Does vitamin D reduce the mortality rate of Plasmodium infection?: a systematic review and meta-analysis.

BACKGROUND: Vitamin D supplementation is recommended as an effective adjunct to counteract malaria pathogenesis, but the evidence on this point is limited and controversial. This systematic review and meta-analysis aimed to investigate the effect of vitamin D administration on the survival rate of Plasmodium-infected animals in experimentally-induced malaria on days 6 and 10 post-infection. METHODS: Five electronic databases were searched up to 20 December 2021. The pooled risks ratio (RR) and associated 95% confidence interval were estimated using the Restricted-maximum likelihood (REML) random-effects model. Heterogeneity was assessed by Cochran's Q test and I2 value. Sub-group analyses were used to identify the sources of heterogeneity for several variables, such as type of vitamin D, type of intervention, and dose of vitamin D. RESULTS: Out of 248 articles found in the electronic database, six were eligible for inclusion in the meta-analysis. The current study found that the pooled random effect of risks ratio favored a statistically significant effect of vitamin D administration on survival rate in infected mice on day 6 post Plasmodium infection (RR = 1.08, 95%CI 1.03, 1.15, p < 0.99; I2 = 0%). It also found that vitamin D administration significantly affected the survival rate on day 10 post-infection (RR = 1.94, 95%CI 1.39, 2.71, p < 0.001; I2 = 69.02%). Subgroup analyses demonstrated a significant pooled RRs of the positive effect of vitamin D administration for cholecalciferol (RR = 3.11, 95%CI 2.41, 4.03, p < 0.001; I2 = 0%), doses higher than 50 µg/kg (RR = 3.37, 95%CI 2.55, 4.27, p < 0.001; I2 = 0%), and oral administration (RR = 3.01, 95%CI 2.37, 3.82, p < 0.001; I2 = 0%). CONCLUSION: This systematic review and meta-analysis showed that vitamin D administration positively affects the survival rate in Plasmodium-infected mice. Since, the mouse model may not accurately reproduce the clinical and pathological features of human malaria, future research should investigate the impact of vitamin D in human malaria.

The effects of royal jelly supplementation on oxidative stress, inflammatory mediators, mental health, cognitive function, quality of life, and clinical outcomes of patients with ischemic stroke: study protocol for a randomized controlled trial.

BACKGROUND: Stroke is a debilitating disease that affects over 15 million people worldwide each year, resulting in the death of one-third of those people and severe disability in two-thirds of survivors. Previous studies reported various health benefits of Royal jelly in the context of its anti-inflammatory properties. We will aim to investigate the effects of royal jelly supplementation on oxidative stress, inflammatory mediators, mental health, cognitive function, quality of life, and clinical outcomes of patients with ischemic stroke. METHODS: The present study will be a triple-blind randomized placebo trial. Patients who meet our eligibility criteria will be assigned to the intervention or the control groups to receive allocated intervention for 12 weeks. Individuals of the intervention group will consume 1000 mg of Royal jelly dragee daily after breakfast. Subjects of the control group will receive a placebo dragee identical to the Royal jelly dragee. The severity of the stroke, cognitive function, mental health, quality of life, clinical outcomes, and biochemical measures will be assessed at baseline and post-intervention. DISCUSSION: The current study is designed to investigate the effectiveness and safety of royal jelly supplementation in a randomized, parallel, two-arms, single-center, triple-blind, placebo-controlled manner. This study will provide evidence as a phase III clinical trial. TRIAL REGISTRATION: IRCT20180818040827N4, registered on 16 October 2021. https://www.irct.ir/trial/59275.

Effect of omega-3 fatty acids supplementation on adipokines: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Although a large body of literature reported the beneficial effects of omega-3 fatty acids (omega-3 FAs) consumption on adipokines levels, but recent findings from clinical trials are not univocal. The aim of this systematic review and meta-analysis was to evaluate the effect of omega-3 FAs supplements on adipokines. METHODS: We searched Medline, Web of Science, Scopus, Embase, and Cochrane Library from inception to August 2020 without any particular language limitations. Outcomes were summarized as standardized mean difference (SMD) with 95% confidence intervals (CIs) estimated from Hedge's g and random effects modeling. RESULTS: Fifty-two trials involving 4,568 participants were included. Omega-3 FAs intake was associated with a significant increase in plasma adiponectin levels (n = 43; 3,434 participants; SMD: 0.21, 95% CI: 0.04, 0.37; p = 0.01; I2= 80.14%). This meta-analysis indicates that supplementing participants with omega-3 fatty acids more than 2000 mg daily and more than 10 weeks resulted in a significant and more favorable improvement in plasma adiponectin levels. However, omega-3 FAs intake had no significant effect on leptin levels (SMD: -0.02, 95% CI: -0.20, 0.17, I2= 54.13%). CONCLUSION: The evidence supports a beneficial effect of omega-3 FAs intake on serum adiponectin levels but does not appear to impact on leptin concentrations. Larger well-designed RCTs are still required to evaluate the effect of omega-3 FAs on leptin in specific diseases.

Diabetes, Age, and Duration of Supplementation Subgroup Analysis for the Effect of Coenzyme Q10 on Oxidative Stress: A Systematic Review and Meta-Analysis.

BACKGROUND: Coenzyme Q10 (CoQ10) has been known as ubiquinone or ubidecarenone, which is a kind of lipid-soluble and vitamin-like antioxidant. It has a potent antioxidant effect against oxidation status via various mechanisms, including its ability to regenerate other antioxidants, such as vitamin E and vitamin C, and to increase antioxidant enzymes. Moreover, CoQ10 can quench free radicals and prevent lipid peroxidation. The aim of this systematic review and meta-analysis was to evaluate the effect of CoQ10 on oxidative stress variables. METHODS: A comprehensive electronic database search in Scopus, Web of Science, Embase, Cochrane Library, and Medline was performed to identify eligible randomized clinical trials. A meta-analysis of included studies was performed on selected variables using a random-effects model. Quality assessment was conducted by means of the Cochrane risk of bias assessment tool. RESULTS: To evaluate the effect of CoQ10 supplementation, 17 trials and 972 participants were included for the meta-analysis. The pooled analysis of primary studies showed that CoQ10 increased serum total antioxidant capacity (standardized mean difference [SMD] 0.62 mmol/L, 95% CI 0.18-1.05, I2 = 76.1%, p ˂ 0.001) and superoxide dismutase (SMD 0.40 U/mg, 95% CI 0.12-0.67, I2 = 9.6%, p ˂ 0.345) levels and decreased malondialdehyde (SMD -1.02 mmol/L, 95% CI -1.60 to -0.44, I2 = 88.2%, p ˂ 0.001) level significantly compared to the placebo group. Although the effect of CoQ10 on nitric oxide (SMD 1.01 µmol/L, 95% CI -1.53 to 3.54, p ˂ 0.001, I2 = 97.8%) and glutathione peroxidase (SMD -0.01 mmol/L, 95% CI -0.86 to 0.84, p ˂ 0.001, I2 = 88.6%) was not significant, CoQ10 can be mentioned as an improvement in antioxidant defense status against reactive oxygen species. CONCLUSION: These supplements have positive effects on antioxidant defense against oxidizing agents and elevate antioxidant enzyme levels in the body. However, due to limited research the results should be taken with caution.

Effects of curcumin supplementation on blood glucose, insulin resistance and androgens in patients with polycystic ovary syndrome: A randomized double-blind placebo-controlled clinical trial.

BACKGROUND: Curcumin is a biologically active phytochemical ingredient found in turmeric. It has several pharmacologic effects that might benefit patients with polycystic ovary syndrome (PCOS). OBJECTIVE: We hypothesized curcumin to be effective in improving blood sugar levels, insulin resistance and hyperandrogenism in individuals with PCOS. METHODS: In a randomized double-blind placebo-controlled trial, individuals with PCOS were treated with curcumin (500 mg three times daily) or placebo for 12 weeks. Primary outcome measures were fasting plasma glucose (FPG), fasting insulin (FI), sex hormone levels, and hirsutism (Ferriman-Gallwey [mFG] score). Secondary outcomes included anthropometric measurements. RESULTS: Of 72 randomized individuals, 67 completed the trial. The two groups were comparable at baseline. At the end of the study, FPG and Dehydroepiandrosterone levels had decreased significantly in the intervention group compared to control (difference of change (post-pre) between intervention and placebo groups: -4.11 mg/dL; 95% CI: -8.35, -0.35 mg/dL; p = 0.033 and -26.53 microg/dL; 95% CI: -47.99, -4.34 µg/dL; p = 0.035, respectively). We also observed a statistically non-significant increase (p = 0.082) in Estradiol levels in the intervention group compared to control. No serious adverse events were reported throughout the trial. CONCLUSIONS: Curcumin might be a safe and useful supplement to ameliorate PCOS-associated hyperandrogenemia and hyperglycemia. However, longer trials investigating different dosages in longer durations are needed to underpin these findings.

The effect of cinnamon supplementation on glycemic control in women with polycystic ovary syndrome: A systematic review and meta-analysis.

Several clinical trials have identified glycemic-lowering effects of cinnamon, while other studies have reported conflicting findings. A comprehensive systematic search on Embase, PubMed, Scopus, Web of Science, and Cochrane Library was conducted using defined keywords in any language through June 2020. Studies that compared the effect of cinnamon with placebo on insulin resistance (IR) indices, as the primary outcome, in women with polycystic ovary syndrome (PCOS) were considered eligible. Standard Mean difference (SMD) (with 95% confidence intervals) for endpoints were calculated using the random-effects model. Finally, five RCTs which met the criteria were included in the meta-analysis. After pooling data, cinnamon supplementation significantly reduced homeostatic model assessment for insulin resistance (HOMA-IR) scores in women with PCOS (SMD: -0.84, 95% CI: -1.52, -0.16, p = .010). Cinnamon supplementation likely improves certain IR markers in patients with PCOS. PRACTICAL APPLICATIONS: There are controversies reports for cinnamon intake, which animal models have suggested that it decreases IR via promotion of insulin action, stimulating insulin signaling pathways, and enhancing insulin sensitivity. This study provides comprehensive information about the effect of cinnamon on insulin resistance (IR) indices in women with PCOS. In this regard, our results indicated that cinnamon supplementation significantly reduced homeostatic model assessment for insulin resistance (HOMA-IR) scores in women with PCOS. Therefore, consumption of cinnamon can be safe and this can be a useful recommendation for improving IR and promotion of healthy life which indeed are the potential or actual uses of this research.

The effects of omega-3 fatty acid supplementation on inflammatory factors in HIV-infected patients: A systematic review and meta-analysis of randomized clinical trials.

High concentrations of C-reactive protein (CRP) and inflammatory markers are common in human immunodeficiency virus (HIV)-infected patients and are associated with non-HIV related comorbidity and mortality. Data on the benefits of omega-3 fatty acid (omega-3 FA) supplementation for improving inflammation status in HIV-infected patients are controversial. Thus, we conducted a systematic review and meta-analysis on the beneficial effects of omega-3 FAs on controlling inflammation in HIV-infected patients. We conducted a comprehensive search of the major biomedical databases, including PubMed, EMBASE, Scopus, Web of Science and Cochrane library, for all potentially relevant studies published without restriction from the beginning of time to June 2020. Overall, nine RCTs were included comprising a total of 427 participants. A random-effects model was used to calculate 95% confidence intervals (CI) and the effect was measured as standardized mean difference (SMD). Supplementation of omega-3 FAs showed a significant reduction of CRP (SMD: -0.27, 95% CI: -0.48 to -0.07, P = 0.007). There was no significant difference in levels of TNF-α (SMD: 0.03, 95% CI: -0.79 to 0.85, P = 0.94, I2 = 87%) and IL-6 (SMD: -0.13, 95% CI: -0.59 to 0.32, P = 0.57, I2 = 73%, Fig. 3). The results indicate that the supplementation of omega-3 FAs in HIV-infected patients significantly decreases serum CRP levels when compared to the control group, however has no significant effect on IL-6 and TNF-α levels.

Effects of Melissa officinalis (Lemon Balm) on cardio-metabolic outcomes: A systematic review and meta-analysis.

Recent evidence indicates a beneficial effect of Melissa officinalis (MO) intake on several chronic diseases. However, the effects of MO intake have not yet been systematically reviewed. Therefore, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the effect of MO intake and focused on several cardiometabolic outcomes. MEDLINE, Scopus, EMBASE, Web of Science and the Cochrane Central Register of Controlled Trials were searched for MO-RCTs evaluating cardiometabolic outcomes. Random-effects meta-analyses estimated the pooled standardized mean differences (SMD) between intervention and control groups. Risk of bias was assessed with the Cochrane Collaboration's tool for assessing the risk of bias in RCTs. Seven RCTs were finally deemed eligible. MO intake was associated with a reduced total cholesterol (TC) (SMD: -0.26; 95% CI: -0.52, -0.01; I2 = 13.7%; k = 6) and a reduced systolic blood pressure (SBP) (SMD: -0.56; 95% CI: -0.85, -0.27; I2 = 00.0%; k = 3). MO intake was not associated with statistically significant changes in triglycerides, low-density lipoprotein, diastolic blood pressure, high sensitivity c-reactive protein levels, fasting blood sugar, HbA1c, insulin or high-density lipoprotein levels. No serious adverse events were reported. The risk of bias was high in a considerable amount of studies. Our study suggests that MO is a safe supplement with beneficial effects on TC and SBP. However, the findings of our study must be seen in the light of major limitations such as a low number of included studies and a serious risk of bias. High-quality RCTs are needed for firm conclusions concerning the effects of MO on cardiometabolic outcomes.

Effect of Calcium and Vitamin D Co-supplementation on Blood Pressure: A Systematic Review and Meta-Analysis.

PURPOSE: Vitamin D and calcium insufficiency has been related to elevated blood pressure (BP) and cardiovascular complications. This systematic review and meta-analysis investigates the effect of calcium and vitamin D co-supplementation on BP. METHODS: A systematic search was conducted of electronic databases, including Web of Sciences, MEDLINE, Scopus, EMBASE, and the Cochrane Library, along with searches of gray literature and reference lists from included trials. There were no language restrictions, and the databases were searched from inception to October 2019. Randomized controlled trials, using calcium and vitamin D co-supplementation and reporting mean systolic BP and/or diastolic BP (DBP) with SDs, were included in the systematic review. Articles were evaluated independently by 2 researchers based on inclusion and exclusion criteria. A random effects model was conducted to synthesize the data. FINDINGS: Eight trials were included in the meta-analysis. Meta-analysis of these 8 trials indicated a nonsignificant reduction in systolic BP in the calcium and vitamin D co-supplementation group compared with control (standardized mean difference, -0.23; 95% CI, -0.52 to 0.06). Conversely, there was a statistically significant decrease in DBP (standardized mean difference, -0.29; 95% CI, -0.55 to -0.02). Subgroup analysis suggested that young adults achieve a greater reduction in DBP than other age groups. IMPLICATIONS: Calcium and vitamin D co-supplementation can modulate DBP and should be investigated more specifically in large, well-designed trials of hypertensive populations. (Clin Ther. 2020;42:XXX-XXX) © 2020 Elsevier HS Journals, Inc.

Intrauterine infusion of autologous platelet-rich plasma in women undergoing assisted reproduction: A systematic review and meta-analysis.

Prior studies have provided conflicting results regarding the use of platelet-rich plasma (PRP) in women undergoing in-vitro fertilization (IVF) or intracytoplasmic injection (ICSI). The objective of this study was to evaluate the effect of the intrauterine infusion of PRP on the outcome of embryo transfer (ET) in women undergoing IVF/ICSI. We searched databases, including PubMed, Embase, Scopus, Web of Science, and the Cochrane Database of Clinical Trials (CENTRAL). Meta-analysis using a random-effects model was performed to calculate the pooled estimates. Seven studies involving 625 patients (311 cases and 314 controls) were included. The probability of chemical pregnancy (n = 3, risk ratio (RR): 1.79, 95 % confidence intervals (CI): 1.29, 2.50; P < 0.001, I2 = 0 %), clinical pregnancy (n = 7, RR: 1.79, 95 % CI: 1.37, 2.32; P < 0.001, I2 = 16 %), and implantation rate (n = 3, RR: 1.97, 95 % CI: 1.40, 2.79; P < 0.001, I2 = 0 %) was significantly higher in women who received PRP compared with control. There was no difference between women who received PRP compared with control group regarding miscarriage (RR: 0.72, 95 % CI: 0.27, 1.93; P = 0.51, I2 = 0 %). Following the intervention, endometrial thickness increased in women who received PRP compared to control group (SMD: 1.79, 95 % CI: 1.13, 2.44; P < 0.001, I2 = 64 %). The findings of this systematic review suggest that PRP is an alternative treatment strategy in patients with thin endometrium and recurrent implantation failure (RIF). Further prospective, large, and high quality randomized controlled trials (RCTs) are needed to identify the subpopulation that would most benefit from PRP.

Efficacy of Salvia officinalis extract on the prevention of insulin resistance in euglycemic patients with polycystic ovary syndrome: A double-blinded placebo-controlled clinical trial.

OBJECTIVES: At the present study, we aimed at evaluating the effect of Salvia officinalis (S. officinalis) extract on "anthropometric indices" and "insulin resistance markers" in Polycystic Ovary Syndrome (PCOS) patients. DESIGN AND SETTING: This was a randomized, triple-blinded, controlled trial performed in gynecology hospitals affiliated to Iran University of Medical Sciences. PARTICIPANTS: Sixty PCOS patients diagnosed according to Rotterdam criteria. INTERVENTIONS: Consumption of the 330 mg oral S. officinalis extract or placebo capsules daily for eight weeks. MAIN OUTCOME MEASURES: Body mass index (BMI), waist to hip ratio (WHR), blood pressure, homoeostatic model assessment-insulin resistance (HOMA-IR), and quantitative insulin sensitivity check index (QUICKI). RESULTS: Results showed a statistically significant decrease in the BMI (P = 0.001) in S. officinalis group, but, there were no significant differences between the two groups for WHR (P = 0.164). Although we failed to find a significant effect of S. officinalis extract on systolic blood pressure (P = 0.283) but using a multivariate model showed a significant difference between two groups regarding diastolic blood pressure (P = 0.025). Also, the consumption of S. officinalis extract, compared to the placebo, resulted in a significant decrease in Insulin levels (P < 0.001), and HOMA-IR (P < 0.001). As well as, S. officinalis extract supplementation resulted in a greater increase in QUICKI (P < 0.001) compared with placebo groups. CONCLUSION: S. officinalis extract at a dose of 330 mg/day could decrease BMI and systolic blood pressure, and it could enhance insulin resistance markers in euglycemic PCOS patients. TRIAL REGISTRATION: Iranian Registry of Clinical Trials (IRCT201504146917N2, 2015-10-03).

The effect of pomegranate on oxidative stress parameters: A systematic review and meta-analysis.

OBJECTIVE: Pomegranate contains remarkable amounts of phenolic ingredients and it has been related to the antioxidant capacity of this fruit. Several primary studies show that pomegranate intake can improve antioxidant status. The objective of this systematic review and meta-analysis consisted in investigating the effect of pomegranate on oxidative stress (OS) parameters. METHODS: A comprehensive electronic database search in Scopus, Web of science, Embase, Cochrane library and Medline was performed to identify eligible randomized controlled trials (RCTs). A meta-analysis of included studies was performed on selected variables using a random-effects model. Quality assessment was conducted by means of Cochrane risk of bias assessment tool. RESULTS: Systematic search yielded 575 references. A total of 11 RCTs reporting data from 484 participants included. Meta-analysis of data from 11 included RCTs did not support convincing evidence as to a significant increasing effect of pomegranate intake in TAC (SMD: 0.43 ; 95 %CI: -0.19, 1.06), Gpx (SMD: 0.18, 95 % CI: -0.25, 0.62, p = 0.4) and paraxonase (SMD: 0.36, 95 % CI: -0.50, 1.22, p= 0.41) as well as not significant decrease in Malondialdehyde (MDA) (SMD: -0.81, 95 % CI: -1.79, 0.09, P = 0.08). CONCLUSION: Future well-designed clinical trials are needed before definite conclusive claims can be made about the effect of pomegranate on OS parameters.

Effect of omega-3 fatty acid plus vitamin E Co-Supplementation on oxidative stress parameters: A systematic review and meta-analysis.

BACKGROUND & AIMS: The impact of combined omega-3 FAs and vitamin E supplementation on oxidative stress (OS) has been evaluated in several studies. However the results are inconsistent. Therefore, we performed a systematic review and meta-analysis to assess the role of omega-3 FAplus vitamin E on anti-oxidant and OS parameters. METHODS: We searched five databases (PubMed, Embase, Web of Sciences, Scopus and the Cochrane Central Register of Controlled Trials) from inception until March 15th 2018 for RCT covering OS parameters combined with omega-3 FAs and vitamin E. The effect of omega-3 FAs plus vitamin E combination on OS factors was determined as the standardized mean difference (SMD) calculated according to DerSimonian and Laird for the random effects model. RESULTS: Nine articles were included in our analyses, significant improvements were observed in trials supplementing with omega-3 FAs plus vitamin E vs placebo for total antioxidant capacity (TAC) (SMD=0.63, 95%CI: 0.31 to 0.95, P<0.001) and nitric oxide (NO) (SMD=0.55, 95%CI: 0.23 to 0.87, P<0.001). Significant reduction was observed for malondialdehyde (MDA) (SMD: -0.48, 95%CI: -0.68 to -0.28, P<0.001). However, the results of meta-analysis did not show a significant difference in levels of glutathione (GSH) (SMD=0.34, 95%CI: -0.07 to 0.75, P=0.10), superoxide dismutase (SOD) activity (SMD: 0.07, 95% CI: -0.58 to 0.73, P=0.82) and Catalase (CAT) activity (SMD: 0.74, 95% CI: -0.30 to 1.79, P=0.16). CONCLUSION: Co-supplementation with omega-3 FAs and vitamin E increases the levels of NO and TAC, while MDA levels decrease compared to placebo. However, the results showed no significant alterations on GSH concentrations, CAT, and SOD activities.

Omega-3 fatty acids supplementation and oxidative stress parameters: A systematic review and meta-analysis of clinical trials.

Omega-3 fatty acids (omega-3 FAs) supplementation effects on oxidants and antioxidants are always controversial. Oxidative stress (OS) is one of the major mechanisms that contribute to the pathogenesis of several chronic diseases. The present systematic review and meta-analysis aimed to summarize the finding of randomized clinical trials (RCTs) examining the effects of omega-3 FAs on OS markers. Five databases including PubMed, Embase, Scopus, Web of science, and Cochrane were searched up to May 5th, 2019 with no language restriction. RCTs included if they compared OS indices among subjects who received omega-3 FAs supplements and subjects who supplemented with placebo. To estimate the effects of omega-3 FAs supplementation, standardized mean difference (SMD) with 95% confidence intervals (95% CI) were pooled using random effects model. Of 5,887 publications, 39 trials involving 2,875 participants were included for the meta-analysis. The pooled analysis of data indicated that omega-3 FAs significantly increased serum total antioxidant capacity (TAC) (SMD: 0.48, 95% CI: 0.23, 0.72, P< 0.001; I2= 60%), glutathione peroxidase (GPx) (SMD: 0.73, 95% CI: 0.30, 1.16, P= 0.001; I2= 83%) activity and decreased malondialdehyde (MDA) (SMD= -0.42, 95% CI: -0.62, -0.21; P < 0.001; I2= 74%) compared to the placebo group. However, the effects of omega-3 FAs on nitric oxide (NO) (SMD: -0.17 , 95% CI: -0.77, 0.43, P = 0.57; I2= 91%), reduced glutathione (GSH) (SMD= 0.23, 95% CI= -0.17, 0.64, P= 0.25; I2= 75%), superoxide dismutase (SOD) (0.12 , 95% CI: -0.40, 0.65, P= 0.64; I2= 89%) and catalase (CAT) (0.16, 95% CI: -0.33, 0.65, P= 0.52; I2= 75%,) activities was not significant. Supplementation with omega-3 FAs significantly improves MDA, TAC levels, and GPx activity. Thus, omega-3 FAs can be mentioned as enhancer factors in antioxidant defense against reactive oxygen species (ROS).

Effect of omega-3 fatty acid plus vitamin E Co-Supplementation on lipid profile: A systematic review and meta-analysis.

BACKGROUND: Dyslipidemia is linked to chronic inflammation, which in return leads to a set of chronic disorders. Omega-3 fatty acids have been reported to reduce inflammation. Furthermore, Vitamin E is a fat-soluble vitamin which has antioxidant and anti-inflammatory effects. Vitamin E and omega-3 fatty acids co-supplementations may be more effective than the single supplementation in control dyslipidemia. Therefore, we designed and conducted the current systematic review and meta-analysis to investigate the effect of co-supplementation of vitamin E and omega-3 fatty acids on the lipid profile. METHODS: A comprehensive search for studies published between January 1990 and July 2018 was performed. The initial search extracted 3015 potentially relevant articles. After studying these publications, 9 RCTs were potentially eligible and retrieved in full text. RESULTS: The meta-analysis indicate that on total cholesterol, HDL, LDL and triglyceride individually did not show any significant difference between intervention and control groups, but vitamin E an omega-3 fatty acids co-supplementations significantly reduce VLDL levels. CONCLUSIONS: Based on the available evidence, omega-3 fatty acid and vitamin E co-supplementation can reduce VLDL, although its effect on other lipid profile parameters requires more well-designed studies.

The effect of melatonin supplementation on lipid profile and anthropometric indices: A systematic review and meta-analysis of clinical trials.

BACKGROUND: Epidemiological evidence suggests that melatonin has some effects on the serum lipid. However, these results are controversial. The aim of this systematic review and meta-analysis is to examine the effect of melatonin supplement on dyslipidemia and anthropometric indices. METHODS: We searched electronic databases including Medline, Embase, Scopus, Web of Science and Cochrane Library up to Des 2018 without any language restriction. To compare the effects of melatonin with placebo, differences in standardized means difference (SMD) with 95% confidence intervals (95% CI) were pooled using random effects model. RESULTS: Twelve trials including 641 participants included in meta-analysis finally. The dose of melatonin was reported at 0.8-30 mg. Comparing with the control group, melatonin may improve low density lipoprotein cholesterol (LDL-C) (-0.31 mmol/L, 95% CI (-0.61, 0.01), P = 0.049, I2 = 42%) and triglyceride (TG) level (SMD = -0.45 mmol/L; 95% CI, -0.77, -0.13, P = 0.006, I2 = 47%). No significant effect of melatonin on high density lipoprotein cholesterol (HDL-C) and anthropometric indices was found. CONCLUSIONS: The results of our systematic review and Meta-analyzes showed that supplementation of melatonin could be effective in improving lipid parameters and should be considered in the prevention of cardiovascular disease, although the effect of this supplement on anthropometric indices needs further investigation.

Impact of Dietary Calcium Supplement on Circulating Lipoprotein Concentrations and Atherogenic Indices in Overweight and Obese Individuals: A Systematic Review.

Dyslipidemia is the main risk factor for developing cardiovascular disease. There are discrepancies in the effects of calcium supplementation on modulation of lipid status. Therefore, we aimed to summarize the effects of dietary calcium supplement on circulating lipoprotein concentrations and atherogenic indices in overweight and obese individuals. We conducted a systematic literature search from 2000 until July 2016. PubMed, Scopus, Cochran Library, and ISI Web of Science databases were searched for clinical trials written in English. Placebo controlled clinical trials on calcium or calcium with vitamin D supplement in overweight and obese indiciduals were considered. Finally, 11 clinical trials met the criteria and were included. Most studies (n = 9) evaluated Ca/D co-supplementation. Positive effects of calcium supplementation alone or with vitamin D were as follows: serum levels of total cholesterol (TC; n = 1), triglyceride (TG) concentrations (n = 1), serum levels of low-density lipoprotein cholesterol (LDL-C; n = 5) and high-density lipoprotein cholesterol (HDL-C; n = 3). Seven clinical trials reported atherogenic indices and three of them demonstrated beneficial effects of calcium supplementation on at least one atherogenic index. Calcium supplementation may not be helpful to reduce serum levels of TC and TG in overweight and obese individuals. However, it may modulate LDL-C and HDL-C concentration. More studies are warranted to clarify the effects of calcium supplementation on each atherogenic index.

The effect of vitamin D supplementation on oxidative stress parameters: A systematic review and meta-analysis of clinical trials.

Recent studies have shown that vitamin D supplementation beneficially decreases oxidative stress (OS) parameters; however, there is no consensus on this subject. In this systematic review and meta-analysis we aimed to investigate the effect of vitamin D supplementation on OS parameters. We searched electronic databases including Medline, Embase, Scopus, Web of Science and Cochrane Library up to July 2018 without any language restriction. Trials were reviewed using preferred reporting items for systematic reviews and meta-analyses (PRISMA) and Cochrane handbook. To compare the effects of vitamin D with placebo, standardized mean difference (SMD) with 95% confidence intervals (CI) were pooled using random effects model. Across thirteen clinical trials, we found that vitamin D supplementation increased serum levels of total antioxidant capacity (TAC) (SMD: 0.54 mmol/L, 95% CI: 0.29 to 0.79; I2 = 65.4%, P = 0.001) and glutathione (GSH) (SMD: 0.33; 95% CI: 0.11 to 0.54, P = 0.003; I2 = 61.2%, P = 0.001). Besides, malondialdehyde (MDA) concentration decreased significantly (SMD: -0.40 mmol/L, 95% CI: -0.60 to -0.21, P < 0.001) following vitamin D supplementation compared to placebo. However, its effects on nitric oxide (NO) was not significant (0.17, 95% CI: -0.10 to 0.45, I2 = 71.1%, P = 0.21). Finally, we showed that vitamin D supplementation can improve OS parameters; however, this finding may not be clinically significant. Further large prospective clinical trials are needed to confirm the effect of vitamin D supplement on other OS parameters.

Effect of sumac (Rhus Coriaria) on blood lipids: A systematic review and meta-analysis.

Cardiovascular diseases (CVD) are the prominent cause of mortality worldwide. Hypercholesterolemia is a chief risk factor for the progress of atherosclerotic vascular disease. Complementary and alternative medicine (CAM) such as herbal interventions has received much attention in literature. Rhus Coriaria (RC) with the general name Sumac is a medicinal spice, especially in Middle Eastern countries which is well known as an anti-lipid spice. This study aimed to summarize the existing findings regarding the effect of RC on the lipid profile. In this review randomized controlled trials (RCTs) assessing the effect of RC on blood lipids were included. Electronic searches using the MeSH terms were conducted in the following databases: Medline, Embase, Scopus, Web of Science and The Cochrane Library. The effect of RC on serum lipid concentration were measured as standardized mean difference (SMD) and 95% confidence intervals (CI) by the random-effects model. The initial search extracted 119 potentially relevant articles. After studying these publications, 4 were potentially eligible and retrieved in full text (four RCTs). Based on the results of the systematic review, RC has positive effects on different indices of the lipid profile including increasing Apo A-I and HDL; decreasing Apo B, Apo B/ Apo A1 ratio, total cholesterol, LDL and triglyceride. However the meta-analysis conducted on three studies on total cholesterol, HDL, LDL and triglyceride individually did not show any significant difference between intervention and control groups. No definite conclusion could be made on the effect of RC on serum blood lipids due to lack of sufficient clinical trials and variable inconsistency. Future trials with desirable designs that would eliminate the limitations in the current evidence are needed before conclusive claims can be made about the effect of RC on the lipid profile.