolism of polyunsaturated fatty acids. A variety of lipid mediators are generated from fatty acids and these molecules may have either neuroprotective or neurodegenerative effects on the post-stroke brain tissue; therefore, they largely contribute to the outcome and recovery from stroke. In this review, we provide an overview of serum lipids associated with the risk of ischemic stroke. We also discuss the role of lipid mediators, with particular emphasis on eicosanoids, in the pathology of ischemic stroke. Finally, we summarize the latest research on potential targets in lipid metabolic pathways for ischemic stroke treatment and on the development of new stroke risk biomarkers for use in clinical practice.

Associations of habitual fish oil supplementation with cardiovascular outcomes and all cause mortality: evidence from a large population based cohort study

OBJECTIVES

To evaluate the associations of habitual fish oil supplementation with cardiovascular disease (CVD) and mortality in a large prospective cohort.

DESIGN

Population based, prospective cohort study.

SETTING

UK Biobank.

PARTICIPANTS

A total of 427 678 men and women aged between 40 and 69 who had no CVD or cancer at baseline were enrolled between 2006 and 2010 and followed up to the end of 2018.

MAIN EXPOSURE

All participants answered questions on the habitual use of supplements, including fish oil.

MAIN OUTCOME MEASURES

All cause mortality, CVD mortality, and CVD events.

RESULTS

At baseline, 133 438 (31.2%) of the 427 678 participants reported habitual use of fish oil supplements. The multivariable adjusted hazard ratios for habitual users of fish oil versus non-users were 0.87 (95% confidence interval 0.83 to 0.90) for all cause mortality, 0.84 (0.78 to 0.91) for CVD mortality, and 0.93 (0.90 to 0.96) for incident CVD events. For CVD events, the association seemed to be stronger among those with prevalent hypertension (P for interaction=0.005).

CONCLUSIONS

Habitual use of fish oil seems to be associated with a lower risk of all cause and CVD mortality and to provide a marginal benefit against CVD events among the general population.

Prevention of Cardiovascular Events with Omega-3 Polyunsaturated Fatty Acids and the Mechanism Involved

An epidemiological study of Greenlandic Inuit suggested that fish oil, or omega-3 polyunsaturated fatty acids (PUFA), was important in preventing atherosclerotic disease. After this landmark study, many large-scale epidemiological studies and meta-analyses have examined the health benefits of omega-3 PUFA as part of a fatty acid-rich diet to demonstrate its beneficial roles in the prevention of cardiovascular diseases. Recent research has also focused attention on the anti-inflammatory effects of omega-3 PUFA and on specialized pro-resolving mediators. Findings of these studies have led to the development of omega-3 PUFA preparations for the treatment of dyslipidemia, including a highly purified eicosapentaenoic acid (EPA)-ethyl ester product (Epadel®) in Japan and an EPA/docosahexaenoic acid (DHA) preparation (Lotriga®) in the United States and Europe. Although various large-scale clinical trials on the cardiovascular preventive effect of omega-3 PUFA were conducted and reported, the results were not always consistent. The issues of not targeting subjects with hypertriglyceridemia and using low dose of omega-3 PUFA have been suggested to contribute to the failure of demonstrating the preventive effect of omega-3 PUFA in these clinical trials. Taking into account the above issues, the REDUCE-IT trial evaluated a highly purified EPA preparation at a high dose of 4 g/day in patients with hypertriglyceridemia and high cardiovascular risk, and demonstrated an extraordinary outcome of 25% relative reduction in cardiovascular events. This article reviews studies on omega-3 fatty acids during the last 50 years, including the progress in elucidating molecular mechanisms and recent large-scale clinical studies.

Habitual Fish Consumption, n-3 Fatty Acids, and Nuclear Magnetic Resonance Lipoprotein Subfractions in Women

Background

Supplementation with omega‐3 (n‐3) fatty acid or dietary fish may protect against atherosclerosis, but the potential mechanisms are unclear. Prior studies found modest triglyceride‐lowering effects and slight increases in LDL (low‐density lipoprotein) cholesterol. Limited evidence has examined n‐3 effects on more detailed lipoprotein biomarkers.

Methods and Results

We conducted a study of 26 034 healthy women who reported information on fish and n‐3 intake from a 131‐item food‐frequency questionnaire. We measured plasma lipids, apolipoproteins, and nuclear magnetic resonance spectroscopy lipoproteins and examined their associations with dietary intake of fish, total n‐3, and the n‐3 subtypes (eicosapentaenoic, docosahexaenoic, and α‐linolenic acids). Top‐ versus bottom‐quintile intake of fish and n‐3 were significantly associated with lower triglyceride and large VLDL (very‐low‐density lipoprotein) particles. Fish intake, but not total n‐3, was positively associated with total cholesterol, LDL cholesterol, apolipoprotein B, and larger LDL size, but only α‐linolenic acid was associated with lower LDL cholesterol. Total n‐3, docosahexaenoic acid, and α‐linolenic acid intake were also positively associated with larger HDL (high‐density lipoprotein) size and large HDL particles. High eicosapentaenoic acid intake was significantly associated with only a decreased level of VLDL particle concentration and VLDL triglyceride content. The n‐3 fatty acids had some similarities but also differed in their associations with prospective cardiovascular disease risk patterns.

Conclusions

Higher consumption of fish and n‐3 fatty acids were associated with multiple measures of lipoproteins that were mostly consistent with cardiovascular prevention, with differences noted for high intake of eicosapentaenoic acid versus docosahexaenoic acid and α‐linolenic acid that were apparent with more detailed lipoprotein phenotyping. These hypothesis‐generating findings warrant further study in clinical trials.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000479.

Low-Dose Omega-3 Fatty Acid and Vitamin D for Anthropometric, Biochemical Blood Indices and Respiratory Function. Does it work?

Abstract. Omega-3 fatty acids and vitamin D3 have beneficial effects on different blood, cardiovascular parameters and physical performance. However, the effect of low-dose omega-3 fatty acid supplementation remains unclear. 84 office workers aged 40–60 years, participated in a 16-week open, randomized, placebo-controlled, parallel-group study. The experimental group received 330 mg of omega-3 fatty acid and 0.005 mg (200 IU) of vitamin D3 per day and the control group received placebo. Anthropometric, biochemical blood and respiratory indices were measured at 12 and 16 weeks. Body mass (BM) and body mass index (BMI) significantly reduced in both the experimental (BM from 74.4 ± 13.04 to 73.2 ± 13.02 kg, p < 0.001; BMI from 25.8 ± 4.1 to 25.4 ± 4.3 kg/m2, p < 0.001) and the placebo groups (BM from 69.5 ± 11. to 68.7 ± 11.4 kg, p < 0.05; BMI from 24.1 ± 4.0 to 23.8 ± 4.2 kg/m2, p < 0.05). Omega-3 fatty acid supplementation significantly improved glucose (from 5.12 ± 0.55 to 4.97 ± 0.62 mmol/l; p = 0.05), total cholesterol (from 5.86 ± 1.0 to 5.32 ± 1.55 mmol/l; p = 0.003), and vitamin D levels (from 35.07 ± 21.65 to 68.63 ± 25.94 nmol/l; p = 0.000). Maximal oxygen consumption (from 33.7 ± 2.4 to 36.6 ± 3.2 ml/kg/min, p = 0.035), forced vital capacity (from 3.5 ± 0.6 to 3.9 ± 0.9 l, p = 0.044), forced expiratory volume (from 3.2 ± 0.6 to 3.5 ± 0.7 l, p = 0.014), and peak expiratory flow (from 6.7 ± 1.4 to 7.5 ± 1.6 l/s, p = 0.019) also slightly improved in the omega-3 fatty acid group. Daily supplementation of 330 mg of omega-3 fatty acids had a slight positive impact on total cholesterol and glucose level, while there was no effect on low and high density lipoproteins, and triglycerides levels. Therefore, dose of 330 mg per day seems as insufficient.

Metabolic disparities of different oxidative stress‑inducing conditions in HTR8/SVneo cells

Placental oxidative stress is present throughout the duration of pregnancy, but it is when oxidative stress exceeds the normal physiological level that complications can occur. Trophoblast cell lines are commonly utilized for oxidative stress research due to their distinct uniform cell population and easy-to-apply interventions. However, conflicting results are often reported when different oxidative stress cell models are used. In this study, the aim was to characterize the intracellular and extracellular metabolite profiles of different oxidative stress cell models commonly used in the research of pregnancy complications. HTR8/SVneo human trophoblast cell lines were treated with five different oxidative stress-inducing conditions: Hypoxia (1% oxygen); hypoxia and reoxygenation; cobalt chloride (CoCl₂; 300 µmol/l); sodium nitroprusside (SNP; 2.5 mmol/l); and the serum of women with preeclampsia (10% v/v). Intracellular metabolites were extracted from cells and extracellular metabolites were collected from spent media for metabolomic analysis via gas chromatography-mass spectrometry. The results demonstrated that there were distinct differences in the intracellular and extracellular metabolome between the different cell models. Meanwhile, treatments with exogenous drugs, such as CoCl₂ and SNP, resulted in more similar metabolite profiles. These disparities between the different oxidative stress cell models will have implications for the applications of these results, and highlight the need for the standardization of oxidative stress cell models in obstetric research.

A Dietary Pattern Derived from Reduced Rank Regression and Fatty Acid Biomarkers Is Associated with Lower Risk of Type 2 Diabetes and Coronary Artery Disease in Chinese Adults

BACKGROUND

Combinations of circulating fatty acids may affect the risk of type 2 diabetes (T2D) and coronary artery disease (CAD). No previous studies have identified a dietary pattern predicting fatty acid profiles using reduced rank regression (RRR) and evaluated its associations with the risk of T2D and CAD.

OBJECTIVE

The aim of this study was to derive a dietary pattern to explain variation in plasma fatty acid concentrations using RRR and evaluate these in relation to risk of T2D and CAD.

METHODS

We derived a dietary pattern using fatty acid concentrations from 711 controls of a nested case-control study in the Singapore Chinese Health Study using RRR with 36 food and beverages as predictors and 19 fatty acid biomarkers as responses. Dietary pattern scores were then calculated for the full cohort of men and women (mean age: 56 y). We followed up 45,411 and 58,065 participants for incident T2D and CAD mortality, respectively. Multivariable Cox regression models were used to estimate HRs and 95% CIs.

RESULTS

We identified a dietary pattern high in soy, vegetables, fruits, tea, tomato products, bread, fish, margarine and dairy, and low in rice, red meat, coffee, alcohol, sugar-sweetened beverages, and eggs. This pattern predicted higher circulating n-3 (ω-3) PUFAs (18:3n-3, 20:3n-3, 20:5n-3), odd-chain fatty acids (15:0, 17:0), 18:2n-6 and 20:1, and lower 20:4n-6 and 16:1. During a mean follow-up of 11 y and 19 y, 5207 T2D and 3016 CAD mortality events, respectively, were identified. Higher dietary pattern scores were associated with a lower risk of T2D [multivariable-adjusted HR comparing extreme quintiles, 0.86 (95% CI: 0.79, 0.95); P-trend <0.001] and CAD mortality [HR, 0.76 (95% CI: 0.68, 0.86); P-trend <0.001].

CONCLUSIONS

Dietary patterns reflecting higher circulating n-3 PUFAs, odd-chain fatty acids, and linoleic acid may be associated with lower T2D and CAD risk in Chinese adults. This trial was registered at www.clinicaltrials.gov as NCT03356340.

Addition of marine omega-3 fatty acids to statins in familial hypercholesterolemia does not affect in vivo or in vitro endothelial function

BACKGROUND

Prestatin trials reported positive effects of omega-3 polyunsaturated fatty acids (n-3 PUFA) in cardiovascular disease, whereas recent studies and meta-analyses have not reproduced these results. The effect of n-3 PUFA in patients with familial hypercholesterolemia (FH), a group with particularly high risk of cardiovascular disease, is not well established.

OBJECTIVE

We investigated the effect of n-3 PUFA in the early stage of atherosclerosis in FH patients by evaluating in vivo (peripheral arterial tonometry [PAT]) and in vitro (plasma asymmetric dimethylarginine and E-selectin) endothelial function.

METHODS

This was a double-blind, placebo-controlled cross-over study with 34 FH patients on statin treatment (mean age 46.6 years). In random order, all individuals were treated for 3 months with high-dose n-3 PUFA (2 g, ×2) and 3 months placebo (olive oil, 2 g ×2), separated by a 3-month washout period. Anthropometric data, blood samples, and PAT were collected at 4 time points.

RESULTS

There were no significant changes in reactive hyperemia index measured by PAT after n-3 PUFA compared with placebo, median reactive hyperemia index after n-3 PUFA was 1.98 and after placebo 1.96 (P = .51). No significant changes were detected in the soluble endothelial marker asymmetric dimethylarginine (in 2 different assays) when comparing n-3 PUFA and placebo (P = .92 and .14, respectively). Finally, the level of E-selectin did not change significantly during the trial (P = .26).

CONCLUSION

Addition of n-3 PUFA to standard lipid-lowering treatment in genetically verified FH patients did not affect the in vivo endothelial function or soluble endothelial markers.

Marine-Derived Omega-3 Polyunsaturated Fatty Acids and Heart Failure: Current Understanding for Basic to Clinical Relevance

Heart failure (HF) is a rapidly growing global public health problem. Since HF results in high mortality and re-hospitalization, new effective treatments are desired. Although it remains controversial, omega 3 polyunsaturated fatty acids (n-3 PUFAs), such as the eicosapentaenoic acid and docosahexaenoic acid, have been widely recognized to have benefits for HF. In a large-scale clinical trial regarding secondary prevention of HF by n-3 PUFA (GISSI-HF trial), the supplementation of n-3 PUFA significantly reduced cardiovascular mortality and hospitalization. Other small clinical studies proposed that n-3 PUFA potentially suppresses the ventricular remodeling and myocardial fibrosis, which thereby improves the ventricular systolic and diastolic function both in ischemic and non-ischemic HF. Basic investigations have further supported our understanding regarding the cardioprotective mechanisms of n-3 PUFA against HF. In these reports, n-3 PUFA has protected hearts through (1) anti-inflammatory effects, (2) intervention of cardiac energy metabolism, (3) modification of cardiac ion channels, (4) improvement of vascular endothelial response, and (5) modulation of autonomic nervous system activity. To clarify the pros and cons of n-3 PUFA on HF, we summarized recent evidence regarding the beneficial effects of n-3 PUFA on HF both from the clinical and basic studies.

Can Yellow Stripe Scad Compete with Salmon on Its Role in Platelet Phospholipid Membrane and Its Cardiovascular Benefits?

This review article stresses the effective role of dietary fish fillet docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on overweight as a risk factor of cardiovascular disease (CVD) via platelet phospholipid modification. Several reports have demonstrated that saturated fat in overweight evokes systemic inflammation and more importantly predisposes it to cardiovascular disorder. Prospective studies have shown that saturated fat is directly proportional to the level of arachidonic acids (AA), precursor of thromboxane in the platelet phospholipid membrane as omega-6 fatty acid in overweight and obese people. Some literature has demonstrated that omega-3 fatty acid from fish fillet ameliorates inflammation, reduces proinflammatory cytokine, inhibits signaling pathway, and regulates the physical composition of inflammatory leukocytes and free radicals (ROS). Yellow stripe scad (YSS) is a local Malaysian fish that has been shown to contain a comparable level of EPA/DHA content as observed in salmon. This review article will focus on the dietary role of fish fillet that will balance the omega-6 fatty acid/omega-3 fatty acid ratio in platelet phospholipid from YSS to manage and prevent healthy overweight/obesity-related risk factor of CVD and to avoid the risk orthodox drug treatment.

Rounding the corner on residual risk: Implications of REDUCE-IT for omega-3 polyunsaturated fatty acids treatment in secondary prevention of atherosclerotic cardiovascular disease

Patients with established atherosclerotic cardiovascular (CV) disease remain at increased risk of major adverse cardiovascular events even during optimal lipid-lowering therapy. Recent studies using the methods of Mendelian randomization, as well as analyses of data from large statin trials, have concluded that elevated triglyceride (TG) levels contribute to that increased risk. Omega-3 polyunsaturated fatty acids (omega-3 PUFAs) from fish and shellfish (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) reduce TG levels when added to the diet in sufficient amounts, and they have favorable effects on several other markers of CV risk. However, trials of omega-3 PUFAs have had inconsistent findings regarding CV risk reduction. Recently, the REDUCE-IT (Reduction of Cardiovascular Events with EPA-Intervention Trial) trial reported that treatment of such high-risk patients with icosapent ethyl, a purified and stabilized ethyl ester of EPA, reduced the risk of the trial's primary CV endpoint by 25% (95% confidence intervals [CI], 32%-17%; P < .001). To appreciate the clinical implications of this result, it is important to understand how the REDUCE-IT trial differed from previous trials, especially with regard to patient enrollment criteria and treatment dosing. We discuss these design features relative to other trials. TG lowering can account for only part of the risk reduction seen with icosapent ethyl; we also consider other potential contributory mechanisms.

Deficiency or activation of peroxisome proliferator-activated receptor α reduces the tissue concentrations of endogenously synthesized docosahexaenoic acid in C57BL/6J mice

BACKGROUND/OBJECTIVES

Docosahexaenoic acid (DHA), an n-3 long chain polyunsaturated fatty acid (LCPUFA), is acquired by dietary intake or the in vivo conversion of α-linolenic acid. Many enzymes participating in LCPUFA synthesis are regulated by peroxisome proliferator-activated receptor alpha (PPARα). Therefore, it was hypothesized that the tissue accretion of endogenously synthesized DHA could be modified by PPARα.

MATERIALS/METHODS

The tissue DHA concentrations and mRNA levels of genes participating in DHA biosynthesis were compared among PPARα homozygous (KO), heterozygous (HZ), and wild type (WT) mice (Exp I), and between WT mice treated with clofibrate (PPARα agonist) or those not treated (Exp II). In ExpII, the expression levels of the proteins associated with DHA function in the brain cortex and retina were also measured. An n3-PUFA depleted/replenished regimen was applied to mitigate the confounding effects of maternal DHA.

RESULTS

PPARα ablation reduced the hepatic Acox, Fads1, and Fads2 mRNA levels, as well as the DHA concentration in the liver, but not in the brain cortex. In contrast, PPARα activation increased hepatic Acox, Fads1, Fads2 and Elovl5 mRNA levels, but reduced the DHA concentrations in the liver, retina, and phospholipid of brain cortex, and decreased mRNA and protein levels of the brain-derived neurotrophic factor in brain cortex.

CONCLUSIONS

LCPUFA enzyme expression was altered by PPARα. Either PPARα deficiency or activation-decreased tissue DHA concentration is a stimulus for further studies to determine the functional significance.

Fish, Shellfish, and Children's Health: An Assessment of Benefits, Risks, and Sustainability

American children eat relatively little fish and shellfish in comparison with other sources of animal protein, despite the health benefits that eating fish and shellfish may confer. At the same time, fish and shellfish may be sources of toxicants. This report serves to inform pediatricians about available research that elucidates health risks and benefits associated with fish and shellfish consumption in childhood as well as the sustainability of fish and shellfish harvests.

Associations of medium and long chain omega-3 polyunsaturated fatty acids with blood pressure in Hispanic and non-Hispanic smokers and nonsmokers

Epidemiology studies and clinical trials have shown that omega-3 polyunsaturated fatty acids (n-3 PUFAs) are inversely associated with blood pressure. We sought to determine the influence of cigarette smoking and Hispanic ethnicity on this association. Age- and sex-matched smokers and nonsmokers (n = 98) 19-50 years old lacking cardiovascular disease were recruited. Systolic and diastolic blood pressure (SBP, DBP), heart rate, HbA1c, lipids, BMI, and RBC fatty acids were measured. The omega-3 index (percent eicosapentaenoic and docosahexaenoic acid, EPA+DHA, in RBCs) was significantly lower in smokers (Smokers: 3.19 ± 0.86%; Nonsmokers, 3.88 ± 1.05%, p = 0.001) and Hispanics (Hispanic 3.32 ± 0.93%; Non-Hispanic, 3.82 ± 1.03%, p = 0.006). DHA exhibited a significant inverse association with BP in both smokers and nonsmokers, while alpha-linolenic acid (ALA) exhibited a significant positive association with BP only in smokers. Multiple regression analyses showed that BMI, DHA, smoking status, and smoking status*ALA interaction significantly predicted SBP (p < 0.0001, R2 = 0.44) and DBP (p < 0.0001, R2 = 0.33), while ethnicity had no effect. The observed lower BP when DHA levels are high suggests a possible protective role of DHA on BP in normotensive smokers and nonsmokers. Additionally, the observed higher BP when ALA levels are high only in smokers suggests that ALA may influence the BP-lowering effects of chronic smoking.

Differences in peripheral blood mononuclear cell gene expression and triglyceride composition in lipoprotein subclasses in plasma triglyceride responders and non-responders to omega-3 supplementation

Background

Intake of the marine omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) reduces fasting triglyceride (TG) levels and may thereby lower cardiovascular disease risk. However, there are large inter-individual differences in the TG-lowering effect of omega-3 supplementation. Genotype differences partly explain this variation, but gene-environment interactions leading to gene expression differences may also be important. In this study, we aimed to investigate baseline differences and differences in the change in peripheral blood mononuclear cell (PBMC) gene expression and lipoprotein subclass TG levels between TG responders and non-responders to omega-3 fatty acid supplementation.

Methods

In a previous randomized controlled trial, healthy normotriglyceridemic subjects (n = 35, 71% women) received 1.6 g EPA + DHA/day for 7 weeks. In this exploratory sub-study, we defined TG responders as subjects having a TG reduction beyond the 20% day-to-day variation and non-responders as having a TG change between − 20% and + 20% after omega-3 supplementation. PBMC gene expression was measured using microarray, and lipoprotein subclasses were measured using nuclear magnetic resonance spectroscopy.

Results

Eight subjects were defined as responders with a median TG reduction of 37%, and 16 subjects were defined as non-responders with a median TG change of 0%. At baseline, responders had higher TG levels in two of four high-density lipoprotein (HDL) subclasses and 909 gene transcripts (p ≤ 0.05) were differentially expressed compared to non-responders. During the intervention, the plasma TG reduction among responders was reflected in TG reductions in four of six different very low-density lipoprotein subclasses and three of four different HDL subclasses. Compared to non-responders, the expression of 454 transcripts was differentially altered in responders (p ≤ 0.05). Pathway analyses revealed that responders had altered signaling pathways related to development and immune function. In addition, two of the top 10 enriched pathways in responders compared to non-responders were related to lysophosphatidic acid signaling.

Conclusion

TG responders and non-responders to omega-3 supplementation have different lipoprotein subclass and PBMC gene expression profiles at baseline and different lipoprotein subclass and PBMC gene expression responses to omega-3 supplementation. These gene expression differences may partially explain the variability in TG response observed after omega-3 supplementation.

Graphical abstract

Based on free images from Servier Medical Art (Creative Commons Attribution License) and image from www.colourbox.com.

Electronic supplementary material

The online version of this article (10.1186/s12263-019-0633-y) contains supplementary material, which is available to authorized users.

Docosahexaenoic acid reduces resting blood pressure but increases muscle sympathetic outflow compared with eicosapentaenoic acid in healthy men and women

Supplementation with monounsaturated or ω-3 polyunsaturated fatty acids ( n-3 PUFA) can lower resting blood pressure (BP) and reduce the risk of cardiovascular events. The independent contributions of the n-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on BP, and the mechanisms responsible, are unclear. We tested whether EPA, DHA, and olive oil (OO), a source of monounsaturated fat, differentially affect resting hemodynamics and muscle sympathetic nerve activity (MSNA). Eighty-six healthy young men and women were recruited to participate in a 12-wk, randomized, double-blind trial examining the effects of orally supplementing ~3 g/day of EPA ( n = 28), DHA ( n = 28), or OO ( n = 30) on resting hemodynamics; MSNA was examined in a subset of participants ( n = 31). Both EPA and DHA supplements increased the ω-3 index ( P < 0.01). Reductions in systolic BP were greater [adjusted intergroup mean difference (95% confidence interval)] after DHA [−3.4 mmHg (−0.9, −5.9), P = 0.008] and OO [−3.0 mmHg (−0.5, −5.4), P = 0.01] compared with EPA, with no difference between DHA and OO ( P = 0.74). Reductions in diastolic BP were greater following DHA [−3.4 mmHg (−1.3,−5.6), P = 0.002] and OO [−2.2 mmHg (0.08,−4.3), P = 0.04] compared with EPA. EPA increased heart rate compared with DHA [4.2 beats/min (−0.009, 8.4), P = 0.05] and OO [4.2 beats/min, (0.08, 8.3), P = 0.04]. MSNA burst frequency was higher after DHA [4 bursts/min (0.5, 8.3), P = 0.02] but not OO [−3 bursts/min (−6, 0.6), P = 0.2] compared with EPA. Overall, DHA and OO evoked similar responses in resting BP; however, DHA, but not OO, increased peripheral vasoconstrictor outflow. These findings may have implications for fatty acid supplementation in clinical populations characterized by chronic high BP and sympathetic overactivation.

NEW & NOTEWORTHY We studied the effects of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and olive oil supplementation on blood pressure (BP) and muscle sympathetic nerve activity (MSNA). After 12 wk of 3 g/day supplementation, DHA and olive oil were associated with lower resting systolic and diastolic BPs than EPA. However, DHA increased MSNA compared with EPA. The reductions in BP with DHA likely occur via a vascular mechanism and evoke a baroreflex-mediated increase in sympathetic activity.