Effects of a convenience drink fortified with n-3 fatty acids on the n-3 index

Effect of six month's treatment with omega-3 acid ethyl esters on long-term outcomes after acute myocardial infarction: The OMEGA-REMODEL randomized clinical trial

BACKGROUND

Omega-3 polyunsaturated fatty acids (O3-FA) have been shown to reduce inflammation and adverse cardiac remodeling after acute myocardial infarction (AMI). However, the impact of O3-FA on long-term clinical outcomes remains uncertain.

AIMS

To investigate the impact of O3-FA on adverse cardiac events in long-term follow up post AMI in a pilot-study.

METHODS

Consecutive patients with AMI were randomized 1:1 to receive 6 months of O3-FA (4 g/daily) or placebo in the prospective, multicenter OMEGA-REMODEL trial. Primary endpoint was a composite of major adverse cardiovascular events (MACE) encompassing all-cause death, heart failure hospitalizations, recurrent acute coronary syndrome, and late coronary artery bypass graft (CABG).

RESULTS

A total of 358 patients (62.8% male; 48.1 ± 16.1 years) were followed for a median of 6.6 (IQR: 5.0-9.1) years. Among those receiving O3-FA (n = 180), MACE occurred in 65 (36.1%) compared to 62 (34.8%) of 178 assigned to placebo. By intention-to-treat analysis, O3-FA treatment assignment did not reduce MACE (HR = 1.014; 95%CI = 0.716-1.436; p = 0.938), or its individual components. However, patients with a positive response to O3-FA treatment (n = 43), defined as an increase in the red blood cell omega-3 index (O3I) ≥5% after 6 months of treatment, had lower annualized MACE rates compared to those without (2.9% (95%CI = 1.2-5.1) vs 7.1% (95%CI = 5.7-8.9); p = 0.001). This treatment benefit persisted after adjustment for baseline characteristics (HRadjusted = 0.460; 95%CI = 0.218-0.970; p = 0.041).

CONCLUSION

In long-term follow-up of the OMEGA-REMODEL randomized trial, O3-FA did not reduce MACE after AMI by intention to treat principle, however, patients who achieved a ≥ 5% increase of O3I subsequent to treatment had favorable outcomes.

Omega-3 Fatty Acids and Markers of Thrombosis in Patients with Atrial Fibrillation

Omega-3 fatty acids (n-3 FAs) are associated with a lower risk of ischemic stroke in patients with atrial fibrillation (AF). Antithrombotic mechanisms may in part explain this observation. Therefore, we examined the association of n-3 FAs with D-dimer and beta-thromboglobulin (BTG), markers for activated coagulation and platelets, respectively. The n-3 FAs eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), docosapentaenoic acid (DPA) and alpha-linolenic acid (ALA) were determined via gas chromatography in the whole blood of 2373 patients with AF from the Swiss Atrial Fibrillation cohort study (ClinicalTrials.gov Identifier: NCT02105844). In a cross-sectional analysis, we examined the association of total n-3 FAs (EPA + DHA + DPA + ALA) and the association of individual fatty acids with D-dimer in patients with detectable D-dimer values (n = 1096) as well as with BTG (n = 2371) using multiple linear regression models adjusted for confounders. Median D-dimer and BTG levels were 0.340 ug/mL and 448 ng/mL, respectively. Higher total n-3 FAs correlated with lower D-dimer levels (coefficient 0.94, 95% confidence interval (Cl) 0.90-0.98, p = 0.004) and lower BTG levels (coefficient 0.97, Cl 0.95-0.99, p = 0.003). Likewise, the individual n-3 FAs EPA, DHA, DPA and ALA showed an inverse association with D-dimer. Higher levels of DHA, DPA and ALA correlated with lower BTG levels, whereas EPA showed a positive association with BTG. In patients with AF, higher levels of n-3 FAs were associated with lower levels of D-dimer and BTG, markers for activated coagulation and platelets, respectively. These findings suggest that n-3 FAs may exert antithrombotic properties in patients with AF.

Dietary Intake, Biological Status, and Barriers towards Omega-3 Intake in Elite Level (Tier 4), Female Athletes: Pilot Study

Omega-3 polyunsaturated fatty acids (n-3 PUFA) have unique properties which benefit athlete populations. The literature investigating NCAA collegiate, rugby sevens and German endurance athletes indicates suboptimal n-3 PUFA dietary intake and biological status. The aims of this study were: (i) to explore the dietary intakes and FA profiles of elite level, team-based, female athletes and (ii) to understand perceived barriers towards achieving n-3 dietary guidelines. A total of 35 athletes (24.8 ± 4.5 years) completed both a questionnaire and a finger prick test. All the participants reported consuming fish and seafood over the previous six months however only nine athletes consumed ≥ 2 servings of fish per week. Four participants reported using an n-3 supplement. The mean omega-3 index (O3I; including supplementers) was below target levels of >8% (5.19 ± 0.86%). O3I was significantly higher (p < 0.001) in those consuming ≥ 2 servings of fish per week and/or supplements (5.91 ± 0.81%) compared with those who did not (4.82 ± 0.63%). The main barriers reported by those not consuming two servings of fish per week were sensory (n = 11; 42%), cooking skills (n = 10; 38%) and knowledge of n-3 benefits (n = 7; 27%). The current study shows that elite level female athletes present with suboptimal n-3 dietary intake and O3I due to their food preferences, cooking skills and n-3 knowledge.

Long-term fasting: Multi-system adaptations in humans (GENESIS) study-A single-arm interventional trial

Fasting provokes fundamental changes in the activation of metabolic and signaling pathways leading to longer and healthier lifespans in animal models. Although the involvement of different metabolites in fueling human fasting metabolism is well known, the contribution of tissues and organs to their supply remains partly unclear. Also, changes in organ volume and composition remain relatively unexplored. Thus, processes involved in remodeling tissues during fasting and food reintroduction need to be better understood. Therefore, this study will apply state-of-the-art techniques to investigate the effects of long-term fasting (LF) and food reintroduction in humans by a multi-systemic approach focusing on changes in body composition, organ and tissue volume, lipid transport and storage, sources of protein utilization, blood metabolites, and gut microbiome profiles in a single cohort. This is a prospective, single-arm, monocentric trial. One hundred subjects will be recruited and undergo 9 ± 3 day-long fasting periods (250 kcal/day). We will assess changes in the composition of organs, bones and blood lipid profiles before and after fasting, as well as high-density lipoprotein (HDL) transport and storage, untargeted metabolomics of peripheral blood mononuclear cells (PBMCs), protein persulfidation and shotgun metagenomics of the gut microbiome. The first 32 subjects, fasting for 12 days, will be examined in more detail by magnetic resonance imaging (MRI) and spectroscopy to provide quantitative information on changes in organ volume and function, followed by an additional follow-up examination after 1 and 4 months. The study protocol was approved by the ethics board of the State Medical Chamber of Baden-Württemberg on 26.07.2021 and registered at ClinicalTrials.gov (NCT05031598). The results will be disseminated through peer-reviewed publications, international conferences and social media.

Clinical trial registration

[ClinicalTrials.gov], identifier [NCT05031598].

Effectiveness of a fortified drink in improving B vitamin biomarkers in older adults: a controlled intervention trial

Background

Older adults are reported to have sub-optimal B vitamin status; targeted food-based solutions may help to address this. The objectives of the OptiAge food intervention study were to develop and investigate the effectiveness of a B vitamin-fortified drink in improving B vitamin biomarkers in older Irish adults with a primary outcome of change in the B vitamin biomarker status.

Methods

A double-blinded randomised controlled trial was performed in parallel at University College Dublin and Ulster University. Participants aged > 50 years were recruited following screening for exclusion criteria (i.e. taking medications known to interfere with B vitamin metabolism, supplements containing B vitamins, consuming > 4 portions of B vitamin-fortified foods per week or diagnosed with gastrointestinal, liver or pulmonary disease). Recruited participants meeting the inclusion criteria were randomised (by sex and study centre) to receive daily for 16 weeks either B vitamin-fortified or placebo drinks as developed by Smartfish, Norway. Each B vitamin-fortified drink (200 ml) contained 200 µg folic acid, 10 µg vitamin B12, 10 mg vitamin B6 and 5 mg riboflavin, while the placebo was an identical, isocaloric formulation without added B vitamins. Fasting blood samples were collected pre- and post-intervention which were used to measure the primary outcome of change in B vitamin biomarker levels.

Results

A total of 95 participants were randomised, of which 81 commenced the trial. Of these, 70 completed (37 in the active and 33 in the placebo groups). Intention to treat (ITT) analysis of the B vitamins demonstrated a significant improvement in all B vitamin biomarkers in the active compared to placebo groups: p < 0.01 for each of serum folate, serum vitamin B12 and plasma pyridoxal 5′-phosphate (vitamin B6) and the functional riboflavin biomarker, erythrocyte glutathione reductase activation coefficient (EGRac). Correspondingly, a significant lowering of serum homocysteine from 11.9 (10.3–15.1) µmol/L to 10.6 (9.4–13.0) µmol/L was observed in response to the active treatment (P < 0.001). Similar results were seen in a per-protocol analysis.

Conclusions

The results demonstrate that a B vitamin-fortified drink was effective in optimising B vitamin status, making this a useful intervention option to improve B vitamin status in older adults.

Trial registration ISRCTN, ISRCTN61709781—Retrospectively registered, https://www.isrctn.com/ISRCTN61709781

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-021-00630-8.

Associations Between Erythrocyte Membrane Fatty Acid Compositions and Biomarkers of Vascular Health in Adults With Type 1 Diabetes With and Without Insulin Resistance: A Cross-Sectional Analysis

OBJECTIVES

The aim of this study was to assess the relationship between specific erythrocyte fatty acid levels and vascular health in type 1 diabetes (T1D) with and without insulin resistance (IR).

METHODS

We analyzed baseline pretreatment data in a subset of 23 patients with T1D from a previously published randomized controlled trial consisting of comprehensive erythrocyte-derived fatty acid profiles and a panel of inflammation-associated endothelial markers. Estimated glucose disposal rate was used to identify and categorize patients with IR. We utilized principal component analysis (PCA) to cluster vascular biomarkers to compute a single "vascular signal" and utilized univariate linear regression models to investigate the association with IR and fatty acid profiles.

RESULTS

Subjects with IR displayed significantly higher levels of linoleic acid (p=0.001), lower levels of eicosapentaenoic acid (EPA) (p<0.001), lower levels of omega-3 polyunsaturated fatty acid (n-3PUFA) (p<0.006) and an increased omega-6 (n-6)PUFA:n-3PUFA ratio (p=0.001). IR was associated with significantly higher linoleic acid levels, total n-6PUFA and an increased ratio of n-6PUFA:n-3PUFA, and negatively associated with arachidonic acid and EPA levels, total saturated fatty acid and total n-3PUFA. The PCA-derived vascular biomarker cluster was positively associated with linoleic acid and n-6PUFA:n-3PUFA ratio, and inversely associated with EPA.

CONCLUSIONS

Specific erythrocyte membrane fatty acid compositions are associated with impaired vascular health and IR in adults with T1D. These findings suggest that IR and risk of associated complications may be influenced by specific fatty acid profiles, and thus potentially modified by the selective targeting of dietary fatty acids.

The Omega-3 Fatty Acid Eicosapentaenoic Acid (EPA) Correlates Inversely with Ischemic Brain Infarcts in Patients with Atrial Fibrillation

The omega-3 fatty acid (n-3 FA) eicosapentaenoic acid (EPA) reduces stroke in patients with atherosclerotic cardiovascular disease. Whether EPA affects stroke or cerebral small vessel dis-ease in patients with atrial fibrillation (AF) remains uncertain. EPA, docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), and alpha-linolenic acid (ALA) were determined by gas chromatography in 1657 AF patients from the Swiss Atrial Fibrillation study. All patients underwent brain MRI to detect ischemic brain infarcts, classified as large noncortical or cortical infarcts (LNCCIs); markers of small vessel disease, classified as small noncortical infarcts (SNCIs), number of microbleeds, and white matter lesion (WML) volumes. Individual and total n-3 FAs (EPA + DHA + DPA + ALA) were correlated with LNCCIs and SNCIs using logistic regression, with numbers of microbleeds using a hurdle model, and WML volumes using linear regression. LNCCIs were detected in 372 patients (22.5%). EPA correlated inversely with the prevalence of LNCCIs (odds ratio [OR] 0.51 per increase of 1 percentage point EPA, 95% confidence interval [CI] 0.29-0.90). DPA correlated with a higher LNCCI prevalence (OR 2.48, 95%CI 1.49-4.13). No associations with LNCCIs were found for DHA, ALA, and total n-3 FAs. Neither individual nor total n-3 FAs correlated with markers of small vessel disease. In conclusion, EPA correlates inversely with the prevalence of ischemic brain infarcts, but not with markers of small vessel disease in patients with AF.

Influence of Omega-3 PUFA on Non-invasive factors determining the risk of arrhYthmias eXcess and sudden cardiac death in patients with HFpEF with ischemic etiology (ONYX)

Aim Patients with heart failure with reduced left ventricular (LV) ejection fraction (HFrEF) who have had acute myocardial infarction have an unfavorable prognosis, largely due to ventricular arrhythmias (VA) and risk of sudden cardiac death (SCD). The optimal treatment (triple neurohormonal blockade plus implantable cardioverter defibrillator and cardiac resynchronization therapy) reduced the risk of SCD primarily due to reverse cardiac remodeling, but has not solved this problem completely. Efficacy of purified ω-3 polyunsaturated fatty acid esters (PUFA) in low doses (1 g/day) in reducing VA and risk of SCD in HFrEF patients was demonstrated in two large randomized clinical trials. The PUFA effects was suggested to be related also with increased heart rhythm variability (HRV) and chronotropic action, which might depend on the drug dose. The present open, prospective, randomized, comparative study in parallel groups evaluated the effect of Omacor in different doses on noninvasive markers of SCD risk in patients with ischemic HFrEF receiving the optimal drug therapy.Methods Patients (n=40) were randomized at a 1:1:2 ratio to the control group (n=10), the Omacor 1 g/day treatment group (n=10), and the Omacor 2 g/day treatment group (n=20) and were followed up for 12 months. Clinical evaluation included changes in the CHF functional class (FC) and Clinical Condition Scale (CCS) score; concentration of N-terminal pro-hormone brain natriuretic peptide (NT-proBNP); and peak oxygen consumption during exercise (peak VO2). The LV function was evaluated by LVEF. Holter ECG monitoring was used for evaluation of HRV (SDNN), average 24-h heart rate (HR), number of ventricular extrasystoles (VE) per hour and severity of VA, and presence of paired VE and VT runs.Results Improvement of CHF FC became significant only with the high-dose Omacor treatment (2 g/day). The CCS score showed a tendency towards decrease also with a lower dose (1 g/day) whereas the level of NT-proBNP significantly decreased with both Omacor doses. The increase in LV EF was significant only with the use of Omacor 2 g/day (+3 %, р=0.002). A negative chronotropic effect of ω-3 PUFA was observed. Average 24-h HR decreased by 8 bpm (р=0.05) and 11 bpm (р<0.001) with Omacor 1 g/day and 2 g/day, respectively. Either dose of ω-3 PUFA significantly improved VO2, which directly correlated with LV EF and inversely correlated with HR. The decrease in number of VE was associated not only with improved HRV (SDNN) but also with the decrease in 24-h HR, and thus Omacor 2 g/day significantly decreased the number of VE (by 16 per hour) and dangerous VA (paired VE and VT runs ceased to be detected in 40 % of patients).Conclusion Since HR, HRV, and VA are closely interrelated, the effect of ω-3 PUFA specifically on these noninvasive markers apparently determines its ability to decrease the risk of SCD in patients with ischemic HFrEF. The antiarrhythmic effect of Omacor was greater with higher doses of this drug.

High levels of eicosapentaenoic acid are associated with lower pericoronary adipose tissue attenuation as measured by coronary CTA

BACKGROUND AND AIMS

Higher pericoronary adipose tissue (PCAT) attenuation, a novel marker of inflammation in coronary CT angiography (CTA), has been shown to indicate increased cardiac mortality. Supplementation of eicosapentaenoic acid (EPA) has been shown to decrease cardiovascular death. Whether blood levels of n-3 fatty acids are associated with differences in PCAT attenuation is unknown.

METHODS

This is a cross-sectional analysis including 64 symptomatic patients who underwent coronary CTA. PCAT attenuation was measured in Hounsfield Units (HU) around the proximal 40 mm of the right coronary artery using semi-automated software. Erythrocyte membrane fatty acid composition was analyzed using gas chromatography. Individual fatty acids were expressed as a percentage of total identified fatty acids.

RESULTS

The patient cohort was divided into two groups using the median PCAT attenuation of -78.1 HU (each n = 32). No differences were seen in age, sex, BMI or traditional cardiovascular risk factors (CVRF) between groups (all p > 0.05). In univariable analysis, significantly higher values of EPA (1.00% [0.78; 1.26] vs. 0.78% [0.63; 0.99]; p = 0.02) were seen in patients with lower PCAT attenuation. All other fatty acids showed no differences (all p > 0.05). Moreover, a significant negative correlation was seen between PCAT attenuation and EPA (CC: 0.38; p = 0.002). In multivariable analysis, an inverse association of EPA with PCAT attenuation existed (ß = -0.31, p = 0.017), independent of age, gender, BMI and number of CVRF (all p > 0.1).

CONCLUSIONS

High levels of EPA are associated with lower PCAT attenuation on coronary CTA. This may indicate a different composition of pericoronary adipose tissue, potentially caused by a lower degree of coronary inflammation.

Investigation of gene-gene interactions in cardiac traits and serum fatty acid levels in the LURIC Health Study

Epistasis analysis elucidates the effects of gene-gene interactions (G×G) between multiple loci for complex traits. However, the large computational demands and the high multiple testing burden impede their discoveries. Here, we illustrate the utilization of two methods, main effect filtering based on individual GWAS results and biological knowledge-based modeling through Biofilter software, to reduce the number of interactions tested among single nucleotide polymorphisms (SNPs) for 15 cardiac-related traits and 14 fatty acids. We performed interaction analyses using the two filtering methods, adjusting for age, sex, body mass index (BMI), waist-hip ratio, and the first three principal components from genetic data, among 2,824 samples from the Ludwigshafen Risk and Cardiovascular (LURIC) Health Study. Using Biofilter, one interaction nearly met Bonferroni significance: an interaction between rs7735781 in XRCC4 and rs10804247 in XRCC5 was identified for venous thrombosis with a Bonferroni-adjusted likelihood ratio test (LRT) p: 0.0627. A total of 57 interactions were identified from main effect filtering for the cardiac traits G×G (10) and fatty acids G×G (47) at Bonferroni-adjusted LRT p < 0.05. For cardiac traits, the top interaction involved SNPs rs1383819 in SNTG1 and rs1493939 (138kb from 5’ of SAMD12) with Bonferroni-adjusted LRT p: 0.0228 which was significantly associated with history of arterial hypertension. For fatty acids, the top interaction between rs4839193 in KCND3 and rs10829717 in LOC107984002 with Bonferroni-adjusted LRT p: 2.28×10⁻⁵ was associated with 9-trans 12-trans octadecanoic acid, an omega-6 trans fatty acid. The model inflation factor for the interactions under different filtering methods was evaluated from the standard median and the linear regression approach. Here, we applied filtering approaches to identify numerous genetic interactions related to cardiac-related outcomes as potential targets for therapy. The approaches described offer ways to detect epistasis in the complex traits and to improve precision medicine capability.

Omega-3 polyunsaturated fatty acid supplementation versus placebo on vascular health, glycaemic control, and metabolic parameters in people with type 1 diabetes: a randomised controlled preliminary trial

Background

The role of omega-3 polyunsaturated fatty acids (n-3PUFA), and the potential impact of n-3PUFA supplementation, in the treatment and management of type 1 diabetes (T1D) remains unclear and controversial. Therefore, this study aimed to examine the efficacy of daily high-dose-bolus n-3PUFA supplementation on vascular health, glycaemic control, and metabolic parameters in subjects with T1D.

Methods

Twenty-seven adults with T1D were recruited to a 6-month randomised, double-blind, placebo-controlled trial. Subjects received either 3.3 g/day of encapsulated n-3PUFA or encapsulated 3.0 g/day corn oil placebo (PLA) for 6-months, with follow-up at 9-months after 3-month washout. Erythrocyte fatty acid composition was determined via gas chromatography. Endpoints included inflammation-associated endothelial biomarkers (vascular cell adhesion molecule-1 [VCAM-1], intercellular adhesion molecule-1 [ICAM-1], E-selectin, P-selectin, pentraxin-3, vascular endothelial growth factor [VEGF]), and their mediator tumor necrosis factor alpha [TNFα] analysed via immunoassay, vascular structure (carotid intima-media thickness [CIMT]) and function (brachial artery flow mediated dilation [FMD]) determined via ultrasound technique, blood pressure, glycosylated haemoglobin (HbA1c), fasting plasma glucose (FPG), and postprandial metabolism.

Results

Twenty subjects completed the trial in full. In the n-3PUFA group, the mean ± SD baseline n-3PUFA index of 4.93 ± 0.94% increased to 7.67 ± 1.86% (P < 0.001) after 3-months, and 8.29 ± 1.45% (P < 0.001) after 6-months. Total exposure to n-3PUFA over the 6-months (area under the curve) was 14.27 ± 3.05% per month under n-3PUFA, and 9.11 ± 2.74% per month under PLA (P < 0.001). VCAM-1, ICAM-1, E-selectin, P-selectin, pentraxin-3, VEGF, TNFα, CIMT, FMD, blood pressure, HbA1c, FPG, and postprandial metabolism did not differ between or within groups after treatment (P > 0.05).

Conclusions

This study indicates that daily high-dose-bolus of n-3PUFA supplementation for 6-months does not improve vascular health, glucose homeostasis, or metabolic parameters in subjects with T1D. The findings from this preliminary RCT do not support the use of therapeutic n-3PUFA supplementation in the treatment and management of T1D and its associated complications.

Trial Registration ISRCTN, ISRCTN40811115. Registered 27 June 2017, http://www.isrctn.com/ISRCTN40811115.

Omega-3 index in 2018/19

The omega-3 index, the percentage of EPA plus DHA in erythrocytes (measured by standardised analysis), represents a human body's status in EPA and DHA. An omega-3 index is measured in many laboratories around the world; however, even small differences in analytical methods entail large differences in results. Nevertheless, results are frequently related to the target range of 8-11 %, defined for the original and scientifically validated method (HS-Omega-3 Index®), raising ethical issues, and calling for standardisation. No human subject has an omega-3 index <2 %, indicating a vital minimum. Thus, the absence of EPA and DHA cannot be tested against presence. Moreover, clinical events correlate with levels, less with the dose of EPA and DHA, and the bioavailability of EPA and DHA varies inter-individually. Therefore, the effects of EPA and DHA are difficult to demonstrate using typical drug trial methods. Recent epidemiologic data further support the relevance of the omega-3 index in the cardiovascular field, since total mortality, cardiovascular mortality, cardiovascular events such as myocardial infarction or stroke, or blood pressure all correlate inversely with the omega-3 index. The omega-3 index directly correlates with complex brain functions. Compiling recent data supports the target range for the omega-3 index of 8-11 % in pregnancy. Many other potential applications have emerged. Some, but not all health issues mentioned have already been demonstrated to be improved by increasing intake of EPA and DHA. Increasing the omega-3 index into the target range of 8-11 % with individualised doses of toxin-free sources for EPA and DHA is tolerable and safe.

High Variability in Erythrocyte, Plasma and Whole Blood EPA and DHA Levels in Response to Supplementation

(1) Aim: the aim of this secondary analysis was to report the variability in response to n-3 long chain polyunsaturated fatty acids (LCPUFA) supplementation in erythrocytes, plasma and whole blood of a previously published dose response study. (2) Methods: a randomized, double-blind, placebo-controlled trial of parallel design was conducted, whereby pre-menopausal women were randomly assigned to consume 0, 0.35, 0.7 or 1 g/day of supplemental eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA). Fasted blood samples were taken at baseline and after eight weeks intervention. Erythrocyte, plasma and whole blood fatty acids were extracted using the method of Lepage and Roy and analysed using gas chromatography. (3) Results: There were significant increases in EPA plus DHA levels in the 0.7 g and 1 g dose groups, with the highest increase with the 1 g dose notably: in erythrocytes (from 5.69% to 7.59%), plasma (from 2.94% to 5.48%) and in whole blood (from 3.81% to 6.03%). There was high variability in response to the supplement in erythrocytes, plasma and whole blood across the different doses. (4) Conclusion: there is high individual variability in n-3 LCPUFA levels in response to n-3 LCPUFA supplementation, which should be taken into account in clinical trials using n-3 LCPUFA supplements.

Omega-3 Fatty Acids in Pregnancy-The Case for a Target Omega-3 Index

Scientific societies recommend increasing intake of docosahexaenoic acid (DHA) by 200 mg/day during pregnancy. However, individually, clinical events correlate quite strongly with levels of eicosapentaenoic acid (EPA) and DHA in blood, but these levels poorly correlate with amounts ingested. EPA and DHA in erythrocytes (Omega-3 Index) have a low biologic variability. If analyzed with a standardized analytical procedure (HS-Omega-3 Index^®), analytical variability is low. Thus, the largest database of any fatty acid analytical method was provided. Pregnant women in Germany had a mean Omega-3 Index below the target range suggested for cardiovascular disease of 8–11%, with large interindividual variation, and quite independent of supplementation with EPA and DHA. In Germany, premature birth is a major health issue. Premature birth and other health issues of pregnant women and their offspring correlate with levels of EPA and DHA in blood and can be reduced by increasing intake of EPA and DHA, according to individual trials and pertinent meta-analyses. Very high intake or levels of EPA and DHA may also produce health issues, like bleeding, prolonged gestation, or even premature birth. While direct evidence remains to be generated, evidence from various scientific approaches supports that the target range for the Omega-3 Index of 8–11% might also pertain to pregnancy and lactation.

Degenerative rotator cuff tears are associated with a low Omega-3 Index

BACKGROUND

The etiology of degenerative rotator cuff tears is multifactorial but chronic inflammation plays an important role in the pathogenesis. Some polyunsaturated fatty acids (PUFA) can modulate inflammation and marine n-3 (Omega-3) PUFA have anti-inflammatory effects. We hypothesized that the Omega-3 Index is lower in patients with degenerative rotator cuff tears when compared to controls without rotator cuff tendinopathy.

METHODS

From 684 consecutive patients with full thickness rotator cuff tears 655 were excluded because of possible bias. In the remaining 29 patients (22 m, 7 f; 53,9 y) with degenerative full thickness rotator-cuff tears, erythrocyte fatty acids were analyzed using the HS-Omega-3 Index^® methodology. 15 healthy volunteers (10 m, 5 f; 52.5y) served as a control.

RESULTS

The Omega-3 Index (% EPA + DHA) was 5.01% (95% CI: 3.81-4.66) in patients and 6.01% (95% CI: 4.48-5.72) in controls (p = 0.028) CONCLUSIONS: Patients with full thickness degenerative rotator cuff tears had a significantly lower Omega-3 Index than controls without rotator cuff tendinopathy. Whether a lower Omega-3 Index represents an independent risk factor for degenerative rotator cuff tears should be further investigated, e.g. in a longitudinal study.

A randomised trial of the effect of omega-3 polyunsaturated fatty acid supplements on the human intestinal microbiota

OBJECTIVE

Omega-3 polyunsaturated fatty acids (PUFAs) have anticolorectal cancer (CRC) activity. The intestinal microbiota has been implicated in colorectal carcinogenesis. Dietary omega-3 PUFAs alter the mouse intestinal microbiome compatible with antineoplastic activity. Therefore, we investigated the effect of omega-3 PUFA supplements on the faecal microbiome in middle-aged, healthy volunteers (n=22).

DESIGN

A randomised, open-label, cross-over trial of 8 weeks' treatment with 4 g mixed eicosapentaenoic acid/docosahexaenoic acid in two formulations (soft-gel capsules and Smartfish drinks), separated by a 12-week 'washout' period. Faecal samples were collected at five time-points for microbiome analysis by 16S ribosomal RNA PCR and Illumina MiSeq sequencing. Red blood cell (RBC) fatty acid analysis was performed by liquid chromatography tandem mass spectrometry.

RESULTS

Both omega-3 PUFA formulations induced similar changes in RBC fatty acid content, except that drinks were associated with a larger, and more prolonged, decrease in omega-6 PUFA arachidonic acid than the capsule intervention (p=0.02). There were no significant changes in α or β diversity, or phyla composition, associated with omega-3 PUFA supplementation. However, a reversible increased abundance of several genera, including Bifidobacterium, Roseburia and Lactobacillus was observed with one or both omega-3 PUFA interventions. Microbiome changes did not correlate with RBC omega-3 PUFA incorporation or development of omega-3 PUFA-induced diarrhoea. There were no treatment order effects.

CONCLUSION

Omega-3 PUFA supplementation induces a reversible increase in several short-chain fatty acid-producing bacteria, independently of the method of administration. There is no simple relationship between the intestinal microbiome and systemic omega-3 PUFA exposure.

TRIAL REGISTRATION NUMBER

ISRCTN18662143.

Public health relevance of drug-nutrition interactions

The public health relevance of drug–nutrition interactions is currently highly undervalued and overlooked. This is particularly the case for elderly persons where multi-morbidity and consequently polypharmacy is very common. Vitamins and other micronutrients have central functions in metabolism, and their interactions with drugs may result in clinically relevant physiological impairments but possibly also in positive effects. On 12 April 2016, the University Medical Center Groningen (The Netherlands), as part of its Healthy Ageing program, organized a workshop on the public health relevance of drug–nutrient interactions. In this meeting, experts in the field presented results from recent studies on interactions between pharmaceuticals and nutrients, and discussed the role of nutrition for elderly, focusing on those persons receiving pharmaceutical treatment. This paper summarizes the proceedings of the symposium and provides an outlook for future research needs and public health measures. Since food, pharma and health are closely interconnected domains, awareness is needed in the medical community about the potential relevance of drug–nutrition interactions. Experts and stakeholders should advocate for the integration of drug–nutrition evaluations in the drug development process. Strategies for the individual patients should be developed, by installing drug review protocols, screening for malnutrition and integrating this topic into the general medical advice.

Cognitive Impairment Is Associated with a Low Omega-3 Index in the Elderly: Results from the KORA-Age Study

BACKGROUND

Omega-3 polyunsaturated fatty acids (PUFA) may affect the risk of cognitive decline in older adults.

METHODS

Cross-sectional analysis was conducted among 720 (50.4% women) participants aged 68-92 years (mean age: 77.6, SD ±6.2) of the population-based KORA-Age study. Eicosapentaenoic acid and docosahexaenoic acid (omega-3 index) were measured in erythrocytes as a percentage of total fatty acids. The categories low (<5.7), intermediate (5.7-6.8), and high (>6.8) levels of the omega-3 index were built using tertiles. The association between cognitive status and omega-3 levels was assessed by logistic regression analyses with adjustments for important concurrent risk factors of cognitive decline.

RESULTS

In the sex- and age-adjusted model (model 1), subjects with a low omega-3 index were at a significantly higher risk for cognitive impairment (OR: 1.77, 95% CI: 1.15-2.73, p = 0.009). This association remained stable after further adjusting for educational level (model 2; OR: 1.75, 95% CI: 1.13-2.71, p = 0.01) and metabolic risk factors (model 3; OR: 1.77, 95% CI: 1.14-2.75, p = 0.01). After further controlling for affective disorders (model 4), the association did not attenuate (OR: 1.77, 95% CI: 1.14-2.76, p = 0.01).

CONCLUSION

A robust association was found between low omega-3 levels and cognitive impairment in an elderly population. Further research is needed to understand the link between omega-3 PUFA and cognitive functioning.

Cold-Induced Brown Adipose Tissue Activity Alters Plasma Fatty Acids and Improves Glucose Metabolism in Men

CONTEXT

Mounting evidence suggests beneficial effects of brown adipose tissue (BAT) activation on glucose and lipid metabolism in humans. It is unclear whether cold-induced BAT activation affects not only insulin sensitivity but also insulin secretion. Likewise, the role in clearing circulating fatty acids (FAs) has not been fully explored.

OBJECTIVE

Exploring the effects of cold-induced BAT activation on insulin sensitivity and secretion, as well as on plasma FA profiles.

DESIGN

Fifteen healthy men participated in a cross-balanced repeated within-subject study with two experimental conditions. Subjects were exposed to thermoneutrality (22°C) and to moderate cold (18.06°C, shivering excluded) by use of a water-perfused whole body suit. Cold-induced BAT activation was quantified by [18F]-fluorodeoxyglucose positron emission tomography-computed tomography in a subset of volunteers. A Botnia clamp procedure was applied to determine pancreatic first phase insulin response (FPIR) and insulin sensitivity. Hormones and metabolites, including 26 specific plasma FAs, were sampled throughout the experiment.

RESULTS

Cold exposure induced BAT activity. Plasma noradrenaline and dopamine concentrations increased in response to cold. Peripheral glucose uptake and insulin sensitivity significantly improved by ∼20%, whereas FPIR remained stable. Lignoceric acid (C24:0) concentrations increased, whereas levels of eicosanoic acid (C20:1n9), nervonic acid (C24:1n9), and behenic acid (C22:0) decreased.

CONCLUSIONS

Cold-exposure induces sympathetic nervous system activity and BAT metabolism in humans, resulting in improved glucose metabolism without affecting pancreatic insulin secretion. In addition, BAT activation is associated with altered circulating concentrations of distinct FAs. These data support the concept that human BAT metabolism significantly contributes to whole body glucose and lipid utilization in a coordinated manner.

International Society for the Study of Fatty Acids and Lipids 2016 Debate: For Science-Based Dietary Guidelines on Fats, Meta-Analysis and Systematic Reviews Are Decisive

This paper summarizes a debate on whether meta-analyses and systematic reviews are decisive in formulating guidelines for dietary fat. Held during the 12th congress of the International Society for the Study of Fatty Acids and Lipids in Stellenbosch, South Africa, September 7, 2016, the debate was hosted by the International Union of Nutritional Sciences and the International Expert Movement to Improve Dietary Fat Quality (IEM, www.theiem.org). Clemens von Schacky, Ludwig Maximilians-University, Munich, Germany, supported the statement, describing the types of weaknesses in individual studies and clinical trials. With examples of how to overcome such limitations, he concluded that nutritional guidelines on fat need a proper scientific basis in which randomized controlled trials (RCTs) with clinical endpoints and their meta-analyses are essential and decisive. In contention, Ingeborg Brouwer, Vrije Universiteit, Amsterdam, declared that recommendations on dietary fat intake should always be based on the totality of the evidence, including physiologic and biochemical knowledge and associations from observational epidemiology. RCTs and meta-analyses have their shortcomings, but well-conducted systematic reviews and meta-analyses support a transparent process for developing dietary fat guidelines. Participants agreed that evidence-based decision-making for dietary guidance should consider all the best available evidence using a transparent, systematic review.

Recommendations of the Spanish Menopause Society on the consumption of omega-3 polyunsaturated fatty acids by postmenopausal women

The consumption of long-chain omega-3 polyunsaturated fatty acids (LCO3-PUFAs) has shown a great variety of beneficial effects, including cardiovascular, metabolic and inflammatory effects, which make them interesting for the postmenopausal woman. Because LCO3-PUFAs could be effective and safe during this period, a panel of experts from the Spanish Menopause Society met to establish a set of recommendations for their use in postmenopausal women based on the best available evidence. The decrease in triglycerides is the most consistent effect observed with LCO3-PUFAs (at doses greater than 3g/day). In addition, LCO3-PUFAs have antiarrhythmic effects, reduce blood pressure, improve depressive and psychotic symptoms, and do not increase the risk of cancer. However, further studies are needed to confirm the benefit of LCO3-PUFAs in the relief of menopause symptoms and osteoporosis.

Bioavailability of Dietary Omega-3 Fatty Acids Added to a Variety of Sausages in Healthy Individuals

A low Omega-3 Index (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in erythrocytes) is associated with cardiac, cerebral, and other health issues. Intake of EPA and DHA, but not of alpha-linolenic acid (ALA), increases the Omega-3 Index. We investigated bioavailability, safety, palatability and tolerability of EPA and DHA in a novel source: a variety of sausages. We screened 96 healthy volunteers, and recruited 44 with an Omega-3 Index <5%. Participants were randomly assigned to receive a variety of sausages enriched with approximately 250 mg EPA and DHA per 80 g (n = 22) daily for 8 weeks, or matching placebo sausages (n = 22). All sausages contained approximately 250 mg ALA/80 g. In the verum group, the mean Omega-3 Index increased from 4.18 ± 0.54 to 5.72 ± 0.66% (p < 0.001), while it remained unchanged in the placebo group. While ALA levels increased only in the placebo group, DPA levels increased in both groups. Inter-individual variability in the response was large. The mean increase of the Omega-3 Index per intake of EPA and DHA we observed was higher than for other sources previously studied, indicating superior bioavailability. As increasing production of EPA and DHA is difficult, improvements of bioavailability can facilitate reaching the target range for the Omega-3 Index (8-11%).

Low long chain omega-3 fatty acid status in middle-aged women

INTRODUCTION

Long-chain (LC) omega-3 fatty acids (n-3 PUFAs) have beneficial effects on cardiovascular health and cognitive decline. Several studies have shown that the LC n-3 PUFA status in women in western countries is low. The aim of this study was to assess the LC n-3 PUFA status in middle-aged German women and to identify variables that might affect the status.

MATERIAL AND METHODS

From the nationwide and cross-sectional German VitaMinFemin study, fatty acid levels in the erythrocyte membrane (% of total erythrocyte fatty acids) were ascertained for 446 women (40-60 years).

RESULTS

The average omega-3 index (% of eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) of the total study population was 5.49±1.17%. A total of 62.8% of women had a low omega-3 index (>4-6%). The omega-3 index was affected by age and smoking, with slightly higher values in women ≥50 years (p=0.032) and non-smokers (p=0.002). Women taking hormonal contraceptives showed a lower EPA level (p<0.001), a lower ratio of EPA/alpha-linoleic acid (p<0.001) and a higher ratio of DHA/EPA (p<0.001) than women without hormonal contraception.

CONCLUSION

The low LC n-3 PUFA status in middle-aged German women (40-60 years) is related to an increased risk of cardiovascular diseases and possibly other diseases and should therefore be improved. Further studies are needed to determine the influence of estrogen on the effect on LC n-3 PUFA status.

Omega-3 fatty acids predict recurrent venous thromboembolism or total mortality in elderly patients with acute venous thromboembolism

Essentials The role of omega-3 fatty acids (n-3 FAs) in recurrent venous thromboembolism (VTE) is unknown. Association of n-3 FAs with recurrent VTE or total mortality was investigated in 826 patients. Whole blood n-3 FAs were inversely correlated with recurrent VTE or total mortality. Major and non-major bleeding was not increased in patients with higher levels of n-3 FAs.

SUMMARY

Background The role of omega-3 fatty acids (n-3 FAs) in recurrent venous thromboembolism (VTE) remains unknown. Objectives To investigate the association of n-3 FAs with recurrent VTE or total mortality at 6 months and 3 years. Methods N-3 FAs were assessed in 826 patients aged ≥ 65 years, categorized into low, medium and high based on the 25th and 75th percentile. Mean follow-up was 29 months. Results At 6 months, subjects with medium (adjusted hazard ratio [HR], 0.37; 95% confidence interval [CI], 0.22-0.62) and high n-3 FA levels (adjusted HR, 0.36; 95% CI, 0.20-0.67) were less likely to develop recurrent VTE or total mortality, compared with those with low n-3 FAs. At 3 years, medium levels (adjusted HR, 0.67; 95% CI, 0.47-0.96) were associated with lower risk of recurrent VTE or total mortality. As compared with low n-3 FAs, the adjusted sub-hazard ratio [SHR] of recurrent VTE was 0.39 (95% CI, 0.15-0.99) in patients with medium and 0.17 (95% CI, 0.03-0.82) in patients with high n-3 FAs. The cumulative incidence of recurrent VTE was lower in the medium and high n-3 FA groups as compared with the low n-3 FA groups, but seems to have worn off after 3 years. The incidence of major and non-major bleeding was not greater in the high n-3 FA group. Conclusion Higher levels of n-3 FAs were associated with a lower risk of recurrent VTE or total mortality in elderly patients with VTE, but not with greater bleeding risk.

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.

Comparison of fatty acid intakes assessed by a cardiovascular-specific food frequency questionnaire with red blood cell membrane fatty acids in hyperlipidaemic Australian adults: a validation study

BACKGROUND/OBJECTIVES

Limited dietary intake tools have been validated specifically for hyperlipidaemic adults. The Australian Eating Survey (AES) Food Frequency Questionnaire (FFQ) was adapted to include foods with cardio-protective properties (CVD-AES). The aims were to estimate dietary fatty acid (FA) intakes derived from the CVD-AES and AES and compare them with red blood cell (RBC) membrane FA content.

SUBJECTS/METHODS

Dietary intake was measured using the semi-quantitative 120-item AES and 177-item CVD-AES. Nutrient intakes were calculated using AUSNUT 2011-2013. Fasting RBC membrane FAs were assessed using gas chromatography. Extent of agreement between intakes estimated by AES or CVD-AES and RBC membrane composition (% of total FAs) for linoleic acid (LA), alpha-linolenic acid (ALA), eicosapentanoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) were assessed using Spearman's correlation coefficients, adjusted linear regressions and Kappa statistics.

RESULTS

Data from 39 participants (72% female, 59.3±11.1 years) indicate stronger positive correlations between RBC membrane FAs and CVD-AES dietary estimates compared with the AES. Significant (P<0.05) moderate-strong correlations were found between CVD-AES FAs and FA proportions in RBC membranes for EPA (r=0.62), DHA (r=0.53) and DPA (r=0.42), with a moderate correlation for LA (r=0.39) and no correlation with ALA. Significant moderate correlations were found with the AES for DHA (r=0.39), but not for LA, ALA, EPA or DPA.

CONCLUSIONS

The CVD-AES provides a more accurate estimate of long chain FA intakes in hyperlipidaemic adults, compared with AES estimates. This indicates that a CVD-specific FFQ should be used when evaluating FA intakes in this population.

Data on gender and subgroup specific analyses of omega-3 fatty acids in the Ludwigshafen Risk and Cardiovascular Health Study

This paper contains additional data related to the research article “Omega-3 fatty acids and mortality in patients referred for coronary angiography – The Ludwigshafen Risk and Cardiovascular Health Study” (Kleber et al., in press) [1]. The data shows characteristics of the Ludwigshafen Risk and Cardiovascular Health (LURIC) study according to tertiles of omega-3 fatty acids as well as stratified by gender. The association of proportions of omega-3 fatty acids measured in erythrocyte membranes with different causes of death is investigated with a special focus on modeling the association of EPA with mortality in a nonlinear way. Further, the association of omega-3 fatty acids with all-cause mortality adjusted for high-sensitive C-reactive protein as a marker of systemic inflammation is examined as well as the association of EPA with cause-specific death.

Conducting omega-3 clinical trials with cardiovascular outcomes: Proceedings of a workshop held at ISSFAL 2014

In contrast to earlier long-chain (LC) omega-3 (i.e. EPA and DHA) investigations, some recent studies have not demonstrated significant effects of EPA and DHA on cardiovascular disease (CVD) outcomes. The neutral findings may have been due to experimental design issues, such as: maintenance on aggressive cardiovascular drug treatment overshadowing the benefits of LC omega-3s, high background LC omega-3 intake, too few subjects in the study, treatment duration too short, insufficient LC omega-3 dosage, increase in omega-6 fatty acid intake during the study, failure to assess the LC omega-3 status of the subjects prior to and during treatment and lack of clarity concerning which mechanisms were expected to produce benefits. At the 11th ISSFAL Congress, a workshop was held on conducting LC omega-3 clinical trials with cardiovascular outcomes, with the goal of gaining a better understanding concerning aspects of experimental design that should be considered when planning clinical studies related to EPA and DHA and potential cardiovascular benefits.

Nutrient reference value: non-communicable disease endpoints--a conference report

Nutrition is complex-and seemingly getting more complicated. Most consumers are familiar with "essential nutrients," e.g., vitamins and minerals, and more recently protein and important amino acids. These essential nutrients have nutrient reference values, referred to as dietary reference intakes (DRIs) developed by consensus committees of scientific experts convened by the Institute of Medicine of the National Academy of Sciences, Engineering, and Medicine and carried out by the Food and Nutrition Board. The DRIs comprise a set of four nutrient-based reverence values, the estimated average requirements, the recommended dietary allowances (RDAs), the adequate intakes and the tolerable upper intake levels for micronutrient intakes and an acceptable macronutrient distribution range for macronutrient intakes. From the RDA, the US Food and Drug Administration (FDA) derives a labeling value called the daily value (DV), which appears on the nutrition label of all foods for sale in the US. The DRI reports do not make recommendations about whether the DV labeling values can be set only for what have been defined to date as "essential nutrients." For example, the FDA set a labeling value for "dietary fiber" without having the DV. Nutrient reference values-requirements are set by Codex Alimentarius for essential nutrients, and regulatory bodies in many countries use these Codex values in setting national policy for recommended dietary intakes. However, the focus of this conference is not on essential nutrients, but on the "nonessential nutrients," also termed dietary bioactive components. They can be defined as "Constituents in foods or dietary supplements, other than those needed to meet basic human nutritional needs, which are responsible for changes in health status (Office of Disease Prevention and Health Promotion, Office of Public Health and Science, Department of Health and Human Services in Fed Regist 69:55821-55822, 2004)." Substantial and often persuasive scientific evidence does exist to confirm a relationship between the intake of a specific bioactive constituent and enhanced health conditions or reduced risk of a chronic disease. Further, research on the putative mechanisms of action of various classes of bioactives is supported by national and pan-national government agencies, and academic institutions, as well as functional food and dietary supplement manufacturers. Consumers are becoming educated and are seeking to purchase products containing bioactives, yet there is no evaluative process in place to let the public know how strong the science is behind the benefits or the quantitative amounts needed to achieve these beneficial health effects or to avoid exceeding the upper level (UL). When one lacks an essential nutrient, overt deficiency with concomitant physiological determents and eventually death are expected. The absence of bioactive substances from the diet results in suboptimal health, e.g., poor cellular and/or physiological function, which is relative and not absolute. Regrettably at this time, there is no DRI process to evaluate bioactives, although a recent workshop convened by the National Institutes of Health (Options for Consideration of Chronic Disease Endpoints for Dietary Reference Intakes (DRIs); March 10-11, 2015; http://health.gov/dietaryguidelines/dri/ ) did explore the process to develop DVs for nutrients, the lack of which result in increased risk of chronic disease (non-communicable disease) endpoints. A final report is expected soon. This conference (CRN-International Scientific Symposium; "Nutrient Reference Value-Non-Communicable Disease (NRV-NCD) Endpoints," 20 November in Kronberg, Germany; http://www.crn-i.ch/2015symposium/ ) explores concepts related to the Codex NRV process, the public health opportunities in setting NRVs for bioactive constituents, and further research and details on the specific class of bioactives, n-3 long-chain polyunsaturated fatty acids (also termed omega-3 fatty acids) and their constituents, specifically docosahexaenoic acid and eicosapentaenoic acid.

Association between Blood Omega-3 Index and Cognition in Typically Developing Dutch Adolescents

The impact of omega-3 long-chain polyunsaturated fatty acids (LCPUFAs) on cognition is heavily debated. In the current study, the possible association between omega-3 LCPUFAs in blood and cognitive performance of 266 typically developing adolescents aged 13–15 years is investigated. Baseline data from Food2Learn, a double-blind and randomized placebo controlled krill oil supplementation trial in typically developing adolescents, were used for the current study. The Omega-3 Index was determined with blood from a finger prick. At baseline, participants finished a neuropsychological test battery consisting of the Letter Digit Substitution Test (LDST), D2 test of attention, Digit Span Forward and Backward, Concept Shifting Test and Stroop test. Data were analyzed with multiple regression analyses with correction for covariates. The average Omega-3 Index was 3.83% (SD 0.60). Regression analyses between the Omega-3 Index and the outcome parameters revealed significant associations with scores on two of the nine parameters. The association between the Omega-3 Index and both scores on the LDST (β = 0.136 and p = 0.039), and the number of errors of omission on the D2 (β = −0.053 and p = 0.007). This is a possible indication for a higher information processing speed and less impulsivity in those with a higher Omega-3 Index.

Resolution Pharmacology: Opportunities for Therapeutic Innovation in Inflammation

Current medicines for the clinical management of inflammatory diseases act by inhibiting specific enzymes or antagonising specific receptors or blocking their ligands. In the past decade, a new paradigm in our understanding of the inflammatory process has emerged with the appreciation of genetic, molecular, and cellular mechanisms that are engaged to actively resolve inflammation. The 'resolution of acute inflammation' is enabled by counter-regulatory checkpoints to terminate the inflammatory reaction, promoting healing and repair. It may be possible to harness this knowledge for innovative approaches to the treatment of inflammatory pathologies. Here we discuss current translational attempts to develop agonists at proresolving targets as a strategy to rectify chronic inflammatory status. We reason this new approach will lead to the identification of better drugs that will establish a new branch of pharmacology, 'resolution pharmacology'.

What Is the Most Effective Way of Increasing the Bioavailability of Dietary Long Chain Omega-3 Fatty Acids--Daily vs. Weekly Administration of Fish Oil?

The recommendations on the intake of long chain omega-3 polyunsaturated fatty acids (n-3 LC-PUFA) vary from eating oily fish ("once to twice per week") to consuming specified daily amounts of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) ("250-500 mg per day"). It is not known if there is a difference in the uptake/bioavailability between regular daily consumption of supplementsvs. consuming fish once or twice per week. In this study, the bioavailability of a daily dose of n-3 LC-PUFA (Constant treatment), representing supplements, vs. a large weekly dose of n-3 LC-PUFA (Spike treatment), representing consuming once or twice per week, was assessed. Six-week old healthy male Sprague-Dawley rats were fed either a Constant treatment, a Spike treatment or Control treatment (no n-3 LC-PUFA), for six weeks. The whole body, tissues and faeces were analysed for fatty acid content. The results showed that the major metabolic fate of the n-3 LC-PUFA (EPA+docosapentaenoic acid (DPA) + DHA) was towards catabolism (β-oxidation) accounting for over 70% of total dietary intake, whereas deposition accounted less than 25% of total dietary intake. It was found that significantly more n-3 LC-PUFA were β-oxidised when originating from the Constant treatment (84% of dose), compared with the Spike treatment (75% of dose). Conversely, it was found that significantly more n-3 LC-PUFA were deposited when originating from the Spike treatment (23% of dose), than from the Constant treatment (15% of dose). These unexpected findings show that a large dose of n-3 LC-PUFA once per week is more effective in increasing whole body n-3 LC-PUFA content in rats compared with a smaller dose delivered daily.

Bioavailability of fatty acids from krill oil, krill meal and fish oil in healthy subjects--a randomized, single-dose, cross-over trial

Background

Krill contains two marine omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), mainly bound in phospholipids. Typical products from krill are krill oil and krill meal. Fish oils contain EPA and DHA predominantly bound in triglycerides. The difference in the chemical binding of EPA and DHA has been suggested to affect their bioavailability, but little is known on bioavailability of EPA and DHA in krill meal.

This study was undertaken to compare the acute bioavailability of two krill products, krill oil and krill meal, with fish oil in healthy subjects.

Methods

A randomized, single-dose, single-blind, cross-over, active-reference trial was conducted in 15 subjects, who ingested krill oil, krill meal and fish oil, each containing approx. 1 700 mg EPA and DHA. Fatty acid compositions of plasma triglycerides and phospholipids were measured repeatedly for 72 hours. The primary efficacy analysis was based on the 72 hour incremental area under the curve (iAUC) of EPA and DHA in plasma phospholipid fatty acids.

Results

A larger iAUC for EPA and DHA in plasma phospholipid fatty acids was detected after krill oil (mean 89.08 ± 33.36% × h) than after krill meal (mean 44.97 ± 18.07% x h, p < 0.001) or after fish oil (mean 59.15 ± 22.22% × h, p=0.003). Mean iAUC’s after krill meal and after fish oil were not different. A large inter-individual variability in response was observed.

Conclusion

EPA and DHA in krill oil had a higher 72-hour bioavailability than in krill meal or fish oil. Our finding that bioavailabilities of EPA and DHA in krill meal and fish oil were not different argues against the interpretation that phospholipids are better absorbed than triglycerides. Longer-term studies using a parameter reflecting tissue fatty acid composition, like erythrocyte EPA plus DHA are needed.

Trial registration

NCT02089165

Omega-3 fatty acids in cardiovascular disease--an uphill battle

In cardiology, results of recent large intervention trials with eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) supplements were neutral. In contrast, in epidemiologic studies, an inverse relation between clinical events and intake of EPA+DHA was found which was steeper for higher levels of EPA+DHA. A standardized way of determining levels is the Omega-3 Index, which is the percentage of EPA+DHA of a total of 26 fatty acids measured in erythrocytes. According to current criteria, a low Omega-3 Index is a cardiovascular risk factor. What can explain this contradiction? Trial participants were recruited irrespective of their baseline status in EPA+DHA - an important predictor of events. Levels of EPA+DHA have a statistically normal distribution; together with the large inter-individual variability of levels' responding to increased intake, this created a large overlap of EPA+DHA levels between intervention and control groups. Moreover, trial participants were advised to take EPA+DHA supplements with breakfast, frequently a low fat meal, resulting in poor bioavailability. As a result, there is an urgent need for new intervention trials in cardiology, for which participants with a low baseline omega-3 index are recruited, and then treated with individually tailored doses of EPA+DHA to a prespecified target range.

Associations between Omega-3 Index increase and triacylglyceride decrease in subjects with hypertriglyceridemia in response to six month of EPA and DHA supplementation

INTRODUCTION

Ingestion of long-chain n-3 PUFA effectively decreases serum triacylglycerol (TAG) levels and increases the Omega-3 Index, defined as the % of EPA and DHA in erythrocyte fatty acids. However, it remains unclear whether there is a relationship between the Omega-3 Index increase (ΔO3I increase) and the TAG level decrease (ΔTAG). We hypothesized that TAG reduction is strongly depended on Omega-3 Index increase.

SUBJECTS AND METHODS

Secondary analyses of data from a former double-blind placebo-controlled trial in which 150 dyslipidemic statin-treated subjects were randomized to four capsules of fish oil daily either as re-esterified TAG or ethyl esters in identical doses (1.01 g EPA+0.67 g DHA) or corn oil as a placebo for a period of six month.

RESULTS

108 subjects fulfilled the criteria of the current study protocol and were included in the analyses. A weak but significant negative correlation between ΔO3I and ΔTAG was observed (r=-0.211, p<0.05). However, the relation between ΔO3I and serum ΔTAG was not linear (coefficients of determination R(2): 0.044). After sub-grouping the study population into Omega-3 Index response groups, the group with a mean ΔO3I of>4% after six months of n-3 PUFA treatment demonstrated the greatest TAG reduction.

DISCUSSION AND CONCLUSIONS

A weak association between Omega-3 Index increase and TAG level decrease was found. This may be explained by highly fluctuating TAG levels, a large inter-individual difference in response of the Omega-3 Index, a cohort of subjects with only slightly elevated TAG levels and high Omega-3 Index values at baseline, and possibly to insufficient statistical power. Since there was no strong association between Omega-3 Index increase and the TAG level decrease, we conclude that changes in serum TAG levels are not a viable substitute for the Omega-3 Index to monitor treatment with EPA and DHA.

Omega-3 index and cardiovascular health

Recent large trials with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the cardiovascular field did not demonstrate a beneficial effect in terms of reductions of clinical endpoints like total mortality, sudden cardiac arrest or other major adverse cardiac events. Pertinent guidelines do not uniformly recommend EPA + DHA for cardiac patients. In contrast, in epidemiologic findings, higher blood levels of EPA + DHA were consistently associated with a lower risk for the endpoints mentioned. Because of low biological and analytical variability, a standardized analytical procedure, a large database and for other reasons, blood levels of EPA + DHA are frequently assessed in erythrocytes, using the HS-Omega-3 Index® methodology. A low Omega-3 Index fulfills the current criteria for a novel cardiovascular risk factor. Neutral results of intervention trials can be explained by issues of bioavailability and trial design that surfaced after the trials were initiated. In the future, incorporating the Omega-3 Index into trial designs by recruiting participants with a low Omega-3 Index and treating them within a pre-specified target range (e.g., 8%-11%), will make more efficient trials possible and provide clearer answers to the questions asked than previously possible.

Habitual diets rich in dark-green vegetables are associated with an increased response to ω-3 fatty acid supplementation in Americans of African ancestry

Although substantial variation exists in individual responses to omega-3 (ω-3) (n-3) fatty acid supplementation, the causes for differences in response are largely unknown. Here we investigated the associations between the efficacy of ω-3 fatty acid supplementation and a broad range of nutritional and clinical factors collected during a double-blind, placebo-controlled trial in participants of African ancestry, randomly assigned to receive either 2 g eicosapentaenoic acid (EPA) + 1 g docosahexaenoic acid (n = 41) or corn/soybean oil placebo (n = 42) supplements for 6 wk. Food-frequency questionnaires were administered, and changes in erythrocyte lipids, lipoproteins, and monocyte 5-lipoxygenase-dependent metabolism were measured before and after supplementation. Mixed-mode linear regression modeling identified high (n = 28) and low (n = 13) ω-3 fatty acid response groups on the basis of changes in erythrocyte EPA abundance (P < 0.001). Compliance was equivalent (∼88%), whereas decreases in plasma triglycerides and VLDL particle sizes and reductions in stimulated monocyte leukotriene B4 production were larger in the high-response group. Although total diet quality scores were similar, the low-response group showed lower estimated 2005 Healthy Eating Index subscores for dark-green and orange vegetables and legumes (P = 0.01) and a lower intake of vegetables (P = 0.02), particularly dark-green vegetables (P = 0.002). Because the findings reported here are associative in nature, prospective studies are needed to determine if dietary dark-green vegetables or nutrients contained in these foods can enhance the efficacy of ω-3 fatty acid supplements. This trial was registered at clinicaltrials.gov as NCT00536185.

Plasma phospholipid omega-3 fatty acids and incidence of postoperative atrial fibrillation in the OPERA trial

Background

Long‐chain polyunsaturated omega‐3 fatty acids (n‐3 PUFA) demonstrated antiarrhythmic potential in experimental studies. In a large multinational randomized trial (OPERA), perioperative fish oil supplementation did not reduce the risk of postoperative atrial fibrillation (PoAF) in cardiac surgery patients. However, whether presupplementation habitual plasma phospholipid n‐3 PUFA, or achieved or change in n‐3 PUFA level postsupplementation are associated with lower risk of PoAF is unknown.

Methods and Results

In 564 subjects undergoing cardiac surgery between August 2010 and June 2012 in 28 centers across 3 countries, plasma phospholipid levels of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) were measured at enrollment and again on the morning of cardiac surgery following fish oil or placebo supplementation (10 g over 3 to 5 days, or 8 g over 2 days). The primary endpoint was incident PoAF lasting ≥30 seconds, centrally adjudicated, and confirmed by rhythm strip or ECG. Secondary endpoints included sustained (≥1 hour), symptomatic, or treated PoAF; the time to first PoAF; and the number of PoAF episodes per patient. PoAF outcomes were assessed until hospital discharge or postoperative day 10, whichever occurred first. Relative to the baseline, fish oil supplementation increased phospholipid concentrations of EPA (+142%), DPA (+13%), and DHA (+22%) (P<0.001 each). Substantial interindividual variability was observed for change in total n‐3 PUFA (range=−0.7% to 7.5% after 5 days of supplementation). Neither individual nor total circulating n‐3 PUFA levels at enrollment, morning of surgery, or change between these time points were associated with risk of PoAF. The multivariable‐adjusted OR (95% CI) across increasing quartiles of total n‐3 PUFA at enrollment were 1.0, 1.06 (0.60 to 1.90), 1.35 (0.76 to 2.38), and 1.19 (0.64 to 2.20); and for changes in n‐3 PUFA between enrollment and the morning of surgery were 1.0, 0.78 (0.44 to 1.39), 0.89 (0.51 to 1.55), and 1.01 (0.58 to 1.75). In stratified analysis, demographic, medication, and cardiac parameters did not significantly modify these associations. Findings were similar for secondary PoAF endpoints.

Conclusions

Among patients undergoing cardiac surgery, neither higher habitual circulating n‐3 PUFA levels, nor achieved levels or changes following short‐term fish oil supplementation are associated with risk of PoAF.

Clinical Trial Registration

URL: Clinicaltrials.gov Unique identifier: NCT00970489

Docosahexaenoic acid supplementation, vascular function and risk factors for cardiovascular disease: a randomized controlled trial in young adults

Background

A high consumption of omega‐3 long‐chain polyunsaturated fatty acids, and particularly docosahexaenoic acid (DHA), has been suggested to reduce the risk of cardiovascular disease (CVD). However, while DHA supplementation may have benefits for secondary prevention, few studies have investigated the role of DHA in the primary prevention of CVD. Here, we tested the hypothesis that DHA supplementation improves endothelial function and risk factors for CVD.

Methods and Results

Healthy volunteers (n=328), aged 18 to 37 years, were randomly assigned to 1.6 g DHA/day (from a microalgae source) together with 2.4 g/day carrier oil (index group) or to 4.0 g/day olive oil (control) (both given in eight 500‐mg capsules/day for 16 weeks). Flow‐mediated endothelium‐dependent vasodilation (FMD) of the brachial artery (primary outcome) was measured before and after the intervention (n=268) using high‐resolution vascular ultrasound. FMD was the same in both groups at randomization (mean, SD; 0.27, 0.1 mm), but postintervention was higher in the control group (0.29, 0.1 mm) compared with the DHA‐supplemented group (0.26, 0.1 mm; mean difference −0.03 mm; 95% CI −0.005 to −0.06 mm; P=0.02). Of other outcomes, only triglyceride (mean difference −28%, 95% CI −40% to −15%; P<0.0001) and very low‐density lipoprotein concentrations were significant lower in DHA‐supplemented individuals compared with controls.

Conclusions

DHA supplementation did not improve endothelial function in healthy, young adults. Nevertheless, lower triglyceride concentrations with DHA supplementation was consistent with previous reports and could have benefits for the prevention of CVD.

Clinical Trial Registration Information

URL: http://www.controlled-trials.com/ Unique identifier: ISRCTN no: 19987575.

Bioavailability of long-chain omega-3 fatty acids

Supplements have reached a prominent role in improving the supply of long-chain omega-3 fatty acids, such as Eicosapentaenoic acid (EPA 20:5n-3) and Docosahexaenoic acid (DHA 22:6n-3). Similar to other nutrients, the availability of omega-3 fatty acids is highly variable and determined by numerous factors. However, the question of omega-3 fatty acids bioavailability has long been disregarded, which may have contributed to the neutral or negative results concerning their effects in several studies. This review provides an overview of the influence of chemical binding form (free fatty acids bound in ethylesters, triacylglycerides or phospholipids), matrix effects (capsule ingestion with concomitant intake of food, fat content in food) or galenic form (i.e. microencapsulation, emulsification) on the bioavailability of omega-3 fatty acids. There is a need to systematically investigate the bioavailability of omega-3 fatty acids formulations, which might be a key to designing more effective studies in the future.