Effects of curcumin on blood pressure: A systematic review and dose-response meta-analysis.

AIMS: This systematic review and dose-response meta-analysis were conducted to summarize data from available clinical trials on the effects of curcumin supplementation on systolic BP (SBP) and diastolic BP (DBP). DATA SYNTHESIS: Using related keywords, multiple databases, including the Web of Sciences, Scopus, Embase, PubMed, Cochrane Library, and Google Scholar, were searched until November 2022. We chose the studies that examined the effects of curcumin on systolic blood pressure (SBP) and diastolic blood pressure (DBP). Seventeen eligible studies with a total sample size of 1377 participants were included in the meta-analysis. The findings of the meta-analysis did not indicate any significant effect of curcumin on SBP (WMD = -0.06 mmHg, 95% CI: -0.62, 0.50, p = 0.85; I2 = 44.2%) and DBP (WMD = -0.18 mmHg, 95% CI: -1.17, 0.82, p = 0.62; I2 = 77.2%). Moreover, in our dose-response analysis, we found that the dose and duration of curcumin supplementation were non-significantly associated with the reduction of SBP and DBP. However, subgroup analysis revealed a significant reduction only in DBP levels (WMD: -0.76 mmHg, 95% CI: -1.46,-0.05; P = 0.03) but not in SBP in studies with ≥12-week supplementation. Also, a significant reduction in SBP (WMD: -1.55 mmHg, 95% CI: -2.85, -0.25; P = 0.01) and DBP (WMD: -1.73 mmHg, 95% CI: 2.67, -0.79; P < 0.01) was noticed by curcumin supplementation in studies performed on women. CONCLUSIONS: The current study suggests that consuming curcumin may improve DBP when administered for long durations ≥12 weeks. However, more trials are required to confirm these findings.

The effects of whey protein on blood pressure: A systematic review and dose-response meta-analysis of randomized controlled trials.

AIMS: This systematic review and dose-response meta-analysis was conducted to summarize data from available clinical trials on the effects of whey protein (WP) supplementation on blood pressure (BP) in adults. DATA SYNTHESIS: A comprehensive literature search was conducted in the electronic databases PubMed, Web of Science, ProQuest, Embase, and SCOPUS from inception to October 2022. Weighted mean differences (WMD) and 95% confidence intervals (CI) were calculated to assess pooled effect sizes. Heterogeneity between studies was assessed using the Cochran's Q test and I2. Subgroup analysis was performed to assess potential sources of heterogeneity. The dose-response relationship was assessed using fractional polynomial modeling. Of the 2,840 records, 18 studies with 1,177 subjects were included. Pooled analysis showed that whey protein supplementation resulted in a significant reduction in systolic blood pressure (WMD: -1.54 mmHg; 95% CI: -2.85 to -0.23, p = 0.021), with significant heterogeneity between studies (I2 = 64.2%, p < 0.001), but not for diastolic blood pressure (DBP) (WMD: -0.27 mmHg; 95% CI: -1.14, 0.59, p = 0.534) with high heterogeneity between studies (I2 = 64.8%, p < 0.001). However, WP supplementation significantly reduced DBP at a dose of ˃30 g/day, in RCTs that used WP isolate powder for their intervention, in sample sizes ≤100, in studies with an intervention duration of ≤10 weeks, and in those studies that were conducted in patients with hypertension and had participants with a BMI of 25-30 kg/m2. CONCLUSION: This meta-analysis demonstrated that WP intake significantly reduced SBP levels. Further large-scale studies are needed to specify the exact mechanism, and optimal dosage of WP supplementation to obtain a beneficial effect on BP.

The Possible Mediatory Role of Inflammatory Markers on the Association of Dietary Insulin Index and Insulin Load with Metabolic Syndrome in Women with Overweight and Obesity: A Cross-Sectional Study.

Background: Metabolic syndrome (MetS) is associated with increased inflammation. Diet plays an important role in the prevention and management of MetS, while some dietary factors can also increase or decrease markers of systemic inflammation. In this study, we aimed to determine the mediated association of inflammatory markers induced by dietary insulin index (DII) and dietary insulin load (DIL) with MetS and its components. Methods: This cross-sectional study was conducted with 219 women aged 18-28 years. Dietary intake was assessed by a 147-item food frequency questionnaire (FFQ). DII and DIL were calculated using the standard formula. The guidelines of the National Cholesterol Education Program's Adult Treatment Panel III were used to define MetS. Biochemical parameters and anthropometric and blood pressure measures were evaluated by standard protocols. Results: After the adjustment for potential confounders, a marginally significant association was found between DII and MetS (OR = 2.11; 95% CI = 0.93-4.82; P = 0.06). However, we did not find a significant association between DIL and MetS. Furthermore, DII was significantly associated with waist circumference (WC) (OR = 1.67; 95% CI = 1.09- 4.03; P = 0.03) and marginally associated with triglyceride (TG) (OR = 1.10; 95% CI = 0.92-2.33; P = 0.07) and systolic blood pressure/diastolic blood pressure (SBP/DBP) (OR = 1.84; 95% CI = 0.85-3.99; P = 0.07). Moreover, there was a significant association between DIL and SBP/DBP (OR = 1.74; 95% CI = 1.54-5.61; P = 0.04). Also, we found that MCP-1 may have a mediatory role in the association between DII and DIL with MetS and several components of MetS. Hs-CRP did not have mediatory role in the association between DII and MetS. However, hs-CRP had a mediatory role in several MetS components. Furthermore, hs-CRP may have a mediatory role in the association of DIL with MetS and with some of its components. Conclusions: A higher DII score may increase the odds of MetS and its components. DIL was not significantly associated with the odds of MetS, but the association of DIL and SBP/DBP was significant. MCP-1 may have a mediatory role in associations between DII and DIL with MetS. In addition, hs-CRP may have a mediatory role in the association between DIL and MetS.

The association between dietary polyphenol intake and attention-deficit hyperactivity disorder: a case-control study.

BACKGROUND: Previous research found that diets high in fruits and vegetables improved symptoms of attention deficit hyperactivity disorder (ADHD). Nevertheless, the relationship between dietary polyphenol intake and the risk of ADHD was not assessed. OBJECTIVE: The purpose of this study was to see if there was a relationship between dietary polyphenol intake and the risk of ADHD in children in preschool and elementary school. METHODS: A total of 400 children aged 4 to 12 years old participated in this case-control research (200 children with diagnosed ADHD and 200 healthy controls). The presence of ADHD was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders-V criteria. To calculate dietary polyphenol intake, a 168-item food frequency questionnaire and the Phenol-Explorer database were used. RESULTS: A significant negative association was observed between one unit increase in dietary polyphenol intake and risk of ADHD (OR: 0.995, 95% CI = 0.994 to 0.996, P < 0.001) in the crude model. This finding was still significant even after adjusting for body mass index, energy intake, socioeconomic status, gender, and age (OR: 0.992, 95% CI = 0.989 to 0.995, P < 0.001). CONCLUSION: We found that the increased dietary intake of polyphenols is associated with a lower risk of ADHD in preschool and school children. Prospective studies are needed to corroborate these observations.

A systematic review, meta-analysis, dose-response, and meta-regression of the effects of acarbose intake on glycemic markers in adults.

Purpose: Prior research has yielded mixed results regarding the impact of acarbose intake on glycemic markers. To provide a more comprehensive analysis, a systematic review and meta-analysis was performed to compile data from various randomized controlled trials (RCTs) examining the effects of acarbose intake on fasting blood sugar (FBS), insulin, hemoglobin A1C (HbA1c), and homeostasis model assessment of insulin resistance (HOMA-IR) in adults. Methods: To identify relevant literature up to April 2023, a comprehensive search was conducted on various scholarly databases, including PubMed, Web of Science, and Scopus databases. The effect size of the studies was evaluated using a random-effects model to calculate the weighted mean differences (WMD) and 95% confidence intervals (CI). Heterogeneity between studies was assessed using Cochran's Q test and I2. Results: This systematic review and meta-analysis included a total of 101 RCTs with a total of 107 effect sizes. The effect sizes for FBS in milligrams per deciliter (mg/dl), insulin in picomoles per liter (pmol/l), hemoglobin A1C (HbA1c) in percentage (%), and homeostasis model assessment of insulin resistance (HOMA-IR) were 92, 46, 80, and 22, respectively. The pooled analysis indicated that acarbose intake resulted in significant decreases in FBS (p = 0.018), insulin (p < 0.001), HbA1c (p < 0.001), and HOMA-IR (p < 0.001). Conclusion: The findings of this systematic review and meta-analysis suggest that acarbose intake can potentially lead to significant improvements in glycemic parameters by decreasing the levels of FBS, HbA1c, and insulin. However, larger and more rigorously designed studies are still needed to further evaluate and strengthen this association.

The association between plant and animal protein intake and quality of life in patients undergoing hemodialysis.

Background: Hemodialysis (HD) patients often experience a significant reduction in quality of life (QOL). The source of dietary protein intake may influence the renal function and complications of HD patients. The present study assessed the relationship between plant and animal protein intake and QOL in HD patients. Methods: 264 adult patients under dialysis for at least three months were included in this cross-sectional study. Dietary intakes were collected using a valid and reliable 168-item semi-quantitative food frequency questionnaire (FFQ) over the past year. Total, animal, and plant proteins were calculated for each patient. To evaluate QOL, Kidney Disease Quality of Life Short Form (KDQOL-SF 1/3) was used. Anthropometric measures were assessed according to standard protocols. Results: In this study, the average age of participants was 58.62 ± 15.26 years old; most (73.5%) were men. The mean of total, plant, and animal proteins intake were 66.40 ± 34.29 g/d, 34.60 ± 18.24 g/d, and 31.80 ± 22.21 g/d. Furthermore, the mean score of QOL was 59.29 ± 18.68. After adjustment for potential confounders, a significant positive association was found between total dietary protein intake and QOL (ß = 0.12; p = 0.03). Moreover, there was a significant association between plant-based protein intake and QOL (ß = 0.26; p < 0.001). However, the association between animal protein intake and QOL was insignificant (ß = 0.03; p = 0.60). Conclusion: Higher total and plant proteins intake were associated with better QOL in HD patients. Further studies, particularly prospective ones, are needed to corroborate these associations.

The effects of royal jelly supplementation on anthropometric indices: a GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials.

Inconsistent data are available about the effect of royal jelly supplementation on anthropometric indices in humans. This systematic review and meta-analysis was done to summarize data from available randomized controlled trials (RCTs) on the effect of royal jelly supplementation on anthropometric indices such as body weight (BW), body mass index (BMI), and fat mass (FM) in adults. We systematically searched Embase, PubMed, Web of Science, and Scopus databases up to March 2023. All RCTs assessing the effect of royal jelly on anthropometric indices were included. Data were pooled using the random-effects method and were expressed as weighted mean difference (WMD) and 95% confidence intervals (CIs). Sensitivity and subgroup analyses were also performed. Out of 1,492 records, 10 studies that enrolled 512 participants were included. There was no significant effect on BW (WMD: -0.29 kg, 95% CI: -1.24, 0.65, p = 0.543), BMI (WMD: 0.11 kg/m2, 95% CI: -0.29, 0.52, p = 0.583), and FM (WMD: 0.02%, 95% CI: -0.41, 0.46, p = 0.84). However, we observed a reduction in BW and BMI following royal jelly intake in subgroup of royal jelly dosage <3,000 mg/day. Although the royal jelly supplementation significantly reduced BW and BMI at the dosages <3,000 mg/day, until additional trials have been conducted to assess the effects on obesity measures, it is best to prescribe royal jelly with caution.