A Food-Based Intervention in a Military Dining Facility Improves Blood Fatty Acid Profile

Enhancing dietary omega-3 highly unsaturated fatty acids (n-3 HUFA) intake may confer neuroprotection, brain resiliency, improve wound healing and promote cardiovascular health. This study determined the efficacy of substituting a few common foods (chicken meat, chicken sausage, eggs, salad dressings, pasta sauces, cooking oil, mayonnaise, and peanut butter) lower in omega-6 polyunsaturated fatty acids (n-6 PUFA) and higher in n-3 HUFA in a dining facility on blood fatty acid profile. An eight-week prospective, between-subjects (n = 77), repeated measures, parallel-arm trial was conducted. Participants self-selected foods consumed from conventionally produced foods (control), or those lower n-6 PUFA and higher n-3 HUFA versions (intervention). Changes in blood omega-3 index, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), n-6 PUFA, lipid profile, and food satisfaction were main outcomes. Between-group differences over time were assessed using a linear mixed model to measure the effect of diet on blood serum fatty acids and inflammatory markers. The intervention group achieved a higher omega-3 index score (3.66 ± 0.71 vs. 2.95 ± 0.77; p < 0.05), lower total n-6 (10.1 ± 4.6 vs. 15.3 ± 6.7 µg/mL; p < 0.05), and higher serum concentration of EPA (5.0 ± 1.31 vs. 4.05 ± 1.56 µg/mL; p < 0.05) vs. controls. Satisfaction in intervention foods improved or remained consistent. Substitution of commonly eaten dining facility foods with like-items higher in DHA and EPA and lower in n-6 PUFA can favorably impact fatty acid status and the omega-3 index.     

Validation of an Australian electronic food frequency questionnaire to measure polyunsaturated fatty acid intake

Objective

To develop and validate a simple non-invasive method that estimates the intakes of omega-3 and omega-6 polyunsaturated fatty acids (PUFA) in a healthy adult population.

Methods

A new electronic PUFA food frequency questionnaire (FFQ) was validated by comparison with a 3-d weighed food record and blood biomarkers (erythrocytes and plasma) using the method of triads model and tested for reproducibility. Healthy subjects were recruited from the local Illawarra Region, New South Wales, Australia.

Results

The PUFA FFQ adequately estimated intakes for eicosapentaenoic acid, docosahexaenoic acid, total long chain omega-3 PUFA, linoleic acid, total omega-6 PUFA, and total PUFA, which were comparable with results from the 3-d food record. Eicosapentaenoic acid, docosahexaenoic acid, and total long chain omega-3 showed high validity coefficients for erythrocytes (and plasma) 0.92 (0.87), 0.69 (0.64), and 0.78 (0.73) (P < 0.05), respectively. Spearman’s rank correlation coefficients ranged from 0.48 to 0.76 when the PUFA FFQ was tested for reproducibility (P < 0.05).

Conclusion

The electronic PUFA questionnaire was found to be reproducible and is a valid tool to assess PUFA intakes in a healthy adult population.     

Bioavailability of long-chain omega-3 polyunsaturated fatty acid enriched luncheon meats

(Nutr Diet 2005;62:130–137) Objective: To determine the acute and chronic effects of low doses of long chain (LC) n‐3 polyunsaturated fatty acids (PUFA) on plasma LC n‐3 PUFA levels. Design: In the acute study, six healthy omnivores, avoiding fish meals on the day prior to the study, provided a fasting blood sample initially and post prandially at four hours. In the chronic study, 12 healthy subjects provided a fasting blood sample at baseline and three weeks after daily consumption of the test food. Main outcome measures: Plasma non‐esterified fatty acid and phospholipid LC n‐3 PUFA composition. Statistical analysis: Differences in plasma non‐esterified fatty acids and phospholipid LC n‐3 PUFA. A pre‐ and post‐consumption of the test food were assessed using paired t‐tests (spss ). Results: The acute study demonstrated that a low dose of LC n‐3 PUFA (25% eicosapentaenoic acid and 75% docosahexaenoic acid) significantly increased eicosapentaenoic acid levels in plasma of human subjects postprandially from 0.30% to 0.42% of total non‐esterified fatty acids, a per cent change of 39% (P < 0.05). The chronic study demonstrated a significant increase in total n‐3 phospholipids from zero weeks (5.48% of total fatty acids) to three weeks (7.92% of total fatty acids), representing a per cent increase of 44% (P = 0.006). The n‐6 to n‐3 ratio of LC PUFA phospholipids demonstrated a significant reduction from 5.1 at zero weeks to 4.07 at three weeks, representing a reduction of 20% (P = 0.006). Conclusions: These findings demonstrate the bioavailability of LC n‐3 PUFA consumed as a low‐fat omega‐3‐enriched luncheon meat.     

Cardiac mortality is associated with low levels of omega-3 and omega-6 fatty acids in the heart of cadavers with a history of coronary heart disease

The benefits of omega-3 (ie, eicosapentaenoic acid and docosahexaenoic acid [DHA]) and omega-6 (ie, linoleic acid and arachidonic acid [AA]) fatty acids on reducing cardiac mortality are still debated. In this study, we tested the hypothesis that high levels of omega-3 and omega-6 fatty acids in heart tissues are associated with low cardiac mortality in Thai cadavers. One hundred fresh cadavers were examined in this study. The cause of death, history of coronary heart disease (CHD), and fish consumption habits were obtained from death certificates, cadaver medical record profiles, and a questionnaire to a person who lived with the subject before death. In each cadaver, biopsies of cardiac tissues were taken from the interventricular septum for measurement of fatty acid. Of the 100 cadavers (average age, 69 ± 13 years), 60 were men. The frequency of fish consumption was directly associated with omega-3 and omega-6 fatty acids in heart tissues (P < .01). History of CHD and cause of death (cardiac vs noncardiac) were not significantly associated with levels of omega-3 or omega-6 fatty acids. However, in cadavers with a history of CHD, high levels of omega-3 and omega-6, particularly DHA and AA, were associated with low cardiac mortality (P < .05). Fish consumption is associated with levels of omega-3 and omega-6 fatty acids in heart tissues. Although omega-3 and omega-6 fatty acids are not associated with cardiac mortality in the overall studied population, their low levels (especially DHA and AA) in heart tissues are associated with high cardiac mortality in cadavers with a history of CHD.     

Dietary and Plasma Phospholipid Profiles in Vegans and Omnivores—Results from the RBVD Study

Over the last few years, the vegan diet has become increasingly popular in Germany. It has been proposed that this diet is generally lower in fat, but less is known about the impact on fatty acid (FA) profiles. Therefore, the cross-sectional “Risks and Benefits of a Vegan Diet” (RBVD) study (n = 72) was used to investigate dietary FA intake as well as plasma phospholipid FA in vegans (n = 36) compared to omnivores (n = 36). Vegans had a significantly lower dietary intake of total fat (median 86 g/day, IQR 64–111) in comparison to omnivores (median 104 g/day, IQR 88–143, p = 0.004). Further, vegans had a lower intake of saturated fatty acids (SFA) (p < 0.0001) and monounsaturated fatty acids (MUFA) (p = 0.001) compared to omnivores. Vegans had a higher intake in total polyunsaturated fatty acids (PUFA), omega-3 and omega-6 PUFA compared to omnivores, but without statistical significance after Bonferroni correction. According to plasma phospholipid profiles, relatively lower proportions of SFA (p < 0.0001), total trans fatty acids (TFA) (p = 0.0004) and omega-3-FA (p < 0.0001), but higher proportions of omega-6-FA (p < 0.0001) were observed in vegans. With the exception of omega-3 PUFA, a vegan diet is associated with a more favorable dietary fat intake and more favorable plasma FA profiles and therefore may reduce cardiovascular risk.     

An acute intake of a walnut-enriched meal improves postprandial adiponectin response in healthy young adults

A deficit in adiponectin plays an important causal role in insulin resistance and metabolic syndrome. We hypothesized that as seen during the fasting state, the intake of a walnut-enriched meal increased postprandial adiponectin. Twenty-one healthy white men followed a 4-week baseline diet and then consumed 3 fat-loaded meals that included 1 g fat/kg body weight (65% fat) according to a randomized crossover design: olive oil–enriched meal (22% saturated fatty acids [SFA], 38% monounsaturated fatty acids [MUFA], 4% polyunsaturated fatty acids [PUFA]), butter-enriched meal (35% SFA, 22% MUFA, 4% PUFA), and walnut-enriched meal (20% SFA, 24% MUFA, 16% PUFA, and 4% α-linolenic acid). Leptin, resistin, adiponectin, and free fatty acids were determined at 0, 3, 6, and 8.5 hours after the fat load. After the walnut-enriched meal, plasma adiponectin concentrations were higher at 3 and 6 hours (P = .011, P = .046, respectively) compared with the butter-enriched meal and higher at 6 hours compared with the olive oil–enriched meal (P = .036). Free fatty acid levels decreased from baseline at 3 hours after the walnut-enriched meal (P = .001). No differences were observed between the 3 meals for leptin and resistin responses. Our data confirmed a beneficial profile in the postprandial response to walnuts, source of omega-3 PUFA with an increased postprandial adiponectin and lower postprandial free fatty acid responses. These findings suggest that the postprandial state is important for understanding the possible cardioprotective effects associated with omega-3 PUFA dietary fat.     

Association between Polymorphisms in the Fatty Acid Desaturase Gene Cluster and the Plasma Triacylglycerol Response to an n-3 PUFA Supplementation

Eicosapentaenoic and docosahexaenoic acids have been reported to have a variety of beneficial effects on cardiovascular disease risk factors. However, a large inter-individual variability in the plasma lipid response to an omega-3 (n-3) polyunsaturated fatty acid (PUFA) supplementation is observed in different studies. Genetic variations may influence plasma lipid responsiveness. The aim of the present study was to examine the effects of a supplementation with n-3 PUFA on the plasma lipid profile in relation to the presence of single-nucleotide polymorphisms (SNPs) in the fatty acid desaturase (FADS) gene cluster. A total of 208 subjects from Quebec City area were supplemented with 3 g/day of n-3 PUFA, during six weeks. In a statistical model including the effect of the genotype, the supplementation and the genotype by supplementation interaction, SNP rs174546 was significantly associated (p = 0.02) with plasma triglyceride (TG) levels, pre- and post-supplementation. The n-3 supplementation had an independent effect on plasma TG levels and no significant genotype by supplementation interaction effects were observed. In summary, our data support the notion that the FADS gene cluster is a major determinant of plasma TG levels. SNP rs174546 may be an important SNP associated with plasma TG levels and FADS1 gene expression independently of a nutritional intervention with n-3 PUFA.     

An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity

In the past three decades, total fat and saturated fat intake as a percentage of total calories has continuously decreased in Western diets, while the intake of omega-6 fatty acid increased and the omega-3 fatty acid decreased, resulting in a large increase in the omega-6/omega-3 ratio from 1:1 during evolution to 20:1 today or even higher. This change in the composition of fatty acids parallels a significant increase in the prevalence of overweight and obesity. Experimental studies have suggested that omega-6 and omega-3 fatty acids elicit divergent effects on body fat gain through mechanisms of adipogenesis, browning of adipose tissue, lipid homeostasis, brain-gut-adipose tissue axis, and most importantly systemic inflammation. Prospective studies clearly show an increase in the risk of obesity as the level of omega-6 fatty acids and the omega-6/omega-3 ratio increase in red blood cell (RBC) membrane phospholipids, whereas high omega-3 RBC membrane phospholipids decrease the risk of obesity. Recent studies in humans show that in addition to absolute amounts of omega-6 and omega-3 fatty acid intake, the omega-6/omega-3 ratio plays an important role in increasing the development of obesity via both AA eicosanoid metabolites and hyperactivity of the cannabinoid system, which can be reversed with increased intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A balanced omega-6/omega-3 ratio is important for health and in the prevention and management of obesity.     

Suboptimal Plasma Long Chain n-3 Concentrations are Common among Adults in the United States,NHANES 2003–2004

Population data on long-chain omega-3 polyunsaturated fatty acid (LCn-3 PUFA) status from biomarkers of dietary intake is lacking. The objectives were to describe plasma LCn-3 PUFA concentrations and compare them to concentrations associated with cardiovascular health and dietary recommendations for two servings of seafood/week. Fasting plasma fatty acids were measured among 1386 subjects ≥20 years from the National Health and Nutrition Examination Survey, 2003–2004. LCn-3 concentrations represent the sum of eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid relative to total fatty acids (expressed as a percentage). Mean LCn-3 PUFA concentration was 2.07% (95% CI 1.95–2.19). Overall, 80.6% of participants had LCn-3 below concentrations recommended for cardiovascular health. Hispanic participants were the most likely to have LCn-3 PUFA below recommended levels. Nearly all participants (95.7%) had LCn-3 below concentrations associated with cardiovascular protection. Older participants (≥60 years) had higher LCn-3 PUFA concentrations than those aged 20–39 years but not aged 40–59 years. LCn-3 PUFA concentrations were lower for Hispanic participants relative to non-Hispanic black participants. Suboptimal LCn-3 concentrations are common among U.S. adults. These findings highlight the need to increase LCn-3 intake among Americans.     

Total dietary fat and fatty acid content modifies plasma phospholipid fatty acids,desaturase activity indices,and urinary prostaglandin E in women

Compared with diets high in fat, low-fat diets are associated with reduced risk of cardiovascular disease. We hypothesized that a low-fat (LF) (20% fat) and an LF high–omega-3 (n-3) fatty acid diet (LFn3) (23% fat with 3% as α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid [DHA]) would enhance n-3 composition of plasma phospholipid fatty acid and reduce urinary prostaglandin E₂ (PGE₂) relative to a high-fat diet (HF) (40% fat) and that these changes would be associated with alterations in δ5 desaturase (D5D) and δ6 desaturase (D6D) activity. Phospholipid fatty acids and urinary PGE₂ were measured, and D5D and D6D activity indices calculated in a crossover trial in 17 postmenopausal women fed each of 3 test diets (HF, LF, and LFn3) for 8-week feeding periods. Desaturase activity indices were calculated as D5D, 20:4n-6/20:3n-6, and D6D, 20:3n-6/18:2n-6. Plasma phospholipid fatty acid, α-linolenic acid, eicosapentaenoic acid, docosapentaenoic acid (DPA), DHA, and total n-3 fatty acids increased, whereas linoleic acid and arachidonic acid decreased with consumption of LFn3. The LF resulted in enhanced arachidonic acid and DHA. High fat reduced D6D, whereas both HF and LF increased D5D. Urinary PGE₂ was reduced in response to both the LF and LFn3 diets. Low-fat diets, with or without long-chain n-3 fatty acids, promote positive health effects due in part to favorable alteration of plasma phospholipid fatty acid profiles and modification in desaturase activity indices, suggesting that the type and amount of fat consumed are modifiable risk factors for the prevention of cardiovascular disease.     

The content of docosahexaenoic acid in serum phospholipid is inversely correlated with plasma homocysteine levels in patients with end-stage renal disease

Patients with end-stage renal disease (ESRD) have a high morbidity and mortality from cardiovascular disease. An elevated homocysteine level is an independent predictor of cardiovascular events in patients with ESRD. Interestingly, some studies have found an inverse relationship between the content of marine n-3 polyunsaturated fatty acids (PUFAs) and homocysteine levels, but data are ambiguous. In patients with ESRD, we hypothesized that serum phospholipid n-3 PUFA content would inversely correlate with homocysteine levels in plasma and that supplementation with n-3 PUFA would reduce plasma homocysteine levels. In a double-blind, randomized, controlled design, 206 patients with documented cardiovascular disease and treated with hemodialysis for a minimum of 6 months were randomized to treatment with daily supplement of 1.7 g n-3 PUFA or placebo (olive oil) for 3 months. The content of n-3 PUFA in serum phospholipids and homocysteine levels in plasma were measured at baseline and after 3 months of intervention. A dietary questionnaire was filled out at baseline, and study participants were divided into groups of low, intermediate, and high fish intake. Docosahexaenoic acid was inversely correlated with homocysteine at baseline (coefficient = −0.161; P = .03). Homocysteine was not related to self-reported fish intake. Supplementation with n-3 PUFA did not reduce homocysteine levels compared with placebo (mean ± SD difference, −0.3 ± 7.8 versus 0.3 ± 7.1; P = .58). The content of docosahexaenoic acid in serum phospholipids is inversely correlated with plasma homocysteine levels, and supplementation with n-3 PUFA does not reduce homocysteine levels in patients with ESRD.     

Alternative Sources of Omega-3 Fats: Can We Find a Sustainable Substitute for Fish?

Increasing demand for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) containing fish oils is putting pressure on fish species and numbers. Fisheries provide fish for human consumption, supplement production and fish feeds and are currently supplying fish at a maximum historical rate, suggesting mass-scale fishing is no longer sustainable. However, the health properties of EPA and DHA long-chain (LC) omega-3 polyunsaturated fatty acids (PUFA) demonstrate the necessity for these oils in our diets. EPA and DHA from fish oils show favourable effects in inflammatory bowel disease, some cancers and cardiovascular complications. The high prevalence of these diseases worldwide indicates the requirement for alternative sources of LC-PUFA. Strategies have included plant-based fish diets, although this may compromise the health benefits associated with fish oils. Alternatively, stearidonic acid, the product of α-linolenic acid desaturation, may act as an EPA-enhancing fatty acid. Additionally, algae oils may be a promising omega-3 PUFA source for the future. Algae are beneficial for multiple industries, offering a source of biodiesel and livestock feeds. However, further research is required to develop efficient and sustainable LC-PUFA production from algae. This paper summarises the recent research for developing prospective substitutes for omega-3 PUFA and the current limitations that are faced.     

Evaluation of the composition of omega-3 fatty acids in dietary oil supplements

Aim: The aim of the present study was to determine the fatty acid composition of 19 dietary oil supplements that are commercially available in Australia, comparing findings with manufacturers' reported omega-3 fatty acid content. Methods: Fifteen fish oil supplements and four non-fish oil supplements were obtained from Australian retail stores. Fatty acids were derivatised, and fatty acid methyl esters were quantitated using classical GC-flame ionisation detection methods. Composition of eicosapentaenoic acid and docosahexaenoic acid reported by supplement manufacturers was compared with experimental values using the Bland-Altman plot. Results: The combined eicosapentaenoic acid and docosahexaenoic acid content in the fish oil and non-fish oil supplements was 17.63–71.45% and 0.00–0.05% respectively. A high level of congruency was observed for the composition of eicosapentaenoic acid and docosahexaenoic acid reported by manufacturers and determined experimentally (mean difference, eicosapentaenoic acid, 13.2 mg; docosahexaenoic acid, 12.8 mg). Conclusion: Current practice in pre-market assessment of complementary medicines in Australia is satisfactory for supplements examined in the present study. Intake of these fish oil supplements can be used to provide high levels of long-chain omega-3 fatty acids that would be otherwise difficult to achieve through normal dietary intake alone.     

Polymorphisms in Genes Involved in Fatty Acid β-Oxidation Interact with Dietary Fat Intakes to Modulate the Plasma TG Response to a Fish Oil Supplementation

A large inter-individual variability in the plasma triglyceride (TG) response to an omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation has been observed. The objective was to examine gene-diet interaction effects on the plasma TG response after a fish oil supplementation, between single-nucleotide polymorphisms (SNPs) within genes involved in fatty acid β-oxidation and dietary fat intakes. Two hundred and eight (208) participants were recruited in the greater Quebec City area. The participants completed a six-week fish oil supplementation (5 g fish oil/day: 1.9–2.2 g EPA and 1.1 g DHA). Dietary fat intakes were measured using three-day food records. SNPs within RXRA, CPT1A, ACADVL, ACAA2, ABCD2, ACOX1 and ACAA1 genes were genotyped using TAQMAN methodology. Gene-diet interaction effects on the plasma TG response were observed for SNPs within RXRA (rs11185660, rs10881576 and rs12339187) and ACOX1 (rs17583163) genes. For rs11185660, fold changes in RXRA gene expression levels were different depending on SFA intakes for homozygotes T/T. Gene-diet interaction effects of SNPs within genes involved in fatty acid β-oxidation and dietary fat intakes may be important in understanding the inter-individual variability in plasma TG levels and in the plasma TG response to a fish oil supplementation.     

Erythrocyte α-linolenic acid is associated with the risk for mild dementia in Korean elderly

n-3 polyunsaturated fatty acids (PUFA) play an important role in brain development and function, but there is conflicting evidence between the relationship of n-3 PUFA and dementia in the elderly. The purpose of the present study was to test the hypothesis that n-3 PUFA content of erythrocytes is associated with mild dementia in elderly Koreans. Fifty-seven elderly (age ≥65 years) patients (19 male, 38 female) were recruited, and indicators of dementia (intake, erythrocyte fatty acid composition, and Mini-Mental Status Examination—Korean Version [MMSE-K]) were evaluated. Patients were divided into groups based on their MMSE-K score: normal control group (score >21 [n = 24]) and deficit group (score ≤21 [n = 33]). Multivariate-adjusted regression analysis showed that a higher level of α-linolenic acid (ALA; 18:3n-3) significantly decreased the risk of mild dementia after adjusting for age, sex, and height. MMSE-K score was also significantly and positively associated with erythrocyte ALA and total n-3 PUFA. However, erythrocyte levels of docosahexaenoic acid (22:6n-3) and eicosapentaenoic acid (20:5n-3) were not significantly related with the risk of mild dementia and MMSE-K score. Dietary intake was also not significantly associated with the risk of mild dementia and MMSE-K score after adjusting for age, sex, height, and energy intake. In conclusion, ALA derived from plant sources of n-3 PUFA, but not eicosapentaenoic acid and docosahexaenoic acid from fish, decreased the risk for mild dementia among the Korean elderly.     

Omega-3 fatty acid supplementation increases 1,25-dihydroxyvitamin D and fetuin-A levels in dialysis patients

Vitamin D deficiency, low levels of fetuin-A, and fibroblast growth factor 23 (FGF-23) are related to vascular calcification, which is associated with cardiovascular disease. We hypothesized that omega-3 fatty acid (FA), which has cardioprotective properties, modifies vitamin D status, fetuin-A, and FGF-23 levels in dialysis patients. In a randomized, open-label, controlled study, a total of 47 patients treated with dialysis for at least 1 year were randomized to treatment for 6 months with omega-3 FAs (Omacor, 3 g/d; Pronova, Sandefjord, Norway) or a control group. Levels of fetuin-A and FGF-23 were measured by enzyme-linked immunoassay, 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were measured by radioimmunoassay. The mean age of the enrolled patients was 57.4 ± 10.4 years, and mean dialysis duration was 46.5 ± 28.1 months. Twenty-seven hemodialysis patients and 16 peritoneal dialysis patients finished this trial. After 6 months, the levels of 1,25-dihydroxyvitamin D and fetuin-A were significantly increased in the group taking the omega-3 FA supplement compared with baseline. Levels of calcium, phosphorous, parathyroid hormone, 25-hydroxyvitamin D, FGF-23, and lipid profiles were not significantly changed in the omega-3 FA–supplemented group after 6 months compared with baseline. The erythrocyte membrane contents of eicosapentaenoic acid and docosahexaenoic acid were significantly increased, and oleic acid content was significantly decreased in the omega-3 FA–supplemented group after 6 months compared with baseline. Regarding vascular calcification and cardiovascular disease, omega-3 FA supplementation may have a clinical benefit caused by activating vitamin D, increasing fetuin-A levels, and modifying erythrocyte membrane FA contents in dialysis patients.     

Beneficial Outcomes of Omega-6 and Omega-3 Polyunsaturated Fatty Acids on Human Health: An Update for 2021

Oxidative stress and inflammation have been recognized as important contributors to the risk of chronic non-communicable diseases. Polyunsaturated fatty acids (PUFAs) may regulate the antioxidant signaling pathway and modulate inflammatory processes. They also influence hepatic lipid metabolism and physiological responses of other organs, including the heart. Longitudinal prospective cohort studies demonstrate that there is an association between moderate intake of the omega-6 PUFA linoleic acid and lower risk of cardiovascular diseases (CVDs), most likely as a result of lower blood cholesterol concentration. Current evidence suggests that increasing intake of arachidonic acid (up to 1500 mg/day) has no adverse effect on platelet aggregation and blood clotting, immune function and markers of inflammation, but may benefit muscle and cognitive performance. Many studies show that higher intakes of omega-3 PUFAs, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are associated with a lower incidence of chronic diseases characterized by elevated inflammation, including CVDs. This is because of the multiple molecular and cellular actions of EPA and DHA. Intervention trials using EPA + DHA indicate benefit on CVD mortality and a significant inverse linear dose–response relationship has been found between EPA + DHA intake and CVD outcomes. In addition to their antioxidant and anti-inflammatory roles, omega-3 fatty acids are considered to regulate platelet homeostasis and lower risk of thrombosis, which together indicate their potential use in COVID-19 therapy.     

Serum lipid profile and fatty acid composition of erythrocyte phospholipids in children and adolescents with primary hyperlipidemia

This study aimed at characterizing the fatty acid (FA) composition of red blood cell (RBC) phospholipids in children and adolescents with primary hyperlipidemia, and to ascertain potential association with serum lipid profile and dietary factors. At this purpose, 54 probands aged 6–17 years were recruited. Subjects showed a low omega-3 index (eicosapentaenoic acid, EPA?+?docosahexaenoic acid, DHA <4%). Compared to males, females had a trend toward lower levels of total monounsaturated fatty acids (MUFA) and MUFA/saturated fatty acids (SFAs) ratio in RBCs. An inverse relationship between MUFA concentration in RBCs and serum cholesterol or HDL-C/triglycerides ratio was found. Omega-6 polyunsaturated fatty acids (n-6 PUFA) were positively associated to serum HDL-C levels, and inversely to dietary cholesterol. Fiber intake was positively associated with MUFA/SFA ratio. In conclusion, we provide the first experimental data on phospholipid FA composition of RBCs in hyperlipidemic children, showing sex differences and an overall low omega 3-index.     

Validity and reliability of an omega-3 fatty acid food frequency questionnaire for first-generation Midwestern Latinas

This study tested the hypothesis that a culturally developed omega-3 (n-3) fatty acid food frequency questionnaire (FFQ) could be an accurate instrument to capture n-3 fatty acid food intakes of first-generation Midwestern Latinas. The goal of the study was to assess validity and test-retest reliability of an FFQ to estimate total n-3 fatty acid (total n-3), α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) intakes. An n-3 FFQ was developed and pilot tested. Two FFQs and 3 nonconsecutive 24-hour recalls were collected from 162 participants. Pearson correlation and paired t test were used to test the hypothesis. Correlation of the 2 FFQs was 0.71 for total n-3, 0.65 for ALA, 0.74 for EPA, and 0.54 for DHA (P < .01). The means of the 2 FFQs and of the 24-hour recalls were not significantly different for total n-3 and ALA (P > .05), but were significantly different for EPA and DHA. The n-3 FFQ had acceptable reliability, validated only total n-3 and ALA, and provided relevant findings about the n-3 eating habits of Midwestern Latinas.     

Heart Rate Variability and Long Chain n-3 Polyunsaturated Fatty Acids in Chronic Kidney Disease Patients on Haemodialysis: A Cross-Sectional Pilot Study

Low heart rate variability (HRV) is independently associated with increased risk of sudden cardiac death (SCD) and all cardiac death in haemodialysis patients. Long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) may exert anti-arrhythmic effects. This study aimed to investigate relationships between dialysis, sleep and 24 h HRV and LC n-3 PUFA status in patients who have recently commenced haemodialysis. A cross-sectional study was conducted in adults aged 40–80 with chronic kidney disease (CKD) stage 5 (n = 45, mean age 58, SD 9, 20 females and 25 males, 39% with type 2 diabetes). Pre-dialysis blood samples were taken to measure erythrocyte and plasma fatty acid composition (wt % fatty acids). Mean erythrocyte omega-3 index was not associated with HRV following adjustment for age, BMI and use of β-blocker medication. Higher ratios of erythrocyte eicosapentaenoic acid (EPA) to docosahexaenoic acid (DHA) were associated with lower 24 h vagally-mediated beat-to-beat HRV parameters. Higher plasma EPA and docosapentaenoic acid (DPAn-3) were also associated with lower sleep-time and 24 h beat-to-beat variability. In contrast, higher plasma EPA was significantly related to higher overall and longer phase components of 24 h HRV. Further investigation is required to investigate whether patients commencing haemodialysis may have compromised conversion of EPA to DHA, which may impair vagally-mediated regulation of cardiac autonomic function, increasing risk of SCD.