The effect of conjugated linoleic acid supplementation in comparison with omega-6 and omega-9 on lipid profile: a graded, dose-response systematic review and meta-analysis of randomized controlled trials.

Conjugated linoleic acid (CLA) is a geometrical isomer of linoleic acid, which has anti-inflammatory, anti-diabetic, anti-cancer, and anti-obesity properties. However, the studies reported inconstant results about the CLA-related effects on lipid profiles. As a result, meta-analysis and systematic review were performed to survey the CLA supplementation-related effect on lipid profile including high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol (TC), and triglycerides (TG). To identify the relevant research, a systematic comprehensive search was initiated on the medical databases such as Scopus and PubMed/Medline until December 2022. The overall effect size was estimated by weighted mean difference (WMD) and 95% confidence interval (CI) in a random effect meta-analysis. In the final quantitative analysis, the meta-analysis considered 35 randomized controlled trials (RCTs) with 1,476 participants (707 controls and 769 cases). The pooled results demonstrated that CLA supplementation, compared with olive oil, significantly increased serum TG levels (WMD: 0.05 mmol/L; 95% CI: 0.01 to 0.1; p = 0.04; I2 = 0.0%, p = 0.91). With regard to TC level, CLA supplementation compared with placebo significantly reduced TC concentrations (WMD: -0.08 mmol/L; 95% CI: -0.14 to -0.02; p < 0.001; I2 = 82.4%). Moreover, the non-linear dose-response analysis indicated a decreasing trend of TC serum level from the 15th week of CLA supplementation compared with olive oil (Pnon-linearity = 0.01). The present meta-analysis and systematic review of 35 RCTs showed that the CLA intervention was able to raise the level of TG in comparison to olive oil; however, it can decrease TC level compared with placebo and olive oil.

What is the influence of policosanol supplementation on liver enzymes? A systematic review and dose-response meta-analysis of randomized controlled trials.

OBJECTIVE: Policosanol is a mixture of long chain alcohols refined from sugar cane. Significant reductions in liver enzymes have been observed in some studies. However, the impact of policosanol on liver enzymes remained controversial. The current meta-analysis aims to evaluate the effect of policosanol supplementation on the levels of alanine transaminase (ALT) and aspartate transaminase (AST). METHODS: The literature was systematically searched for studies published up to November 2023 in PubMed/Medline, Google Scholar, EMBASE, and Scopus. Randomized controlled trial (RCT) studies were included to evaluate the intervention effect of policosanol compared to placebo on ALT and AST. DerSimonian and Laird models were used to calculate effect sizes. RESULTS: Twenty-three trials including 2535 participants were included in the study. The combination of effect sizes, regarding the random-effects model, demonstrated significant changes in ALT serum levels after intervention (WMD: -1.48 U/L; 95% CI: -2.33 to -0.64; P = 0.001), and AST (WMD: -1.10 U/L; 95% CI: -1.70 to -0.51; P < 0.001). Subgroup analysis of AST and ALT showed that this reduction effect was most often observed at the dose of 20 mg/d. The dose-response analysis represented a non-significant non-linear connection between the dosage and duration of policosanol intervention in ALT and AST serum reduction. CONCLUSION: Policosanol supplementation exerts a beneficial effect on liver enzymes as well as ALT and AST concentrations in adults. However, further long-term and well-designed RCTs with better quality are needed to further assess and confirm these results.

The effects of Garcinia cambogia (hydroxycitric acid) on lipid profile: A systematic review and meta-analysis of randomized controlled trials.

Garcinia cambogia (GC) has antioxidant, anticancer, antihistamine, and antimicrobial properties. To determine the effect of GC on lipid profiles, a systematic review and meta-analysis was carried out. Up to February 9, 2023, six electronic databases (Web of Science, Cochrane Library, Embase, PubMed, Scopus, and Google Scholar) were searched at any time without limitations. Trials examining the impact of GC on serum levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol (HDL-C) in adults were included. The total effect was shown as a weighted mean difference (WMD) and 95% confidence interval (CI) in a random-effects meta-analysis approach. This systematic review and meta-analysis included 14 trials involving 623 subjects. Plasma levels of TC (WMD: -6.76 mg/dL; CI: -12.39 to -0.59, p-value = 0.032), and TG (WMD: -24.21 mg/dL; CI: -37.84 to -10.58, p < 0.001) were significantly reduced after GC use, and plasma HDL-C (WMD: 2.95 mg/dL; CI: 2.01 to 3.89, p < 0.001) levels increased. low-density lipoprotein cholesterol levels (WMD: -1.15 mg/dL; CI: -16.08 to 13.78, p-value = 0.880) were not significantly affected. The effects of lowering TC and TG were more pronounced for periods longer than 8 weeks. Consuming GC has a positive impact on TC, TG, and HDL-C concentrations. The limitations of this study include the short duration of analyzed interventions and significant heterogeneity. Nevertheless, it is imperative to conduct well-structured, and high-quality long-term trials to comprehensively evaluate the clinical effectiveness of GC on lipid profile, and validate these findings.

The effects of purslane consumption on blood pressure, body weight, body mass index, and waist circumference: a systematic review and meta-analysis of randomised controlled.

The effects of purslane consumption on anthropometric measurements and blood pressure have been studied in numerous experiments. However, the research findings conflict with one another. In order to assess the impact of purslane on weight, body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), and diastolic blood pressure (DBP), this meta-analysis was carried out. Up until February 2023, PubMed, Web of Science, Scopus, Google Scholar, and the reference lists of the identified pertinent randomised controlled trials (RCTs) were all searched. The random-effects model was used to calculate the effect size and then to describe it as a weighted mean difference (WMD) and 95 % confidence interval (CI) (CRD42023427955). The systematic review was able to incorporate seven RCTs. Meta-analysis showed that purslane significantly decreased body weight (WMD): -0⋅73 kg, 95 % confidence interval (CI): -1⋅37, -0⋅09, P=0⋅025), BMI (WMD: -0⋅35 kg/m2, 95 % CI: -0⋅64, -0⋅07, P=0⋅016), and SBP (WMD: -3⋅64 mmHg, 95 % CI: -6⋅42, -0⋅87, P = 0⋅01), and for WC, there was no discernible effect (WMD: -0⋅86 cm; 95 % CI, -1⋅80 to 0⋅07; P = 0⋅06) and DBP (WMD: -0⋅36 mmHg; 95 % CI, -1⋅75 to 1⋅03; P = 0⋅61). Purslane consumption, especially in participants with a BMI of <30, might play a role in decreasing SBP, body weight, BMI, and WC. Purslane consumption significantly reduced body weight, BMI, and SBP; however, WC and DBP did not experience a reduction. More investigation is needed to verify the impact of purslane consumption on anthropometric parameters and blood pressure.

Does folic acid supplementation have a positive effect on improving memory? A systematic review and meta-analysis of randomized controlled trials.

Introduction: The results of randomized controlled trials (RCTs) on the effect of folic acid supplementation on memory status due to various heterogeneity, dosage, duration, and cognitive function assessments were inconclusive. Therefore, we have performed a systematic review and meta-analysis to investigate the effect of folic acid supplementation on memory in RCTs. Method: Comprehensive computerized systematic searches were conducted throughout Scopus, PubMed/Medline, and Google Scholar from inception until February 2022 to investigate the effect of folic acid supplementation memory levels in RCTs. The standardized mean difference (SMD) and 95% confidence interval (CIs) were used to estimate the overall effect size using random-effects meta-analyses. Results: The overall results of nine trials with 641 participants, revealed that folic acid supplementation did not significantly change memory score compared to placebo (SMD: 0.12; 95% CI: -0.17, 0.40, p = 0.418; I 2 = 62.6%). However, subgroup analyses showed that supplementation with folic acid had favorable effects on memory levels considering the following conditions: (1) doses lower than 1 mg/day, (2) treatment lasting more than 6 months, (3) conducted in eastern countries, and (4) in participants equal to or older than 70 years old. The dose-response analysis suggested a significant favorable effect on memory status at doses of 6-11 mg/d and a significant decline at doses of 17-20 mg/d. Discussion: Although we did not find a significant effect of folic acid supplementation on memory, there were some suggestions of beneficial effects in the subgroup analyses.

Does Ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta-analysis of randomized controlled trials.

Clinical trial studies revealed conflicting results on the effect of Ashwagandha extract on anxiety and stress. Therefore, we aimed to evaluate the effect of Ashwagandha supplementation on anxiety as well as stress. A systematic search was performed in PubMed/Medline, Scopus, and Google Scholar from inception until December 2021. We included randomized clinical trials (RCTs) that investigate the effect of Ashwagandha extract on anxiety and stress. The overall effect size was pooled by random-effects model and the standardized mean difference (SMD) and 95% confidence interval (CIs) for outcomes were applied. Overall, 12 eligible papers with a total sample size of 1,002 participants and age range between 25 and 48 years were included in the current systematic review and meta-analysis. We found that Ashwagandha supplementation significantly reduced anxiety (SMD: -1.55, 95% CI: -2.37, -0.74; p = .005; I2  = 93.8%) and stress level (SMD: -1.75; 95% CI: -2.29, -1.22; p = .005; I2  = 83.1%) compared to the placebo. Additionally, the non-linear dose-response analysis indicated a favorable effect of Ashwagandha supplementation on anxiety until 12,000 mg/d and stress at dose of 300-600 mg/d. Finally, we identified that the certainty of the evidence was low for both outcomes. The current systematic review and dose-response meta-analysis of RCTs revealed a beneficial effect in both stress and anxiety following Ashwagandha supplementation. However, further high-quality studies are needed to firmly establish the clinical efficacy of the plant.

The effects of Anethum graveolens (dill) supplementation on lipid profile and glycemic control: a systematic review and meta-analysis of randomized controlled trials.

There is an increased interest in the potential health benefits of nutraceutical therapies, such as Anethum graveolens (dill). Therefore, this systematic review and meta-analysis aimed to evaluate the effects of Anethum graveolens supplementation on lipid profiles and glycemic indices in adults. A systematic search was performed for literature published through November 2020 via PubMed/Medline, Scopus, ISI Web of Science, and Embase to find randomized controlled trials (RCTs) evaluating the effects of oral supplementation with A. graveolens on lipid profile and measures of glycemic control in adults. The random-effects model was applied to establish the weighted mean difference (WMD) and associated 95% confidence intervals (CI). Seven RCTs with a total number of 330 subjects were included in the final analysis. Pooled results indicated that A. graveolens supplementation significantly decreased low-density lipoprotein cholesterol (LDL) concentration (WMD: -15.64 mg/dL; 95% CI: -24.55 to -6.73; P = 0.001), serum insulin (WMD: -2.28 µU/ml; 95% CI: -3.62 to -0.93; P = 0.001), and HOMA-IR (WMD: -1.06; 95% CI: -1.91 to -0.20; P = 0.01). However, there was no significant effect on serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL), and fasting blood glucose (FBS). Subgroup analysis suggested that using A. graveolens in higher doses and long-term duration had beneficial effects on lipid profiles. Dose-response analysis also showed a significant reduction in FBS at doses of 1500 mg/d. The present meta-analysis indicated that Anethum graveolens could exert favorable effects on insulin resistance and serum LDL. Further research is necessary to confirm our findings.

What is the influence of cinnamon supplementation on liver enzymes? A systematic review and meta-analysis of randomized controlled trials.

Existing evidence has uncovered the potential health benefits of cinnamon intake; however, its effect on liver function is unclear. Thus, the aim of this systematic review and meta-analysis was to examine the effect of cinnamon supplementation on liver enzymes. Relevant articles were identified through a systematic search in PubMed/Medline, Scopus, Web of Science, Cochrane Library, and Embase up to September 2020. All trials assessing the effect of oral cinnamon supplementation on serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) in adults were included. The pooled effect sizes were obtained using the random-effects model and expressed as mean difference (MD) and 95% confidence intervals (CI). A total of seven original trials (nine treatment arms) involving a total of 256 subjects were included in the final analysis. The pooled analysis indicated that cinnamon supplementation had no significant effect on serum levels of ALT, AST, and ALP. However, there was a significant reduction in ALT levels in patients with type 2 diabetes (MD: -4.01 U/L; 95% CI: -6.86, -1.15) and in trials with low-dose supplementation (<1,500 mg/d), follow-up duration longer than 12 weeks, and in the elderly patients (aged>50 years). The beneficial effects of cinnamon intake were also shown in AST levels in patients with type 2 diabetes and trials with long-term follow-up (>12 weeks). Longer-term, oral cinnamon supplementation may improve serum levels of liver enzymes in patients with type 2 diabetes. Further high-quality studies are needed, especially in populations with abnormal liver enzyme levels, to firmly establish the clinical efficacy of cinnamon on liver function.