The association between dietary patterns and metabolic syndrome among Iranian adults, a cross-sectional population-based study (findings from Bandare-Kong non-communicable disease cohort study).

BACKGROUND: Metabolic syndrome is a cluster of metabolic disorders increasing the risk of cardiovascular disease and diabetes. Dietary patterns are supposed to be important and controllable factors in developing metabolic syndrome. The purpose of this study was to investigate the association of dietary patterns with metabolic syndrome and its components. SUBJECTS/METHODS: Cross-sectional data were extracted from the Bandare-Kong cohort study conducted on 4063 people aged 35 to 70. Dietary patterns were extracted using principal component analysis based on thirty-eight pre-defined food groups. Multivariable logistic regression was conducted to investigate the association between metabolic syndrome and its components with quintiles of dietary patterns in crude and adjusted models. RESULTS: Three major dietary patterns were identified (healthy, western, and traditional) in the final analysis of 2823 eligible individuals. After adjusting for covariates, the odds of metabolic syndrome were significantly decreased by 46% in subjects with the highest adherence to the healthy dietary pattern compared to those with the lowest adherence quintile. Results from fully adjusted models on individual metabolic syndrome components showed an inverse association between higher adherence to the healthy dietary pattern and the odds of increased blood glucose, high waist circumference, and elevated blood pressure. However, in fully adjusted models, no significant association was observed between the western and traditional dietary patterns with odds of metabolic syndrome and its components. CONCLUSIONS: Adherence to a healthy dietary pattern containing high amounts of fruits, vegetables, nuts, low-fat dairy products, and legumes, could be recommended to prevent and control metabolic syndrome.

The effect of vitamin D and magnesium supplementation on clinical symptoms and serum inflammatory and oxidative stress markers in patients with COVID-19: a structured summary of a study protocol for a randomized controlled trial.

OBJECTIVES: This study aims to evaluate the effect of vitamin D and magnesium supplementation on clinical symptoms and serum inflammatory and oxidative stress markers in patients with COVID-19. TRIAL DESIGN: This study is a 4-arm randomized, double-blind, placebo-controlled clinical trial with a factorial design and the intervention period is 3 weeks. PARTICIPANTS: This study is conducted on COVID-19 patients admitted to the Shahid Mohammadi hospital in Bandar Abbas, Iran, who are eligible for inclusion in the study. Patients are included only if they meet all of the following criteria: (1) aged from 18 to 65 years old; (2) confirmation of COVID-19 by RT-PCR test; (3) completing informed consent; (4) passing less than 48 h since the patient's hospitalization; (5) no skin or gastrointestinal allergies due to taking multivitamin supplements, vitamin D, and magnesium; and (6) having more than 30 breaths per minute and less than 93% oxygen saturation in room air and sea level. Patients are excluded if they have any of the following conditions: (1) pregnancy or lactation; (2) taking a daily multivitamin or take a vitamin D or magnesium supplement in the last month; (3) participating in other clinical trials; (4) renal failure or dialysis, severe liver disease or cirrhosis; (5) known diagnosis of hypercalcemia; (6) discharging from the hospital less than 24 h after the start of the intervention; (7) history of kidney stones in the last year; (8) transfer the patient to the ICU; (9) baseline vitamin D levels above 80 ng/ml; (10) baseline magnesium levels above 2.6 mg/dl; and (11) unwillingness of the patient to continue the study. INTERVENTION AND COMPARATOR: Participants will be randomly allocated to one of the four following groups: (A) vitamin D (two 50,000 IU capsules at the beginning of the study, two 50,000 IU capsules on the 4th day, one 50,000 IU capsule on the 11th day, and one 50,000 IU capsule on the 17th day) and magnesium supplement (300 mg/day); (B) vitamin D capsule and magnesium placebo; (C) magnesium supplement and vitamin D placebo; and (D) vitamin D placebo and magnesium placebo. MAIN OUTCOMES: The resolution of clinical symptoms (fever, dry cough, shortness of breath, headache, myalgia, oxygen saturation, and mortality rate) and interpretation of laboratory assays (CRP, MDA, TAC, WBC, neutrophils count, lymphocytes count, ratio of neutrophils to lymphocytes, levels of 25 hydroxyvitamin D and magnesium) will be assessed in the study groups. RANDOMIZATION: A computer-generated block randomization list is used for randomization. BLINDING (MASKING): Investigators and patients are blinded to group allocation and treatment. A double-blind design is achieved using matched placebos. NUMBERS TO BE RANDOMIZED (SAMPLE SIZE): A total of 104 eligible patients are randomized into four groups of 26 subjects (1:1:1:1 allocation ratio). DISCUSSION: With the rapid prevalence of COVID-19 in recent years, more attention has been paid to effective dietary supplementation to improve clinical symptoms and biochemical parameters in these patients. To our knowledge, this is the first study to evaluate the effects of vitamin D supplementation in combination with magnesium or alone with respect to this infectious disease. The findings of the current RCT will provide evidence regarding the effectiveness of dietary supplementation strategies to improve COVID-19 outcomes. TRIAL STATUS: Ethical approval of the first version of the study protocol was obtained from the medical ethics committee of Hormozgan University of Medical Sciences, Bandar Abbas, Iran on May 30, 2021 (IR.HUMS.REC.1400.085). Currently, the recruitment phase is ongoing since August 23, 2021, and is anticipated to be complete by the end of August 2022. TRIAL REGISTRATION: The study protocol was registered in the Iranian Registry of Clinical Trials ( https://www.irct.ir ; IRCT20210702051763N1) on August 14, 2021. https://www.irct.ir/trial/57413 FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this letter serves as a summary of the key elements of the full protocol.

The effect of concentrated pomegranate juice on biomarkers of inflammation, oxidative stress, and sex hormones in overweight and obese women with polycystic ovary syndrome: A randomized controlled trial.

Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disorder. Pomegranate juice (PJ) has been known to play anti-inflammatory and antioxidant roles. However, the effects of PJ on inflammation, oxidative stress, and sex hormones in PCOS patients are very little studied, and thus more studies are needed. This randomized controlled trial enrolled 44 women diagnosed with PCOS according to the Rotterdam criteria, body mass index (BMI) ≥ 25 kg/m2 , and aged 18-40 years old. Participants were randomly assigned to take 45 ml/day of concentrated PJ or a control group without intervention. Some biomarkers of sex hormones, inflammation, and oxidative stress were quantified at baseline and after the 8-week intervention. Compared with the controls, serum testosterone levels were significantly decreased in overweight and obese women with PCOS who supplemented with concentrated PJ (-0.004 ± 0.013 vs. 0.039 ± 0.013, p = .039). However, we did not observe significant differences in luteinizing hormone (LH) and sex hormone-binding globulin (SHBG) levels and inflammation and oxidative stress factors between the two groups after adjustment for confounding variables. An 8-week supplementation with concentrated PJ could effectively improve testosterone levels in overweight and obese women with PCOS. This study was registered at www.irct.ir (IRCT20191109045383N1).

The effects of lycopene supplementation on insulin-like growth factor-1 and insulin-like growth factor binding proteins: A systematic review of randomized controlled trials.

Lycopene has been posited to regulate insulin-like growth factor-1 (IGF-1). We aimed to conduct a systematic review of the effects of lycopene on circulating IGF-1 and insulin-like growth factor binding proteins (IGFBPs) in adults. A systematic search was carried out in PubMed, Scopus, ISI Web of Science, and the Cochrane Library databases for randomized controlled trials (RCTs), published from inception until March 2020. A total of 11 studies fulfilled the selection criteria. Eleven studies examined the effect of lycopene supplementation on IGF-1, one of which reported a significant reduction. Moreover, three, four, and ten studies were found for IGFBP-1, IGFBP-2, and IGFBP-3, respectively; where one study found a significant increase in these proteins. In conclusion, no consistent modifying effect of lycopene supplementation on IGF-1 and IGFBPs levels are evident in the literature. More research is needed to explore the effect of lycopene on IGF-1 system.

Does pomegranate consumption improve oxidative stress? A systematic review and meta-analysis of randomized controlled clinical trials.

BACKGROUND: Oxidative stress is related to many chronic diseases such as type 2 diabetes, cancers, hypertension, and heart diseases. Antioxidant activity of pomegranate due to high content of polyphenols, flavonoids, and several other types of antioxidant compounds has been of interest; however, the findings on its antioxidant effects are inconsistent. OBJECTIVE: To assess the effects of pomegranate consumption on multiple oxidative stress biomarkers using a systematic review and meta-analysis of randomized controlled clinical trials (RCTs). METHODS: A comprehensive electronic search on PubMed, Scopus, ISI Web of Science, and Google Scholar was conducted up to May 2021. The risk of bias assessment was evaluated by Cochrane Collaboration's tool and a random-effects model was used to estimate the pooled effect size of the included studies. RESULTS: Our search identified 1692 studies, of which 21 were entered in the final analysis. The results showed that the consumption of pomegranate compared with the control group was associated with a significant elevation in the levels of TAC [SMD = 0.72, 95% confidence interval (CI): 0.42, 1.02, P < 0.001] and SOD [SMD = 0.72, 95% CI: 0.25, 1.19, P = 0.002] and reduction in the levels of MDA [SMD = -0.98, 95% CI: -1.49, -0.46, P < 0.001]. There were no reports of statistically significant differences in the effects of pomegranate on the levels of FRAP, GSH, GSH-Px, ox-LDL, and PON1. CONCLUSIONS: The present meta-analysis provides evidence that pomegranate can effectively improve some oxidative stress factors. Nevertheless, well-designed RCTs are recommended to validate these findings.

Effects of orange juice intake on cardiovascular risk factors: A systematic review and meta-analysis of randomized controlled clinical trials.

Previous investigations exploring the effects of orange juice (OJ) as a nutrient-dense beverage on cardiovascular risk factors were inconsistent. We aimed to conduct a systematic review and meta-analysis of randomized controlled clinical trials to determine the effectiveness of OJ intake on major cardiometabolic markers including anthropometric indices, blood pressure, lipid profile, inflammation, and glycemic control markers. PubMed, Scopus, and ISI Web of Science were searched from inception until January 2021. Fifteen eligible trials with 639 participants were included in the present study. The meta-analysis showed that OJ intake significantly reduces circulating total cholesterol levels (10 trials; weighted mean difference [WMD] = -6.84 mg/dl; 95% CI: -12.38 to -1.29; p = .01) and homeostatic model assessment for insulin resistance (four trials; WMD = -0.39, 95% CI: -0.77 to -0.006; p = .04) compared to control group. The analyses failed to reveal a significant effect of OJ intake on other cardiometabolic risk factors (p > .05). This review suggests that the intake of OJ might be associated with improved serum total cholesterol and insulin sensitivity. Due to low-to-moderate quality of meta-evidence, our results must be interpreted with caution and more well-designed studies are still needed to confirm the current findings.

Effect of hypocaloric high-protein, low-carbohydrate diet supplemented with fennel on androgenic and anthropometric indices in overweight and obese women with polycystic ovary syndrome: A randomized placebo-controlled trial.

OBJECTIVE: The aim of this study was to evaluate the effect of hypocaloric high-protein, low-carbohydrate weight loss diet supplemented with fennel on anthropometric and androgen indices in overweight and obese women with polycystic ovary syndrome (PCOS). METHODS: A randomized controlled trial with a factorial design was performed on sixty-four overweight/obese women with PCOS. Participants were randomly allocated to four groups (n = 16 per group) as follows: 1) hypocaloric standardize diet + fennel (2 capsule/day) (HSDF), 2) hypocaloric high-protein diet + fennel (2 capsule/day) (HHPF), 3) hypocaloric standardize diet + placebo (HSDP), and 4) hypocaloric high-protein diet + placebo (HHPP). RESULTS: The mean (SD) age of the participants was 28.54 (6.80) years and body mass index was 32.24 (4.65) kg/m2. At the end of intervention, protein intake was 20.43 % in the groups that received a high-protein diet versus 16.37 % in the standard diet groups (P < 0.001). Combination of hypocaloric high-protein diet and fennel capsule did not significantly affect change in outcomes compared with groups not receiving them. There was a significant interaction between hypocaloric high-protein diet and fennel on weight (P = 0.019). CONCLUSION: A hypocaloric high-protein diet along with fennel supplementation could not provide additional improvements in anthropometric and androgen indices among PCOS women. Further studies are required to more precisely elucidate these findings.

The combined effects of cholesteryl ester transfer protein (CETP) TaqIB gene polymorphism and canola, sesame and sesame-canola oils consumption on metabolic response in patients with diabetes and healthy people.

Introduction: Cholesteryl ester transfer protein (CETP) is a key regulating enzyme in the lipid metabolism pathway, and its gene polymorphism may be a candidate for modulating the metabolic responses to dietary intervention. We thus examined whether the effects of the CETP TaqIB polymorphism on metabolic profiles were modified by dietary plant oils. Methods: This is a retrospective analysis of data collected during a randomized triple-blind cross over trial. A total of 95 patients with type 2 diabetes and 73 non-diabetes individuals completed a 9-weekof the intake of sesame, canola and sesame-canola oils. Blood samples were collected at the beginning and at the end of each intervention period for biochemical analysis. Genotyping was done using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: In diabetes patients, B1B1 homozygotes of the CETP TaqIB polymorphism compared with B2 carriers (B1B2 + B2B2) had significantly lower diastolic blood pressure, apoB and apoB: apoA-1,and higher Lp(a) after the intake of sesame-canola oil, as well as lower insulin and HOMA-IR after the intake of sesame oil. There was also a significant effect of genotype on adjusted changes of apoB, apoB: apoA-1, insulin, HOMA-IR and QUICKI. A significant genotype-dietary oils combined effects were observed for diastolic blood pressure, and LDL: HDL, TC: HDL and TG: HDL ratios in diabetes patients. No independent or combined effects of dietary oils and genotypes on outcomes were found in healthy people. Conclusion: There was a modulatory effect of the CETP TaqIB polymorphism on some metabolic traits in response to plant oils in patients with diabetes. Taken together, the intake of sesame-canola and canola oils showed more favorable effects in diabetes patients with B1B1 genotype. Future investigations are needed to confirm these results.

Association of rs670 variant of APOA-1 gene with cardiometabolic markers after consuming sesame, canola and sesame-canola oils in adults with and without type 2 diabetes mellitus.

BACKGROUND & AIMS: The inter-individual variations of the metabolic markers in response to dietary interventions may be mediated by genetic factors. We examined whether the type of dietary oils can modulate the effects of -75G/A polymorphism in APOA-1 gene on cardiometabolic markers. METHODS: This study was a randomized, triple-blind, cross-over clinical trial. Participants with and without type 2 diabetes were randomly assigned to replace their regular oil with sesame oil, canola oil and sesame-canola oil for 9 weeks. Genotyping was conducted using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: Ninety-five diabetes patients and 73 healthy individuals completed the study protocol. In patients with type 2 diabetes, the A allele carriers experienced greater decrease in systolic blood pressure compared with GG homozygotes following sesame-canola oil intake. Serum levels of HDL-C and TG: HDL ratio was increased and decreased following canola oil intake in patients carrying the A allele rather than non-A allele carriers, respectively. More reductions for risk of cardiovascular diseases and mortality, except risk of stroke were found in the A allele carriers compared with GG homozygotes after intakes of canola and sesame-canola oils, but not sesame oil. There was also a significant genotype effect as well as genotype-dietary oil interactions on cardiovascular risk scores. In healthy individuals, a considerable decrease in visceral fat was accompanied by a significant increase in HDL-C levels in the A allele carriers compared with non-A allele carriers after sesame oil intake. CONCLUSION: Patients with diabetes carrying the A allele might benefit from canola and sesame-canola oils intakes, and healthy A allele carriers from sesame and sesame-canola oils intakes as well. Future clinical trials are recommended to warrant current findings.

Effects of l-carnitine supplementation on weight loss and body composition: A systematic review and meta-analysis of 37 randomized controlled clinical trials with dose-response analysis.

BACKGROUND AND AIM: Clinical evidence which investigated the effects of l-carnitine, a vitamin-like substance, on weight loss had led to inconsistent results. This study therefore aimed to examine the effect of l-carnitine supplementation on body weight and composition by including the maximum number of randomized controlled trials (RCTs) and to conduct a dose-response analysis, for the first time. METHODS AND RESULTS: Online databases were searched up to January 2019. In total, 37 RCTs (with 2292 participants) were eligible. Meta-analysis showed that l-carnitine supplementation significantly decreased body weight [Weighted mean difference (WMD) = -1.21 kg, 95% confidence interval (CI): -1.73, -0.68; P < 0.001], body mass index (BMI) (WMD = -0.24 kg/m2, 95% CI: -0.37, -0.10; P = 0.001), and fat mass (WMD = -2.08 kg, 95% CI: -3.44, -0.72; P = 0.003). No significant effect was seen for waist circumference (WC) and body fat percent. The meta-analysis of high-quality RCTs only confirmed the effect on body weight. A non-linear dose-response association was seen between l-carnitine supplementation and body weight reduction (P < 0.001) suggesting that ingestion of 2000 mg l-carnitine per day provides the maximum effect in adults. This association was not seen for BMI, WC and body fat percent. CONCLUSIONS: l-carnitine supplementation provides a modest reducing effect on body weight, BMI and fat mass, especially among adults with overweight/obesity.

Hesperidin supplementation has no effect on blood glucose control: A systematic review and meta-analysis of randomized controlled clinical trials.

AIMS: To the best of our knowledge, no study has tried to quantitatively summarize the published evidence regarding the effect of hesperidin supplementation on blood glucose control. The present systematic review and meta-analysis of randomized controlled trials aimed to determine the effectiveness of hesperidin supplementation in improving blood glucose control in adults. METHODS: Electronic databases including PubMed, ISI Web of Science, Scopus, and Google Scholar were searched up to February 2019. The risk of bias in individual studies was assessed using the Cochrane collaboration's tool. The overall estimates and their 95% confidence intervals (CIs) were calculated using a random-effects model. RESULTS: Six trials with 318 participants were reviewed in the present systematic review. The results showed that hesperidin had no significant effect on serum fasting blood glucose (weighted mean difference [WMD] = -1.10 mg/dL, 95% CI: -3.79, 1.57), plasma insulin (WMD = -0.01 µU/mL, 95% CI: -1.20, 1.19), glycated haemoglobin A1c (WMD = -0.04%, 95% CI: -0.14, 0.04), homeostasis model assessment for insulin resistance (WMD = 0.117, 95% CI: -0.06, 0.29) and quantitative insulin sensitivity check index (WMD = 0.135; 95% CI: -0.13, 0.39), with no significant between-study heterogeneity. Subgroup analyses also indicated that the effects were not different based on the studies' design and duration, or the health status of the participants. CONCLUSION: Although several animal studies have proposed that hesperidin supplementation might improve blood glucose control, the present study could not confirm this benefit in humans.

Effects of a healthy Nordic diet on weight loss in adults: a systematic review and meta-analysis of randomized controlled clinical trials.

OBJECTIVES: Studies on the effect of the Nordic diet (ND) on body weight and adiposity indices were conflicting. This study targeted to perform a systematic review and meta-analysis of randomized controlled clinical trials (RCTs) examined the effect of the ND on body weight and composition. METHODS: PubMed, Scopus, ISI web of Science, ProQuest and Google Scholar were searched for the eligible studies up to August 2019. The weighted mean difference (WMD) in body weight and composition indices between the ND and control groups/periods was derived using random-effects model. RESULTS: In total, seven studies (n = 774 participants) were included in the present study. Five studies had illustrated the effect of the ND on weight, three on waist circumference (WC), two on body fat, and two on body mass index (BMI). The pooled analysis of eligible trials showed that those adhered to the ND lost 1.83 kg [95% confidence interval (CI) - 2.94, - 0.73, P = 0.001] more weight compared to controls. Qualitative assessment of other anthropometric indices also showed a beneficial effect of this dietary pattern in improving body fat and BMI values; however, these findings are not conclusive because of limited number of studies. CONCLUSION: Adherence to the ND significantly improves body weight; however, there is also no certainty that this diet is effective for improving other anthropometric indices. Future studies regarding the effect of the ND on weight and body composition in populations other than Nordic populations are highly recommended. Level of evidence Level I, systematic reviews and meta-analyses.

The Efficacy of Vitamin D Supplementation against Nonalcoholic Fatty Liver Disease: A Meta-Analysis.

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver disease worldwide. If this disease is not appropriately controlled, it can eventually cause chronic liver damage, including cirrhosis and hepatocellular carcinoma. Accordingly, the adoption of appropriate interventions to control NAFLD is important for any healthcare system. The aim of the present systematic review and meta-analysis was to clarify the effect of vitamin D supplementation on NAFLD. PubMed, Scopus, Science Direct, ISI Web of Science, and Google Scholar were systematically searched up to March 2019 to find clinical trials that examined the effects of vitamin D supplementation on liver enzyme levels in NAFLD patients. Means for liver enzymes and potential sources of heterogeneity were extracted. A subgroup analysis was performed to detect potential sources of interstudy heterogeneity. Nine trials (10 arms) comprising 467 participants were eligible for meta-analysis. The results from a pooled analysis did not reveal a significant effect of vitamin D intake on alanine aminotransferase (-2.88 U/L; 95% CI, -6.03 to 0.27; I2 = 85%), aspartate aminotransferase (-0.10 U/L; 95% CI, -1.18 to 0.97; I2 = 26%), and γ-glutamyltransferase levels (0.12 U/L; 95% CI, -5.94 to 6.18; I2 = 38%). The meta-analysis suggested a significant reduction in alkaline phosphatase (-13.79 U/L; 95% CI, -22.13 to -5.45; I2 = 72%) following vitamin D supplementation. This effect was robust in the subgroup in which > 3,000 IU/day vitamin D was administered (-19.74 U/L; 95% CI, -25.36 to -14.12; I2 = 0.0%). The present meta-analysis does not suggest the efficacy of vitamin D supplementation on NAFLD treatment.

Does L-carnitine supplementation affect serum levels of enzymes mainly produced by liver? A systematic review and meta-analysis of randomized controlled clinical trials.

BACKGROUND AND AIMS: L-carnitine supplementation is proposed to reduce liver enzymes levels; however, previous findings were equivocal. The current systematic review and meta-analysis of randomized controlled clinical trials (RCTs) were performed to assess the effect of L-carnitine supplementation on serum levels of enzymes mainly produced by liver [alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transpeptidase (GGTP)]. METHODS: Online databases as well as the reference lists of relevant studies were searched from inception up to June 2019. The risk of bias in individual studies was assessed using Cochrane Collaboration's tool. Data were pooled using the random-effects model and expressed as mean differences (MDs) with 95% confidence intervals (CIs). RESULTS: In total, 18 RCTs (1161 participants) met the eligibility criteria. L-carnitine supplementation dose ranged from 500 to 4000 mg/day. L-carnitine supplementation significantly reduced serum ALT (MD = - 8.65 IU/L, 95% CI - 13.40, - 3.90), AST (MD = - 8.52 IU/L, 95% CI - 12.16, - 4.89), and GGTP (MD = - 8.80 IU/L, 95% CI - 13.67, - 3.92) levels. The subgroup analysis showed that L-carnitine might be more effective in reducing the enzymes when supplemented in higher doses (≥ 2000 mg/day), for longer durations (> 12 weeks), and among patients with liver diseases. The meta-evidence was graded as "moderate" for ALT and AST, and "low" for GGTP according to NutriGrade scoring system. CONCLUSION: L-carnitine supplementation significantly improves circulating ALT, AST and GGTP levels; therefore, it might positively affect liver function, especially among patients with liver diseases. Further high-quality RCTs are recommended to confirm our results.

The healthy Nordic diet for blood glucose control: a systematic review and meta-analysis of randomized controlled clinical trials.

AIMS: Investigations on the possible effect of the Nordic diet (ND) on the glycemic control and the risk of diabetes have led to inconsistent results. The present study tried to determine the effect of the ND on the markers of blood glucose control using a systematic review and meta-analysis of randomized controlled clinical trials (RCTs). METHODS: Predefined keywords were used to search PubMed, ISI Web of Science, Scopus and Google Scholar up to April 2019. The random effects model was used to compute the overall estimates. RESULTS: In total, six RCTs with 618 participants (6-26 weeks of follow-up period) were included in the present study. The meta-analysis revealed that the ND might not have a considerable effect on fasting blood glucose levels [weighted mean difference (WMD) = -0.05 mmol/l, 95% CI - 0.13, 0.01, P = 0.112]. In contrast, the analyses showed that the ND significantly reduces serum insulin concentrations (WMD = -1.12 mU/l, 95% CI - 1.84, - 0.39, P = 0.002) and the homeostasis model assessment for insulin resistance (HOMA-IR) (WMD = - 0.34, 95% CI - 0.53, - 0.14, P = 0.001) compared to control diets. The effect on serum insulin levels was sensitive to one of the included studies. This dietary pattern did not significantly affect 2-h post-prandial blood glucose and Matsuda index. CONCLUSIONS: Adherence to the ND might improve serum insulin and HOMA-IR levels; however, this effect was not confirmed for other markers of blood glucose control. Future well-designed and long-term clinical trials are highly recommended.

Effects of cinnamon supplementation on body weight and composition in adults: A systematic review and meta-analysis of controlled clinical trials.

BACKGROUND: This systematic review and meta-analysis aimed to investigate the effect of cinnamon on body weight, body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), and body fat mass including the maximum number of studies. METHODS: Medline, ISI Web of Science, Scopus, Google Scholar, and Cochrane library were searched with no limitation from inception up to August 2019 for relevant randomized controlled clinical trials (RCTs). The RCTs' risk of bias was assessed using the Cochrane collaboration's tool. Random-effects model was used for meta-analysis. RESULTS: Twenty-one RCTs with 1,480 participants were included. The meta-analysis showed that cinnamon supplementation significantly reduces BMI [weighted mean difference (WMD) = -0.40 kg/m2 , 95% confidence interval (CI): -0.57, -0.22 kg/m2 , p < .001, I2 = 78.9%], body weight (WMD = -0.92 kg; 95% CI: -1.51, -0.33 kg; p = .002; I2 = 84.2%), and WHR (WMD = -0.02, 95% CI: -0.038, -0.018; p < 0.001; I2 = 0%). Cinnamon supplementation did not significantly affect the WC (WMD = -1.76 cm, 95% CI: -3.57, -0.045 cm; p = .056; I2 = 90.8%) and body fat mass (WMD = -0.87%, 95% CI: -1.87, 0.025%; p = .057; I2 = 78.6%). CONCLUSION: Cinnamon supplementation significantly reduces body weight, BMI, and WHR. Future high-quality long-term RCTs are recommended to confirm these results.

Effect of saffron (Crocus sativus L.) on lipid profile, glycemic indices and antioxidant status among overweight/obese prediabetic individuals: A double-blinded, randomized controlled trial.

OBJECTIVE: To investigate the effects of saffron (Crocus sativus L.) on lipid profile, glycemic and antioxidant status in overweight/obese individuals with prediabetes. METHODS: In this randomized, double-blind, placebo-controlled trial, the prediabetic patients were randomly assigned to receive saffron (15 mg/d) pills or placebo for eight weeks. Serum levels of lipid profile, fasting blood sugar (FBS), glycosylated hemoglobin (HbA1c), blood urea nitrogen (BUN), creatinine, and diphenylpycrylhydrazyl (DPPH) radical scavenging activity were assessed biochemically at baseline and at 8 weeks after treatment. The adverse events, if any, were also recorded. RESULTS: Seventy-five of participants (36 in treatment and 39 in placebo groups) completed the study. Within-group comparisons revealed a significant effect of saffron supplementation on FBS (118.11 ± 3.55 vs. 109.14 ± 6.23), HbA1c (5.85 ± 0.12 vs. 5.70 ± 0.11), and DPPH (11.06 ± 3.24 vs. 13.46 ± 3.33) levels (P < 0.005 for all). In adjusting models, there was a significant reduction in FBS by -7.97 mg/dL, and HbA1c by -0.15% in saffron group compared to placebo. Moreover, saffron intake tended to increase in DPPH radical scavenging activity (2.4% vs. -0.85% in saffron and placebo groups, respectively). However, no significant changes in anthropometric measures, lipid profile, and renal markers were observed after saffron intake compared with placebo. CONCLUSION: Saffron supplementation could improve glycemic and antioxidant indices in overweight/obese individuals with prediabetes, however, no beneficial effect was observed on lipid profile and anthropometric parameters. (IRCT20120913010826N19).

Effects of a Paleolithic Diet on Cardiovascular Disease Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

There is some evidence supporting the beneficial effects of a Paleolithic Diet (PD) on cardiovascular disease risk factors. This diet advises consuming lean meat, fish, vegetables, fruits, and nuts and avoiding intake of grains, dairy products, processed foods, and added sugar and salt. This study was performed to assess the effects of a PD on cardiovascular disease risk factors including anthropometric indexes, lipid profile, blood pressure, and inflammatory markers using data from randomized controlled trials. A comprehensive search was performed in the PubMed, Scopus, ISI Web of Science, and Google Scholar databases up to August, 2018. A meta-analysis was performed using a random-effects model to estimate the pooled effect size. Meta-analysis of 8 eligible studies revealed that a PD significantly reduced body weight [weighted mean difference (WMD) = -2.17 kg; 95% CI: -3.48, -0.87 kg], waist circumference (WMD = -2.90 cm; 95% CI: -4.51, -1.28 cm), body mass index (in kg/m2) (WMD = -1.15; 95% CI: -1.68, -0.62), body fat percentage (WMD = -1.38%; 95% CI: -2.08%, -0.67%), systolic (WMD = -4.24 mm Hg; 95% CI: -7.11, -1.38 mm Hg) and diastolic (WMD = -2.95 mm Hg; 95% CI: -4.72, -1.18 mm Hg) blood pressure, and circulating concentrations of total cholesterol (WMD = -0.22 mg/dL; 95% CI: -0.42, -0.03 mg/dL), TGs (WMD = -0.23 mg/dL; 95% CI: -0.46, -0.01 mg/dL), LDL cholesterol (WMD = -0.13 mg/dL; 95% CI: -0.25, -0.01 mg/dL), and C-reactive protein (CRP) (WMD = -0.41 mg/L; 95% CI: -0.81, -0.008 mg/L) and also significantly increased HDL cholesterol (WMD = 0.05 mg/dL; 95% CI: 0.005, 0.10 mg/dL). However, sensitivity analysis revealed that the overall effects of a PD on lipid profile, blood pressure, and circulating CRP concentrations were significantly influenced by removing some studies, hence the results must be interpreted with caution. Although the present meta-analysis revealed that a PD has favorable effects on cardiovascular disease risk factors, the evidence is not conclusive and more well-designed trials are still needed.

The effect of hesperidin supplementation on inflammatory markers in human adults: A systematic review and meta-analysis of randomized controlled clinical trials.

BACKGROUND: Hesperidin (a flavanone found in citrus fruits) supplementation is suggested to inversely affect inflammation; however, clinical trials have led to inconsistent results. OBJECTIVE: To examine the effect of hesperidin supplementation on inflammatory markers using systematic review and meta-analysis of randomized controlled clinical trials (RCTs). PATIENT AND METHODS: Online databases including PubMed, Scopus, ISI Web of Science, and Google Scholar were searched up to December 2018. A random-effects model was used to compare the mean changes in the inflammatory markers between hesperidin supplemented and control subjects. RESULTS: Six eligible RCTs with 296 participants were included in the systematic review. The meta-analysis revealed that hesperidin significantly reduces Vascular Cell Adhesion Molecule 1 (VCAM-1) levels [weighted mean difference (WMD) = -22.81 ng/L, P = 0.041, n = 3]. No considerable changes was observed for serum C-reactive protein (CRP) levels (WMD = -0.69 mg/L, P = 0.079, n = 5); the subgroup analysis showed a significant reduction in studies with a parallel design (WMD = -0.72 mg/L, P = 0.024, n = 3), and studies with more than 4 weeks of follow-up (WMD = -0.76 mg/L, P = 0.020, n = 2). Hesperidin supplementation had no signification effect on circulating E-selectin, interleukin 6, and Intercellular Adhesion Molecule 1 (ICAM-1) levels. CONCLUSION: The present study suggests that although hesperidin supplementation significantly improves VCAM-1 levels; however, other inflammatory markers might not be affected. Further high-quality systematic reviews exploring the effect of hesperidin particularly on VCAM-1, ICAM-1, E-selectin, and interleukin 6 are still needed to confirm these results.