Effects of Vitamin D and E Supplementation on Prevention of Bronchopulmonary Dysplasia (BPD) in Premature Neonates: A Systematic Review and Meta-Analysis.

BACKGROUND: Bronchopulmonary Dysplasia (BPD) has a multifactorial etiology. Vitamin E and vitamin D play an important role in lung development and can potentially be beneficial in the prevention of BPD. OBJECTIVE: The study aimed to compare the risk of BPD occurrence in preterm neonates supplemented with vitamin D or E versus those who did not get supplementation. METHODS: The literature search was conducted for this systematic review by searching the PubMed, Scopus, and Web of Science databases up to December 2022. Randomized controlled trials involved administering vitamin D or E to preterm neonates and examining the occurrence of BPD. We excluded non-English articles, and articles with non-relevant and insufficient data. We used the Critical Appraisal Skills Programme (CASP) checklist to assess the quality of the included studies. We used Egger's test to evaluate the risk of bias among the included studies. Heterogeneity was also assessed through Q-test and I2. We applied the random effect model for analysis. A P-value less than 0.05 was considered as significant. All the statistical analysis in the current study was performed using STATA 14. The Relative Risk (RR) was calculated as the effect size with 95% Confidence Interval (CI). RESULTS: Three eligible studies seeking the role of vitamin D in the prevention of BPD were analysed. Meta-analysis revealed that receiving vitamin D supplementation can significantly reduce the risk of BPD in preterm infants (RR = 0.357, 95% CI: 0.189-0.675, I2 = 0.0%; p = 0.002). Similarly, for assessing the role of Vitamin E in the prevention of BPD, three eligible studies were analysed. Vitamin E supplementation was not found to play a significant role in the reduction of BPD (RR = 0.659, 95%CI = 0.243-1.786, I2 = 38.7%; p = 0.412). CONCLUSION: Vitamin D supplementation could be beneficial in preventing BPD in preterm infants. However, evidence is not enough regarding vitamin E's role in reducing the incidence of BPD in preterm infants.

Effects of NAD+ precursors on blood pressure, C-reactive protein concentration and carotid intima-media thickness: A meta-analysis of randomized controlled trials.

BACKGROUND: There are contradictory effects regarding the effect of NAD+ precursor on blood pressure and inflammation. In order to obtain a better viewpoint from them, this study aimed to comprehensively investigate the effects of NAD+ precursor supplementation on blood pressure, C-reactive protein (CRP) and carotid intima-media thickness (CIMT). METHODS: PubMed/MEDLINE, Web of Science, SCOPUS and Embase databases were searched using standard keywords to identify all controlled trials investigating the effects of NAD+ precursor on blood pressure, CRP and CIMT. Pooled weighted mean difference (WMD) and 95% confidence intervals (95% CI) were achieved by random-effects model analysis for the best estimation of outcomes. RESULTS: Twenty-nine articles (with 8664 participants) were included in this article. Results from meta-analyses of RCTs from random-effects models indicated a significant reduction in systolic (SBP) (weighted mean difference (WMD): -2.54 mmHg, p < .001) and diastolic blood pressure (DBP) (WMD: -2.15 mmHg, p < .001), as well as in CRP (WMD: -.93 mg/L, 95% CI -1.47 to -.40, p < .001) concentrations and CIMT (WMD: -.01 mm, 95% CI -.02 to -.00, p = .005) with the NAD+ precursors supplementation compared with the control group. In addition, a greater effect of supplementation with NAD+ precursors in reducing blood pressure (BP) were observed with the highest dose (≥2 g) and duration of the intervention (>12 weeks), as well as with NA supplementation when compared to NE. CONCLUSIONS: Overall, these findings suggest that NAD+ precursor supplementation might have a beneficial effect on cardiovascular risk factors such as BP, CRP concentration and CIMT.

Comparing the effects of docosahexaenoic and eicosapentaenoic acids on cardiovascular risk factors: Pairwise and network meta-analyses of randomized controlled trials.

BACKGROUND: Evidence from clinical trial studies suggests that docosahexaenoic acids (DHA) may have greater potential effects on improving cardiovascular risk factors than eicosapentaenoic acid (EPA). However, this evidence has not yet been meta-analyzed and quantified. The aim of this study was to evaluate and compare the effect of DHA and EPA monotherapy on cardiovascular risk factors based on paired and network meta-analysis. METHODS: Relevant articles published up to January 2022 were systematically retrieved from relevant databases. We included all Randomized Controlled Trials (RCTs) on adults that directly compared the effects of DHA with EPA and RCTs of indirect comparisons (DHA and EPA monotherapy compared to control groups). Data were pooled by pairwise and network meta-analysis and expressed as mean differences (MDs) with 95% CIs. The study protocol was registered with PROSPERO (Registration ID: CRD42022328630). RESULTS: Network meta-analysis of comparisons of DHA and EPA suggested significant comparable effects only on LDL-C (MD EPA versus DHA = -8.51 mg/L; 95% CI: -16.67; -0.35). However, the Network meta-analysis not show a significant effect for other risk factors. Furthermore, pairwise meta-analysis of direct comparisons of DHA and EPA showed significant difference in their effects on plasma glucose (MD EPA versus DHA = -0.31 mg/L; 95% CI: -0.60, -0.02), Insulin (MD EPA versus DHA = -2.14 mg/L; 95% CI: -3.26, -1.02), but the results were not significant for risk factors. CONCLUSION: Our findings suggest that both EPA and DHA act similarly on the markers under study, with slight changes in plasma glucose, insulin, and LDL-C.

The effects of chitosan supplementation on anthropometric indicators of obesity, lipid and glycemic profiles, and appetite-regulated hormones in adolescents with overweight or obesity: a randomized, double-blind clinical trial.

BACKGROUND: Chitosan is one of dietary fiber that has received great attention in improving obesity-related markers, but little is known on its effects on adolescents. OBJECTIVES: To analyze the effects of chitosan supplementation on obesity-related cardiometabolic markers and appetite-related hormones in adolescents with overweight or obesity. METHODS AND ANALYSIS: A randomized clinical trial was performed on 64 adolescents with overweight and obesity, who were randomly allocated to receive chitosan supplementation (n = 32) or placebo as control (n = 32) for 12 weeks. Anthropometric measures, lipid and glycemic profiles, and appetite-related hormones were examined. RESULTS: Sixty-one participants completed study (chitosan = 31, placebo = 30). Chitosan supplementation significantly improved anthropometric indicators of obesity (body weight: - 3.58 ± 2.17 kg, waist circumference: - 5.00 ± 3.11 cm, and body mass index: - 1.61 ± 0.99 kg/m2 and - 0.28 ± 0.19 Z-score), lipid (triglycerides: - 5.67 ± 9.24, total cholesterol: - 14.12 ± 13.34, LDL-C: - 7.18 ± 10.16, and HDL-C: 1.83 ± 4.64 mg/dL) and glycemic markers (insulin: - 5.51 ± 7.52 µIU/mL, fasting blood glucose: - 5.77 ± 6.93 mg/dL, and homeostasis model assessment of insulin resistance: - 0.24 ± 0.44), and appetite-related hormones (adiponectin: 1.69 ± 2.13 ng/dL, leptin - 19.40 ± 16.89, and neuropeptide Y: - 41.96 ± 79.34 ng/dL). When compared with the placebo group, chitosan supplementation had greater improvement in body weight, body mass index (kg/m2 and Z-score), waist circumference, as well as insulin, adiponectin, and leptin levels. Differences were significant according to P-value < 0.05. CONCLUSION: Chitosan supplementation can improve cardiometabolic parameters (anthropometric indicators of obesity and lipid and glycemic markers) and appetite-related hormones (adiponectin, leptin, and NPY) in adolescents with overweight or obesity.

Impact of Omega-3 supplementation on homocysteine levels in humans: A systematic review and meta-regression analysis of randomized controlled trials.

AIMS: Although some evidence suggests that omega-3 polyunsaturated fatty acids (PUFAs) supplementation influences enzymes involved in forming homocysteine (Hcy) and improving hyperhomocysteinemia, these findings are still contradictory in humans. The aim of this systematic and meta-analysis study was to investigate the effects of omega-3 supplementation on Hcy using existing randomized controlled trials (RCTs). DATA SYNTHESIS: Available databases, including PubMed/MEDLINE, Web of Science, Scopus, Cochrane Library, and Embase, were searched to find relevant RCTs up to June 2021. The effect size was expressed as weighted mean difference (WMD) and 95% confidence interval (CI). CONCLUSION: A total of 20 RCT studies with 2676 participants were included in this article. Our analyses have shown that omega-3 supplementation significantly reduced plasma Hcy levels (WMD: 1.34 µmol/L; 95% CI: 1.97 to -0.72; P < 0.001) compared to the control group. The results of subgroup analysis showed that omega-3 supplementation during the intervention <12 weeks and with a dose ≥3 gr per day causes a more significant decrease in Hcy levels than the intervention ≥12 weeks and at a dose <3 gr. In addition, omega-3 supplements appear to have more beneficial effects in individuals with high levels of normal Hcy. This meta-analysis showed that omega-3 supplementation significantly improved Hcy. However, further studies are needed to confirm the findings.

Meta-analysis: efficacy of exclusive enteral nutrition as induction therapy on disease activity index, inflammation and growth factors in paediatric Crohn's disease.

BACKGROUND: There is evidence of inconsistency in sequelae of exclusive enteral nutrition (EEN) as induction therapy in paediatric patients with Crohn's disease (CD). AIM: To investigate the potential effects of EEN on paediatric Crohn's disease activity index (PCDAI), inflammation and biochemical parameters in paediatric patients with CD. METHODS: We performed a comprehensive systematic search of PubMed/MEDLINE, Web of Science, SCOPUS and Embase until 8 January 2022 regardless of the time of publication or language. Random-effects model was applied to combine the datasets. The main outcomes were analysed through mean difference (MD) and its 95% confidence interval (CI). RESULTS: Forty six studies met eligibility criteria and were included in the meta-analysis. Pooled findings indicated that PCDAI score (MD of -27.24; 95% CI -31.84 to -22.64), calprotectin (MD of -842.83 mg/kg; CI -1018.24 to -667.42), CRP (pooled MD of -2.36 mg/dl; CI -2.68 to -2.03), and ESR (MD of -21.09 mm/h; CI -23.79 to -18.38), albumin (MD of 0.65 g/dl; CI 0.58 to 0.72), haemoglobin (MD of 1.12 g/dl; CI 0.87 to 1.37), weight (MD of 4.30 kg; CI 3.39 to 5.22), and height (MD of 0.98 cm; CI 0.35 to 1.62) improved significantly with EEN. CONCLUSIONS: Adherence to EEN can have significant, beneficial effects as induction therapy in paediatric patients with CD.

The Effect of Vitamin D Supplementation on Treatment-Induced Pain in Cancer Patients: A Systematic Review.

OBJECTIVES: Despite the widespread use of complementary and alternative medicine by patients and physicians alike, there is no accurate evidence regarding the effects of vitamin D supplementation on treatment-induced pain in cancer patients. Thus, the aim of this systematic review of randomized controlled trials (RCTs) was to evaluate the impact of vitamin D administration on therapy-related pain in subjects diagnosed with malignant disorders. REVIEW ANALYSIS METHODS: We searched the Web of Science, Scopus, PubMed/Medline, Embase, and Google Scholar databases up to October 2020 to identify published RCTs that investigated the use of vitamin D in the management of treatment-induced pain in individuals with cancer. RESULTS: Nine RCTs were detected. The median duration of the intervention was of 24 weeks (range 12-52 weeks) and dose of vitamin D employed was 2000-50000 IU of vitamin D3 weekly orally each day. Six RCTs reported a significant reduction in pain, whereas three did not detect a notable decrease of this variable. Of the six studies that reported an alleviation of pain, an RCT which recruited 60 participants and lasted for 24 weeks consisted of supplementation with high doses of vitamin D2 weekly for 8 weeks in women receiving anastrozole as adjuvant therapy, then supplementation with vitamin D2 monthly for 4 months, effectively alleviated the aromatase inhibitor-associated musculoskeletal syndrome (AIMSS). The results of the same RCT also suggested a beneficial effect of vitamin D on musculoskeletal pain. CONCLUSIONS: Our results suggest that the supplementation with high doses of vitamin D in cancer patients with low serum levels of vitamin D, can be effective in reducing treatment-related pain.

The effects of probiotic/synbiotic supplementation compared to placebo on biomarkers of oxidative stress in adults: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND AIMS: During the last decades, there has been a burst of scientific literature hypothesizing the antioxidant effect of probiotics. However, the results of these studies are inconsistent and a final conclusion has yet to be reached. Thus, the aim of this study was to assess the effects of probiotic/synbiotic supplementation on serum total antioxidant capacity (TAC), glutathione (GSH), malondialdehyde (MDA) and nitric oxide (NO) levels in adults. METHODS AND RESULTS: The following online databases were searched until August 26th 2020: PubMed/Medline, Scopus, Clarivate Analytics Web of Science, Cochrane Central Register of Controlled Trials, Science Direct, Google Scholar and Igaku Chuo Zasshi. The effect sizes were expressed as the weighted mean difference (WMD) with 95% confidence intervals (CI). A total of 31 eligible trials with 1681 participants (839 cases and 842 controls) were included in this meta-analysis. The results revealed that the supplementation with probiotics/synbiotics, significantly increased serum TAC (WMD: 54.14 mmol/L, 95% CI: 27.87, 80.40, P < 0.001), GSH (WMD: 40.38 µmol/L, 95% CI: 20.72, 60.03, P < 0.001) and NO (WMD: 3.54 µmol/L, 95% CI: 1.73, 5.34, P < 0.001) levels. In addition, MDA levels were significantly reduced (WMD: -0.45 µmol/L, 95% CI: -0.58,-0.32, P < 0.001) following probiotic/synbiotic supplementation. None of the variables showed a significant change in the sensitivity analysis. CONCLUSION: Available evidence suggests that probiotic/synbiotic supplementation can significantly increase serum TAC, GSH and NO, as well as reduce MDA levels in adults. Therefore, probiotic/synbiotic supplementation may play a role in improving antioxidant indices and reducing oxidative stress in the body.

Impact of orange juice consumption on cardiovascular disease risk factors: a systematic review and meta-analysis of randomized-controlled trials.

Cardiovascular disease (CVD) is the greatest cause of premature death and disability globally. Numerous therapeutic strategies have been developed to improve and prevent the adverse cardiovascular events, including nutritional approaches. This systematic review and meta-analysis summarized the evidence on orange juice consumption on CVD risk factors. Four databases were searched up to September 2020. Ten randomized controlled trials were included in the final analysis. Pooled results demonstrated a significant effect of orange juice on glucose (WMD: -2.92 mg/dl, 95% CI: -5.327, -0.530, p = 0.017), insulin (WMD: -1.229 µU/ml, 95% CI: -2.083, -0.374, p = 0.005), HOMA-IR (WMD: -0.464, 95% CI: -0.747, -0.181, p = 0.001), total cholesterol (WMD: -9.84 mg/dl, 95% CI: -15.43, -4.24, p = 0.001), LDL-C (WMD: -9.14 mg/dl, 95% CI: -15.79, -2.49, p = 0.007), and CRP (WMD: -0.467 mg/l, 95% CI: -0.815, -0.120, p = 0.008) compared to control group. However, the effect of orange juice on body composition factors and other CVD risk factors was not significant compared to control group. These lowering effects of glucose, HOMA-IR, total cholesterol, and LDL-C were robust in subgroups with orange juice consumption ≥500 ml/day. This meta-analysis suggests that orange juice may be beneficial in improving several CVD risk factors.

The association between vitamin D status and inflammatory bowel disease among children and adolescents: A systematic review and meta-analysis.

Aim: Vitamin D deficiency is very common among children with IBD. Since there are conflicting results regarding the association of vitamin D with IBD, we conducted this systematic review to confirm the association of vitamin D with IBD. Methods: We conducted a systematic search in Scopus, Cochrane Library, Web of Science, PubMed, and Google Scholar to find relevant studies. Articles with cross-sectional and case-control designs that reported the association between vitamin D and IBD among children were included. Results: Eventually, 9 studies (with 16 effect sizes) reported the mean and SD or the median and the interquartile range of serum vitamin D levels in both subjects with IBD and control subjects. The random effects meta-analysis revealed that subjects with IBD had -1.159 ng/ml (95% CI: -2.783, 0.464) lower serum vitamin D concentrations compared with their healthy counterparts, but this difference was not significant. A total of 14 studies (with 18 effect sizes) with 2,602 participants provided information for the prevalence of vitamin D deficiency or insufficiency in patients with IBD as 44% (95% CI: 0.34-0.54) with significant heterogeneity noted among studies (p < 0.001; I2 = 97.31%). Conclusion: This systematic and meta-analysis study revealed that vitamin D deficiency was associated with IBD. Longitudinal studies should be conducted in the future to confirm our findings. Large randomized controlled trials assessing the doses of supplementation of vitamin D would provide a better understanding of the association between vitamin D and IBD.

The impact of rice bran oil consumption on the serum lipid profile in adults: a systematic review and meta-analysis of randomized controlled trials.

Dyslipidemia/hyperlipidemia is recognized among the risk factors for lifestyle related diseases. A healthy diet, rich in vegetable oils such as rice bran oil (RBO), may aid to improve serum lipid levels. Thus, the aim of this study was to assess the effects of rice bran oil (RBO) consumption on serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c) and triglyceride (TG) levels in adults. The following online databases were searched for manuscripts published until October 7th 2020: PubMed/Medline, Scopus, Clarivate Analytics' Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar. The effect sizes were expressed as weighted mean difference (WMD) with 95% confidence intervals (CI). A total of 8 eligible trials with 14 effect sizes were included in this meta-analysis. Our analysis revealed that the consumption of RBO significantly decreased serum TC (WMD: -7.29 mg/dL, 95% CI: -11.32, -3.25, P = 0.000), LDL-c (WMD: -7.62 mg/dL, 95% CI: -11.10, -4.14, P = 0.000) and TG (WMD: -9.19 mg/dL, 95% CI: -17.99, -0.38, P = 0.041) levels. So, available evidence suggests that RBO consumption can significantly decrease serum TC, LDL-c and TG levels. Hence, it may play a role in reducing dyslipidemia/hyperlipidemia risk.

The beneficial effects of cinnamon among patients with metabolic diseases: A systematic review and dose-response meta-analysis of randomized-controlled trials.

This systematic review and meta-analysis aims to summarize and conclude the clinical evidence regarding the use of cinnamon among patients with metabolic diseases. A comprehensive literature search without any limitation on language was conducted using the following bibliographical databases: ISI Web of Science, Embase, Scopus, PubMed, and Google Scholar. Search was conducted up to 23 January 2020. A total of 35 clinical trials were included for final analysis. Pooling of results showed a significant reducing effect of cinnamon on total cholesterol (TC) (weighted mean difference (WMD) = -11.67 mg/dL; P = 0.010), triglyceride (TG) (WMD = -16.27 mg/dL; P < 0.001), low density lipoprotein-cholesterol (LDL-C) (WMD = -6.36 mg/dL; P < 0.001), serum glucose (WMD = -11.39 mg/dL; P < 0.001), serum insulin (WMD = -1.27 µIU/mL; P = 0.028), and waist circumstance (WC) (WMD = -1.68 cm; P = 0.016). These lowering effects on TG, TC, LDL-C, and serum glucose levels were robust in studies that used cinnamon supplementation dose ≤1.5 g. Also, our findings of the present meta-analysis showed that cinnamon supplementation could have favorable effects on high density lipoprotein-cholesterol (HDL-C, WMD = 1.35; P = 0.038) as well as systolic (WMD = -3.95 mmHg; P = 0.018) and diastolic (WMD = -3.36; P = 0.001) blood pressure among patients with metabolic diseases. The present meta-analysis suggests that cinnamon might exert beneficial effects on various cardiometabolic risk factors among patients with metabolic diseases.

The effect of inositol supplementation on blood pressure: A systematic review and meta-analysis of randomized-controlled trials.

BACKGROUND & AIMS: Potential effects of inositol supplementation on blood pressure (BP) have been examined in several interventional studies. Nevertheless, findings in this context are controversial. Therefore, the current systematic review and meta-analysis aimed to comprehensively assess the impact of inositol supplementation on BP. METHODS: Five online databases including Web of Science, Scopus, Embase, Cochrane, Google Scholar, and PubMed were systematically searched from inception to March 2020. We included all randomized clinical trials (RCTs) evaluating the effects of inositol supplementation on systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) in humans. RESULTS: The random-effects meta-analysis of 7 eligible RCTs demonstrated the significant decline in both SBP (WMD - 5.69 mmHg; 95% CI - 7.35 to - 4.02, P < 0.001) and DBP (WMD - 7.12 mmHg; 95% CI - 10.18 to - 4.05, P < 0.001) following supplementation with inositol. Subgroup analysis showed that studies performed in individuals with metabolic syndrome with a longer duration (>8 weeks) and a dose of 4000 mg resulted in a more effective reduction in SBP and DBP with acceptable homogeneity. CONCLUSIONS: The current meta-analysis, indicated that supplementation with inositol significantly decrease SBP and DBP. Further large-scale RCTs with better design are needed to confirm these findings.

The Impact of Chromium Supplementation on Blood Pressure: A Systematic Review and Dose-Response Meta­Analysis of Randomized­Controlled Trials.

INTRODUCTION: Potential effects of chromium supplementation on blood pressure (BP) have been examined in several interventional studies. Nevertheless, findings in this context are controversial. AIM: Therefore, the current systematic review and meta-analysis aimed to comprehensively assess the impact of chromium supplementation on BP. METHODS: Five online databases including Web of Science, Scopus, Embase, Google Scholar, and PubMed were systematically searched from inception to March 2020. We included all randomized clinical trials (RCTs) evaluating the effects of chromium supplementation on systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) in humans. RESULTS: The random-effects meta-analysis of 11 eligible RCTs with 637 participants demonstrated the significant decline in both SBP (WMD - 2.51 mmHg; 95% CI - 4.97 to - 0.05, p = 0.04) and DBP (WMD - 1.04 mmHg; 95% CI - 1.96 to - 0.12, p = 0.026) following supplementation with chromium. In subgroup analysis, studies that were administered chromium yeast and brewer's yeast, showed greater decrease in SBP. Also, in stratification based on participants' health status, significant reduction in SBP only was seen in diabetic patients with chronic heart disease (CHD). Nonlinear dose-response analysis revealed a significant influence of chromium dosage on SBP changes. CONCLUSION: The current meta-analysis, indicated that supplementation with chromium significantly decrease SBP and DBP. In subgroup analysis, administration of chromium yeast and brewer's yeast resulted in greater reduction in SBP. Further large-scale RCTs with better design are needed to confirm these findings.

The effect of nigella sativa on biomarkers of inflammation and oxidative stress: A systematic review and meta-analysis of randomized controlled trials.

Inflammation and oxidative stress are involved in the pathogenesis of a myriad of chronic disorders. This systematic review and meta-analysis was designed to determine the effects of Nigella Sativa (NS) seed and seed oil consumption on several biomarkers of inflammation and oxidative stress. The Scopus, Web of Science, and PubMed-MEDLINE databases were systematically searched until August 2019. The quality assessment and heterogeneity of the selected randomized clinical trials (RCTs) were measured using the Jadad checklist, and Q and I2 tests, respectively. Finally, a total of 10 clinical RCTs were found to be eligible for this meta-analysis. The pooled findings showed that NS consumption significantly reduced serum high-sensitivity C-reactive protein (hs-CRP; WMD: -0.67, 95% CI: -1.29, -0.05, I2  = 95.7%), tumor necrosis factor-alpha (TNF-α; WMD: -2.29, 95% CI: -4.48, -0.11, I2  = 93%), and malondialdehyde (MDA; WMD: -1.18, 95% CI: -2.24, -0.12, I2  = 85.4%), and significantly increased total antioxidant capacity (TAC; WMD: 0.35, 95% CI: 0.10, 0.59, I2  = 77.1%), and superoxide dismutase (SOD; WMD: 66.30, 95% CI: 1.03, 131.57, I2  = 99.4%) levels. Overall, the results of this systematic review and meta-analysis imply that NS consumption may decrease inflammatory response and oxidative stress markers. PRACTICAL APPLICATIONS: Overall, the evidence supports the consumption of NS to reduce hs-CRP, TNF-α, and MDA, and to increase SOD and TAC levels. In addition, the subgroup analyses findings concluded that lower dosages of NS, longer durations of the intervention, and the use of NS seed oil may result in more effective action on inflammatory markers, but because of the limited number of trials, the results must be analyzed with caution, especially for the subgroup analysis. However, further prospective studies regarding the effect of NS consumption on biomarkers of inflammation and oxidative stress, with larger sample sizes, from various countries and longer follow-up periods, are required to confirm whether NS possesses veritable anti-inflammatory and antioxidant effects.

Association between abnormal maternal serum levels of vitamin B12 and preeclampsia: a systematic review and meta-analysis.

CONTEXT: Some evidence has shown an association between maternal vitamin B12 levels and the development of preeclampsia in pregnant women, but the relationship between preeclampsia and vitamin B12 is not clear. OBJECTIVE: The aim of this systematic review was to compare serum vitamin B12 levels in women with preeclampsia with those in normotensive pregnant women. DATA SOURCES: The PubMed/MEDLINE, Scopus, and Web of Science databases were searched up to August 2019, along with the reference lists of included articles. STUDY SELECTION: The literature was searched for observational studies that investigated vitamin B12 levels in women with preeclampsia. DATA EXTRACTION: Data were extracted independently by 2 authors. Data were pooled using a random-effects model. RESULTS: Vitamin B12 levels in women with preeclampsia were significantly lower than those in healthy women (mean, -15.24 pg/mL; 95%CI, -27.52 to -2.954; P < 0.015), but heterogeneity between studies was high (I2 = 97.8%; P = 0.0103). Subgroup analyses based on folic acid supplementation, homocysteine concentrations, and gestational age at the time of sampling for vitamin B12 assessment did not identify the sources of heterogeneity. CONCLUSIONS: Women with preeclampsia had significantly lower vitamin B12 concentrations than normotensive pregnant women.

The effect of L-arginine supplementation on obesity-related indices: A systematic review and meta-analysis of randomized clinical trials.

The clinical studies regarding the effect of L-arginine in human anthropometry have not been fully consistent, therefore, we carried out a systematic review and meta-analysis of randomized clinical trials in order to precisely evaluate and quantify the efficacy of L-arginine on weight, waist circumference, and BMI. We searched online databases including PubMed, SCOPUS, and Google Scholar for relevant articles up to September 2017. Eligible articles were reviewed by two independent investigators. Mean differences of the outcomes were used for calculation of weighted mean difference (WMD) derived from the random-effects model. Statistical heterogeneity between studies was examined using Cochran's Q-test and I2 index. Funnel plot and Egger's tests were performed to assess the publication bias. In our initial search, we found 1598 publications, of which 8 RCTs (9 treatment arms) were included. The results of the meta-analysis displayed a significant reduction in WC following L-arginine supplementation (WMD: -2.97 cm; 95% CI: -4.75 to -1.18, P = 0.001). However, L-arginine intervention had not elicited a significant effect on BMI (WMD: -0.51 kg/m2; 95% CI: -1.11 to .08, P = 0.09) and body weight (WMD: -0.57 kg; 95% CI: -1.77 to 0.61, P = 0.34). Subgroup analyses displayed that longer-term interventions (≥8 weeks) had a positive effect on body weight and using < 8 g/day L-arginine with longer duration (≥8 weeks) could significantly decrease BMI. In conclusion, this meta-analysis result suggested L-arginine supplementation could reduce waist circumference without any significant effect on body weight and body mass index.

Association of dietary fiber and depression symptom: A systematic review and meta-analysis of observational studies.

BACKGROUND: A potential relationship between depression and the intake of dietary fiber has been hypothesized in several studies. However, no meta-analysis has been conducted so far to explore the association between these two variables. Hence, we designed the present meta-analysis to elucidate the relationship between the intake of dietary fiber and depression. METHODS: A comprehensive search was performed using the PubMed/Medline, Scopus, Web of Science and Google Scholar databases to identify any relevant studies published from inception to October 2019. Observational studies (cross-sectional and case-control) were included in the analysis. RESULTS: Pooled analysis from the random-effects model of four case-control studies revealed that the consumption of dietary fiber in patients with depression was significantly lower versus healthy controls (WMD: -1.41 mg/dl, 95 % CI: -2.32, -0.51, P = 0.002). No significant heterogeneity was demonstrated among the analyzed studies (I2 = 4.0 %, P = 0.37). By pooling 5 effect sizes of cross-sectional studies (with a total of 97,023 subjects), we demonstrated that a higher dietary consumption of fiber was associated with significantly lower odds of depression (OR = 0.76; 95 % CI: 0.64, 0.90; P = 0.010), with a low heterogeneity seen among the retrieved studies (I2 = 43.9 %; P = 0.12). CONCLUSION: An increased intake of total dietary fiber is associated with lower odds of depression. Further studies are needed to evaluate the relationship between the different types of dietary fiber and depression.