Dietary Antioxidant Capacity Indices are Negatively Correlated to LDL-Oxidation in Adults.

Introduction: Former research studies have demonstrated controversial associations between dietary indices and oxidative stress biomarkers including oxidized low-density lipoprotein (ox-LDL) and malondialdehyde (MDA). So, in this cross-sectional study, we aimed to assess the association of dietary total antioxidant capacity (DTAC), oxidative balance score, and phytochemical index (PI) with ox-LDL/MDA in a healthy adult population of Shiraz, Iran. Methods: 236 individuals participated in this cross-sectional study. DTAC, OBS, and PI were calculated using a 168-item food frequency questionnaire (FFQ), which was previously validated in Iran. We measured ox-LDL and MDA in blood samples of the participants using commercially existing kits. Crude and adjusted models of linear regression were used to evaluate the relation of dietary indices with ox-LDL and MDA. Results: There was a significant association between ox-LDL and DTAC in both crude (ß = -1.55; 95% CI: -2.53, -0.58; P-trend = 0.002) and adjusted (ß = -1.65 95% CI: -2.66, -0.64; P-trend = 0.001) models. Also, a negative association was observed between ox-LDL and PI in the crude (ß = -1.26 95% CI: -2.33, -0.29; P-trend = 0.01) and adjusted (ß = -1.36 95% CI: -2.38, -0.34; P-trend = 0.01) models. Conclusion: Results of this study showed that DTAC and PI were inversely associated with ox-LDL as markers of lipid peroxidation. But no correlations were seen between MDA and dietary antioxidant indices.

Antioxidant and anti-inflammatory effects of curcumin/turmeric supplementation in adults: A GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials.

Turmeric and its prominent bioactive compound, curcumin, have been the subject of many investigations with regard to their impact on inflammatory and oxidative balance in the body. In this systematic review and meta-analysis, we summarized the existing literature on randomized controlled trials (RCTs) which examined this hypothesis. Major databases (PubMed, Scopus, Web of Science, Cochrane Library and Google Scholar) were searched from inception up to October 2022. Relevant studies meeting our eligibility criteria were obtained. Main outcomes included inflammatory markers (i.e. C-reactive protein(CRP), tumour necrosis factorα(TNF-α), interleukin-6(IL-6), and interleukin 1 beta(IL-1ß)) and markers of oxidative stress (i.e. total antioxidant capacity (TAC), malondialdehyde(MDA), and superoxide dismutase (SOD) activity). Weighted mean differences (WMDs) were reported. P-values < 0.05 were considered significant. Sixty-six RCTs were included in the final analysis. We observed that turmeric/curcumin supplementation significantly reduces levels of inflammatory markers, including CRP (WMD: -0.58 mg/l, 95 % CI: -0.74, -0.41), TNF-α (WMD: -3.48 pg/ml, 95 % CI: -4.38, -2.58), and IL-6 (WMD: -1.31 pg/ml, 95 % CI: -1.58, -0.67); except for IL-1ß (WMD: -0.46 pg/ml, 95 % CI: -1.18, 0.27) for which no significant change was found. Also, turmeric/curcumin supplementation significantly improved anti-oxidant activity through enhancing TAC (WMD = 0.21 mmol/l; 95 % CI: 0.08, 0.33), reducing MDA levels (WMD = -0.33 µmol /l; 95 % CI: -0.53, -0.12), and SOD activity (WMD = 20.51 u/l; 95 % CI: 7.35, 33.67). It seems that turmeric/curcumin supplementation might be used as a viable intervention for improving inflammatory/oxidative status of individuals.

Effect of Bariatric Surgery on the Circulating Level of Adiponectin, Chemerin, Plasminogen Activator Inhibitor-1, Leptin, Resistin, and Visfatin: A Systematic Review and Meta-Analysis.

Different adipokines secreted from adipose tissue, exert a range of physiological effects. The aim of present systematic review and meta-analysis was to critically investigate the consequence of bariatric surgery on circulating adipokines, that is, adiponectin, leptin, visfatin, resistin, plasminogen activator inhibitor, and chemerin. After systematically checking the following electronic databases: ISI web of Science, Scopus and PubMed without limitation in time and language up to February 2019, a pool based on a random effect model was established. Eighty-five eligible studies were entered for quantitative analysis. Our meta-analysis revealed that circulating adiponectin increased significantly after bariatric surgery [Standardized mean difference (SMD)=1.401, 95% CI: 1.101, 1.701, p<0.001]; whilst leptin (SMD=-2.178, 95% CI: -2.433, -1.923, p<0.001), PAI-1 (-14.928 ng/ml 95% CI: -21.794, -8.063, p<0.001), and chemerin (-50.238 ng/ml 95% CI: -85.708, -14.768, p<0.001) decreased. However, serum visfatin (2.05 ng/ml, 95% CI: -5.07, 9.17, p=0.573) and resistin (-2.080 ng/ml, 95% CI: -5.352, 1.192, p=0.21) were unchanged. In conclusion, bariatric surgery is associated with a reduction in specific adipokines including leptin, chemerin, and PAI-1, whereas adiponectin is raised, adaptations that could be indicative of improved fat mass and function.

A Comparative Study of the Effect of Flaxseed Oil and Sunflower Oil on the Coagulation Score, Selected Oxidative and Inflammatory Parameters in Metabolic Syndrome Patients.

Metabolic syndrome (MetS) is a chronic disease with inflammatory and hypercoagulable states. The current study aimed to compare the effects of flaxseed oil and sunflower oil consumption on the coagulation score and selected oxidative and inflammatory parameters in patients with MetS. In this randomized controlled clinical trial, 60 patients with MetS were allocated into 2 groups. One group received 25 mL/day flaxseed oil and the other group received 25 mL/day sunflower oil for 7 weeks. Maintenance diet including 15% protein, 55% carbohydrate, and 30% fat from daily total energy intake was designed for each participant. Serum levels of total antioxidant capacity (TAC) and interleukin 6 (IL-6), as well as coagulation score were measured before and after the intervention. Three 24-hour food records were taken during the study. Fifty-two of participants (27 in sunflower oil and 25 in flaxseed oil groups) completed the study. The baseline characteristics and dietary intakes were similar between patients. After 7 weeks, no significant difference was observed between the 2 groups regarding the serum TAC level and coagulation score (p > 0.05). However, serum IL-6 levels significantly decreased in the flaxseed oil group compared to the sunflower oil group (p = 0.017). No side effect was observed during the study due to the use of sunflower and flaxseed oils. We observed that consumption of flaxseed oil improved serum IL-6 levels but had no effect on oxidative stress and coagulation score in patients with MetS. Further studies are needed to confirm the veracity of our results. TRIAL REGISTRATION: Iranian Registry of Clinical Trials Identifier: IRCT2015012020737N1.

Effect of flaxseed supplementation on markers of inflammation and endothelial function: A systematic review and meta-analysis.

OBJECTIVES: The rationale for the current study was to evaluate the efficacy of flaxseed supplementation on important adhesion molecules and inflammatory cytokines in adults. METHODS: We conducted searches of published literature in PubMed, Scopus, Web of Science, and Google Scholar databases from inception until May 2019. All randomized controlled trials (RCTs) which investigated the effects of flaxseed supplementation on the circulating concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), vascular cell adhesion protein 1 (VCAM-1), E-selectin, and intercellular adhesion molecule 1 (ICAM-1) were included in our analysis. Results were summarized using weighted mean differences (WMDs) by random-effects model. RESULTS: Forty eligible RCTs, including 2520 participants were identified. The results of the meta-analysis revealed flaxseed supplementation reduced the concentrations of CRP (WMD = -0.387 mg/L; 95% CI: -0.653, -0.121, p = 0.004), IL-6 (WMD = -0.154 pg/Ml; 95% CI: -0.299, -0.010, p = 0.036), and VCAM-1 (WMD = -22.809 ng/ml; 95% CI: -41.498, -4.120, p = 0.017) but had no significant effect on TNF-α (WMD = -0.077 pg/mL; 95% CI: -0.317, 0.163, p = 0.530), ICAM-1 (WMD = -8.610 ng/ml; 95% CI: -21.936, 4.716, p = 0.205), and E-selectin (WMD = -1.427 ng/ml; 95% CI: -4.074, 1.22, p = 0.291). CONCLUSIONS: These findings showed that flaxseed supplementation may improve some circulating concentrations of specific adhesion molecules and inflammatory cytokines. However, well-designed trials are needed to confirm the range of non-significant and/or equivocal findings.

Effect of Bariatric Surgery on Serum Inflammatory Factors of Obese Patients: a Systematic Review and Meta-Analysis.

Obesity is one of the main causes of inflammation. Previous studies have reported inconclusive results regarding the effect of bariatric surgery on inflammatory markers. This systematic review and meta-analysis is aimed at describing the effect of bariatric surgery on C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α). PubMed/Medline and Scopus were systematically searched for all eligible studies from inception to June 2018. Results are expressed as weighted mean difference (MD) with 95% confidence intervals (CI) using a random effects model. Overall, 116 studies which evaluated serum CRP, IL-6, and TNF-α after bariatric surgery were included. Pooled effect size showed significant reduction in serum CRP (- 5.30 mg/l, 95% CI - 5.46, - 5.15, P < 0.001), IL-6 (- 0.58 pg/ml, 95% CI - 0.64, - 0.53, P < 0.001), and TNF-α (- 0.20 pg/ml, 95% CI - 0.39, - 0.02, P = 0.031) with significant heterogeneity across studies (> 95% for all factors). Bariatric surgery significantly lowered inflammatory factors; however, baseline BMI, follow-up duration and type of surgery could impact the extent of observed effects.