Effect of vitamin D supplementation or fortification on bone turnover markers in women: a systematic review and meta-analysis.

Vitamin D is a vital indicator of musculoskeletal health, as it plays an important role through the regulation of bone and mineral metabolism. This meta-analysis was performed to investigate the effects of vitamin D supplementation/fortification on bone turnover markers in women. All human randomised clinical trials reported changes in bone resorption markers (serum C-terminal telopeptide of type-I collagen (sCTX) and urinary type I collagen cross-linked N-telopeptide (uNTX)) or bone formation factors (osteocalcin (OC), bone alkaline phosphatase (BALP) and procollagen type-1 intact N-terminal propeptide (P1NP)) following vitamin D administration in women (aged ≥ 18 years) were considered. Mean differences (MD) and their respective 95 % CI were calculated based on fixed or random effects models according to the heterogeneity status. Subgroup analyses, meta-regression models, sensitivity analysis, risk of bias, publication bias and the quality of the included studies were also evaluated. We found that vitamin D supplementation had considerable effect on sCTX (MD: -0·038, n 22) and OC (MD: -0·610, n 24) with high heterogeneity and uNTX (MD: -8·188, n 6) without heterogeneity. Our results showed that age, sample size, dose, duration, baseline vitamin D level, study region and quality of studies might be sources of heterogeneity in this meta-analysis. Subgroup analysis also revealed significant reductions in P1NP level in dose less than 600 µg/d and larger study sample size (>100 participants). Moreover, no significant change was found in BALP level. Vitamin D supplementation/fortification significantly reduced bone resorption markers in women. However, results were inconsistent for bone formation markers.

Onion supplementation and health metabolic parameters: A systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Functional foods, such as onions, have been the center of many recent investigations. In this systematic-review and meta-analysis, we aimed to gather up the existing information with regard to the impact of onion supplementation on anthropometric measurements/indices, lipid profile, indices of glycemic control and hepatic health, systolic and diastolic blood pressures (SBP and DBP), and adiponectin and leptin. METHODS: All major online datasets (PubMed, Web of Science, Cochrane, and Scopus) were thoroughly searched from inception up to October 2022. Relevant randomized controlled trials (RCTs) were obtained using the eligibility criteria. Weighted mean differences (WMDs) were calculated and reported. Statistical significance was set as p-values <0.05. RESULTS: Among all the retrieved data, 14 RCTs were eligible to be included. The results of the crude analysis showed that onion supplementation significantly improved body fat percentage (BFP), low-density lipoprotein-cholesterol (LDL-c), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-c), systolic blood pressure, adiponectin, and aspartate aminotransferase (AST). Subgroup analysis revealed that interventions lasting more than 12 weeks can significantly alter weight, waist circumference (WC), body mass index (BMI), BFP, LDL-c, TC, SBP, and DBP. Moreover, the intake of dosages of >300 mg/day of onion supplementation could significantly improve weight, WC, BMI, BFP, LDL-c, HDL-C, TC, AST, ALT, SBP and DBP. CONCLUSION: It seems that the intake of onion supplementation can improve health metabolic parameters. We observed that with either longer follow-up periods or higher dosages of onion supplementation, improvements in cardio-metabolic parameters could be expected.

The relationship between the intake of dietary fatty acids and minerals with sperm parameters in infertile men.

BACKGROUND & AIMS: Infertility has been increasing among Iranian couples. Some epidemiological studies have reported a relationship between infertility and lifestyle patterns, including dietary habits. Our objective was to evaluate the relationship between sperm parameters and the intake of dietary fatty acids and minerals among Iranian infertile men. METHODS: This cross-sectional was performed on 400 newly diagnosed infertile men at Yazd Reproductive Sciences Institute from July to December 2019. Men whose infertility was confirmed by an andrologist based on the World Health Organization (WHO) criteria were selected. They delivered a semen sample and answered a 168-item semi-quantitative food frequency questionnaire. All data were analyzed using SPSS and STATA software. A p-value of less than 0.5 was considered significant. RESULTS: In the adjusted model, a significant negative association between sperm motility and the 3rd quartile (Q) of poly-unsaturated fatty acids compared to the 1st quartile) P = 0.02). Also, in the adjusted model, total mobility was significantly increased in the second, third and last quartiles of omega-3 fatty acids compared to the first quartile (P < 0.001, P = 0.02, P < 0.001, respectively). Furthermore, omega-6 fatty acid intake in the last quartile were positively associated with sperm motility (P = 0.01). Moreover, there was a significant association between omega-3 fatty acid intake in the second, third, and last quartiles and sperm normal morphology (P = 0.003, P = 0.018, and P = 0.005, respectively) compared with the first quartile. Further, we observed a significant association between omega-6 fatty acid intake and sperm normal morphology in the last quartile compared with the reference quartile (P = 0.04). Also, the findings showed a significant negative association between the second quartile of sodium and calcium intake and sperm volume compared with the first quartile (P = 0.04, for both) in the adjusted model. CONCLUSIONS: We concluded that dietary polyunsaturated fatty acid, sodium, and calcium intake are related to sperm morphology, volume, and total motility in Iranian infertile men. However, more research is needed to confirm these relationships and provide evidence to exert these findings into clinical practice.

Effects of curcumin/turmeric supplementation on glycemic indices in adults: A grade-assessed systematic review and dose-response meta-analysis of randomized controlled trials.

INTRODUCTION: Glycemic control is of utmost importance both as a preventive measure in individuals at risk of diabetes and in the management of patients with disturbed glycemia. Turmeric/curcumin has been extensively studied in this field. In the present systematic review and meta-analysis, we aimed at investigating the impact of turmeric/curcumin supplementation on glycemic control. METHODS: Major online databases (PubMed, Scopus, Web of Science, Cochrane Library and Google Scholar) were systematically searched from inception up to October 2022. Relevant randomized controlled trials (RCTs) meeting our eligible criteria were included. Weighted mean differences (WMDs) with confidence intervals (CIs) were expressed using a random-effect model. Subgroup analyses were conducted to find the sources of heterogeneities. To detect risk of bias in the included studies, we used the Cochrane risk-of-bias tool. The registration number was CRD42022374874. RESULTS: Out of 4182 articles retrieved from the initial search, 59 RCTs were included. Our findings suggested that turmeric/curcumin supplementation was significantly effective in improving fasting blood sugar (WMD: 4.60 mg/dl; 95% CI: 5.55, -3.66), fasting insulin levels (WMD: 0.87 µIU/ml; 95% CI: 1.46, -0.27), hemoglobin A1c (HbA1c) (WMD: 0.32%; 95% CI: 0.45, -0.19), and homeostatic model assessment of insulin resistance (HOMA-IR) (WMD: 0.33; 95% CI: 0.43, -0.22). CONCLUSION: Our results indicate that turmeric/curcumin supplementation can be considered as a complementary method in the management of disturbed glycemia.

Effects of curcumin/turmeric supplementation on obesity indices and adipokines in adults: A grade-assessed systematic review and dose-response meta-analysis of randomized controlled trials.

In the present study, we explored the effect of curcumin/turmeric supplementation on anthropometric indices of obesity, leptin, and adiponectin. We searched PubMed, Scopus, Web of Science, Cochrane Library, and Google Scholar up to August 2022. Randomized clinical trials (RCTs) investigating the impact of curcumin/turmeric on obesity indices and adipokines were included. We applied the Cochrane quality assessment tool to evaluate the risk of bias. The registration number is CRD42022350946. Sixty eligible RCTs, with a total sample size of 3691 individuals were included for quantitative analysis. We found that supplementation with curcumin/turmeric significantly reduced body weight (WMD: -0.82 kg, 95% CI: -1.30, -0.35; p = 0.001), body mass index (WMD: -0.30 kg/m2 , 95% CI: -0.53, -0.06, p = 0.013), waist circumference (WMD: -1.31 cm, 95% CI: -1.94, -0.69, p < 0.001), body fat percentage (WMD: -0.88%, 95% CI: -1.51, -0.25, p = 0.007), leptin (WMD = -4.46 ng/mL; 95% CI: -6.70, -2.21, p < 0.001), and increased adiponectin (WMD = 2.48 µg/mL; 95% CI: 1.34, 3.62, p < 0.001). Overall, our study shows that supplementation with curcumin/turmeric significantly improves anthropometric indices of obesity and adiposity-related adipokines (leptin and adiponectin). However, due to high between-studies heterogeneity, we should interpret the results with caution.

Antioxidant and anti-inflammatory effects of curcumin/turmeric supplementation in adults: A GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials.

Turmeric and its prominent bioactive compound, curcumin, have been the subject of many investigations with regard to their impact on inflammatory and oxidative balance in the body. In this systematic review and meta-analysis, we summarized the existing literature on randomized controlled trials (RCTs) which examined this hypothesis. Major databases (PubMed, Scopus, Web of Science, Cochrane Library and Google Scholar) were searched from inception up to October 2022. Relevant studies meeting our eligibility criteria were obtained. Main outcomes included inflammatory markers (i.e. C-reactive protein(CRP), tumour necrosis factorα(TNF-α), interleukin-6(IL-6), and interleukin 1 beta(IL-1ß)) and markers of oxidative stress (i.e. total antioxidant capacity (TAC), malondialdehyde(MDA), and superoxide dismutase (SOD) activity). Weighted mean differences (WMDs) were reported. P-values < 0.05 were considered significant. Sixty-six RCTs were included in the final analysis. We observed that turmeric/curcumin supplementation significantly reduces levels of inflammatory markers, including CRP (WMD: -0.58 mg/l, 95 % CI: -0.74, -0.41), TNF-α (WMD: -3.48 pg/ml, 95 % CI: -4.38, -2.58), and IL-6 (WMD: -1.31 pg/ml, 95 % CI: -1.58, -0.67); except for IL-1ß (WMD: -0.46 pg/ml, 95 % CI: -1.18, 0.27) for which no significant change was found. Also, turmeric/curcumin supplementation significantly improved anti-oxidant activity through enhancing TAC (WMD = 0.21 mmol/l; 95 % CI: 0.08, 0.33), reducing MDA levels (WMD = -0.33 µmol /l; 95 % CI: -0.53, -0.12), and SOD activity (WMD = 20.51 u/l; 95 % CI: 7.35, 33.67). It seems that turmeric/curcumin supplementation might be used as a viable intervention for improving inflammatory/oxidative status of individuals.

Systematic review and meta-analysis of randomized, controlled trials on the effects of soy and soy products supplementation on serum adiponectin levels.

BACKGROUND AND AIMS: Our aim in this meta-analysis was to determine the effect of soy and soy product supplementation on serum adiponectin levels. METHOD: A systematic search was conducted using Medline (PubMed and Web of Science), Scopus, and Cochrane Library for eligible trials up to August 2020. A random-effects model was used to pool calculated effect sizes. RESULTS: Seven trials were included in the overall analysis. Our analysis showed that soy and soy product supplementation did not significantly affect adiponectin concentrations (WMD = -0.77 µg/ml, 95% CI: -0.61, 2.15, P = 0.27) in comparison with a placebo. The between-study heterogeneity was high (I2: 68.2%, P = 0.004). Subgroup analysis, based on participants' health status and duration of the supplementation, could not detect the potential source of the observed heterogeneity. In addition, subgroup analysis showed that the effect was not statistically significant in all subgroups. CONCLUSION: Overall, soy and soy product supplementation did not change the circulatory adiponectin levels. In addition, the results were not affected by the participant's health status and duration of supplementation. However, further studies are needed to confirm the present results.

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

OBJECTIVE: This systematic review and meta-analysis were aimed to determine the effects of grape products on liver enzymes in adults. METHODS: Databases including PubMed/Medline, Cochrane Library, ISI Web of Science, and Scopus were searched up to February 2021. Randomized clinical trials (RCTs) investigating the effect of grape products on serum concentrations of liver enzymes were included. Data were pooled using the random-effects model and weighted mean difference (WMD) was considered as the summary effect size. RESULTS: Eight RCTs enrolling 291 participants met the inclusion criteria for this meta-analysis. The overall effect illustrated no significant change in serum levels of alanine aminotransferase (ALT) (WMD: - 2.04; 95 % CI: - 5.50 to 1.42; P = 0.24; I2 = 72.5 %), and aspartate aminotransferase (AST) (WMD: - 1.40; 95 % CI: - 3.80 to 0.99; P = 0.25; I2 = 76.0 %) in intervention group compared with the control group. Subgroup analyses revealed that the effect of grape products on ALT (WMD: - 4.97; 95 % CI: - 8.73 to - 1.21; P = 0.01) and AST (WMD: - 2.89; 95 % CI: - 5.69 to - 0.08; P = 0.04) levels was significant when the intervention period was equal or more than 12 weeks. CONCLUSION: Overall, grape products had no significant effect on liver enzymes in adults. However, due to the low number of included studies, these findings must be interpreted with great caution. Larger, well-designed RCTs are still needed to further evaluate the capacity of the grape products as a complementary treatment to improve liver enzymes.

Antihypertensive and antihyperlipemic of spirulina (Arthrospira platensis) sauce on patients with hypertension: A randomized triple-blind placebo-controlled clinical trial.

Systemic arterial hypertension is an independent risk factor for coronary heart disease, stroke, heart failure, and chronic kidney diseases. Spirulina is microalgae with nutritious ingredients and has potential attenuating effects on chronic diseases including hypertension. Spirulina can be added to food products in order to develop functional foods. The aim of this study was to assess the effects of 8-week consumption of a salad dressing containing 2 g of spirulina platensis powder versus a placebo dressing on patients with hypertension. In this triple-blind randomized clinical trial, 48 patients with hypertension were enrolled to receive daily either spirulina-fortified dressing or placebo for 2 months. A total of 41 patients completed this study. We observed that the consumption of spirulina dressing significantly reduced systolic blood pressure (p = .02), diastolic blood pressure (p = .03), serum triglyceride (p = .01), total cholesterol, and low-density lipoprotein (LDL) levels, compared to nonsignificant changes in the placebo group. Significant changes in TAC and hs-CRP levels were observed in none of the groups. According to our findings, spirulina-fortified dressing as a functional food can be used a supportive treatment for patients with hypertension along with standard antihypertensive drugs. However, further investigations are required for a more comprehensive conclusion.

The effect of sumac (Rhus coriaria L.) supplementation on glycemic indices: A systematic review and meta-analysis of controlled clinical trials.

BACKGROUND & AIMS: Rhus coriaria L. (Sumac) is a popular spice/herb with several biological functions owing to its antioxidant and insulin-like activities. Many clinical trials have indicated the potent anti-diabetic property of sumac but the results on few glycemic indices were inconclusive. Hence, this systematic review and meta-analysis were aimed to investigate sumac supplementation effect on glycemic indices. METHODS: Systematically searched was performed by two independent reviewers using online databases including: PubMed, Scopus, web of science, EMBASE from inception until November 2020. Data were pooled using a random-effects model and weighted mean difference (WMD) with 95 % confidence intervals (CI). RESULTS: A total of 6 potentially relevant clinical trials met the inclusion criteria with total of 278 participants. Random-effects meta-analysis suggested no significant effects on the levels of fasting blood glucose [-7.08 mg/dl, 95 % CI: -14.85 to 0.70,P = 0.07, I2 = 59.8 %], glycosylated hemoglobin (HbA1c) [-0.48 %, 95 % CI: -1.01 to -0.04, P = 0.07, I2 = 0.0 %], homeostatic model assessment for insulin resistance (HOMA-IR) [-0.97, 95 % CI: -1.96 to 0.02, P = 0.05, I2 = 83.8 %], and insulin [-2.94 Hedges' g, 95 % CI: -6.67 to 0.80, P = 0.12, I2 = 83.1 %] following supplementation with sumac powder. CONCLUSION: This meta-analysis showed no significant effects on any glycemic indices following supplementation with sumac powder.

Sugar consumption, sugar sweetened beverages and Attention Deficit Hyperactivity Disorder: A systematic review and meta-analysis.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is a significant neurobehavioral disorder in children and adolescence which may be affected by diet. OBJECTIVE: To evaluate the possible relationship between sugar consumption and the development of symptoms of ADHD. METHODS: In March 2020, an exhaustive systematic literature search was conducted using Google Scholar, PubMed, and Scopus. In this meta-analysis of observational studies, odds ratios, relative risks, hazard ratios, and their 95% confidence intervals, which was reported for ADHD regarding SSBS, soft drink consumption, and dietary sugars, were used to calculate ORs and standard errors. At first, a fixed-effects model was used to drive the overall effect sizes using log ORs and SEs. If there was any significant between-studies heterogeneity, the random-effects model was conducted. Cochran's Q test and I2 were used to measure potential sources of heterogeneity across studies. The Newcastle-Ottawa scale was used to assess the quality of the included articles. RESULTS: Seven studies, two cross-sectional, two case-control, and three prospective with a total of 25,945 individuals were eligible to include in the current meta-analysis. The association between sugar and soft drink consumption and the risk of ADHD symptoms were provided based on the random-effects model (pooled effect size: 1.22, 95%CI: 1.04-1.42, P = 0.01) (I² = 81.9%, P heterogeneity< 0.0001). CONCLUSION: This meta-analysis indicated a positive relationship between overall sugar and sugar-sweetened beverages consumption and symptoms of ADHD; however, there was heterogeneity among included studies. Future well-designed studies that can account for confounds are necessary to confirm the effect of sugar on ADHD.

The effects of lycopene supplement on the spermatogram and seminal oxidative stress in infertile men: A randomized, double-blind, placebo-controlled clinical trial.

Infertility is a major, worldwide problem that is affected, and mediated, by several factors, in particular, oxidative stress. Thus, the aim of this study was to evaluate the effect of lycopene supplementation on spermatogram and seminal oxidative stress. In this randomized, double-blind, placebo-controlled trial study, 44 infertile men with oligozoospermia were randomly divided into two groups: The experimental group was supplemented with 25 mg of lycopene, and the control group received placebo for 12 weeks. Anthropometric, physical activity and dietary assessment, semen analysis, total antioxidant capacity (TAC), malondialdehyde, and glutathione peroxidase were measured pre- and post-intervention. At the end of the study, there was a significant increase in total sperm count and concentration in the lycopene group, and the latter total count remained significant after adjustment (p < .05). Intragroup analysis showed a significant increase in ejaculate volume, total sperm count, concentration total motility, nonprogressive, and nonmotility in lycopene group (p < .05). The TAC changes, in both groups, remained significant after adjustment (p < .05). Also, within-group analysis showed a significant increase in TAC levels (p < .05). Lycopene supplement can improve sperm parameters and oxidative stress biomarkers in oligozoospermia infertile men; however, further studies with larger sample size and duration are required.

Effect of Nigella sativa (black seed) supplementation on glycemic control: A systematic review and meta-analysis of clinical trials.

This study was aimed to quantify the antihyperglycemic effect of Nigella sativa (N. sativa). An in-depth search to identify clinical trials investigating the impact of N. sativa on glycemic indices via MEDLINE, EMBASE, Scopus, Web of Science, Cochrane Library, and Google scholar databases were performed up to November 2018. We used a random effects model to estimate pooled effect size of fasting plasma glucose (FPG), postprandial blood glucose (PPBG), and hemoglobin A1c (HbA1c). A total of 17 randomized controlled trials investigating the effects of N. sativa on FPG, PPBG, and HbA1c were included. Meta-analysis suggested a significant association between N. sativa supplementation and reduction in FPG (weighted mean difference [WMD]: -9.93 mg/dl, 95% CI [-13.44, -6.41]), PPBG (WMD: -14.79 mg/dl, 95% CI [-24.19, -5.39]), and HbA1c (WMD: -0.57%, 95% CI [-0.77, -0.37]). Subgroup analysis revealed that N. sativa oil was more effective than N. sativa powder in reduction of FPG. To sum up, N. sativa consumption has a significant lowering effect on glycemic status. Further studies with prolonged durations and powerful design are needed to specify the exact mechanism, optimal dosage, and duration of N. sativa supplementation to obtain a beneficial effect on glycemic status.