Dietary (n-3) fatty acids reduce plasma F2-isoprostanes but not prostaglandin F2alpha in healthy humans

Effects of food-borne docosahexaenoic acid supplementation on bone lead mobilisation, mitochondrial function and serum metabolomics in pre-pregnancy lead-exposed lactating rats

Large bone lead (Pb) resulting from high environmental exposure during childhood is an important source of endogenous Pb during pregnancy and lactation. Docosahexaenoic acid (DHA) attenuates Pb toxicity, however, the effect of DHA on bone Pb mobilisation during lactation has not been investigated. We aimed to study the effects of DHA supplementation during pregnancy and lactation on bone Pb mobilisation during lactation and its potential mechanisms. Weaning female rats were randomly divided into control (0.05% sodium acetate) and Pb-exposed (0.05% Pb acetate) groups, after a 4-week exposure by ad libitum drinking and a subsequent 4-week washout period, all female rats were mated with healthy males until pregnancy. Then exposed rats were randomly divided into Pb and Pb + DHA groups, and the latter was given a 0.14% DHA diet, while the remaining groups were given normal feed until the end of lactation. Pb and calcium levels, bone microarchitecture, bone turnover markers, mitochondrial function and serum metabolomics were analyzed. The results showed that higher blood and bone Pb levels were observed in the Pb group compared to the control, and there was a significant negative correlation between blood and bone Pb. Also, Pb increased trabecular bone loss along with slightly elevated serum C-telopeptide of type I collagen (CTX-I) levels. However, DHA reduced CTX-I levels and improved trabecular bone microarchitecture. Metabolomics showed that Pb affected mitochondrial function, which was further demonstrated in bone tissue by significant reductions in ATP levels, Na+-K+-ATPase, Ca2+-Mg2+-ATPase and CAT activities, and elevated levels of MDA, IL-1β and IL-18. However, these alterations were partially mitigated by DHA. In conclusion, DHA supplementation during pregnancy and lactation improved bone Pb mobilisation and mitochondrial dysfunction in lactating rats induced by pre-pregnancy Pb exposure, providing potential means of mitigating bone Pb mobilisation levels during lactation, but the mechanism still needs further study.

Diet, Gut Microbiome, and Their End Metabolites Associate With Acute Pancreatitis Risk

INTRODUCTION

Diet and decreased gut microbiome diversity has been associated with acute pancreatitis (AP) risk. However, differences in dietary intake, gut microbiome, and their impact on microbial end metabolites have not been studied in AP. We aimed to determine differences in (i) dietary intake (ii) gut microbiome diversity and sulfidogenic bacterial abundance, and (iii) serum short-chain fatty acid (SCFA) and hydrogen sulfide (H 2 S) concentrations in AP and control subjects.

METHODS

This case-control study recruited 54 AP and 46 control subjects during hospitalization. Clinical and diet data and stool and blood samples were collected. 16S rDNA sequencing was used to determine gut microbiome alpha diversity and composition. Serum SCFA and H 2 S levels were measured. Machine learning (ML) model was used to identify microbial targets associated with AP.

RESULTS

AP patients had a decreased intake of vitamin D 3 , whole grains, fish, and beneficial eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids. AP patients also had lower gut microbiome diversity ( P = 0.021) and a higher abundance of sulfidogenic bacteria including Veillonella sp. and Haemophilus sp., which were associated with AP risk. Serum acetate and H 2 S concentrations were significantly higher in the AP group ( P < 0.001 and P = 0.043, respectively). ML model had 96% predictive ability to distinguish AP patients from controls.

DISCUSSION

AP patients have decreased beneficial nutrient intake and gut microbiome diversity. An increased abundance of H 2 S-producing genera in the AP and SCFA-producing genera in the control group and predictive ability of ML model to distinguish AP patients indicates that diet, gut microbiota, and their end metabolites play a key role in AP.

The effect of omega-3 fatty acids on active periodontal therapy: A systematic review and meta-analysis

AIM

"Host modulatory therapy" (HMT) with ω-3 fatty acids aims at reducing inflammation. With HMT as an adjunct, a better result of periodontal therapy is expected. The aim of this systematic review and meta-analysis (MA) was to examine the additional effect of ω-3 fatty acids to non-surgical periodontal therapy (SRP) on the probing pocket depth (PPD) and the clinical attachment level (CAL).

MATERIALS AND METHODS

MEDLINE-PubMed and Cochrane-CENTRAL libraries were searched up to January 2021 for randomized controlled trials in patients with chronic periodontitis, treated with SRP/placebo as controls and SRP/ω-3 fatty acids as the test group.

RESULTS

The search identified 173 unique abstracts, and screening resulted in 10 eligible publications. Descriptive analysis showed a significant effect on the PPD and CAL in favour of the groups with ω-3 fatty acids in the majority of comparisons. MA revealed that adjunctive use of ω-3 fatty acids to SRP resulted in 0.39 mm more PPD reduction (95% CI: -0.58; -0.21) and 0.41 mm more CAL gain (95% CI: -0.63; -0.19) than SRP alone.

CONCLUSIONS

In patients with periodontitis, dietary supplementation with ω-3 fatty acids as an adjunct to SRP is more effective in reducing the PPD and improving the CAL than SRP alone. If SRP is indicated, the use of ω-3 fatty acids can be considered for a moderate extra added effect on PPD reduction and CAL gain. The strength of this recommendation is moderate.

Effects of dietary interventions on telomere dynamics

Telomeres play a critical role in maintaining cellular fate through tight regulation of cell division and DNA damage or repair. Over the years, it is established that biological ageing is defined by a gradual derangement in functionality, productivity, and robustness of biological processes. The link between telomeres and ageing is highlighted when derangement in telomere biology often leads to premature ageing and concomitant accompaniment of numerous age-associated diseases. Unfortunately, given that ageing is a biologically complicated intricacy, measures to reduce morbidity and improve longevity are still largely in the infancy stage. Recently, it was discovered that dietary habits and interventions might play a role in promoting successful healthy ageing. The intricate relationship between dietary components and its potential to protect the integrity of telomeres may provide unprecedented health benefits and protection against age-related pathologies. However, more focused prospective and follow-up studies with and without interventions are needed to unequivocally link dietary interventions with telomere maintenance in humans. This review aims to summarise recent findings that investigate the roles of nutrition on telomere biology and provide enough evidence for further studies to consider the topic of nutrigenomics and its contributions toward healthy ageing and concomitant strategy against age-associated diseases.

The Potential Benefit of Monitoring Oxidative Stress and Inflammation in the Prevention of Non-Communicable Diseases (NCDs)

The significant increase in worldwide morbidity and mortality from non-communicable diseases (NCDs) indicates that the efficacy of existing strategies addressing this crisis may need improvement. Early identification of the metabolic irregularities associated with the disease process may be a key to developing early intervention strategies. Unhealthy lifestyle behaviours are well established drivers of the development of several NCDs, but the impact of such behaviours on health can vary considerably between individuals. How can it be determined if an individual's unique set of lifestyle behaviours is producing disease? Accumulating evidence suggests that lifestyle-associated activation of oxidative and inflammatory processes is primary driver of the cell and tissue damage which underpins the development of NCDs. However, the benefit of monitoring subclinical inflammation and oxidative activity has not yet been established. After reviewing relevant studies in this context, we suggest that quantification of oxidative stress and inflammatory biomarkers during the disease-free prodromal stage of NCD development may have clinical relevance as a timely indicator of the presence of subclinical metabolic changes, in the individual, portending the development of disease. Monitoring markers of oxidative and inflammatory activity may therefore enable earlier and more efficient strategies to both prevent NCD development and/or monitor the effectiveness of treatment.

Oxidative stress, telomeres and cellular senescence: What non-drug interventions might break the link?

Telomeres are higher order structures that cap and protect chromosome ends. Telomeric DNA naturally shortens during somatic cell division and as a result of oxidative stress. Excessive shortening disrupts the integrity of the telomere, causing cellular senescence, one of the hallmarks of organismal ageing. The accumulation of senescent cells with ageing contributes to the loss of tissue homeostasis and the development of age-related pathologies. Hence, counteracting telomere shortening may be one relevant approach to develop strategies for healthier ageing. In this review I present the case for the existence of a link between oxidative stress, accelerated telomere shortening and cellular senescence. I also examine findings from human observational studies exploring associations between telomere length and oxidative stress-related parameters. Finally, I discuss results from randomised control trials testing the impact of non-pharmacological lifestyle interventions on the maintenance of telomere length, considering the potential mechanisms that might be involved.

Effects of three products from Antarctic krill on the nitrogen balance, growth, and antioxidation status of rats

A few studies conducted over the past few decades have demonstrated the health benefits of a diet rich in marine products, but limited studies have investigated the effects of different krill products on the nitrogen balance and their potential health benefits. In our study, after a 14-day acclimation period, 50 female Sprague-Dawley rats were randomly assigned to five groups, each of which was fed a different diet, for 28 days. We then evaluated the effect of krill protein complex (KPC), krill powder, and defatted krill powder on the nitrogen balance, growth, and antioxidant activity through analyses of MDA, CAT, GSH-Px, and T-SOD. An in vivo analysis suggested that the nitrogen retention rate, protein digestibility, and bioutilization of krill products were equal to those of casein. Moreover, the KPC diet resulted in the highest nitrogen intake and retention among the groups, and the biological value and net protein utilization obtained with KPC were higher than those obtained with defatted krill powder, which was consistent with the weight gains observed for these two groups. The hematological test also showed that KPC contributed to the production of functional proteins in the body. The antioxidant activity analysis indicated that higher GSH-Px and T-SOD activities were obtained with krill products and KPC, respectively, compared with casein. The results from this study suggested that krill proteins could promote growth and improve the antioxidant status of an organism. Although further studies on the safety of krill products for human consumption are needed, this work provides insights into the use of krill proteins as a potential substitute for other proteins and restructured foods.

Evaluating the efficacy of a ferrous-ion-chelating peptide from Alaska pollock frame for the improvement of iron nutritional status in rats

This study aimed to investigate the effects of ferrous-ion-chelating peptides from Alaska pollock frames (APFP-Fe) on iron deficiency in anaemic rats. We hydrolysed the Alaska pollock frames to obtain a peptide with an average molecular weight of 822 Da. The bioavailability of APFP-Fe was tested using animal experiments. Wistar rats were randomly divided into six groups: an iron deficiency control group, a normal control group, and iron deficiency groups treated with ferrous sulfate (FeSO₄) or low-, medium-, or high-dose APFP-Fe. Rats in the iron deficiency groups were fed an iron-deficient diet to establish the iron deficiency anaemia (IDA) model. After the model was established, different iron supplements were given to rats once per day via intragastric administration for 21 days. The results showed that APFP-Fe had restorative effects, returning the body weight, weight gain, height, and haematological parameters in IDA rats to normal levels. In addition, compared with FeSO₄, APFP-Fe promoted significant weight gain and effectively improved haemoglobin, serum iron and transferrin levels, and recovery of the capacity of iron binding with transferrin, especially at the medium and high doses. These findings suggest that APFP-Fe is an effective source of iron for improving the iron nutritional status in IDA rats and shows promise as a new source of iron supplementation.

Association of nutraceutical supplements with longer telomere length

Telomeres are nucleotide tandem repeats located at the tip of eukaryotic chromosomes that maintain genomic integrity. The gradual shortening of telomeres leads to cellular senescence and apoptosis, a key mechanism of aging and age‑related chronic diseases. Epigenetic factors, such as nutrition, exercise and tobacco can affect the rate at which telomeres shorten and can modify the risk of developing chronic diseases. In this study, we evaluated the effects of a combination of nutraceutical supplements (NS) on telomere length (TL) in healthy volunteers with no medical history of any disease. Participants (n=47) were selected from healthy outpatients visiting a private clinic and were divided into the experimental group (n=16), that received the NS and the control group (n=31). We estimated the length of single telomeres in metaphase spread leukocytes, isolated from peripheral blood, using quantitative‑fluorescent in situ hybridization (Q‑FISH) analysis. The length of the whole telomere genome was significantly increased (P<0.05) for the mean, 1st quartile and median measurements in the experimental group. Similar findings were observed for short TL (20th percentile) (P<0.05) for the median and 3rd quartile measurements in the NS group, compared to the control group. The beneficial effects of the supplements on the length of short telomeres remained significant (P<0.05) following adjustment for age and sex. Telomeres were moderately longer in female patients compared to the male patients. On the whole, the findings of this study suggest that the administration of NS may be linked to sustaining the TL.

Strategies to decrease oxidative stress biomarker levels in human medical conditions: A meta-analysis on 8-iso-prostaglandin F2α

The widespread detection of elevated oxidative stress levels in many medical conditions has led to numerous efforts to design interventions to reduce its effects. Efforts have been wide-ranging, from dietary changes to administration of antioxidants, supplements, e.g., omega-3-fatty acids, and many medications. However, there is still no systemic assessment of the efficacy of treatments for oxidative stress reduction across a variety of medical conditions. The goal of this meta-analysis is, by combining multiple studies, to quantitate the change in the levels of the popular oxidative stress biomarker 8-iso-prostaglandin F2α (8-iso-PGF2α) after a variety of treatment strategies in human populations. Nearly 350 unique publications with 180 distinct strategies were included in the analysis. For each strategy, the difference between pre- or placebo and post-treatment levels calculated using Hedges' g value of effect. In general, administration of antibiotics, antihyperlipidemic agents, or changes in lifestyle (g = - 0.63, - 0.54, and 0.56) had the largest effect. Administration of supplements, antioxidants, or changes in diet (g = - 0.09, - 0.28, - 0.12) had small quantitative effects. To fully interpret the effectiveness of these treatments, comparisons to the increase in g value for each medical condition is required. For example, antioxidants in populations with coronary artery disease (CAD) reduce the 8-iso-PGF2α levels by g = - 0.34 ± 0.1, which is quantitatively considered a small effect. However, CAD populations, in comparison to healthy populations, have an increase in 8-iso-PGF2α levels by g = 0.38 ± 0.04; therefore, the overall reduction of 8-iso-PGF2α levels is ≈ 90% by this treatment in this specific medical condition. In conclusion, 8-iso-PGF2α levels can be reduced not only by antioxidants but by many other strategies. Not all strategies are equally effective at reducing 8-iso-PGF2α levels. In addition, the effectiveness of any strategy can be assessed only in relation to the medical condition investigated.

Effects of n-3 fatty acids and exercise on oxidative stress parameters in type 2 diabetic: a randomized clinical trial

Background

The relationship between diabetes and oxidative stress has been previously reported. Exercise represents a useful non-pharmacological strategy for the treatment in type 2 diabetic (T2DM) patients, but high intensity exercise can induce a transient inflammatory state and increase oxidative stress. Nutritional strategies that may contribute to the reduction of oxidative stress induced by acute exercise are necessary. The aim of this study was to examine if n-3 PUFA supplementation intervention can attenuate the inflammatory response and oxidative stress associated with high intensity exercise in this population. As a primary outcome, lipoperoxidation measurements (TBARS and F2-isoprostanes) were selected.

Methods

Thirty T2DM patients, without chronic complications, were randomly allocated into two groups: placebo (gelatin capsules) or n-3 PUFA (capsules containing 180 mg of eicosapentaenoic acid and 120 mg of docosahexaenoic acid). Blood samples were collected fasting before and after 8 weeks supplementation. In the beginning and at the end of protocol, an acute exercise was performed (treadmill), and new blood samples were collected before and immediately after the exercise for measurements of oxidative stress and high-sensitivity C-reactive protein (hs-CRP).

Results

After the supplementation period, a decrease in triglycerides levels was observed only in n-3 PUFA supplementation group (mean difference and 95% CI of 0.002 (0.000–0.004), p = 0.005). Supplementation also significantly reduced TRAP levels after exercise (mean difference and 95% CI to 9641 (− 20,068–39,351) for − 33,884 (− 56,976 - -10,793), p = 0.004, Cohen’s d effect size = 1.12), but no significant difference was observed in n-3 PUFA supplementation group in lipoperoxidation parameters as TBARS (mean difference and 95% CI to − 3.8 (− 10–2.4) for − 2.9 (− 1.6–7.4) or F2-isoprostanes (mean difference and 95% CI -0.05 (− 0.19–0.10) for − 0.02 (− 0.19–0.16), p > 0.05 for both.

Conclusion

PUFA n-3 supplementation reduced triglycerides as well as TRAP levels after exercise, without a significant effect on inflammatory and oxidative stress markers.

This study is registered at ClinicalTrials.gov with the registration number of NCT03182712.

Dietary fats and F2-isoprostanes: A review of the clinical evidence

Evidence supports that a high dietary fat intake increases oxidative stress and the risk of diet-induced metabolic disorders such as obesity, diabetes and cardiovascular diseases. F₂-isoprostanes (F₂-isoP) are formed by the non-enzymatic oxidation of arachidonic acid and are widely used as reliable biomarkers of oxidative stress in clinical studies. Dietary fats may influence F₂-isoP levels, as they (1) are metabolic substrates for their formation, (2) modify the lipid composition of tissues, and (3) affect the plasma lipoprotein concentrations which are involved in F₂-isoP transport. This review examined the latest clinical evidence on how dietary fats can affect blood circulation and excretion of F₂-isoP in individuals with healthy or deteriorated metabolic profiles. Clinical studies reported that saturated or monounsaturated fat-rich diets did not affect F₂-isoP levels in adults with healthy or deteriorated metabolic profiles. Though, ω-3 polyunsaturated fatty acids decreased F₂-isoP levels in numerous studies, whereas trans-fatty acids raised F₂-isoP excretion. Yet, the reported heterogeneous results reveal important considerations, such as the health status of the participants, the biological fluids used to determine F₂-isoP, the analytical methods employed and the specific F₂-isoP isomers detected. Therefore, future clinical studies should be designed in order to consider these issues in the studies of the effects of fat intake on oxidative stress.

Involvement of the endocannabinoid system in the physiological response to transient common carotid artery occlusion and reperfusion

Background

The transient global cerebral hypoperfusion/reperfusion achieved by induction of Bilateral Common Carotid Artery Occlusion followed by Reperfusion (BCCAO/R) may trigger a physiological response in an attempt to preserve tissue and function integrity. There are several candidate molecules among which the endocannabinoid system (ECS) and/or peroxisome-proliferator activated receptor-alpha (PPAR-alpha) may play a role in modulating oxidative stress and inflammation. The aims of the present study are to evaluate whether the ECS, the enzyme cyclooxygenase-2 (COX-2) and PPAR-alpha are involved during BCCAO/R in rat brain, and to identify possible markers of the ongoing BCCAO/R-induced challenge in plasma.

Methods

Adult Wistar rats underwent BCCAO/R with 30 min hypoperfusion followed by 60 min reperfusion. The frontal and temporal-occipital cortices and plasma were analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS) to determine concentrations of endocannabinoids (eCBs) and related molecules behaving as ligands of PPAR-alpha, and of oxidative-stress markers such as lipoperoxides, while Western Blot and immunohistochemistry were used to study protein expression of cannabinoid receptors, COX-2 and PPAR-alpha. Unpaired Student’s t-test was used to evaluate statistical differences between groups.

Results

The acute BCCAO/R procedure is followed by increased brain tissue levels of the eCBs 2-arachidonoylglycerol and anandamide, palmitoylethanolamide, an avid ligand of PPAR-alpha, lipoperoxides, type 1 (CB1) and type 2 (CB2) cannabinoid receptors, and COX-2, and decreased brain tissue concentrations of docosahexaenoic acid (DHA), one of the major targets of lipid peroxidation. In plasma, increased levels of anandamide and lipoperoxides were observed.

Conclusions

The BCCAO/R stimulated early molecular changes that can be easily traced in brain tissue and plasma, and that are indicative of the tissue physiological response to the reperfusion-induced oxidative stress and inflammation. The observed variations suggest that the positive modulation of the ECS and the increase of proinflammatory substances are directly correlated events. Increase of plasmatic levels of anandamide and lipoperoxides further suggests that dysregulation of these molecules may be taken as an indicator of an ongoing hypoperfusion/reperfusion challenge.

Fit with good fat? The role of n-3 polyunsaturated fatty acids on exercise performance

N-3 PUFA (n-3) polyunsaturated fatty acids (PUFA) are a family of fatty acids mainly found in oily fish and fish oil supplements. The effects of n-3 PUFA on health are mainly derived from its anti-inflammatory proprieties and its influence on immune function. Lately an increased interest in n-3 PUFA supplementation has reached the world of sport nutrition, where the majority of athletes rely on nutrition strategies to improve their training and performance. A vast amount of attention is paid in increasing metabolic capacity, delaying the onset of fatigue, and improving muscle hypertrophy and neuromuscular function. Nutritional strategies are also frequently considered for enhancing recovery, improving immune function and decreasing oxidative stress. The current review of the literature shows that data regarding the effects of n-3PUFA supplementation are conflicting and we conclude that there is, therefore, not enough evidence supporting a beneficial role on the aforementioned aspects of exercise performance.

Oxidative stress in relation to diet and physical activity among premenopausal women

Higher levels of oxidative stress, as measured by F2-isoprostanes, have been associated with chronic diseases such as CVD and some cancers. Improvements in diet and physical activity may help reduce oxidative stress; however, previous studies regarding associations between lifestyle factors and F2-isoprostane concentrations have been inconsistent. The aim of this cross-sectional study was to investigate whether physical activity and intakes of fruits/vegetables, antioxidant nutrients, dietary fat subgroups and alcohol are associated with concentrations of F2-isoprostane and the major F2-isoprostane metabolite. Urinary F2-isoprostane and its metabolite were measured in urine samples collected at enrolment from 912 premenopausal women (aged 35-54 years) participating in the Sister Study. Physical activity, alcohol consumption and dietary intakes were self-reported via questionnaires. With adjustment for potential confounders, the geometric means of F2-isoprostane and its metabolite were calculated according to quartiles of dietary intakes, alcohol consumption and physical activity, and linear regression models were used to evaluate trends. Significant inverse associations were found between F2-isoprostane and/or its metabolite and physical activity, vegetables, fruits, vitamin C, α-carotene, vitamin E, β-carotene, vitamin A, Se, lutein+zeaxanthin and long-chain n-3 fatty acids. Although trans fats were positively associated with both F2-isoprostane and its metabolite, other dietary fat subgroups including SFA, n-6 fatty acids, n-3 fatty acids, MUFA, PUFA, short-chain n-3 fatty acids, long-chain n-3 fatty acids and total fat were not associated with either F2-isoprostane or its metabolite. Our findings suggest that lower intake of antioxidant nutrients and higher intake of trans fats may be associated with greater oxidative stress among premenopausal women.

The interaction between ApoA2 -265T>C polymorphism and dietary fatty acids intake on oxidative stress in patients with type 2 diabetes mellitus

INTRODUCTION

Apolipoprotein A2 (APOA2) -265T>C polymorphism has been studied in relation to oxidative stress and various dietary fatty acids. Since the interaction between APOA2 polymorphism and dietary fatty acids on oxidative stress has not yet discussed, we aimed to investigate the interaction on oxidative stress in type 2 diabetes mellitus (T2DM) patients.

METHODS

The subjects were 180 T2DM patients with known APOA2 genotype, either TT, TC or CC. Superoxide dismutase (SOD) activity was determined by colorimetric method. Total antioxidant capacity (TAC) and serum level of 8-isoprostane F2α were measured by spectrophotometry and ELISA, respectively. Dietary intake was collected through a food frequency questionnaire. Based on the median intake, fatty acids intake was dichotomized into high or low groups. The interaction between APOA2 polymorphism and dietary fatty acids intake was analyzed by ANCOVA multivariate interaction model.

RESULTS

Higher than median intake of omega-6 polyunsaturated fatty acids (n-6 PUFA) was associated with increased serum level of 8-isoprostane F2α in subjects with TT/TC genotype (p = 0.004), and higher than median intake of omega-3 polyunsaturated fatty acids (n-3 PUFA) was associated with increased serum SOD activity in CC genotype (p < 0.001). There was a statistically significant interaction between APOA2 polymorphism and n-6 PUFA intake on 8-isoprostane F2α concentration as well as n-3 PUFA intake on serum SOD activity (p-interaction = 0.04 and 0.02, respectively).

CONCLUSIONS

The current study shows the interaction between APOA2 polymorphism and dietary fatty acids intake on oxidative stress. More investigations on different populations are required to confirm the interaction.

Novel functional foods for optimal oxidative status in healthy ageing

An antioxidant-rich diet has been shown to reduce the incidence of diet-induced metabolic diseases, such as obesity, diabetes and cardiovascular conditions, and contributes to healthy ageing. Yet, clinical trials investigating common dietary antioxidants, such as vitamins, have often failed to find a significant lowering effect on markers of oxidative stress. This review examines the latest clinical evidence on whether three novel potential antioxidant foods-fish omega-3 fatty acids, red wine and dairy products-can affect the oxidative status of healthy individuals. Clinical studies have reported heterogeneous results regarding the effect of fish oil, red wine and dairy products on oxidative stress. However, numerous studies have suggested that omega-3, red wine and dairy products may lower lipid peroxidation, a known trigger of cardiovascular disease, without affecting the oxidative status of healthy individuals. Overall, this review suggests that consumption of 1-2g/day of omega-3, a moderate red wine intake (200-400ml/day) or 2-3 portions/day of dairy products within a healthy diet exert beneficial effects on oxidative markers. Further investigation to ascertain these effects should focus on the antioxidant effects of long-term omega-3 supplementation, and of intake of dealcoholized red wine or higher dairy product consumption.

The isoprostanes--25 years later

Isoprostanes (IsoPs) are prostaglandin-like molecules generated independent of the cyclooxygenase (COX) by the free radical-induced peroxidation of arachidonic acid. The first isoprostane species discovered were isomeric to prostaglandin F2α and were thus termed F2-IsoPs. Since the initial discovery of the F2-IsoPs, IsoPs with differing ring structures have been identified as well as IsoPs from different polyunsaturated fatty acids, including eicosapentaenoic acid and docosahexanenoic acid. The discovery of these molecules in vivo in humans has been a major contribution to the field of lipid oxidation and free radical research over the course of the past 25 years. These molecules have been determined to be both biomarkers and mediators of oxidative stress in numerous disease settings. This review focuses on recent developments in the field with an emphasis on clinical research. Special focus is given to the use of IsoPs as biomarkers in obesity, ischemia-reperfusion injury, the central nervous system, cancer, and genetic disorders. Additionally, attention is paid to diet and lifestyle factors that can affect endogenous levels of IsoPs. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance."

Fish consumption and risk of non-gallstone-related acute pancreatitis: a prospective cohort study

BACKGROUND

Epidemiologic data on the role of diet in acute pancreatitis are sparse.

OBJECTIVE

We examined the association of total fish consumption, as well as of consumption of fatty fish and lean fish separately, with risk of non-gallstone-related acute pancreatitis.

DESIGN

We used data from 2 prospective cohorts, the Cohort of Swedish Men and the Swedish Mammography Cohort, that included 39,267 men and 32,191 women who were aged 45-84 y at the start of a 13-y follow-up period (1998-2010). Fish consumption was assessed by using a food-frequency questionnaire at baseline, and cases of incident non-gallstone-related acute pancreatitis were identified by linkage to the Swedish National Patient Register. HRs were estimated by using Cox proportional hazard models.

RESULTS

During a total follow-up of 860,176 person-years, 320 cases (209 cases in men and 111 cases in women) of incident non-gallstone-related acute pancreatitis were identified. We observed that total fish consumption ≤2.0-3.0 servings/wk was associated with a significantly decreased risk of the disease (P-nonlinearity = 0.017). In comparison with 0.9 servings/wk, multivariable-adjusted HRs were 0.86 (95% CI: 0.76, 0.96), 0.77 (95% CI: 0.62, 0.96), and 0.85 (95% CI: 0.65, 1.10) for 1.4, 2.4, and 3.5 servings/wk, respectively. In the analysis of fatty fish and lean fish, we observed that the consumption of each subtype had a similarly shaped association with risk of non-gallstone-related acute pancreatitis as that observed for total fish consumption, although neither was significant. Multivariable-adjusted HRs were 0.83 for fatty fish (95% CI: 0.65, 1.04) and 0.87 for lean fish (95% CI: 0.69, 1.11) when 0.6-2.0 servings/wk was compared with ≤0.5 servings/wk.

CONCLUSION

Our data suggest that the consumption of total fish (fatty fish and lean fish combined) may be associated with decreased risk of non-gallstone-related acute pancreatitis.

Habitual high intake of fatty fish is related to lower levels of F₂-isoprostane in healthy women

OBJECTIVE

The aim of this study was to determine whether habitual dietary intake of fatty fish, whole grains, fruits and vegetables, or a combination of them all, is associated with oxidative stress levels, measured as urine concentration of 8-iso-prostaglandin F2α (8-iso-PGF2α) in healthy women.

METHODS

Eighty-one participants were included in this cross-sectional study. Mean age of the women was 26.1 ± 6.2 (mean ± SD) years and mean body mass index (BMI) was 22.4 ± 3.0 kg/m(2). The concentration of 8-iso-PGF2α was determined in urine, and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels were determined in blood. Participants' habitual fish, whole grain, fruit, and vegetable intake was estimated from a food frequency questionnaire.

RESULTS

In the multivariate analysis, there was a significant inverse association between 8-iso-PGF2α and high fatty fish intake (P < 0.001). Fatty fish intake was positively correlated to serum phospholipid concentrations of EPA (P = 0.001) and DHA (P = 0.002). A borderline effect of DHA was seen on 8-iso-PGF2α, but higher serum phospholipid concentrations of fatty acids were generally not related to lower F2-isoprostane levels. No overall effect from whole grains or fruits and vegetables was seen.

CONCLUSIONS

The results indicate that high intake of fatty fish is related to lower levels of oxidative stress, but high levels of ω-3 fatty acids in intake may not alone explain the effect. High habitual intake of whole grains or fruits and vegetables did not seem to affect the F2-isoprostane level.

DHA concentration of red blood cells is inversely associated with markers of lipid peroxidation in men taking DHA supplement

An increase in the proportion of fatty acids with higher numbers of double bonds is believed to increase lipid peroxidation, which augments the risk for many chronic diseases. (n-3) Polyunsaturated fatty acids provide various health benefits, but there is a concern that they might increase lipid peroxidation. We examined the effects of docosahexaenoic acid [22:6 (n-3)] supplementation on lipid peroxidation markers in plasma and red blood cells (RBC) and their associations with red blood cell and plasma fatty acids. Hypertriglyceridemic men (n = 17 per group) aged 39–66 years participated in a double-blind, randomized, placebo-controlled, parallel study. They received no supplements for the first 8 days and then received 7.5 g/day docosahexaenoic acid oil (3 g/day docosahexaenoic acid) or olive oil (placebo) for 90 days. Fasting blood samples were collected 0, 45, and 91 days after supplementation. Docosahexaenoic acid supplementation did not change plasma or RBC concentrations of lipid peroxidation markers (total hydroxyoctadecadienoic acid, total hydroxyeicosatetraenoic acid, total 8-isoprostaglandin F_2α, 7α-hydroxycholesterol, 7β-hydroxycholesterol) when pre- and post-supplement values were compared. However, the post-supplement docosahexaenoic acid (DHA) concentration was inversely associated with RBC concentrations of ZE-HODE, EE-HODE, t-HODE, and total 8-isoprostaglandin F_2α, (p<0.05). RBC concentration of hydroxycholesterol was also inversely associated with DHA but it did not attain significance (p = 0.07). Our results suggest that increased concentration of DHA in RBC lipids reduced lipid peroxidation. This may be another health benefit of DHA in addition to its many other health promoting effects.

Novel regulatory roles of omega-3 fatty acids in metabolic pathways: a proteomics approach

Background

Omega-3 polyunsaturated fatty acids (n-3 PUFA) have been shown to alleviate the symptoms of metabolic disorders, such as heart disease, diabetes, obesity and insulin resistance. Several putative mechanisms by which n-3 PUFA elicit beneficial health effects have been proposed; however, there is still a shortage of knowledge on the proteins and pathways that are regulated by n-3 PUFA.

Methods

Using two dimensional polyacrylamide gel electrophoresis (2D-PAGE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, we investigated the effects of diets high or low in n-3 PUFA on hepatic proteomic profile of C57BL/6 mice.

Results

The findings show for the first time that high dietary n-3 PUFA reduced the expression of regucalcin, adenosine kinase and aldehyde dehydrogenase. On the other hand, diets high in n-3 PUFA increased the expression of apolipoprotein A-I, S-adenosylmethionine synthase, fructose-1, 6-bisphosphatase, ketohexokinase, malate dehydrogenase, GTP-specific succinyl CoA synthase, ornithine aminotransferase and protein disulfide isomerase-A3.

Conclusions

Our findings revealed for the first time that n-3 PUFA causes alterations in several novel functional proteins involved in regulating lipid, carbohydrate, one-carbon, citric acid cycle and protein metabolism, suggesting integrated regulation of metabolic pathways. These novel proteins are potential targets to develop therapeutic strategies against metabolic disorders.

Omega-3 fatty acids and cardiovascular disease: epidemiology and effects on cardiometabolic risk factors

Clinical and epidemiological studies provide support that the polyunsaturated omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid from fish and fish oils are cardioprotective, particularly in the setting of secondary prevention.

A new insight to bone turnover: role of ω-3 polyunsaturated fatty acids

Background. Evidence has shown that long-chain polyunsaturated fatty acids (LCPUFA), especially the ω-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are beneficial for bone health and turnover. Objectives. This review summarizes findings from both in vivo and in vitro studies and the effects of LC PUFA on bone metabolism, as well as the relationship with the oxidative stress, the inflammatory process, and obesity. Results. Some studies in humans indicate that LCPUFA can increase bone formation, affect peak bone mass in adolescents, and reduce bone loss. However, the cellular mechanisms of action of the LCPUFA are complex and involve modulation of fatty acid metabolites such as prostaglandins, resolvins and protectins, several signaling pathways, cytokines, and growth factors, although in certain aspects there is still some controversy. LCPUFA affect receptor activator of nuclear factor κβ (RANK), a receptor found on the osteoclast, causing bone resorption, which controls osteoclast formation. Conclusions. Since fatty acids are an endogenous source of reactive oxygen species, free radicals alter the process of bone turnover; however, although there are clinical evidences linking bone metabolism and dietary lipids, more clinical trials are necessary to prove whether ω-3 PUFA supplementation plays a major role in bone health.

New insights regarding tissue Se and Hg interactions on oxidative stress from plasma IsoP and IsoF measures in the Canadian Inuit population

Despite animal and in vitro studies demonstrating pro-oxidative effects of Hg, previous human work showed no relationship between tissue Hg and plasma levels of F2-isoprostanes (IsoPs), a whole-body oxidative stress marker. We hypothesized that another IsoP species, isofurans (IsoFs), was a more sensitive indicator of Hg-mediated oxidative stress, which can be modified by tissue Se status. A cross-sectional study was carried out involving individuals from a random subset (n = 233) of Inuit adults from a population-based survey (n = 2,595) of 36 Canadian Arctic Inuit communities to assess the relationships of plasma IsoPs to Se and Hg status indicators. F2-IsoPs were inversely correlated with blood Se (r = -0.186, P = 0.005) and toenail Se (r = -0.146, P = 0.044), but not correlated with Hg. IsoFs were inversely correlated with blood Se (r = -0.164, P = 0.014) and positively correlated with Hg (r = 0.228, P < 0.001) and Hg:Se (r = 0.340, P < 0.001). The strength of the correlations remained unchanged after multivariate adjustments. Multivariate analysis showed that F2-IsoPs were not positively associated with Hg but with Hg:Se (β = 0.148, P = 0.021). We conclude that Se and Hg status and their interactions are important factors modulating F2-IsoP and IsoF levels such that the Inuit may be protected from Hg-induced oxidative stress because of their high Se status.

Omega-3 fatty acids, oxidative stress, and leukocyte telomere length: A randomized controlled trial

Shorter telomeres have been associated with poor health behaviors, age-related diseases, and early mortality. Telomere length is regulated by the enzyme telomerase, and is linked to exposure to proinflammatory cytokines and oxidative stress. In our recent randomized controlled trial, omega-3 (n-3) polyunsaturated fatty acid (PUFA) supplementation lowered the concentration of serum proinflammatory cytokines. This study assessed whether n-3 PUFA supplementation also affected leukocyte telomere length, telomerase, and oxidative stress. In addition to testing for group differences, changes in the continuous n-6:n-3 PUFA ratio were assessed to account for individual differences in adherence, absorption, and metabolism. The double-blind four-month trial included 106 healthy sedentary overweight middle-aged and older adults who received (1) 2.5g/day n-3 PUFAs, (2) l.25g/day n-3 PUFAs, or (3) placebo capsules that mirrored the proportions of fatty acids in the typical American diet. Supplementation significantly lowered oxidative stress as measured by F2-isoprostanes (p=0.02). The estimated geometric mean log-F2-isoprostanes values were 15% lower in the two supplemented groups compared to placebo. Although group differences for telomerase and telomere length were nonsignificant, changes in the n-6:n-3 PUFA plasma ratios helped clarify the intervention's impact: telomere length increased with decreasing n-6:n-3 ratios, p=0.02. The data suggest that lower n-6:n-3 PUFA ratios can impact cell aging. The triad of inflammation, oxidative stress, and immune cell aging represents important pre-disease mechanisms that may be ameliorated through nutritional interventions. This translational research broadens our understanding of the potential impact of the n-6:n-3 PUFA balance. ClinicalTrials.gov identifier: NCT00385723.

Aging gonads, glands, and gametes: immutable or partially reversible changes?

Decreased ovarian testosterone production, granulosa cell dysfunction, oocyte telomere shortening and mitochondrial defects, and sperm DNA fragmentation all contribute to reproductive aging. Maneuvers aimed at correcting these abnormalities, including reduction of oxidative stress, improved lifestyle and nutrition, and the role of supplements, are reviewed.

The effect of vitamin E and plant extract mixture composed of carvacrol, cinnamaldehyde and capsaicin on oxidative stress induced by high PUFA load in young pigs

The objective of our study was to determine the antioxidative potential of a plant extract (PE) mixture composed of carvacrol, capsicum oleoresin and cinnamaldehyde against high n-3 polyunsaturated fatty acid (PUFA)-induced oxidative stress in young pigs. Thirty-two weaned castrated male crossbred pigs (BW 10.9 kg; n = 32) were randomly assigned to four dietary treatments (n = 8). The negative control diet (Cont) contained 17.2% energy from fat. Oxidative stress was induced in three of the four experimental groups with the inclusion of n-3 PUFA rich linseed oil. Linseed oil substituted wheat starch in the diet to elevate the amount of energy from fat to 34.1%. One of these diets served as a positive control (Oil), one was additionally supplemented with 271.2 mg/kg of PE mixture and one with 90.4 mg/kg α-tocopheryl acetate (Vit E). After 14 days of treatment, blood and urine were collected for the determination of lipid peroxidation and DNA damage. Lipid peroxidation was studied by plasma malondialdehyde (MDA) concentrations, 24 h urinary MDA and F2-isoprostane (iPF2α-VI) excretion, total antioxidant status of plasma and glutathione peroxidase assays. Lymphocyte DNA fragmentation and 24 h urinary 8-hydroxy-2'-deoxyguanosine excretion were measured to determine DNA damage. Consumption of n-3 PUFA rich linseed oil increased the amount of MDA in plasma and urine, and induced DNA damage in lymphocytes, but did not elevate the amount of iPF2α-VI excreted in the urine. The supplementation with PE and with Vit E did not reduce MDA levels in plasma and urine, but it decreased the percentage of DNA damage in lymphocytes (P < 0.001). The PE reduced the urinary iPF2α-VI excretion in comparison to the Cont diet. The results show that PE and Vit E supplemented to pigs in concentrations of 271.2 mg/kg and 90.4 mg/kg, respectively, can effectively protect pig's blood lymphocytes against oxidative DNA damage, thus suggesting their potentially beneficial effects on the immune system under dietary-induced oxidative stress.

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.

Relation of blood cadmium, lead, and mercury levels to biomarkers of lipid peroxidation in premenopausal women

Exposures to cadmium, lead, and mercury are associated with adverse health effects, including cardiovascular disease, which may be promoted by lipid peroxidation. The authors examined cadmium, lead, and mercury in relation to plasma levels of F(2)-8α isoprostanes (isoprostane), 9-hydroperoxy-10,12-octadecadienoic acid (9-HODE), 13-hydroxy-9,11-octadecadienoic acid (13-HODE), and thiobarbituric acid reactive substances (TBARS) in 252 women from western New York State (2005-2007). Healthy premenopausal women were followed for ≤2 menstrual cycles, with biomarkers of lipid peroxidation being assessed ≤8 times per cycle. Metals were measured at baseline in whole blood. Linear mixed models were used to estimate the association between cadmium, lead, and mercury and lipid peroxidation biomarkers. Median cadmium, lead, and mercury levels were 0.30 μg/L, 0.86 μg/dL, and 1.10 μg/L, respectively. Blood cadmium, lead, and mercury were not associated with increases in isoprostane, TBARS, 9-HODE, or 13-HODE levels. Isoprostane levels decreased 6.80% (95% confidence interval: -10.40, -3.20) per 1% increase in mercury. However, after adjustment for a simulated strong confounding factor, such as precisely measured fish consumption, the observed association was attenuated, suggesting that this unexpected association could be attributable to unmeasured confounding. In this population of healthy premenopausal women with low exposure levels, cadmium, lead, and mercury were not associated with elevated lipid peroxidation biomarkers.

Effect of acute administration of Pistacia lentiscus L. essential oil on rat cerebral cortex following transient bilateral common carotid artery occlusion

BACKGROUND

Ischemia/reperfusion leads to inflammation and oxidative stress which damages membrane highly polyunsaturated fatty acids (HPUFAs) and eventually induces neuronal death. This study evaluates the effect of the administration of Pistacia lentiscus L. essential oil (E.O.), a mixture of terpenes and sesquiterpenes, on modifications of fatty acid profile and endocannabinoid (eCB) congener concentrations induced by transient bilateral common carotid artery occlusion (BCCAO) in the rat frontal cortex and plasma.

METHODS

Adult Wistar rats underwent BCCAO for 20 min followed by 30 min reperfusion (BCCAO/R). 6 hours before surgery, rats, randomly assigned to four groups, were gavaged either with E.O. (200 mg/0.45 ml of sunflower oil as vehicle) or with the vehicle alone.

RESULTS

BCCAO/R triggered in frontal cortex a decrease of docosahexaenoic acid (DHA), the membrane highly polyunsaturated fatty acid most susceptible to oxidation. Pre-treatment with E.O. prevented this change and led further to decreased levels of the enzyme cyclooxygenase-2 (COX-2), as assessed by Western Blot. In plasma, only after BCCAO/R, E.O. administration increased both the ratio of DHA-to-its precursor, eicosapentaenoic acid (EPA), and levels of palmytoylethanolamide (PEA) and oleoylethanolamide (OEA).

CONCLUSIONS

Acute treatment with E.O. before BCCAO/R elicits changes both in the frontal cortex, where the BCCAO/R-induced decrease of DHA is apparently prevented and COX-2 expression decreases, and in plasma, where PEA and OEA levels and DHA biosynthesis increase. It is suggested that the increase of PEA and OEA plasma levels may induce DHA biosynthesis via peroxisome proliferator-activated receptor (PPAR) alpha activation, protecting brain tissue from ischemia/reperfusion injury.

Enhanced prostaglandin F2α formation in human pregnancy and the effect of increased oily fish intake: results from the Salmon in Pregnancy Study

Oily fish intake during pregnancy may reduce the risk of allergic diseases in infancy possibly by shifts in the fatty acid balance and subsequent altered prostaglandin (PG) formation. This intervention is the first study to evaluate if increased oily fish intake affects in vivo PGF(2α) formation during pregnancy. British pregnant women were randomised to two portions of farmed salmon weekly (n=47), or maintenance of their normal diet low in fish (n=41), from pregnancy week 20 until parturition. The concentrations of eicosapentaenoic and docosahexaenoic acids in plasma phosphatidylcholine (PC) were higher and the concentration of arachidonic acid in plasma PC was lower in the salmon group than the control group at weeks 34 and 38 of pregnancy. PGF(2α) formation was evaluated by urinary measurement of 15-keto-dihydro-PGF(2α), a major PGF(2α) metabolite, at 20, 34 and 38 weeks. In both the salmon and control groups urinary 15-keto-dihydro-PGF(2α) concentrations increased significantly during pregnancy, which may be of physiological importance. Oily fish intervention altered fatty acid concentrations but did not affect urinary 15-keto-dihydro-PGF(2α) concentrations in pregnant women.

An exploratory study to determine the association between assessed facial skin aging and plasma isoprostane levels in middle-aged Japanese women

BACKGROUND

One of the central mechanisms of aging is hypothesized to be oxidative stress. Quantification of oxidative stress in human organ systems has been difficult. One of the best methods is using plasma isoprostane levels, which have been shown to reflect oxidative stress in multiple nondermatologic organ systems.

OBJECTIVE

To determine whether severity of aging of human skin is associated with plasma isoprostane levels, specifically prostaglandin F2a (PGF2a) and 8-iso-PGF2a while controlling for covariates such as body mass index, ultraviolet light exposure, diet, medication, supplement use, and stress levels.

METHODS AND MATERIALS

Facial skin aging assessments performed by four blinded dermatologists were correlated with plasma isoprostane levels in 46 healthy, nonsmoking Japanese women aged 45 to 60.

RESULTS

Individuals whose assessed skin age exceeded chronological age had mean plasma isoprostane levels of PGF2a and 8-iso-PGF2a that were higher than those whose skin age was assessed to be less than chronological age (p = .001 and .001, respectively). These results remained statistically significant when adjusted for confounding variables (8-iso-PGF2a, p = .02; PGF2a, p = .03).

CONCLUSIONS

Plasma isoprostanes as markers of accelerated aging of the skin merit further study.

Oxidised fish oil does not influence established markers of oxidative stress in healthy human subjects: a randomised controlled trial

Intake of fish oil reduces the risk of CHD and CHD deaths. Marine n-3 fatty acids (FA) are susceptible to oxidation, but to our knowledge, the health effects of intake of oxidised fish oil have not previously been investigated in human subjects. The aim of the present study was to investigate markers of oxidative stress, lipid peroxidation and inflammation, and the level of plasma n-3 FA after intake of oxidised fish oil. In a double-blinded randomised controlled study, healthy subjects (aged 18–50 years, n 54) were assigned into one of three groups receiving capsules containing either 8 g/d of fish oil (1·6 g/d EPA+DHA; n 17), 8 g/d of oxidised fish oil (1·6 g/d EPA+DHA; n 18) or 8 g/d of high-oleic sunflower oil (n 19). Fasting blood and morning spot urine samples were collected at weeks 0, 3 and 7. No significant changes between the different groups were observed with regard to urinary 8-iso-PGF2α; plasma levels of 4-hydroxy-2-hexenal, 4-hydroxy-2-nonenal and α-tocopherol; serum high sensitive C-reactive protein; or activity of antioxidant enzymes in erythrocytes. A significant increase in plasma level of EPA+DHA was observed in both fish oil groups, but no significant difference was observed between the fish oil groups. No changes in a variety of in vivo markers of oxidative stress, lipid peroxidation or inflammation were observed after daily intake of oxidised fish oil for 3 or 7 weeks, indicating that intake of oxidised fish oil may not have unfavourable short-term effects in healthy human subjects.

The effects of rosuvastatin alone or in combination with fenofibrate or omega 3 fatty acids on inflammation and oxidative stress in patients with mixed dyslipidemia

OBJECTIVE

Mixed dyslipidemia, oxidative stress and inflammation are related to a high risk for cardiovascular events. The aim of this open-label randomized study was to compare the effects of high-dose rosuvastatin, low-dose rosuvastatin plus fenofibrate and low-dose rosuvastatin plus omega 3 fatty acids on inflammation and oxidative stress indices in patients with mixed dyslipidemia.

METHODS

Ninety patients with mixed dyslipidemia participated in the study. Patients were randomly allocated to receive rosuvastatin 40 mg (n = 30, group R), rosuvastatin 10 mg plus fenofibrate 200 mg (n = 30, group RF) or rosuvastatin 10 mg plus omega 3 fatty acids 2 g daily (n = 30, group RΩ). Plasma and high-density lipoprotein (HDL)-associated lipoprotein-associated phospholipase A2 (LpPLA2) activities, high-sensitivity C reactive protein (hsCRP), plasma isoprostane and paraoxonase (PON1) activities were measured at baseline and after 3 months of treatment.

RESULTS

Serum concentrations of non-HDL cholesterol and low-density lipoprotein cholesterol (LDL-C) were significantly reduced in all study groups. However, these changes were more pronounced in the rosuvastatin monotherapy group. In all treatment groups a significant reduction in total plasma LpPLA2 activity was observed (by 41, 38 and 30% for groups R, RF and RΩ, respectively). This decrease was greater in the R and RF groups compared with the RΩ combination (p < 0.05). HDL-LpPLA2 activity was increased more in the RF group (+43%) compared with the R and RΩ groups (+ 18% and + 35%, respectively; p < 0.05 for both comparisons). In all treatment groups there was a nonsignificant reduction in plasma 8-iso-PGF2α levels. A 53% reduction of hsCRP levels was observed in the R group, while in the RF and RΩ groups the reduction was 28 and 23%, respectively (p < 0.05 and p < 0.01 for the comparisons of group R with groups RF and RΩ, respectively). No significant changes were observed in PON activities in all treatment groups.

CONCLUSION

The greater non-HDL-C- and LDL-C-lowering efficiency of rosuvastatin monotherapy along with its more potent effect on LpPLA2 activity and hsCRP levels indicate that this regimen is a better treatment option for patients with mixed dyslipidemia.

In vivo antioxidant potential of Sweet chestnut (Castanea sativa Mill.) wood extract in young growing pigs exposed to n-3 PUFA-induced oxidative stress

BACKGROUND

Farm animals in intensive farming systems are frequently exposed to oxidative stress, which demands adequate antioxidant protection. The aim of this study was to evaluate the antioxidant potential of different concentrations of Sweet chestnut wood extract (SCW; 0.75, 1.5 and 3 g kg⁻¹) in case of n-3 PUFA-induced oxidative stress in young pigs.

RESULTS

The highest concentration (3 g kg⁻¹) of SCW decreased malondialdehyde excretion in urine by 31.7%, but had no effect on plasma malondialdehyde. A linear trend towards decrease of urine isoprostanes iPF(2α)-VI was observed with the addition of SCW. All three concentrations of SCW efficiently protected blood lymphocytes from DNA damage and lowered plasma alanine aminotransferase levels. The antioxidative and antigenotoxic effect of 3 g SCW kg⁻¹ feed was comparable to the effect of 90.4 mg kg⁻¹ of added vitamin E.

CONCLUSION

The results from this study show that, besides being known as antihelmintic, antimicrobial and antiviral agent, Sweet chestnut wood extract could also be considered as a promising natural antioxidant in animal nutrition.

Reduced thrombin formation and altered fibrin clot properties induced by polyunsaturated omega-3 fatty acids on top of dual antiplatelet therapy in patients undergoing percutaneous coronary intervention (OMEGA-PCI clot)

OBJECTIVE

The goal of this study was to investigate whether omega-3 polyunsaturated fatty acids (n-3 PUFA) are able to alter plasma fibrin clot properties and reduce thrombin formation in stable coronary artery disease patients undergoing percutaneous coronary intervention (PCI).

METHODS AND RESULTS

In an investigator-initiated, prospective, double-blind, placebo-controlled, randomized study, patients undergoing PCI who received standard pharmacotherapy were assigned to the treatment with 1 g/day n-3 PUFA (n = 30) or placebo (n = 24) for 1 month. Plasma fibrin clot permeability (K(s)); lysis time (t(50%)); prothrombin fragment 1.2; and peak thrombin generation from automated thrombogram, 8-isoprostaglandin F(2α) (8-iso-PGF(2α), an oxidative stress marker), and C-reactive protein were determined at baseline, 3 to 5 days after randomization, and 30 days after randomization. At baseline, both treatment groups did not differ significantly. A 1-month treatment with n-3 PUFA compared with placebo was associated with 15.3% higher K(s), indicating larger pores in the fibrin network (P = 0.0005); 14.3% shorter t(50%), indicating increased susceptibility to fibrinolysis (P<0.0001); 33.8% lower prothrombin fragment 1.2 (P = 0.0013); 13.4% lower peak thrombin generation (P = 0.04); and 13.1% lower 8-iso-PGF(2α) (P = 0.009). Treatment with n-3 PUFA had no effect on fibrinogen and C-reactive protein. After 1 month of treatment, fibrinogen (r = -0.53, P<0.0001), treatment assignment (r = 0.29, P = 0.006) and 8-iso-PGF(2α) (r = -0.27, P = 0.015) were independently associated with clot permeability (P<0.0001, R(2) = 0.66).

CONCLUSIONS

Adding n-3 PUFA to standard therapy in stable patients undergoing PCI significantly decreases thrombin formation and oxidative stress and favorably alters fibrin clot properties. These findings indicate novel antithrombotic effects induced by n-3 PUFA in humans.

The omega-3 fatty acids EPA and DHA decrease plasma F(2)-isoprostanes: Results from two placebo-controlled interventions

Omega-3 (omega3) fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), protect against cardiovascular disease. Despite these benefits, concern remains that omega3 fatty acids may increase lipid peroxidation. It has previously been shown that urinary F(2)-isoprostanes (F(2)-IsoPs) were reduced following omega3 fatty acid supplementation in humans. It is now determined whether EPA or DHA supplementation affects plasma F(2)-IsoPs. In two 6-week placebo-controlled interventions, Study A: overweight, dyslipidaemic men; and Study B: treated-hypertensive Type 2 diabetic, patients were randomized to 4 g daily EPA, DHA. Post-intervention plasma F(2)-IsoPs were significantly reduced by EPA (24% in Study A, 19% in Study B) and by DHA (14% in Study A, 23% in Study B) relative to the olive oil group. The fall in plasma F(2)-IsoPs was not altered in analyses that corrected for changes in plasma arachidonic acid, which was reduced with EPA and DHA supplementation. Neither F(3)- nor F(4)-IsoPs were observed in plasma in both studies. These results show that in humans, EPA and DHA reduce in vivo oxidant stress as measured in human plasma and urine.

Effect of omega-3 fatty acids on plasma level of 8-isoprostane in kidney transplant patients

OBJECTIVE

It has been shown previously that the serum level of F2-isoprostanes acts as an indicator of oxidative stress, which is a risk factor for vascular disease especially in end-stage renal disease. It is not known whether n-3 polyunsaturated fatty acids can decrease oxidative stress in renal recipient patients.

DESIGN, SETTING, AND SUBJECTS

In this single blind, randomized, placebo-controlled study, the effect of 3 and 6 months of fish oil administration on 8-isoprostane levels in renal transplant recipients was evaluated.

INTERVENTION

Twenty-two renal transplant patients who fulfilled inclusion and exclusion criteria randomly received either fish oil dietary supplementation, 6 g/day (720 mg of DHA and 1,080 mg of EPA) or placebo for 6 months.

MAIN OUTCOME MEASURE

Serum 8-isoprostane concentration was measured as markers of oxidative stress.

RESULTS

A significant decrease in 8-isoprostane levels was observed only in the placebo group after transplantation compared to baseline (P < 0.05). However, the group receiving fish oil had a significantly lower cholesterol level than that of the placebo group (P < 0.05).

CONCLUSION

On the basis of our results, omega-3 fatty acids supplementation decreased the beneficial effects of kidney transplantation on oxidative stress.

Adding monounsaturated fatty acids to a dietary portfolio of cholesterol-lowering foods in hypercholesterolemia

BACKGROUND

Higher intake of monounsaturated fat may raise high-density lipoprotein (HDL) cholesterol without raising low-density lipoprotein (LDL) cholesterol. We tested whether increasing the monounsaturated fat content of a diet proven effective for lowering LDL cholesterol (dietary portfolio) also modified other risk factors for cardiovascular disease, specifically by increasing HDL cholesterol, lowering serum triglyceride and further reducing the ratio of total to HDL cholesterol.

METHODS

Twenty-four patients with hyperlipidemia consumed a therapeutic diet very low in saturated fat for one month and were then randomly assigned to a dietary portfolio low or high in monounsaturated fatty acid for another month. We supplied participants' food for the two-month period. Calorie intake was based on Harris-Benedict estimates for energy requirements.

RESULTS

For patients who consumed the dietary portfolio high in monounsaturated fat, HDL cholesterol rose, whereas for those consuming the dietary portfolio low in monounsaturated fat, HDL cholesterol did not change. The 12.5% treatment difference was significant (0.12 mmol/L, 95% confidence interval [CI] 0.05 to 0.21, p = 0.003). The ratio of total to HDL cholesterol was reduced by 6.5% with the diet high in monounsaturated fat relative to the diet low in monounsaturated fat (-0.28, 95% CI -0.59 to -0.04, p = 0.025). Patients consuming the diet high in monounsaturated fat also had significantly higher concentrations of apolipoprotein AI, and their C-reactive protein was significantly lower. No treatment differences were seen for triglycerides, other lipids or body weight, and mean weight loss was similar for the diets high in monounsaturated fat (-0.8 kg) and low in monounsaturated fat (-1.2 kg).

INTERPRETATION

Monounsaturated fat increased the effectiveness of a cholesterol-lowering dietary portfolio, despite statin-like reductions in LDL cholesterol. The potential benefits for cardiovascular risk were achieved through increases in HDL cholesterol, further reductions in the ratio of total to HDL cholesterol and reductions in C-reactive protein. (ClinicalTrials.gov trial register no. NCT00430430.).

Differential effects of hypothalamic long-chain fatty acid infusions on suppression of hepatic glucose production

Our objective was to investigate whether the direct bilateral infusion of the monounsaturated fatty acid (MUFA) oleic acid (OA) within the mediobasal hypothalamus (MBH) is sufficient to reproduce the effect of administration of OA (30 nmol) in the third cerebral ventricle, which inhibits glucose production (GP) in rats. We used the pancreatic basal insulin clamp technique (plasma insulin ∼20 mU/ml) in combination with tracer dilution methodology to compare the effect of MBH OA on GP to that of a saturated fatty acid (SFA), palmitic acid (PA), and a polyunsaturated fatty acid (PUFA), linoleic acid (LA). The MBH infusion of 200 but not 40 pmol of OA was sufficient to markedly inhibit GP (by 61% from 12.6 ± 0.6 to 5.1 ± 1.6 mg·kg(-1)·min(-1)) such that exogenous glucose had to be infused at the rate of 6.0 ± 1.2 mg·kg(-1)·min(-1) to prevent hypoglycemia. MBH infusion of PA also caused a significant decrease in GP, but only at a total dose of 4 nmol (GP 5.8 ± 1.6 mg·kg(-1)·min(-1)). Finally, MBH LA at a total dose of 0.2 and 4 nmol failed to modify GP compared with rats receiving MBH vehicle. Increased availability of OA within the MBH is sufficient to markedly inhibit GP. LA does not share the effect of OA, whereas PA can reproduce the potent effect of OA on GP, but only at a higher dose. It remains to be determined whether SFAs need to be converted to MUFAs to exert this effect or whether they activate a separate signaling pathway to inhibit GP.

Limited effect of dietary saturated fat on plasma saturated fat in the context of a low carbohydrate diet

We recently showed that a hypocaloric carbohydrate restricted diet (CRD) had two striking effects: (1) a reduction in plasma saturated fatty acids (SFA) despite higher intake than a low fat diet, and (2) a decrease in inflammation despite a significant increase in arachidonic acid (ARA). Here we extend these findings in 8 weight stable men who were fed two 6-week CRD (12%en carbohydrate) varying in quality of fat. One CRD emphasized SFA (CRD-SFA, 86 g/d SFA) and the other, unsaturated fat (CRD-UFA, 47 g SFA/d). All foods were provided to subjects. Both CRD decreased serum triacylglycerol (TAG) and insulin, and increased LDL-C particle size. The CRD-UFA significantly decreased plasma TAG SFA (27.48 ± 2.89 mol%) compared to baseline (31.06 ± 4.26 mol%). Plasma TAG SFA, however, remained unchanged in the CRD-SFA (33.14 ± 3.49 mol%) despite a doubling in SFA intake. Both CRD significantly reduced plasma palmitoleic acid (16:1n-7) indicating decreased de novo lipogenesis. CRD-SFA significantly increased plasma phospholipid ARA content, while CRD-UFA significantly increased EPA and DHA. Urine 8-iso PGF_2α, a free radical-catalyzed product of ARA, was significantly lower than baseline following CRD-UFA (−32%). There was a significant inverse correlation between changes in urine 8-iso PGF_2α and PL ARA on both CRD (r = −0.82 CRD-SFA; r = −0.62 CRD-UFA). These findings are consistent with the concept that dietary saturated fat is efficiently metabolized in the presence of low carbohydrate, and that a CRD results in better preservation of plasma ARA.

Effects of dietary fat modification on oxidative stress and inflammatory markers in the LIPGENE study

Subjects with the metabolic syndrome (MetS) have enhanced oxidative stress and inflammation. Dietary fat quality has been proposed to be implicated in these conditions. We investigated the impact of four diets distinct in fat quantity and quality on 8-iso-PGF2α (a major F2-isoprostane and oxidative stress indicator), 15-keto-13,14-dihydro-PGF2α (15-keto-dihydro-PGF2α, a major PGF2α metabolite and marker of cyclooxygenase-mediated inflammation) and C-reactive protein (CRP). In a 12-week parallel multicentre dietary intervention study (LIPGENE), 417 volunteers with the MetS were randomly assigned to one of the four diets: two high-fat diets (38 % energy (%E)) rich in SFA or MUFA and two low-fat high-complex carbohydrate diets (28 %E) with (LFHCC n-3) or without (LFHCC) 1·24 g/d of very long chain n-3 fatty acid supplementation. Urinary levels of 8-iso-PGF2α and 15-keto-dihydro-PGF2α were determined by RIA and adjusted for urinary creatinine levels. Serum concentration of CRP was measured by ELISA. Neither concentrations of 8-iso-PGF2α and 15-keto-dihydro-PGF2α nor those of CRP differed between diet groups at baseline (P>0·07) or at the end of the study (P>0·44). Also, no differences in changes of the markers were observed between the diet groups (8-iso-PGF2α, P = 0·83; 15-keto-dihydro-PGF2α, P = 0·45; and CRP, P = 0·97). In conclusion, a 12-week dietary fat modification did not affect the investigated markers of oxidative stress and inflammation among subjects with the MetS in the LIPGENE study.

Effects of weight loss and seafood consumption on inflammation parameters in young, overweight and obese European men and women during 8 weeks of energy restriction

BACKGROUND/OBJECTIVES

In vitro studies have shown that long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs) can affect inflammation; however, results from intervention studies in overweight or obese individuals are contradicting. The aim of this study was to investigate the effects of weight loss and seafood consumption on inflammation parameters during energy restriction.

SUBJECTS/METHODS

In this 8-week intervention trial, 324 subjects (aged 20-40 years, body mass index 27.5-32.5 kg/m(2) from Iceland, Spain and Ireland) were randomized to one of four energy-restricted diets (-30% relative to estimated requirements): salmon (3 x 150 g/week, 2.1 g LC n-3 PUFA per day); cod (3 x 150 g/week, 0.3 g LC n-3 PUFA per day); fish oil capsules (1.3 g LC n-3 PUFA per day); and control (sunflower oil capsules, no seafood). Body weight, high-sensitivity C-reactive protein (CRP), interleukin-6 (IL-6), glutathione reductase and prostaglandin F2 alpha (PGEF2alpha) were measured at baseline and end point.

RESULTS

Subjects experienced weight loss (-5.2+/-3.2 kg, P<0.001). Taken together for all subjects, there were significant decreases in all inflammation parameters. On a group level, salmon consumption was most effective, three of the four inflammation parameters decreased in the salmon group (high-sensitivity CRP=-32.0%; IL-6=-18.4%; PGEF2alpha=-18.5%; all P<0.05). Cod consumption decreased high-sensitivity CRP and IL-6 (-21.5 and -10.8%, respectively, both P<0.05). Changes in the other two groups were not significant, which can be partly explained by the large s.d.

CONCLUSIONS

The mean concentrations of inflammation parameters decreased during a period of weight loss and dietary intervention. In our study, salmon consumption was most effective, three of the four measured inflammation parameters decreased significantly in the salmon group.

Postprandial oxidative stress is modified by dietary fat: evidence from a human intervention study

Previous evidence supports the concept that increased oxidative stress may play an important role in MetS (metabolic syndrome)-related manifestations. Dietary fat quality has been proposed to be critical in oxidative stress and the pathogenesis of the MetS. In the present study, we investigated whether oxidative stress parameters are affected by diets with different fat quantity and quality during the postprandial state in subjects with the MetS. Patients were randomly assigned to one of four isoenergetic diets distinct in fat quantity and quality for 12 weeks: a high-saturated-fatty-acid (HSFA) diet, a high-mono-unsaturated-fatty-acid (HMUFA) diet and two low-fat/high-complex carbohydrate diets [supplemented with 1.24 g/day of long-chain n−3 polyunsaturated fatty acid (LFHCC n−3) or with 1 g/day of sunflower oil high in oleic acid (LFHCC) as placebo]. The HMUFA diet enhanced postprandial GSH (reduced glutathione) levels and the GSH/GSSH (oxidized glutathione) ratio, compared with the other three diets. In addition, after the HMUFA-rich diet postprandial lipid peroxide levels, protein carbonyl concentrations, SOD (superoxide dismutase) activity and plasma H2O2 levels were lower compared with subjects adhering to the HSFA-rich diet. Both LFHCC diets had an intermediate effect relative to the HMUFA and HSFA diets. In conclusion, our data support the notion that the HMUFA diet improves postprandial oxidative stress in patients with the MetS. These findings suggest that the postprandial state is important for understanding the possible cardioprotective effects associated with mono-unsaturated dietary fat, particularly in subjects with the MetS.