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. © 2021 Wiley Periodicals LLC

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. © 202

Impact of soy milk consumption on cardiometabolic risk factors: A systematic review and meta-analysis of randomized controlled trials

Background: Soy milk contains some beneficial components such as isoflavones which can exert favorable effects on the cardiovascular health. The current study aimed to comprehensively evaluate the potential effects of soy milk consumption on cardiometabolic risk factors in adults. Methods: Relevant articles published up to June 2020 were systematically retrieved from SCOPUS, PubMed/MEDLINE, EMBASE, and Web of Science databases. In our study, we included all the randomized controlled trials (RCTs) investigating the impact of soy milk consumption on various cardiometabolic risk factors in adults (age � 18 years). A meta-analysis of the eligible studies was performed using the random-effects model. Results: The quantitative meta-analysis of 18 eligible RCTs (665 participants, age range 18�65 years) demonstrated that the consumption of soy milk significantly reduced systolic (P < 0.001) and diastolic (P = 0.002) blood pressure, total (P = 0.001) and low-density lipoprotein (P = 0.041) cholesterol, waist circumference (P = 0.005), C-reactive protein (P < 0.001), and tumor necrosis factor-alpha (P = 0.016). Significant between-study heterogeneity was found for the pooled effect sizes of blood pressure and low-density lipoprotein cholesterol. In addition, the subgroup analyses indicated that the decrease in systolic blood pressure (SBP) was more pronounced when soy milk was consumed for � 4 weeks. However, there were no significant differences between soy milk and control groups for the other factors, namely body weight, body mass index (BMI), high-density lipoprotein cholesterol, triglycerides, fasting blood glucose (FBG), and fasting insulin, interleukin-6, and fibrinogen. Conclusions: The current systematic review and meta-analysis revealed that incorporating soy milk into the diet might favorably affect several cardiometabolic risk factors in both healthy and unhealthy individuals. © 2021 The Author

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. © 2021 Wiley Periodicals LLC

Association between glycemic index and Helicobacter pylori infection risk among adults: A case-control study

Objectives: The aim of this case-control study was to investigate the relationships between carbohydrate consumption, glycemic load (GL), glycemic index (GI), and the risk of Helicobacter pylori infection among adults admitted to an Iranian hospital. Methods: In this case-control study, we recruited 150 participants with H. pylori infection and 302 healthy participants ages 18 to 55. Dietary GI and GL were assessed using a validated 168-item quantitative food frequency questionnaire. Dietary GL was calculated as a function of GI, carbohydrate content, and the frequency of intake of certain foods. Results: After adjustment for potential confounders, and comparing the highest tertile with the lowest tertile, a significant direct association was observed between the consumption of carbohydrates (odds ratio OR = 2.87; 95% confidence interval CI, 1.18�6.96; P for trend = 0.017), GI (OR = 3.70; 95% CI, 2.01�6.81; P for trend < 0.001), GL (OR = 3.06; 95% CI, 1.43�6.54; P for trend = 0.001), the consumption of bread and refined-grain products (OR = 4.24; 95% CI, 2.22�8.11; P for trend < 0.001), and the odds of H. pylori infection (OR = 2.22; 95% CI, 1.30�3.79; P for trend = 0.003). Conclusions: Our data suggest that a high dietary GL, high GI, and high consumption of dietary carbohydrates significantly elevate the risk of H. pylori infection. Also, the amount of bread and refined-grain products consumed had a significant positive relationship with H. pylori infection. © 202

The effect of paleolithic diet on glucose metabolism and lipid profile among patients with metabolic disorders: a systematic review and meta-analysis of randomized controlled trials

Objective: Several randomized clinical trials (RCTs) have investigated the effects of the Paleolithic diet (PD) in adult patients suffering from metabolic disorders. However, the results of these RCTs are conflicting. Therefore, we conducted a systematic review and meta-analysis to assess the effects of the PD in patients with metabolic disorders. Methods: We searched the PubMed/Medline, Scopus, Cochrane Databases, Google Scholar, Web of Science, and Embase databases up to June, 2020. The data were pooled using a random-effects model. From the eligible publications, 10 articles were selected for inclusion in this systematic review and meta-analysis. The meta-analysis was performed using a random-effects model. The heterogeneity was determined using the I2 statistics and the Cochrane Q test. Results: The pooled results from the random-effects model showed a significant reduction of the homeostatic model assessment of insulin resistance (HOMA-IR) (weighted mean difference, WMD: �0.39, 95 CI: �0.70, �0.08), fasting insulin (WMD: �12.17 μU/mL, 95 CI: �24.26, �0.08), total cholesterol (WMD: �0.32 mmol/l, 95 CI: �0.49, �0.15), triglycerides (WMD: �0.29 mmol/L, 95 CI: �0.42, �0.16), low-density lipoprotein cholesterol (WMD: �0.35 mmol/L, 95 CI: �0.67, �0.03), blood pressure (BP)(WMD � 5.89 mmHg; 95 CI � 9.973 to � 1.86 for the systolic BP and WMD � 4.01 mmHg; 95 CI � 6.21 to � 1.80 for the diastolic BP values) and C-reactive protein (CRP) levels (WMD: �0.84, mg/L, 95 CI: �1.62, �0.06) in the PD group versus control group. Conclusions: Our findings provide better insights into the effect of the PD on the modulation of the glucose and lipid metabolism factors in patients with metabolic disorders, providing comprehensive information for the development of future RCTs with a high quality design. © 2021 Taylor & Francis Group, LLC