The effects of green tea extract supplementation on body composition, obesity-related hormones and oxidative stress markers: a grade-assessed systematic review and dose-response meta-analysis of randomised controlled trials

Research indicates that green tea extract (GTE) supplementation is beneficial for a range of conditions, including several forms of cancer, CVD and liver diseases; nevertheless, the existing evidence addressing its effects on body composition, oxidative stress and obesity-related hormones is inconclusive. This systematic review and meta-analysis aimed to investigate the effects of GTE supplementation on body composition (body mass (BM), body fat percentage (BFP), fat mass (FM), BMI, waist circumference (WC)), obesity-related hormones (leptin, adiponectin and ghrelin) and oxidative stress (malondialdehyde (MDA) and total antioxidant capacity (TAC)) markers. We searched proper databases, including PubMed/Medline, Scopus and Web of Science, up to July 2022 to recognise published randomised controlled trials (RCT) that investigated the effects of GTE supplementation on the markers mentioned above. A random effects model was used to carry out a meta-analysis. The heterogeneity among the studies was assessed using the I2 index. Among the initial 11 286 studies identified from an electronic database search, fifty-nine studies involving 3802 participants were eligible to be included in this meta-analysis. Pooled effect sizes indicated that BM, BFP, BMI and MDA significantly reduced following GTE supplementation. In addition, GTE supplementation increased adiponectin and TAC, with no effects on FM, leptin and ghrelin. Certainty of evidence across outcomes ranged from low to high. Our results suggest that GTE supplementation can attenuate oxidative stress, BM, BMI and BFP, which are thought to negatively affect human health. Moreover, GTE as a nutraceutical dietary supplement can increase TAC and adiponectin.

The effects of guar gum supplementation on lipid profile in adults: a GRADE-assessed systematic review, meta-regression and dose-response meta-analysis of randomised placebo-controlled trials

Recent meta-analytic work indicated that guar gum supplementation might improve lipid profile markers in different populations. However, critical methodological limitations such as the use of some unreliable data and the lack of inclusion of several relevant studies, and the scarcity in assessments of regression and dose-specific effects make it difficult to draw meaningful conclusions from the meta-analysis. Therefore, current evidence regarding the effects of guar gum supplementation on lipid profile remains unclear. The present systematic review, meta-regression and dose-response meta-analysis aimed to examine the effects of guar gum supplementation on lipid profile (total cholesterol (TC), LDL, TAG and HDL) in adults. Relevant studies were obtained by searching the PubMed, SCOPUS, Embase and Web of Science databases (from inception to September 2021). Weighted mean differences (WMD) and 95 % CI were estimated via a random-effects model. Heterogeneity, sensitivity analysis and publication bias were reported using standard methods. Pooled analysis of nineteen randomised controlled trials (RCT) revealed that guar gum supplementation led to significant reductions in TC (WMD: -19·34 mg/dl, 95 % CI -26·18, -12·49, P < 0·001) and LDL (WMD: -16·19 mg/dl, 95 % CI -25·54, -6·83, P = 0·001). However, there was no effect on TAG and HDL among adults in comparison with control group. Our outcomes suggest that guar gum supplementation lowers TC and LDL in adults. Future large RCT on various populations are needed to show further beneficial effects of guar gum supplementation on lipid profile and establish guidelines for clinical practice.

The effects of green tea supplementation on cardiovascular risk factors: A systematic review and meta-analysis

Purpose

A bulk of observational studies have revealed the protective role of green tea supplementation in cardiovascular diseases. The current systematic review and meta-analysis study aimed to establish the effects of green tea supplementation on cardiovascular risk factors including lipid profile, blood pressure, glycemic control markers and CRP.

Methods

A systematic literature search of randomized clinical trials (RCTs) that investigated the effects of green tea supplementation and cardiovascular risk factors was undertaken in online databases including PubMed/Medline, Scopus, Web of Science, and Embase using a combination of green tea and cardiovascular risk factors search terms. Meta-analyses were carried out using a random-effects model. The I2 index was used to assess the heterogeneity of RCTs.

Results

Among the initial 11,286 studies that were identified from electronic databases search, 55 eligible RCTs with 63 effect sizes were eligible. Results from the random effects meta-analysis showed that GTE supplementation significantly reduced TC (WMD = -7.62; 95% CI: -10.51, -4.73; P = < 0.001), LDL-C (WMD = -5.80; 95% CI: -8.30, -3.30; P = < 0.001), FBS (WMD = -1.67; 95% CI: -2.58, -0.75; P = < 0.001), HbA1c (WMD = -0.15; 95% CI: -0.26, -0.04; P = 0.008), DBP (WMD = -0.87; 95% CI: -1.45, -0.29; P = 0.003), while increasing HDL-C (WMD = 1.85; 95% CI: 0.87, 2.84; P = 0.010). Subgroup analyses based on the duration of supplementation (≥ 12 vs. < 12 weeks), dose of green tea extract (GTE) (≥1,000 vs. < 1,000 mg/d), sex (male, female, and both), baseline serum levels of lipid profile, and glycemic control factors demonstrated different results for some risk factors.

Conclusion

The current study suggests improvements in the lipid and glycemic profiles following green tea supplementation. These findings support previous evidence showing the health benefits of green tea supplementation on cardiometabolic risk factors.

The effect of grape products on liver enzymes: A systematic review and meta-analysis of randomized controlled trials

The favorable influence of grape consumption on metabolic diseases has previously been shown in studies. We sought to assess the effects of grape intake on liver enzymes, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP), in adults. We performed literature search in online databases, to find eligible randomized controlled trials (RCTs). we considered RCTs that met the following criteria: RCTs consisted of use of grape products on ALT, AST, and ALP in adults (≥18 years) with at least 2 weeks intervention duration. Pooling data from 11 trials showed that grape products intake significantly reduced ALP (p = .010), without any significant changes in ALT (p = .234) and AST (p = .300). In subgroup analysis, we found a significant reduction in ALP, ALT, and AST when the duration of intervention was ≥12 weeks, and when grape seed extract (GSE) was administered. The variable duration and dosage of intervention was one of the sources of bias in our meta-analysis. Additionally, participants involved in included studies had different physiological status and various age groups. Grape products administration may significantly improve ALT, AST, and ALP in adults in long-term interventions and/or when GSE is administered. It should be noted that the favorable effects of grape consumption were small and may not reach clinical importance.

The effects of selenium supplementation on blood lipids and blood pressure in adults: A systematic review and dose-response meta-analysis of randomized control trials

BACKGROUND

Previous studies evaluating the effects of selenium supplementation on lipid profile and blood pressure (BP) offer contradictory findings. This systematic review and meta-analysis assessed the effects of selenium supplementation on these lipid profile and BP.

METHODS

In order to identify interrelated clinical trials, we performed a comprehensive literature search in the online databases, including PubMed, Scopus, Embase, and ISI web of science, up to December 2021.

RESULTS

The analysis of the data established that selenium supplementation did not significantly affect TG level (WMD: -0.84 mg/dL; 95 % CI: -4.74, 3.05, p = 0.671), LDL-C (WMD: 0.86 mg/dL; 95 % CI: -1.21, 2.95, p = 0.416), and HDL-C (WMD: 0.3 mg/dL; 95 % CI: -0.66, 1.27, p = 0.535). however, there was a significant reduction in TC levels following selenium supplementation (WMD: -2.11 mg/dL; 95 % CI: -4.09, -0.13, p = 0.037). After subgroup analysis, when the baseline levels of LDL-C were < 130 mg/dL, selenium supplementation elicited a significant increase in LDL-C levels (WMD: 2.89 mg/dL; 95 % CI: 0.26, 5.51, p = 0.031). For BP, selenium supplementation significantly increased SBP (WMD: 2.02 mmHg; 95 % CI: 0.50, 3.55, p = 0.009), while it had no significant effect on DBP (WMD: 0.39 mmHg; 95 % CI: (-0.89, 1.68, p = 0.551)).

CONCLUSION

Although our findings suggest selenium may have possible therapeutic effects in improving TC and VLDL, because of its negative effects on LDL and BP, selenium supplementation for cardiovascular protection should be recommended with caution.

The effects of conjugated linoleic acid supplementation on lipid profile in adults: A systematic review and dose-response meta-analysis

Background

The findings of trials investigating the effect of conjugated linoleic acid (CLA) administration on lipid profile are controversial. This meta-analysis of randomized controlled trials (RCTs) was performed to explore the effects of CLA supplementation on lipid profile.

Methods

Two authors independently searched electronic databases including PubMed, Web of Science, and Scopus until March 2022, in order to find relevant RCTs. The random effects model was used to evaluate the mean and standard deviation.

Results

In total, 56 RCTs with 73 effect sizes met the inclusion criteria and were eligible for the meta-analysis. CLA supplementation significantly alter triglycerides (TG) (WMD: 1.76; 95% CI: -1.65, 5.19), total cholesterols (TC) (WMD: 0.86; 95% CI: -0.42, 2.26), low-density lipoprotein cholesterols (LDL-C) (WMD: 0.49; 95% CI: -0.75, 2.74), apolipoprotein A (WMD: -3.15; 95% CI: -16.12, 9.81), and apolipoprotein B (WMD: -0.73; 95% CI: -9.87, 8.41) concentrations. However, CLA supplementation significantly increased the density lipoprotein cholesterol (HDL-C) (WMD: -0.40; 95% CI: -0.72, -0.07) concentrations.

Conclusion

CLA supplementation significantly improved HDL-C concentrations, however, increased concentrations of TG, TC, LDL-C, apolipoprotein A, and apolipoprotein B.

Systematic review registration

https://www.crd.york.ac.uk/prospero/#recordDetails, identifier: CRD42022331100.

Food groups and nutrients consumption and risk of endometriosis: a systematic review and meta-analysis of observational studies

Dietary factors may play a role in the etiology of endometriosis and dietary intake of some food groups and nutrients could be associated with endometriosis risk. This systematic review and meta-analysis of observational studies was conducted to summarize the findings on the association between dietary intakes of selected food groups and nutrients (dairy, fats, fruits, vegetables, legumes, and animal-derived protein sources), and the risk of endometriosis among adult women. PubMed, Scopus, and ISI Web of Science were systematically searched up to September 2022. The inverse variance-weighted fixed-effect method was used to estimate the effect size and corresponding 95% CI. A total of 8 publications (4 studies) including 5 cohorts and 3 case-control with a sample size ranging from 156 to 116,607 were included in this study. A higher intake of total dairy [all low-fat and high-fat dairy foods] was associated with decreased risk of endometriosis (RR 0.90; 95% CI, 0.85 to 0.95; P < 0.001; I² = 37.0%), but these associations were not observed with intakes of low or high-fat dairy, cheese or milk. Increased risk of endometriosis was associated with higher consumption of red meat (RR 1.17; 95% CI, 1.08 to 1.26; P < 0.001; I² = 82.4%), trans fatty acids (TFA) (RR 1.12; 95% CI, 1.02 to 1.23; P = 0.019; I² = 73.0%), and saturated fatty acids (SFA) (RR 1.06; 95% CI, 1.04 to 1.09; P < 0.001; I² = 57.3%). The results of this meta-analysis suggest that there may be differing associations between dietary intake of dairy foods, red meat, SFAs, and TFAs and the risk of endometriosis. It may be useful to extend the analysis to other types of food groups and dietary patterns to obtain a complete picture. Additionally, further investigations are needed to clarify the role of diet in the incidence and progression of endometriosis.Trial registration: PROSPERO, CRD42020203939.

Effects of almond on cardiometabolic outcomes in patients with type 2 diabetes: A systematic review and meta-analysis of randomized controlled trials

An enhanced risk for cardiovascular disease (CVD) still exists even when T2DM patients have tight control on blood sugar. Thus, identification of treatment approaches that address CVD risk factors may be useful for patients beyond the blood sugar management. Although emerging evidence suggests that nuts consumption have beneficial effects on cardiometabolic health, the effects of almond intake in patients with type 2 diabetes are still controversial. Therefore, our objective was to investigate the effect of almond on cardiometabolic outcomes in patients with T2DM through a systematic review and meta-analysis of available randomized controlled trials (RCTs). A systematic search was conducted in PubMed, Web of Science, Scopus, Embase, and Google Scholar to identify relevant RCTs up to March 2021. There was no language and time limitation. Weighted mean difference (WMD) was pooled using a random effects model. Heterogeneity, sensitivity analysis, and publication bias were reported using standard methods. Nine RCTs were included in the final analysis. Almond intake resulted in significant reduction in low-density lipoprotein cholesterol (LDL-C) (WMD: -5.28 mg/dL; 95% CI, -9.92, -0.64; p = .026) compared with the control group. This lowering effect of LDL-C was robust in subgroups with almond consumption >50 g/day, and baseline LDL-C level <130 mg/dL. However, the effect of almond on total cholesterol, triglycerides, high-density lipoprotein cholesterol, fasting plasma glucose, insulin, hemoglobin A1c, body mass index, weight, body fat, systolic and diastolic blood pressure, and CRP was not significant compared with the control group. In summary, the current meta-analysis indicated that almond consumption decreased LDL-C, and had no favorable effect on other cardiometabolic outcomes in patients with T2DM. However, further high-quality studies are needed to firmly establish the clinical efficacy of the almond.

The beneficial effect of Alpha-lipoic acid supplementation as a potential adjunct treatment in episodic migraines

The current study was performed to evaluate the effects of alpha-lipoic acid (ALA) supplementation on lactate, nitric oxide (NO), vascular cell adhesion molecule-1 (VCAM-1) levels, and clinical symptoms in women with episodic migraines. Considering the inclusion and exclusion criteria, ninety-two women with episodic migraines participated in this randomized, double-blind, placebo-controlled, parallel-design trial. The participants were randomly assigned to receive either 300 mg/day ALA or placebo, twice per day for 12 weeks. The primary outcomes included headache severity, headache frequency per month, and duration of attacks and the secondary outcomes included lactate (a marker of mitochondrial function), NO, and VCAM-1 serum levels were measured at baseline and the end of the intervention. At the end of the study, there was a significant decrease in lactate serum levels (- 6.45 ± 0.82 mg/dl vs - 2.27 ± 1.17 mg/dl; P = 0.039) and VCAM-1 (- 2.02 ± 0.30 ng/ml vs - 1.21 ± 0.36 ng/ml; P = 0.025) in the ALA as compared to the placebo group. In addition, the severity (P < 0.001), frequency (P = 0.001), headache impact test (HIT-6) (P < 0.001), headache dairy results (HDR) (P = 0.003), and migraine headache index score (MHIS) (P < 0.001) had significantly decreased in the intervention as compared to the control group. No significant changes were observed for NO levels and duration of migraine pains. ALA supplementation can be considered a potential adjunct treatment in patients with migraine due to its improving mitochondrial and endothelial functions and clinical symptoms.

Folic acid supplementation and blood pressure: a GRADE-assessed systematic review and dose-response meta-analysis of 41,633 participants

Hypertension is a predisposing factor for cardiovascular disease (CVD). The extant literature regarding the effects of folic acid supplementation on blood pressure (BP) is inconsistent. Therefore, this systematic review and meta-analysis of randomized controlled trials was conducted to summarize the effects of folic acid supplementation on BP. A systematic search was carried out in PubMed, Scopus, ISI Web of Science, and Cochrane library, from database inception to August 2021. Data were pooled using the random-effects method and were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI). The pooled results of 22 studies, including 41,633 participants, showed that folic acid supplementation significantly decreased systolic BP (SBP) (WMD: -1.10 mmHg; 95% CI: -1.93 to -0.28; p = 0.008). Subgroup analysis showed that the results remained significant when baseline SBP was ≥120 mmHg, intervention duration was ≤6 weeks, intervention dose was ≥5 mg/d, in patients with CVD, males and females, and overweight participants, respectively. Furthermore, the changes observed in diastolic BP (DBP) (WMD: -0.24 mmHg; 95% CI: -0.37 to -0.10; p < 0.001) were also statistically significant. However, subgroup analysis showed that the results remained significant in subject with elevated DBP, long term duration of intervention (>6 weeks), low dose of folic acid (<5 mg/day), CVD patients, both sexes and male, and participants with normal BMI. Dose-response analysis showed that folic acid supplementation changed SBP and DBP significantly based on dose and duration. However, meta-regression analysis did not reveal any significant association between dose and duration of intervention with changes in SBP. The present study demonstrates the beneficial effects of folic acid supplementation on BP by decreasing both SBP and DBP.

The efficacy of alpha-lipoic acid in improving oxidative, inflammatory, and mood status in women with episodic migraine in a randomised, double-blind, placebo-controlled clinical trial

AIM

Migraine is a common neurovascular disorder, which is associated with severe to moderate disabling headaches. Oxidative stress and inflammation might play a role in migraine pathogenesis and the mood disorders. Considering the antioxidant and anti-inflammatory properties of alpha-lipoic acid (ALA), this study was designed to investigate its effect on oxidative, inflammatory, and mood conditions in women with episodic migraine.

METHODS

In total, 92 women with episodic migraine participated in the study. The patients were randomly divided into two groups, receiving a 300-mg capsule of ALA or placebo twice daily for 3 months. To assess the oxidative and inflammatory status, the serum levels of total antioxidant capacity (TAC), total oxidant status (TOS), glutathione (GSH), malondialdehyde (MDA), oxidative stress index (OSI), and C-reactive protein (CRP) were determined at the beginning and at the end of the intervention. A depression, anxiety, stress scale (DASS-21-items) questionnaire was used to evaluate mood status.

RESULTS

Finally, 79 patients reached the final analysis stage. At the end of the intervention, a significant decrease in the serum levels of MDA (means difference [MD]: -0.83, 95% confidence intervals (CI): -1.04, -0.62 nmol/mL vs MD: -0.32, CI: -0.48, -0.15 nmol/mL; P < .001) and CRP (MD: -0.78, CI: -1.17, -0.39 mg/L vs MD: -0.63, CI: -1.80, 0.52 mg/L; P < .001) was observed in the ALA as compared with the placebo group, but changes in serum GSH (P = .086), TAC (P = .068), TOS (P = .225), and OSI (P = .404) were not statistically significant. In addition, depression, anxiety, and stress (with P < .001, in all cases) had significantly decreased in the intervention as compared with the control group.

CONCLUSION

The results of this study suggest that ALA supplementation for 3 months has beneficial effects on improving the oxidative, inflammatory, and mood conditions of patients suffering from episodic migraine.

Folic Acid Supplementation Improves Glycemic Control for Diabetes Prevention and Management: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials

Background: There is a growing interest in the considerable benefits of dietary supplementations, such as folic acid, on the glycemic profile. We aimed to investigate the effects of folic acid supplementation on glycemic control markers in adults. Methods: Randomized controlled trials examining the effects of folic acid supplementation on glycemic control markers published up to March 2021 were detected by searching online databases, including Scopus, PubMed, Embase, and ISI web of science, using a combination of related keywords. Mean change and standard deviation (SD) of the outcome measures were used to estimate the mean difference between the intervention and control groups at follow-up. Meta-regression and non-linear dose-response analysis were conducted to evaluate the association between pooled effect size and folic acid dosage (mg/day) and duration of the intervention (week). From 1814 detected studies, twenty-four studies reported fasting blood glucose (FBG), fasting insulin, hemoglobin A1C (HbA1C), and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) as an outcome measure. Results: Results revealed significant reductions in FBG (weighted mean difference (WMD): −2.17 mg/dL, 95% CI: −3.69, −0.65, p = 0.005), fasting insulin (WMD: −1.63 pmol/L, 95% CI: −2.53, −0.73, p < 0.001), and HOMA-IR (WMD: −0.40, 95% CI: −0.70, −0.09, p = 0.011) following folic acid supplementation. No significant effect was detected for HbA1C (WMD: −0.27%, 95% CI: −0.73, 0.18, p = 0.246). The dose-response analysis showed that folic acid supplementation significantly changed HOMA-IR (r = −1.30, p-nonlinearity = 0.045) in non-linear fashion. However, meta-regression analysis did not indicate a linear relationship between dose, duration, and absolute changes in FBG, HOMA-IR, and fasting insulin concentrations. Conclusions: Folic acid supplementation significantly reduces some markers of glycemic control in adults. These reductions were small, which may limit clinical applications for adults with type II diabetes. Further research is necessary to confirm our findings.

Effects of chromium supplementation on blood pressure, body mass index, liver function enzymes and malondialdehyde in patients with type 2 diabetes: A systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND

Several studies reported beneficial effects of chromium supplementation for management of type 2 diabetes mellitus (T2DM). The present study aimed to provide a systematic review and meta-analysis of randomized controlled trials (RCTs) examining the effects of chromium supplementation on blood pressure, body mass index (BMI), liver function enzymes and malondialdehyde (MDA) in patients with T2DM.

METHODS

PubMed, Scopus, and Embase were searched up to 15 November 2020 with no language and time restriction. RCTs that reported the effects of chromium supplementation on blood pressure, BMI, liver function enzymes and MDA in patients with T2DM were included. A random-effects model was used to compute weighted mean differences (WMDs) with 95 % confidence intervals (CIs). Between-study heterogeneity was assessed by Cochran's Q test and quantified by I² statistic.

RESULTS

Of 3586 publications, 15 RCTs were included for the meta-analysis. Pooled effect sizes indicated that chromium significantly reduced diastolic blood pressure (DBP) (WMD): -2.36 mmHg, 95 % CI: -4.14, -0.60; P = 0.008), and MDA (WMD: -0.55 umol/l, 95 % CI: -0.96, -0.14; P = 0.008). However, chromium supplementation did not significantly affect BMI, systolic blood pressure (SBP), alanine aminotransferase (ALT), aspartate aminotransferase (AST). Meta-regression analysis did not show significant linear relationship between dose of chromium and change in BMI (p = 0.412), SBP (p = 0. 319), DBP (p = 0.102), ALT (p = 0.923), AST (p = 0.986) and MDA (p = 0.055).

CONCLUSION

The present systematic review and meta-analysis shows that supplementation with chromium at dose of 200-1000 μg/day may reduce DBP and MDA in T2DM patients.

Effects of chromium supplementation on lipid profile in patients with type 2 diabetes: A systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND

The purpose of this study was to determine the influence of chromium supplementation on lipid profile in patients with type 2 diabetes mellitus (T2DM).

METHODS

A systematic search was performed in Scopus, Embase, Web of Science, the Cochrane library and PubMed databases to find randomized controlled trials (RCTs) related to the effect of chromium supplementation on lipid profile in patients with T2DM, up to June 2020. Meta-analyses were performed using the random-effects model, and I² index was used to evaluate heterogeneity.

RESULTS

The primary search yielded 725 publications. 24 RCTs (with 28 effect size) were eligible. Our meta-analysis indicated that chromium supplementation resulted in a significant decrease in serum levels of triglyceride (TG) (MD: -6.54 mg/dl, 95 % CI: -13.08 to -0.00, P = 0.050) and total cholesterol (TC) (WMD: -7.77 mg/dl, 95 % CI: -11.35 to -4.18, P < 0.001). Furthermore, chromium significantly increases high-density lipoprotein (HDL) (WMD: 2.23 mg/dl, 95 % CI: 0.07-4.40, P = 0.043) level. However, chromium supplementation did not have significant effects on low-density lipoprotein (LDL) (WMD: -8.54 mg/dl, 95 % CI: -19.58 to 2.49, P = 0.129) level.

CONCLUSION

Chromium supplementation may significantly improve lipid profile in patients with T2DM by decreasing TG and TC and increasing HDL. However, based on our analysis, chromium failed to affect LDL. It should be noted that the lipid-lowering properties of chromium supplementation were small and may not reach clinical importance.

Beneficial effects of folic acid supplementation on lipid markers in adults: A GRADE-assessed systematic review and dose-response meta-analysis of data from 21,787 participants in 34 randomized controlled trials

Folic acid supplementation has received considerable attention in the literature, yet there is a large discrepancy in its effects on lipid markers in adults. Therefore, this systematic review and meta-analysis of 38 randomized controlled trials (RCTs) evaluated the effects of folic acid supplementation on triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol concentrations in a cohort of 21,787 participants. A systematic search current as of March 2021 was performed in PubMed/Medline, Scopus, Web of Science, and Embase using relevant keywords to identify eligible studies. A fix or random-effects model was used to estimate the weighted mean difference (WMD) and 95% confidence intervals (CIs). Thirty-four RCTs were included in this meta-analysis. The pooled analysis revealed that serum TG (WMD: -9.78 mg/dL; 95% CI: -15.5 to -4.00; p = 0.001, I²=0.0%, p = 0.965) and TC (WMD: -3.96 mg/dL; 95% CI: -6.71 to -1.21; p = 0.005, I²=46.9%, p = 0.001) concentrations were significantly reduced following folic acid supplementation compared to placebo. However, folic acid supplementation did not affect serum concentrations of LDL (WMD: -0.97 mg/dL; 95% CI: -6.82 to 4.89; p = 0.746, I²=60.6%, p < 0.001) or HDL cholesterol (WMD: 0.44 mg/dL; 95% CI: -0.53 to 1.41; p = 0.378, I²= 0.0%, p = 0.831). A significant dose-response relationship was observed between the dose of folic acid supplementation and serum concentrations of HDL cholesterols (r = 2.22, p = 0.047). Folic acid supplementation reduced serum concentrations of TG and TC without affecting LDL or HDL cholesterols. Future large RCTs on various populations are needed to show further beneficial effects of folic acid supplementation on lipid profile.

Effect of green coffee bean extract supplementation on liver function and inflammatory biomarkers: A meta-analysis of randomized clinical trials

Inflammation is considered a major contributor to non-alcoholic fatty liver disease (NAFLD) and several chronic diseases such as, cardiovascular disease and type two diabetes. Green coffee bean extract (GCBE) supplementation has been suggested to enhancing antioxidant capacity in people with obesity but results across studies are mixed. We conducted a meta-analysis of randomized controlled trials of GCBE supplementation in overweight/obese with normal liver function and NAFLD adults with ALT, AST, γ-GTP, ALP, LDH, CRP, IL-6, and TNF-α as outcomes by searching PubMed and other databases. Eight studies were included, totaling 330 participants randomized to GCBE supplementation or placebo ranging from 50 mg/day to 1200 mg/day for 8-12 weeks. GCBE supplementation resulted in lower levels of TNF-α (mean difference = 1.37 pg/mL [95% CI = 0.97-1.76]; p < 0.00001). No significant difference was found in the remaining markers. In conclusion, GCBE supplementation attenuated TNF-α, a circulating inflammatory marker mediator which may be linked with lower systemic inflammation. However, potential cellular and molecular mechanisms by which GCBE exerts this positive effect warrants further investigations in human model studies.

The effects of soy supplementation on inflammatory biomarkers: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Soy products contain several compounds with anti-inflammatory properties like genistein and daidzein which reported to act through different pathways. Present study conducted considering the inconsistent results and lack of any comprehensive review regarding randomized controlled trials which assess the effect of soy products on inflammatory markers.

METHODS

Following electronic databases were searched up to March 2020: PubMed, Scopus, ISI web of science, and Cochrane Library All randomized trials which assessed the effect of soy product supplementation on c-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were included for last analysis. Treatment effects were expressed as mean difference (MD) and the standard deviation (SD) of outcomes. To estimate the overall effect the random-effects model was employed.

RESULTS

Finally, 51 randomized trial were included for present study. Last analysis showed that soy product supplementation lead to significant reduction in CRP (MD -0.27 mg/L; 95% CI: -0.51, -0.02, p = 0.028) but it did not affect IL-6 (MD 0.0 pg/ml; 95% CI: -0.06, 0.06, p = 0.970) and TNF-α (MD = -0.04 pg/ml; 95% CI: -0.11, 0.03, p = 0.252). Subgroup analysis showed that soy supplementation had a significant impact on decreasing IL-6 and TNF-α levels when studies had a long-term intervention (≥12 weeks) and used low dose isoflavone (<100 mg/day).

CONCLUSION

In conclusion, present systematic review and meta-analysis found a significant reduction in CRP levels after soy supplementation whiles IL-6 and TNF-α did not affect.

The Association between Nuts Intake and Non-Alcoholic Fatty Liver Disease (NAFLD) Risk: a Case-Control Study

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease. Nuts are nutrient- and calorie-dense foods with several health-promoting compounds. In this case-control study, we investigated the association between nut intake and NAFLD risk. Hundred ninety-six subjects with NAFLD and eight hundred three controls were recruited. The participants' dietary intakes were assessed by a valid and reliable semi-quantitative food frequency questionnaire (FFQ). Participants were categorized according to deciles of daily nuts intake. Multivariable logistic regression models were used with NAFLD as the dependent and deciles of daily nuts intake as an independent variables. Range of age was 18 to 75 years. Forty three percent of participants were male. Range of nuts intake was between 0 to 90.90 g/day. In model 3, after adjusting for potential confounding variables including, age, sex, BMI, alcohol consumption, smoking, diabetes and physical activity, the relation between daily nuts intake and risk of NAFLD was positive and significant in the deciles 9 and 10 compared to the lowest decile (odds ratio [OR], 3.22; 95% confidence interval [CI], 1.04-7.49; p = 0.039 and OR, 3.03; 95% CI, 1.03-8.90; p = 0.046, respectively). However, in the final model after additional adjusting for energy intake, no significant association was found. According to the findings, there is not any significant relationship between nuts intake and NAFLD risk; while higher intake of nuts is related to the higher risk of NAFLD mediated by energy intake.