Influence of dietary supplementation with long-chain n-3 or n-6 polyunsaturated fatty acids on blood inflammatory cell populations and functions and on plasma soluble adhesion molecules in healthy adults

Long chain n-3 polyunsaturated fatty acids are not associated with circulating T-helper type 1 cells: Results from the Multi-Ethnic Study of Atherosclerosis (MESA)

T-helper type 1 (Th1) cells are pro-inflammatory and provide signals to immune cells. Animal models and in vitro human cell culture experiments have indicated that long chain n-3 polyunsaturated fatty acids (LCn3PUFAs) reduce Th1 cell levels; however, the association is unknown in healthy humans. We hypothesized that circulating levels and dietary intake of LCn3PUFAs have an inverse association with circulating levels of Th1 cells and studied 895 participants in the Multi-Ethnic Study of Atherosclerosis (age 61 ± 10 years at exam 1, 52% women, 44% white, 21% African-American, 24% Hispanic-American, 11% Chinese-American). Phospholipid LCn3PUFAs (% of total fatty acids), measured by gas chromatography, and intake of LCn3PUFAs, evaluated by food frequency questionnaire, were evaluated at exam 1 (2000-02) and defined as the sum of eicosapentaenoic and docosahexaenoic acids. Th1 cells were measured by flow cytometry at exam 4 (2005-07), expressed as a percentage of CD4⁺ lymphocytes that were interferon-γ⁺ (%Th1: CD4⁺IFN-γ⁺). Median (interquartile range) plasma LCn3PUFA, dietary LCn3PUFA, and %Th1 levels were 4.31% (3.40-5.82%), 0.09 (0.05-0.16) g/day, and 14.4% (9.8-20.0%), respectively. When the association of LCn3PUFA-quartiles with %Th1 was analyzed using general linear models, neither plasma nor dietary LCn3PUFAs were significantly associated with %Th1 (P-trend = 0.58 and 0.80, respectively), which remained even after adjusting for demographics, lifestyle factors, lipids, season, and cytomegalovirus titers. In this multi-ethnic U.S. population, circulating levels and dietary intake of LCn3PUFAs were not significantly associated with Th1 cell levels. Further research is needed to assess potential benefits of supplementation and much higher dietary consumption of LCn3PUFAs on Th1 cells.

Eicosapentaenoic acid and docosahexaenoic acid containing supplements modulate risk factors for cardiovascular disease: a meta-analysis of randomised placebo-control human clinical trials

BACKGROUND

Over 200 clinical trials have examined the effect of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplements on risk factors associated with cardiovascular disease. However, an updated analysis of the evidence is lacking. The aim of the present meta-analysis was to quantify the effect of supplements containing EPA and DHA on risk factors for cardiovascular disease.

METHODS

An analysis was carried on 171 clinical trials with acceptable quality (Jadad score ≥3) that were identified from a comprehensive electronic search strategy of two databases (Pubmed and Cochrane Library). A random effect model was used to obtain an overall estimate on outcomes of interest. Heterogeneity between trial results was tested for using a standard chi-squared test.

RESULTS

Compared with control, EPA and DHA supplements produced significant reductions of triglycerides of 0.368 mmol L^-1 [95% confidence interval (CI) = -0.427 to -0.309], systolic blood pressure of 2.195 mmHg (95% CI = -3.172 to -1.217), diastolic blood pressure of 1.08 mmHg (95% CI = -1.716 to -0.444), heart rate of 1.37 bpm (95% CI = -2.41 to -0.325) and C-reactive protein of 0.343 mg L^-1 (95% CI = -0.454 to -0.232). This analysis indicates an increase in both low-density lipoprotein cholesterol (mean difference = 0.150 mmol L^-1 ; 95% CI = 0.058-0.243) and high-density lipoprotein cholesterol (mean difference = 0.039 mmol L^-1 ; 95% CI = 0.024-0.054). The triglyceride-lowering effect was dose-dependent.

CONCLUSIONS

The lipid-lowering, hypotensive, anti-arrhythmic and anti-inflammatory actions of EPA and DHA supplements were confirmed in this analysis of randomised placebo-control blinded clinical trials.

Omega-3-Fortified Lipid-Based Nutrient Supplement: Development, Characterization, and Consumer Acceptability

Background:

Incorporation of omega-3 polyunsaturated fatty acid (PUFA) sources to lipid-based nutrition supplement (LNS) formulations for undernourished populations presents a challenge due to reduced shelf life and poor consumer acceptability.

Objective:

To systematically develop an omega-3-fortified LNS formulation, using flaxseed oil (FO), by optimizing its processing stability and evaluating its sensory acceptance.

Methods:

LNS formulations were formulated to yield approximately 452 kcal, 13.2 g of protein, 30 g of fat, and 53 g of carbohydrates per 100 g. Response surface methodology (RSM) with 4-factor-3-level: omega-3 fatty acid source (FO; 0%-10%), antioxidant (ascorbyl palmitate: 0.0%-0.03%), emulsifier (soy lecithin: 0.5%-1.5%), and storage time (0-6 months at 40°C) was used to optimize LNS’s functionality and storage stability. Factor effects were evaluated for peroxide value, oil separation, water activity, moisture content, hardness, and vitamin C content of the samples. Consumer acceptability was assessed using a 9-point hedonic scale.

Results:

After 6 months of accelerated storage, the addition of FO to LNS formula resulted in increased peroxide values (7.75 mEq/kg fat) and lipid separation and a reduction in vitamin C and water activity. Optimal levels to maximize storage time and FO and minimize oxidation were 0.02% antioxidant, 1.5% emulsifier, and 4.9% FO. Indian women and students accepted LNS formulations with or without FO similar to other commercial supplements.

Conclusion:

An LNS containing FO with improved omega-6/omega-3 PUFA ratio was successfully formulated with staple Indian ingredients and optimized for storage stability using RSM.

Ketogenic Diet and Cancer-a Perspective

Research of the last two decades showed that chronic low-grade inflammation, elevated blood glucose and insulin levels may play role in the onset of a number of non-communicable diseases such as type 2 diabetes and some forms of cancer. Regular exercise and fasting can ameliorate high blood glucose and insulin levels as well as increase the concentration of plasma ketone bodies. These, in consequence, may lead to reduction of inflammation. Exercise or severe restriction of caloric intake is not always advisable for patients, in particular those suffering from cancer. The ketogenic diet (KD), characterized by high fat, moderate protein and very low carbohydrate composition can evoke a physiological state similar to that triggered by exercise or fasting. These attributes of KD prompted its possible use in treatment of a number of metabolic diseases, including several types of malignancies. Although results from clinical studies employing KD in the treatment of cancer are still limited, the results obtained from animal models are encouraging and show that KD presents a viable option as an adjunct therapy for cancer.

Ageing alters the impact of nutrition on immune function

Immunosenescence during ageing is a major challenge which weakens the ability of older individuals to respond to infection or vaccination. There has been much interest in dietary strategies to improve immunity in older people, but there is an assumption that modulation of the immune response in older people will be based on the same principles as for younger adults. Recent evidence suggests that ageing fundamentally alters the impact of nutrition on immune function. As a result, interpretation of data from studies investigating the impact of diet on immune function is highly dependent on subject age. Study design is critically important when investigating the efficacy of dietary components, and most studies involving older people include rigorous inclusion/exclusion criteria based on medical history, laboratory tests, general health status and often nutritional status. However, immunological status is rarely accounted for, but can vary significantly, even amongst healthy older people. There are several clear examples of age-related changes in immune cell composition, phenotype and/or function, which can directly alter the outcome of an intervention. This review uses two case studies to illustrate how the effects of n-3 PUFA and probiotics differ markedly in young v. older subjects. Evidence from both suggests that baseline differences in immunosenescence influence the outcome of an intervention, highlighting the need for detailed immunological characterisation of subjects prior to interventions. Finally, future work elucidating alterations in metabolic regulation within cells of the immune system as a result of ageing may be important in understanding the impact of diet on immune function in older people.

Diet and Inflammation in Alzheimer's Disease and Related Chronic Diseases: A Review

Inflammation is one of the pathological features of the neurodegenerative disease, Alzheimer's disease (AD). A number of additional disorders are likewise associated with a state of chronic inflammation, including obesity, cardiovascular disease, and type-2 diabetes, which are themselves risk factors for AD. Dietary components have been shown to modify the inflammatory process at several steps of the inflammatory pathway. This review aims to evaluate the published literature on the effect of consumption of pro- or anti-inflammatory dietary constituents on the severity of both AD pathology and related chronic diseases, concentrating on the dietary constituents of flavonoids, spices, and fats. Diet-based anti-inflammatory components could lead to the development of potent novel anti-inflammatory compounds for a range of diseases. However, further work is required to fully characterize the therapeutic potential of such compounds, including gaining an understanding of dose-dependent relationships and limiting factors to effectiveness. Nutritional interventions utilizing anti-inflammatory foods may prove to be a valuable asset in not only delaying or preventing the development of age-related neurodegenerative diseases such as AD, but also treating pre-existing conditions including type-2 diabetes, cardiovascular disease, and obesity.

Omega-3 fatty acids, inflammatory status and biochemical markers of patients with systemic lupus erythematosus: a pilot study

BACKGROUND

Studies have shown that omega-3 fatty acids reduce the concentrations of eicosanoids, cytokines, chemokines, C-reactive protein (CRP) and other inflammatory mediators.

OBJECTIVE

To investigate the effects of omega-3 fatty acids on circulating levels of inflammatory mediators and biochemical markers in women with systemic lupus erythematosus (SLE).

METHODS

Experimental clinical study (clinical trial: NCT02524795); 49 women with SLE (ACR1982/1997) were randomized: 22 to the omega-3 group (daily intake of 1080mg EPA+200mg DHA, for 12 weeks) and 27 to the control group. The inflammatory mediators and biochemical markers at T0 and T1 in omega-3 group were compared using Wilcoxon test. U-Mann-Whitney test was used to compare variations of measured variables [ΔV=pre-treatment (T0)-post-treatment (T1) concentrations] between groups. p<0.05 was considered significant.

RESULTS

The median (interquartile range - IQR) of age was 37 (29-48) years old, of disease duration was 7 (4-13) years, and of SLEDAI-2K was 1 (0-2). The median (IQR) of variation in CRP levels between the two groups showed a decrease in omega-3 group while there was an increase in control group (p=0.008). The serum concentrations of IL-6 and IL-10, leptin and adiponectin did not change after a 12 week treatment.

CONCLUSIONS

Supplementation with omega-3 had no impact on serum concentrations of IL-6, IL-10, leptin and adiponectin in women with SLE and low disease activity. There was a significant decrease of CRP levels as well as evidence that omega-3 may impact total and LDL-cholesterol.

ω-3 Polyunsaturated Fatty Acid Biomarkers and Coronary Heart Disease: Pooling Project of 19 Cohort Studies

IMPORTANCE

The role of ω-3 polyunsaturated fatty acids for primary prevention of coronary heart disease (CHD) remains controversial. Most prior longitudinal studies evaluated self-reported consumption rather than biomarkers.

OBJECTIVE

To evaluate biomarkers of seafood-derived eicosapentaenoic acid (EPA; 20:5ω-3), docosapentaenoic acid (DPA; 22:5ω-3), and docosahexaenoic acid (DHA; 22:6ω-3) and plant-derived α-linolenic acid (ALA; 18:3ω-3) for incident CHD.

DATA SOURCES

A global consortium of 19 studies identified by November 2014.

STUDY SELECTION

Available prospective (cohort, nested case-control) or retrospective studies with circulating or tissue ω-3 biomarkers and ascertained CHD.

DATA EXTRACTION AND SYNTHESIS

Each study conducted standardized, individual-level analysis using harmonized models, exposures, outcomes, and covariates. Findings were centrally pooled using random-effects meta-analysis. Heterogeneity was examined by age, sex, race, diabetes, statins, aspirin, ω-6 levels, and FADS desaturase genes.

MAIN OUTCOMES AND MEASURES

Incident total CHD, fatal CHD, and nonfatal myocardial infarction (MI).

RESULTS

The 19 studies comprised 16 countries, 45 637 unique individuals, and 7973 total CHD, 2781 fatal CHD, and 7157 nonfatal MI events, with ω-3 measures in total plasma, phospholipids, cholesterol esters, and adipose tissue. Median age at baseline was 59 years (range, 18-97 years), and 28 660 (62.8%) were male. In continuous (per 1-SD increase) multivariable-adjusted analyses, the ω-3 biomarkers ALA, DPA, and DHA were associated with a lower risk of fatal CHD, with relative risks (RRs) of 0.91 (95% CI, 0.84-0.98) for ALA, 0.90 (95% CI, 0.85-0.96) for DPA, and 0.90 (95% CI, 0.84-0.96) for DHA. Although DPA was associated with a lower risk of total CHD (RR, 0.94; 95% CI, 0.90-0.99), ALA (RR, 1.00; 95% CI, 0.95-1.05), EPA (RR, 0.94; 95% CI, 0.87-1.02), and DHA (RR, 0.95; 95% CI, 0.91-1.00) were not. Significant associations with nonfatal MI were not evident. Associations appeared generally stronger in phospholipids and total plasma. Restricted cubic splines did not identify evidence of nonlinearity in dose responses.

CONCLUSIONS AND RELEVANCE

On the basis of available studies of free-living populations globally, biomarker concentrations of seafood and plant-derived ω-3 fatty acids are associated with a modestly lower incidence of fatal CHD.

Yogurt drink fortified with menaquinone-7 improves vitamin K status in a healthy population

Population-based studies have shown an inverse association between dietary menaquinones (MK-n, vitamin K2) intake, coronary calcification and CHD risk, suggesting a potential role of vitamin K in vascular health. To date, the effects of increased menaquinone intake on (markers of) vascular health have been investigated using predominantly food supplements. Dairy products contain many essential nutrients and can serve as a good matrix for food fortification in order to support health. We were therefore interested to study the effects of a menaquinone-fortified yogurt drink (menaquinone as menaquinone-7 (MK-7); 28 µg MK-7/yogurt drink) on vitamin K status and markers of vascular health. The yogurt drink was also fortified with n-3 PUFA, vitamin D, vitamin C, Ca and Mg to support vascular and/or general health. Healthy men (n 32) and postmenopausal women (n 28) with a mean age of 56 (sd 5) years received either basic or fortified yogurt drink twice per d for 12 weeks. MK-7 was efficiently absorbed from the fortified yogurt drink. Levels of circulating MK-7 were significantly increased from 0·28 to 1·94 ng/ml. In accordance, intake of the fortified yogurt drink improved vitamin K status, as measured by significant decreases in uncarboxylated osteocalcin and desphospho-uncarboxylated matrix Gla-protein. No effects were, however, seen on markers of inflammation, endothelial dysfunction and lipid metabolism. In summary, consumption of a yogurt drink fortified with low doses of among others MK-7 for 3 months significantly improved vitamin K status in a healthy population.

Nutrition in chronic obstructive pulmonary disease: A review

Cachexia and muscle wasting is a frequent but partly reversible complication in patients with chronic obstructive pulmonary disease (COPD), and affects the disease progression and prognosis. Weight loss in COPD is a consequence of increased energy requirements unbalanced by dietary intake. Nutritional supplement therapy has been shown to be effective for maintaining and improving the muscle strength and exercise tolerance in poorly nourished COPD patients, thereby decreasing morbidity and mortality. This mini review discusses the role of nutritional supplement therapy in the treatment of COPD.

Targeting fatty acid metabolism to improve glucose metabolism

Disturbances in fatty acid metabolism in adipose tissue, liver, skeletal muscle, gut and pancreas play an important role in the development of insulin resistance, impaired glucose metabolism and type 2 diabetes mellitus. Alterations in diet composition may contribute to prevent and/or reverse these disturbances through modulation of fatty acid metabolism. Besides an increased fat mass, adipose tissue dysfunction, characterized by an altered capacity to store lipids and an altered secretion of adipokines, may result in lipid overflow, systemic inflammation and excessive lipid accumulation in non-adipose tissues like liver, skeletal muscle and the pancreas. These impairments together promote the development of impaired glucose metabolism, insulin resistance and type 2 diabetes mellitus. Furthermore, intrinsic functional impairments in either of these organs may contribute to lipotoxicity and insulin resistance. The present review provides an overview of fatty acid metabolism-related pathways in adipose tissue, liver, skeletal muscle, pancreas and gut, which can be targeted by diet or food components, thereby improving glucose metabolism.

Dietary Mannan Oligosaccharides: Counteracting the Side Effects of Soybean Meal Oil Inclusion on European Sea Bass (Dicentrarchus labrax) Gut Health and Skin Mucosa Mucus Production?

The main objective of this study was to assess the effects of 4 g kg(-1) dietary mannan oligosaccharides (MOS) inclusion in soybean oil (SBO)- and fish oil (FO)-based diets on the gut health and skin mucosa mucus production of European sea bass juveniles after 8 weeks of feeding. Dietary MOS, regardless of the oil source, promoted growth. The intestinal somatic index was not affected, however dietary SBO reduced the intestinal fold length, while dietary MOS increased it. The dietary oil source fed produced changes on the posterior intestine fatty acid profiles irrespective of MOS dietary supplementation. SBO down-regulated the gene expression of TCRβ, COX2, IL-1β, TNFα, IL-8, IL-6, IL-10, TGFβ, and Ig and up-regulated MHCII. MOS supplementation up-regulated the expression of MHCI, CD4, COX2, TNFα, and Ig when included in FO-based diets. However, there was a minor up-regulating effect on these genes when MOS was supplemented in the SBO-based diet. Both dietary oil sources and MOS affected mean mucous cell areas within the posterior gut, however the addition of MOS to a SBO diet increased the mucous cell size over the values shown in FO fed fish. Dietary SBO also trends to reduce mucous cell density in the anterior gut relative to FO, suggesting a lower overall mucosal secretion. There are no effects of dietary oil or MOS in the skin mucosal patterns. Complete replacement of FO by SBO, modified the gut fatty acid profile, altered posterior gut-associated immune system (GALT)-related gene expression and gut mucous cells patterns, induced shorter intestinal folds and tended to reduce European sea bass growth. However, when combined with MOS, the harmful effects of SBO appear to be partially balanced by moderating the down-regulation of certain GALT-related genes involved in the functioning of gut mucous barrier and increasing posterior gut mucous cell diffusion rates, thus helping to preserve immune homeostasis. This denotes the importance of a balanced dietary n-3/n-6 ratio for an appropriate GALT-immune response against MOS in European sea bass juveniles.

Nutrition and respiratory health--feature review

Diet and nutrition may be important modifiable risk factors for the development, progression and management of obstructive lung diseases such as asthma and chronic obstructive pulmonary disease (COPD). This review examines the relationship between dietary patterns, nutrient intake and weight status in obstructive lung diseases, at different life stages, from in-utero influences through childhood and into adulthood. In vitro and animal studies suggest important roles for various nutrients, some of which are supported by epidemiological studies. However, few well-designed human intervention trials are available to definitively assess the efficacy of different approaches to nutritional management of respiratory diseases. Evidence for the impact of higher intakes of fruit and vegetables is amongst the strongest, yet other dietary nutrients and dietary patterns require evidence from human clinical studies before conclusions can be made about their effectiveness.

The evidence for α-linolenic acid and cardiovascular disease benefits: Comparisons with eicosapentaenoic acid and docosahexaenoic acid

Our understanding of the cardiovascular disease (CVD) benefits of α-linolenic acid (ALA, 18:3n-3) has advanced markedly during the past decade. It is now evident that ALA benefits CVD risk. The expansion of the ALA evidence base has occurred in parallel with ongoing research on eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) and CVD. The available evidence enables comparisons to be made for ALA vs. EPA + DHA for CVD risk reduction. The epidemiologic evidence suggests comparable benefits of plant-based and marine-derived n-3 (omega-3) PUFAs. The clinical trial evidence for ALA is not as extensive; however, there have been CVD event benefits reported. Those that have been reported for EPA + DHA are stronger because only EPA + DHA differed between the treatment and control groups, whereas in the ALA studies there were diet differences beyond ALA between the treatment and control groups. Despite this, the evidence suggests many comparable CVD benefits of ALA vs. EPA + DHA. Thus, we believe that it is time to revisit what the contemporary dietary recommendation should be for ALA to decrease the risk of CVD. Our perspective is that increasing dietary ALA will decrease CVD risk; however, randomized controlled clinical trials are necessary to confirm this and to determine what the recommendation should be. With a stronger evidence base, the nutrition community will be better positioned to revise the dietary recommendation for ALA for CVD risk reduction.

The use of dietary supplements to alleviate androgen deprivation therapy side effects during prostate cancer treatment

Prostate cancer (PCa), the most commonly diagnosed cancer and second leading cause of male cancer death in Western societies, is typically androgen-dependent, a characteristic that underlies the rationale of androgen deprivation therapy (ADT). Approximately 90% of patients initially respond to ADT strategies, however many experience side effects including hot flashes, cardiotoxicity, metabolic and musculoskeletal alterations. This review summarizes pre-clinical and clinical studies investigating the ability of dietary supplements to alleviate adverse effects arising from ADT. In particular, we focus on herbal compounds, phytoestrogens, selenium (Se), fatty acids (FA), calcium, and Vitamins D and E. Indeed, there is some evidence that calcium and Vitamin D can prevent the development of osteoporosis during ADT. On the other hand, caution should be taken with the antioxidants Se and Vitamin E until the basis underlying their respective association with type 2 diabetes mellitus and PCa tumor development has been clarified. However, many other promising supplements have not yet been subjected large-scale clinical trials making it difficult to assess their efficacy. Given the demographic trend of increased PCa diagnoses and dependence on ADT as a major therapeutic strategy, further studies are required to objectively evaluate these supplements as adjuvant for PCa patients receiving ADT.

The role of n - 6 and n - 3 polyunsaturated fatty acids in the manifestation of the metabolic syndrome in cardiovascular disease and non-alcoholic fatty liver disease

Cardiovascular disease (CVD) and non-alcoholic fatty liver disease (NAFLD) are manifestations of the metabolic syndrome. CVD remains the number one cause of mortality in the West, while NAFLD is the most common liver disease. Growing evidence suggests that polyunsaturated fatty acids (PUFA) influence risk factors including circulating lipids and inflammation on the development of CVD and NAFLD. N - 6 and n - 3 PUFA are comprised of distinct family members, which are increasingly recognized for their individual effects. Therefore, this review examines what is currently known about the specific effects of the major n - 3 and n - 6 PUFA on CVD and NAFLD. Overall, this review supports a beneficial effect of n - 3 PUFA and highlights distinctive effects between alpha-linolenic acid found in plant oils relative to marine derived eicosapentaenoic acid and docosahexaenoic acid. This review also highlights contrasting health effects between the n - 6 PUFA, linoleic and arachidonic acid.

Effects of supplemental long-chain omega-3 fatty acids and erythrocyte membrane fatty acid content on circulating inflammatory markers in a randomized controlled trial of healthy adults

The long-chain omega-3 polyunsaturated (n-3 PUFA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), may have anti-inflammatory effects. We evaluated the dose-response effect of EPA+DHA supplementation on circulating TNF-α, IL-6, and CRP and explored associations between red blood cell (RBC) membrane PUFA content and TNF-α, IL-6, and CRP. Young adults with low fish intake (n=116) received one of five doses (0, 300, 600, 900, or 1,800 mg/d EPA+DHA) for 5 months. There were no significant effects of supplemental EPA+DHA on IL-6 or CRP; however, there was a marginal treatment effect for TNF-α (p<0.08). At baseline, higher quartiles of RBC DHA were associated with lower TNF-α (p=0.001); higher quartiles of arachidonic acid were associated with higher TNF-α (p=0.005). EPA+DHA supplementation had no dose-response effect on TNF-α, IL-6, or CRP in healthy young adults; however, associations between inflammatory markers and RBC PUFA warrant further investigation.

[Polyunsaturated omega-3 fatty acids and systemic lupus erythematosus: what do we know?]

Various studies have demonstrated the impact of omega-3 fatty acids on the concentration of C reactive protein (CRP), pro-inflammatory eicosanoids, cytokines, chemokines and other inflammatory mediators. Therefore, the supplementation of these types of lipids may represent additional option treatment for chronic systemic diseases, such as Systemic Lupus Erythematous and other rheumatic diseases. The role of these lipids has not been well established, yet. However, it seems there is a direct relationship between its intake and the decrease of the disease clinical manifestations as well as of the inflammatory status of the patients. Thus, the aim of this manuscript is to present a thorough review on the effects of omega-3 fatty acids in patients with SLE. Bibliographic data set as the Medical Literature Analysis and Retrieval System Online (MEDLINE) and Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) were searched using as key words: systemic lupus erythematous (SLE), polyunsaturated fatty acids omega-3, eicosapentanoic acid (EPA), docosahexanoic acid (DHA), antioxidants and diet. Manuscripts published up to September 2013 were included. There were 43 articles related to the topic, however only 15 pertained human studies, with three review articles and 12 clinical studies.

Higher erythrocyte n-3 PUFAs are associated with decreased blood pressure in middle-aged and elderly Chinese adults

Previous studies suggested that blood fatty acids (FAs) might affect blood pressure (BP), but the findings have been inconclusive. This study evaluated the cross-sectional and prospective associations of erythrocyte FAs with BP in middle-aged and elderly Chinese individuals. Between 2008 and 2010, 1834 participants (1364 women and 470 men) aged 57 ± 5 y had baseline measurements taken of their erythrocyte FAs and BP. A total of 1477 participants (1103 women and 374 men) had their BP measured again after 3.09 ± 0.32 y (range: 2.91-3.26 y). In the cross-sectional analyses (n = 1834), the erythrocyte saturated FA (SFA) content was positively associated with BP, whereas total cis polyunsaturated FAs (PUFAs), their subtypes cis n-3 (ω-3) PUFAs and cis n-6 (ω-6) PUFAs, and the PUFA-to-SFA ratio were inversely associated with BP (all P-trends < 0.05). The longitudinal results (n = 1477) showed marginally inverse associations between cis n-3 PUFAs and the n-3:n-6 PUFA ratio and BP. For individual cis n-3 PUFAs, higher contents of 20:5n-3, 22:5n-3, and 22:6n-3 were significantly associated with reduced increases in SBP over time (the mean change range between quartile 4 and quartile 1 was -0.917 to -0.749 mm Hg for SBP; all P-trends < 0.01), and 20:5n-3 was inversely associated with DBP change (the mean change between quartile 4 and quartile 1 was -0.631; P-trend < 0.001). Path analyses suggested that the associations between cis n-3 PUFAs and BP might be mediated by decreasing serum triglycerides (TGs) and body mass index (BMI). Our findings revealed that a higher content of cis n-3 PUFAs (mainly very long-chain cis n-3 PUFAs) may benefit BP progress, probably mediated by decreasing serum TGs and BMI.

Flaxseed oil increases aortic reactivity to phenylephrine through reactive oxygen species and the cyclooxygenase-2 pathway in rats

BACKGROUND

Flaxseed oil has the highest concentration of omega-3 α-linolenic acid, which has been associated with cardiovascular benefit. However, the mechanism underlying the vascular effects induced through flaxseed oil is not well known. Thus, in the present study, we investigated the effects of flaxseed oil on vascular function in isolated rat aortic rings.

METHODS

Wistar rats were treated daily with flaxseed oil or a control (mineral oil) intramuscular (i.m.) for fifteen days. Isolated aortic segments were used to evaluate cyclooxygenase-2 (COX-2) protein expression, superoxide anion levels and vascular reactivity experiments.

RESULTS

Flaxseed oil treatment increased the vasoconstrictor response of aortic rings to phenylephrine. Endothelium removal increased the response to phenylephrine in aortic segments isolated from both groups, but the effect was smaller in the treated group. L-NAME incubation similarly increased the phenylephrine response in segments from both groups. The TXA2 synthase inhibitor furegrelate, the selective COX-2 inhibitor NS 398, the TP receptor antagonist SQ 29.548, the reactive oxygen species (ROS) scavenger apocynin, the superoxide anion scavengers tiron and the phospholipase A2 inhibitor dexamethasone partially reversed the flaxseed oil-induced increase in reactivity to phenylephrine.

CONCLUSIONS

These findings suggest that flaxseed oil treatment increased vascular reactivity to phenylephrine through an increase in ROS production and COX-2-derived TXA2 production. The results obtained in the present study provide new insight into the effects of flaxseed oil treatment (i.m.) on vascular function.

Acylcarnitines activate proinflammatory signaling pathways

Incomplete β-oxidation of fatty acids in mitochondria is a feature of insulin resistance and type 2 diabetes mellitus (T2DM). Previous studies revealed that plasma concentrations of medium- and long-chain acylcarnitines (by-products of incomplete β-oxidation) are elevated in T2DM and insulin resistance. In a previous study, we reported that mixed D,L isomers of C12- or C14-carnitine induced an NF-κB-luciferase reporter gene in RAW 264.7 cells, suggesting potential activation of proinflammatory pathways. Here, we determined whether the physiologically relevant L-acylcarnitines activate classical proinflammatory signaling pathways and if these outcomes involve pattern recognition receptor (PRR)-associated pathways. Acylcarnitines induced the expression of cyclooxygenase-2 in a chain length-dependent manner in RAW 264.7 cells. L-C14 carnitine (5-25 μM), used as a representative acylcarnitine, stimulated the expression and secretion of proinflammatory cytokines in a dose-dependent manner. Furthermore, L-C14 carnitine induced phosphorylation of JNK and ERK, common downstream components of many proinflammatory signaling pathways including PRRs. Knockdown of MyD88, a key cofactor in PRR signaling and inflammation, blunted the proinflammatory effects of acylcarnitine. While these results point to potential involvement of PRRs, L-C14 carnitine promoted IL-8 secretion from human epithelial cells (HCT-116) lacking Toll-like receptors (TLR)2 and -4, and did not activate reporter constructs in TLR overexpression cell models. Thus, acylcarnitines have the potential to activate inflammation, but the specific molecular and tissue target(s) involved remain to be identified.

Consuming a balanced high fat diet for 16 weeks improves body composition, inflammation and vascular function parameters in obese premenopausal women

OBJECTIVE

Inflammation, insulin resistance and vascular dysfunction characterize obesity and predict development of cardiovascular disease (CVD). Although women experience CVD events at an older age, vascular dysfunction is evident 10years prior to coronary artery disease. Questions remain whether replacing SFA entirely with MUFA or PUFA is the optimal approach for cardiometabolic benefits. This study tested the hypotheses that: a) body composition, inflammation and vascular function would improve with a high fat diet (HFD) when type of fat is balanced as 1/3 SFA, 1/3 MUFA and 1/3 PUFA; and b) body composition, inflammation and vascular function would improve more when balanced HFD is supplemented with 18C fatty acids, in proportion to the degree of 18C unsaturation.

METHODS

Obese premenopausal women were stabilized on balanced HFD and randomized to consume 9g/d of encapsulated stearate (18:0), oleate (18:1), linoleate (18:2) or placebo.

RESULTS

Significant improvements occurred in fat oxidation rate (↑6%), body composition (%fat: ↓2.5±2.1%; %lean: ↑2.5±2.1%), inflammation (↓ IL-1α, IL-1β, 1L-12, Il-17, IFNγ, TNFα, TNFβ) and vascular function (↓BP, ↓PAI-1, ↑tPA activity). When compared to HFD+placebo, HFD+stearate had the greatest effect on reducing IFNγ (↓74%) and HFD+linoleate had the greatest effect on reducing PAI-1 (↓31%).

CONCLUSIONS

Balancing the type of dietary fat consumed (SFA/MUFA/PUFA) is a feasible strategy to positively affect markers of CVD risk. Moreover, reductions in inflammatory molecules involved in vascular function might be enhanced when intake of certain 18C fatty acids is supplemented. Long term effects need to be determined for this approach.

Footprints of directional selection in wild Atlantic salmon populations: evidence for parasite-driven evolution?

Mechanisms of host-parasite co-adaptation have long been of interest in evolutionary biology; however, determining the genetic basis of parasite resistance has been challenging. Current advances in genome technologies provide new opportunities for obtaining a genome-scale view of the action of parasite-driven natural selection in wild populations and thus facilitate the search for specific genomic regions underlying inter-population differences in pathogen response. European populations of Atlantic salmon (Salmo salar L.) exhibit natural variance in susceptibility levels to the ectoparasite Gyrodactylus salaris Malmberg 1957, ranging from resistance to extreme susceptibility, and are therefore a good model for studying the evolution of virulence and resistance. However, distinguishing the molecular signatures of genetic drift and environment-associated selection in small populations such as land-locked Atlantic salmon populations presents a challenge, specifically in the search for pathogen-driven selection. We used a novel genome-scan analysis approach that enabled us to i) identify signals of selection in salmon populations affected by varying levels of genetic drift and ii) separate potentially selected loci into the categories of pathogen (G. salaris)-driven selection and selection acting upon other environmental characteristics. A total of 4631 single nucleotide polymorphisms (SNPs) were screened in Atlantic salmon from 12 different northern European populations. We identified three genomic regions potentially affected by parasite-driven selection, as well as three regions presumably affected by salinity-driven directional selection. Functional annotation of candidate SNPs is consistent with the role of the detected genomic regions in immune defence and, implicitly, in osmoregulation. These results provide new insights into the genetic basis of pathogen susceptibility in Atlantic salmon and will enable future searches for the specific genes involved.

Intakes of PUFAs were inversely associated with plasma C-reactive protein 12 years later in a middle-aged population with vitamin E intake as an effect modifier

Although n-3 (ω-3) polyunsaturated fatty acids (PUFAs) are considered anti-inflammatory components, the role of dietary n-6 PUFAs in inflammation remains controversial. Some mechanistic evidence suggests vitamin E as a potential effect modifier in the relationship between PUFAs and inflammation. Our objectives were to evaluate the long-term associations between dietary intakes of PUFAs and elevated plasma C-reactive protein (CRP) and to investigate potential effect modification by vitamin E. Individuals in the placebo group of the SU.VI.MAX trial who had available CRP measurements in 2007-2009 were included in the study (n = 843). Dietary intakes of n-3 PUFAs, n-6 PUFAs, and vitamin E were assessed in 1994-1996 with at least 6 dietary records. The logistic regression OR for elevated CRP (>3 mg/L) and 95% CI were estimated for individual PUFAs and for total n-3 and n-6 PUFA intakes. Models were adjusted for sociodemographical, lifestyle, anthropometric, and dietary variables. Interactions with vitamin E intakes were also assessed. Inverse associations were observed between intakes of total n-3 PUFAs [α-linolenic acid (ALA; 18:3n-3), ALA + eicosapentaenoic acid (EPA; 20:5n-3), EPA + docosapentaenoic acid (DPA; 22:5n-3), DPA + docosahexaenoic acid (DHA; 22:6n-3)] and n-6 PUFA [linoleic acid (18:2n-6) + arachidonic acid (20:4n-6)] and elevated CRP (OR for tertile 3 vs. tertile 1 of intake: 0.41; 95% CI: 0.21, 0.77; P-trend = 0.01; and OR 0.38; 95% CI: 0.21, 0.70; P-trend = 0.002, respectively). Stratification on vitamin E intakes showed that inverse associations between dietary n-3 and n-6 PUFA intakes and elevated CRP were substantial only in individuals with low intakes of vitamin E. Our results supported the contention that intakes of both n-3 and n-6 PUFAs are inversely associated with plasma CRP concentrations. Vitamin E is a potential effect modifier and should therefore be taken into account in such investigations. This trial was registered at clinicaltrials.gov as NCT00272428.

Lipid emulsions in parenteral nutrition: current applications and future developments

INTRODUCTION

A parenteral lipid emulsion (LE), used as a key source of energy, essential fatty acids (FAs), and fat-soluble vitamins, is an integral part of a parenteral nutrition (PN) regimen. The conventional LEs, such as soybean oil (SO)-based emulsions, have caused concerns about the potential adverse effects involving oxidative stress, inflammation, and immune response probably because of undesirable FA composition.

AREAS COVERED

Recently, alternative LEs, optimizing the FA composition with partial substitution of SO with medium-chain triglyceride (MCT), olive oil (OO), and fish oil (FO), have been developed and applied in clinical practice. This review summarizes the characteristics and beneficial clinical effects of alternative parenteral LEs in critically ill, pediatric, and long-term PN patients.

EXPERT OPINION

More clinical data from sufficiently high-powered studies are required to characterize the integral biological properties of alternative LEs for further selection to fit individual needs and disease characteristics. Simultaneously, potential lipid sources with desirable FA compositions and biological properties should be selected to develop new therapeutic LEs. As supplements to current parenteral lipids, the new LEs with different therapeutic effects are expected to fit specified subpopulations of patients with different diseases. Great efforts should be devoted to the development of parenteral LEs.

The relationship between dietary fatty acids and inflammatory genes on the obese phenotype and serum lipids

Obesity, a chronic low-grade inflammatory condition is associated with the development of many comorbidities including dyslipidemia. This review examines interactions between single nucleotide polymorphisms (SNP) in the inflammatory genes tumor necrosis alpha (TNFA) and interleukin-6 (IL-6) and dietary fatty acids, and their relationship with obesity and serum lipid levels. In summary, dietary fatty acids, in particular saturated fatty acids and the omega-3 and omega-6 polyunsaturated fatty acids, impact the expression of the cytokine genes TNFA and IL-6, and alter TNFα and IL-6 production. In addition, sequence variants in these genes have also been shown to alter their gene expression and plasma levels, and are associated with obesity, measures of adiposity and serum lipid concentrations. When interactions between dietary fatty acids and TNFA and IL-6 SNPs on obesity and serum lipid were analyzed, both the quantity and quality of dietary fatty acids modulated the relationship between TNFA and IL-6 SNPs on obesity and serum lipid profiles, thereby impacting the association between phenotype and genotype. Researching these diet–gene interactions more extensively, and understanding the role of ethnicity as a confounder in these relationships, may contribute to a better understanding of the inter-individual variability in the obese phenotype.

Fish oil administration in older adults: is there potential for adverse events? A systematic review of the literature

Background

Omega-3 (n-3) fatty acid supplementation is becoming increasingly popular. However given its antithrombotic properties the potential for severe adverse events (SAE) such as bleeding has safety implications, particularly in an older adult population. A systematic review of randomized control trials (RCT) was conducted to explore the potential for SAE and non-severe adverse events (non-SAE) associated with n-3 supplementation in older adults.

Methods

A comprehensive search strategy using Medline and a variety of other electronic sources was conducted. Studies investigating the oral administration of n-3 fish oil containing eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) or both against a placebo were sourced. The primary outcome of interest included reported SAE associated with n-3 supplementation. Chi-square analyses were conducted on the pooled aggregate of AEs.

Results

Of the 398 citations initially retrieved, a total of 10 studies involving 994 older adults aged ≥60 years were included in the review. Daily fish oil doses ranged from 0.03 g to 1.86 g EPA and/or DHA with study durations ranging from 6 to 52 weeks. No SAE were reported and there were no significant differences in the total AE rate between groups (n-3 intervention group: 53/540; 9.8%; placebo group: 28/454; 6.2%; p = 0.07). Non-SAE relating to gastrointestinal (GI) disturbances were the most commonly reported however there was no significant increase in the proportion of GI disturbances reported in participants randomized to the n-3 intervention (n-3 intervention group: 42/540 (7.8%); placebo group: 24/454 (5.3%); p = 0.18).

Conclusions

The potential for AEs appear mild-moderate at worst and are unlikely to be of clinical significance. The use of n-3 fatty acids and the potential for SAE should however be further researched to investigate whether this evidence is consistent at higher doses and in other populations. These results also highlight that well-documented data outlining the potential for SAE following n-3 supplementation are limited nor adequately reported to draw definitive conclusions concerning the safety associated with n-3 supplementation. A more rigorous and systematic approach for monitoring and recording AE data in clinical settings that involve n-3 supplementation is required.

Flaxseed reverses atherosclerotic lesion formation and lowers lipoprotein(a) in ovarian hormone deficiency

OBJECTIVE

The incidence of cardiovascular disease dramatically increases during menopause, and postmenopausal women seek natural alternatives to hormone therapy. Flaxseed can slow the progression of atherosclerotic lesion formation; however, it is not known whether it can reverse formation that has already occurred.

METHODS

Seventy-two female Golden Syrian hamsters were randomly divided into six groups (n = 12), sham-operated (sham) or ovariectomized (ovx), and kept on the same diet for 120 days to allow for atherosclerotic lesion development. After this 120-day period, whole flaxseed was introduced to the diets of hamsters in three of the groups: group 1 (sham + casein); group 2 (ovx + casein); group 3 (ovx + 7.5% flaxseed); group 4 (ovx + 15% flaxseed); group 5 (ovx + 22.5% flaxseed); and group 6 (ovx + 17β-estradiol). This diet was maintained for an additional 120 days. Lesion regression was examined histologically, and serum was analyzed for total cholesterol, triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, Apo A, Apo B, and lipoprotein(a).

RESULTS

Results showed that 15% and 22.5% flaxseed, compared with ovx animals, significantly reduced lipoprotein(a) (4.4 mg/dL [ovx] vs 2.15 mg/dL [15% flaxseed] and 0.3 mg/dL [22.5% flaxseed]; P < 0.05) and Apo B (2.8 mg/dL [ovx] vs 2.4 mg/dL [15% flaxseed] and 2.5 mg/dL [22.5% flaxseed]). Flax reduced by 67% the number of animals with aortic arch lesions.

CONCLUSIONS

All three doses of flax reduce the severity of lesion formation compared with ovx controls. These results support the efficacy of flaxseed in reducing cardiovascular disease risk.

α-Linolenic acid and risk of cardiovascular disease: a systematic review and meta-analysis

BACKGROUND

Prior studies of α-linolenic acid (ALA), a plant-derived omega-3 (n-3) fatty acid, and cardiovascular disease (CVD) risk have generated inconsistent results.

OBJECTIVE

We conducted a meta-analysis to summarize the evidence regarding the relation of ALA and CVD risk.

DESIGN

We searched multiple electronic databases through January 2012 for studies that reported the association between ALA (assessed as dietary intake or as a biomarker in blood or adipose tissue) and CVD risk in prospective and retrospective studies. We pooled the multivariate-adjusted RRs comparing the top with the bottom tertile of ALA using random-effects meta-analysis, which allowed for between-study heterogeneity.

RESULTS

Twenty-seven original studies were identified, including 251,049 individuals and 15,327 CVD events. The overall pooled RR was 0.86 (95% CI: 0.77, 0.97; I² = 71.3%). The association was significant in 13 comparisons that used dietary ALA as the exposure (pooled RR: 0.90; 95% CI: 0.81, 0.99; I² = 49.0%), with similar but nonsignificant trends in 17 comparisons in which ALA biomarkers were used as the exposure (pooled RR: 0.80; 95% CI: 0.63, 1.03; I² = 79.8%). An evaluation of mean participant age, study design (prospective compared with retrospective), exposure assessment (self-reported diet compared with biomarker), and outcome [fatal coronary heart disease (CHD), nonfatal CHD, total CHD, or stroke] showed that none were statistically significant sources of heterogeneity.

CONCLUSIONS

In observational studies, higher ALA exposure is associated with a moderately lower risk of CVD. The results were generally consistent for dietary and biomarker studies but were not statistically significant for biomarker studies. However, the high unexplained heterogeneity highlights the need for additional well-designed observational studies and large randomized clinical trials to evaluate the effects of ALA on CVD.

Lycopene inhibits lymphocyte proliferation through mechanisms dependent on early cell activation

SCOPE

Epidemiological evidence suggests that lycopene is potentially cardio-protective. Recruitment and activation of T cells in the arterial wall is a critical process during atherogenesis, but the effects of lycopene on T-cell response remain to be elucidated. We aimed to determine whether lycopene could modulate T-cell function and activity.

METHODS AND RESULTS

Peripheral blood mononuclear cells from 16 healthy adults were cultured in the presence of lycopene-enriched liposomes (0-2.9 μg lycopene/mL) with or without mitogens. Cell cycle as well as the expression of CD69 (marker of early cell activation), CD25 (IL-2 receptor), and CD11a (late activation marker) were measured in T cells, T-helper cells, and T-cytotoxic cells by flow cytometry. IL-2 secretion and cell proliferation were determined by ELISA and [³H]-thymidine incorporation, respectively. Lycopene significantly inhibited lymphocyte proliferation (up to 40%) in activated cells. Lycopene also significantly inhibited CD69 expression (by up to 12%) as well as IL-2 secretion (by up to 29%). However, CD25 and CD11a expression as well as the cell-cycle profile were unaffected by lycopene.

CONCLUSION

Lycopene influences lymphocyte proliferation through its effects on processes involved in early cellular activation, providing one possible mechanism to explain the beneficial effects of tomato-rich diets against cardiovascular disease.

Effect of dietary linoleic acid on markers of inflammation in healthy persons: a systematic review of randomized controlled trials

The majority of evidence suggests that n-6 polyunsaturated fatty acids, including linoleic acid (LA), reduce the risk of cardiovascular disease as reflected by current dietary recommendations. However, concern has been expressed that a high intake of dietary n-6 polyunsaturated fatty acid contributes to excess chronic inflammation, primarily by prompting the synthesis of proinflammatory eicosanoids derived from arachidonic acid and/or inhibiting the synthesis of anti-inflammatory eicosanoids from eicosapentaenoic and/or docosahexaenoic acids. A systematic review of randomized controlled trials that permitted the assessment of dietary LA on biologic markers of chronic inflammation among healthy noninfant populations was conducted to examine this concern. A search of the English- and non-English-language literature using MEDLINE, the Cochrane Controlled Trials Register, and EMBASE was conducted to identify relevant articles. Fifteen studies (eight parallel and seven crossover) met inclusion criteria. None of the studies reported significant findings for a wide variety of inflammatory markers, including C-reactive protein, fibrinogen, plasminogen activator inhibitor type 1, cytokines, soluble vascular adhesion molecules, or tumor necrosis factor-α. The only significant outcome measures reported for higher LA intakes were greater excretion of prostaglandin E2 and lower excretion of 2,3-dinor-thromboxane B(2) in one study and higher excretion of tetranorprostanedioic acid in another. However, the authors of those studies both observed that these effects were not an indication of increased inflammation. We conclude that virtually no evidence is available from randomized, controlled intervention studies among healthy, noninfant human beings to show that addition of LA to the diet increases the concentration of inflammatory markers.

Effect of flaxseed supplementation and exercise training on lipid profile, oxidative stress and inflammation in rats with myocardial ischemia

Background

Flaxseed has recently gained attention in the area of cardiovascular disease primarily because of its rich contents of α-linolenic acid (ALA), lignans, and fiber. Although the benefits of exercise on any single risk factor are unquestionable, the effect of exercise on overall cardiovascular risk, when combined with other lifestyle modifications such as proper nutrition, can be dramatic.

This study was carried out to evaluate the protective role of flaxseed and exercise on cardiac markers, lipids profile and inflammatory markers in isoproterenol (ISO)-induced myocardial ischemia in rats.

Methods

The research was conducted on 40 male albino rats, divided into 4 groups (n=10): group I served as control, group II has acute myocardial ischemia induced by isoproterenol, groups III and IV have acute myocardial ischemia induced by isoproterenol pretreated with flaxseed supplementation orally for 6 weeks, additionally group IV practiced muscular exercise through swimming.

Results

Alterations of lipid profile, cardiac and inflammatory markers (Il-1β, PTX 3 and TNF- α) were observed in myocardial ischemia group. Flaxseed supplementation combined with exercise training showed significant increase of HDL and PON 1, on the other hand cardiac troponin, Il- 1β and TNF- α levels significantly decreased as compared to myocardial ischemic group. Receiver Operating Characteristics (ROC) analysis of cTnI, PTX 3, Il-1β and TNF- α revealed a satisfactory level of sensitivity and specificity.

Conclusion

Regular exercise enhances the improvement in plasma lipoprotein levels and cardiovascular protection that results from flaxseed supplementation by mitigating the pathophysiology of atherosclerosis. Elevation of HDL, the antioxidant PON 1 and the cardioprotective marker PTX 3 emphasizes the protective effects of flaxseed and muscular exercise mutually against the harmful effects of acute myocardial ischemia.

The effect of dietary walnuts compared to fatty fish on eicosanoids, cytokines, soluble endothelial adhesion molecules and lymphocyte subsets: a randomized, controlled crossover trial

We tested the hypothesis that walnut consumption can exert effects on markers of inflammation and endothelial activation similar to those produced by fish consumption. In a crossover dietary intervention trial, 25 normal to mildly hyperlipidemic men and women were randomly assigned to one of three isoenergetic diets: a walnut diet incorporating 42.5 g of walnuts per 10.1 mJ 6 times per week (1.8% of energy n-3 fat); a fish diet providing 113 g of fatty fish per 10.1 mJ 2 times per week (0.8% of energy n-3 fat), or a control diet (no nuts or fish, 0.4% of energy n-3 fat) for 4 weeks on each diet. Both the walnut and fish diets inhibited circulating concentrations of prostaglandin E metabolite (PGEM) and 11-dehydro thromboxane B2, but demonstrated no effect on blood interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α¯ (TNF-α¯), and C-reactive protein (CRP) or the number of circulating lymphocyte subsets. On the walnut diet the proportion of plasma phospholipid α¯-linolenic acid (ALA) increased 140% and arachidonic acid (AA) decreased 7% compared to both the control and fish diets. The proportion of plasma phospholipid eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increased about 200% and 900% respectively on the fish diet relative to either the control or walnut diet. The walnut diet inhibited E-selectin by 12.7% relative to the fish diet, and the fish diet inhibited secretory intercellular adhesion molecule-1 (s-ICAM-1) by 4.5% relative to the control diet. Both walnuts and fish in commonly consumed amounts may have modest albeit distinct effects on circulating adhesion molecules.

Omega-3 long-chain polyunsaturated fatty acids supplementation on inflammatory biomakers: a systematic review of randomised clinical trials

Inflammation is part of the normal host response to infection and injury. Eicosanoids, cytokines, chemokines, adhesion molecules and other inflammatory molecules are frequently produced during this process. Numerous studies in humans have documented the inflammation-limiting properties of omega-3 fatty acids, but only a few have been randomised clinical trials. The aim of this study was to perform a systematic search of randomised clinical trials on omega-3 fatty acids and inflammatory biomarkers in all subjects including healthy and ill persons up to February 2011 using PubMed and LILACS databases, defined by a specific equation using MeSH terms and limited to randomised clinical trials; there was no any a priori decision to include some diseases and not others. The quality of each publication was validated by using the JADAD scale and the CONSORT checklist. Inflammatory biomarkers were considered as primary outcomes. Twenty-six publications of the last 10 years were selected. Studies included healthy subjects and patients with cardiovascular disease and other chronic and acute diseases; all reported the number of subjects, type of study, type and doses of omega-3 fatty acids, main outcomes and major inflammatory biomarkers. Dietary omega-3 fatty acids are associated with plasma biomarker levels, reflecting lower levels of inflammation and endothelial activation in cardiovascular disease and other chronic and acute diseases, including chronic renal disease, sepsis and acute pancreatitis. However, further research is required before definitive recommendations can be made about the routine use of omega-3 fatty acids in critically ill patients or with neurodegenerative or chronic renal disease.

Influence of marine n-3 polyunsaturated fatty acids on immune function and a systematic review of their effects on clinical outcomes in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease of the joints and bones. The n-6 polyunsaturated fatty acid (PUFA) arachidonic acid (ARA) is the precursor of inflammatory eicosanoids which are involved in RA. Some therapies used in RA target ARA metabolism. Marine n-3 PUFAs (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) found in oily fish and fish oils decrease the ARA content of cells involved in immune responses and decrease the production of inflammatory eicosanoids from ARA. EPA gives rise to eicosanoid mediators that are less inflammatory than those produced from ARA and both EPA and DHA give rise to resolvins that are anti-inflammatory and inflammation resolving, although little is known about these latter mediators in RA. Marine n-3 PUFAs can affect other aspects of immunity and inflammation relevant to RA, including dendritic cell and T cell function and production of inflammatory cytokines and reactive oxygen species, although findings for these outcomes are not consistent. Fish oil has been shown to slow the development of arthritis in animal models and to reduce disease severity. A number of randomised controlled trials of marine n-3 PUFAs have been performed in patients with RA. A systematic review included 23 studies. Evidence is seen for a fairly consistent, but modest, benefit of marine n-3 PUFAs on joint swelling and pain, duration of morning stiffness, global assessments of pain and disease activity, and use of non-steroidal anti-inflammatory drugs.

Effects of n-3 PUFA supplementation on plasma soluble adhesion molecules: a meta-analysis of randomized controlled trials

BACKGROUND

Previous studies indicate that oral supplementation with n-3 PUFA protects against atherosclerotic disease by inhibiting inflammatory processes, which underlie atherosclerosis and are reflected by the plasma concentrations of soluble adhesion molecules. However, consistent results were not obtained among studies.

OBJECTIVE

The objective was to assess the effects of n-3 PUFA supplementation on plasma concentrations of soluble adhesion molecules.

DESIGN

We conducted a meta-analysis of randomized controlled trials identified from PubMed, Embase, the Cochrane Library, and reference lists of relevant articles and reviews.

RESULTS

Eighteen studies were included. n-3 PUFA supplementation reduced plasma concentrations of soluble intercellular adhesion molecule-1 [sICAM-1; weighted mean difference (WMD): -5.17; 95% CI: -10.07, -0.27; P = 0.04] but had no significant effects on soluble vascular cell adhesion molecule-1 (WMD: -5.90; 95% CI: -17.63, 5.84; P = 0.32), soluble P-selectin (WMD: -1.53; 95% CI: -4.33, 1.28; P = 0.29), or soluble E-selectin (WMD: 0.46; 95% CI: -1.54, 2.46; P = 0.65). Subgroup analysis stratified by the subjects' health status showed that n-3 PUFA supplementation reduced sICAM-1 concentrations in healthy subjects (WMD: -8.87; 95% CI: -15.20, -2.53; P = 0.006; heterogeneity test: I² = 0%, P = 0.76) and in subjects with dyslipidemia (WMD: -15.31; 95% CI: -26.82, -3.81; P = 0.009; heterogeneity test: I² = 26%, P = 0.26).

CONCLUSIONS

n-3 PUFA supplementation can reduce plasma concentrations of sICAM-1. The effect is identified in both healthy subjects and subjects with dyslipidemia, which supports the hypothesis that n-3 PUFA can be supplemented as a primary or secondary means for preventing the development as well as the progression of atherosclerosis.

(n-3) fatty acids and cardiovascular health: are effects of EPA and DHA shared or complementary?

Considerable research supports cardiovascular benefits of consuming omega-3 PUFA, also known as (n-3) PUFA, from fish or fish oil. Whether individual long-chain (n-3) PUFA have shared or complementary effects is not well established. We reviewed evidence for dietary and endogenous sources and cardiovascular effects on biologic pathways, physiologic risk factors, and clinical endpoints of EPA [20:5(n-3)], docosapentaenoic acid [DPA, 22:5(n-3)], and DHA [22:6(n-3)]. DHA requires direct dietary consumption, with little synthesis from or retroconversion to DPA or EPA. Whereas EPA is also largely derived from direct consumption, EPA can also be synthesized in small amounts from plant (n-3) precursors, especially stearidonic acid. In contrast, DPA appears principally derived from endogenous elongation from EPA, and DPA can also undergo retroconversion back to EPA. In experimental and animal models, both EPA and DHA modulate several relevant biologic pathways, with evidence for some differential benefits. In humans, both fatty acids lower TG levels and, based on more limited studies, favorably affect cardiac diastolic filling, arterial compliance, and some metrics of inflammation and oxidative stress. All three (n-3) PUFA reduce ex vivo platelet aggregation and DHA also modestly increases LDL and HDL particle size; the clinical relevance of such findings is uncertain. Combined EPA+DHA or DPA+DHA levels are associated with lower risk of fatal cardiac events and DHA with lower risk of atrial fibrillation, suggesting direct or indirect benefits of DHA for cardiac arrhythmias (although not excluding similar benefits of EPA or DPA). Conversely, EPA and DPA, but not DHA, are associated with lower risk of nonfatal cardiovascular endpoints in some studies, and purified EPA reduced risk of nonfatal coronary syndromes in one large clinical trial. Overall, for many cardiovascular pathways and outcomes, identified studies of individual (n-3) PUFA were relatively limited, especially for DPA. Nonetheless, the present evidence suggests that EPA and DHA have both shared and complementary benefits. Based on current evidence, increasing consumption of either would be advantageous compared to little or no consumption. Focusing on their combined consumption remains most prudent given the potential for complementary effects and the existing more robust literature on cardiovascular benefits of their combined consumption as fish or fish oil for cardiovascular benefits.

Similarities and differences between the effects of EPA and DHA on markers of atherosclerosis in human subjects

We have reviewed effects of long chain (LC) n-3 PUFA on markers of atherosclerosis in human subjects with a focus on individual effects of EPA and DHA. Initial results from epidemiological studies suggested that LC n-3 PUFA from fish oils (FO) reduced incidence of CVD; those results have been confirmed in interventional studies. Dietary intervention with n-3 PUFA decreased fasting and postprandial TAG, number of remnant-like chylomicron particles, large VLDL, and total and small dense LDL particles. It increased mean size of LDL particles by increasing number of large and decreasing those of small dense particles. With some exceptions, n-3 PUFA decreased blood pressure (BP) and heart rate (HR), flow-mediated dilation (FMD) and plasma concentrations of inflammatory markers. n-3 PUFA also decreased circulating adhesion molecules and intima-media thickness (IMT) in some but not other studies. For IMT, results varied with the sex and artery being examined. EPA effects on FMD are endothelial cell dependent, while those of DHA seem to be endothelial cell independent. Individually, both EPA and DHA decreased TAG and inflammatory markers, but only DHA decreased HR, BP and number of small dense LDL particles. Results varied because of dose and duration of n-3 PUFA, EPA:DHA, health status of subjects and other reasons. Future studies are needed to determine optimal doses of EPA and DHA individually, their synergistic, additive or antagonistic effects, and to understand underlying mechanisms. In conclusion, n-3 PUFA decreased several risk factors for atherosclerosis without any serious adverse effects.

The α-linolenic acid content of flaxseed can prevent the atherogenic effects of dietary trans fat

Dietary intake of industrially hydrogenated trans fatty acids (TFA) has been associated with coronary heart disease. Dietary flaxseed can inhibit atherosclerosis induced by dietary cholesterol. The aim of this study was to determine whether supplementing the diet with flaxseed could protect against atherosclerosis induced by a diet enriched in TFA. Low-density lipoprotein receptor-deficient (LDLr−/−) mice were fed 1 of 14 experimental diets for 14 wk containing one of two fat sources [regular (pork/soy) or trans fat] at two concentrations (4 or 8%) and supplemented with or without dietary cholesterol (2%), whole ground flaxseed, or one of the components of flaxseed [α-linolenic acid (ALA), defatted fiber, or lignan]. Adding flaxseed to the diet partially mitigated the rise in circulating cholesterol levels induced by the cholesterol-enriched diet. Atherosclerosis was stimulated by TFA and/or cholesterol. Including milled flaxseed to an atherogenic diet significantly reduced atherosclerosis compared with the groups that consumed cholesterol and/or TFA. ALA was the only component within flaxseed that could inhibit the atherogenic action of cholesterol and/or TFA on its own. Dietary flaxseed protects against atherosclerotic development induced by TFA and cholesterol feeding through its content of ALA.