Association between sugar-sweetened beverages and waist circumference in adult populations: A meta-analysis of prospective cohort studies.

BACKGROUND & AIM: Based on previous studies, Sugar-Sweetened beverages (SSB) can increase the risk of obesity and obesity-related disorders. However, findings are conflicting. The aim of the present study was to summarize the association between the intake of SSB and waist circumference (WC) in adult populations. METHODS: Four electronic databases including PubMed/Medline, Web of Knowledge, Scopus, and EMBASE were considered to collect eligible papers until 31 January 2019 with English language. RESULTS: Finally, we reached 7 eligible cohort studies for both qualitative and quantitative synthesis. Based on the pooled 10 effect sizes, we found that the consumption of SSB can increase WC by 14%. However, it was not statistically significant and the between-study heterogeneity was high (95%CI: 0.86, 1.51; I2: 90.8%). We also observed that soda drink can increase WC by 31% (95%CI: 1.03, 1.66; I2:0%). CONCLUSION: The current systematic review and meta-analysis revealed that the consumption of SSB can increase WC by 14% in adult populations. However, this value was not statistically significant. However, more prospective studies are necessary to make a decision on the link between the consumption of SSB and abdominal obesity.

Effect of probiotic foods and supplements on blood pressure: a systematic review of meta-analyses studies of controlled trials.

OBJECTIVE: Recent evidences suggested that hypertension was associated with changes in gut microbiota composition. As intervention with probiotics might be considered as one of the approaches for modulating gut microbiota, the objective of the present study was to systematically review the meta-analyses of controlled trials (CTs) to elucidate the effects of probiotics on blood pressure. METHODS: We searched PubMed, Web of Science, and Cochrane Library databases until November 2019 to explore all the meta-analyses conducted on the CTs assessing the efficacy of probiotics in the management of blood pressure (BP). Meta-analyses performed on in vitro, animal or observational studies were excluded from the study. References of the included studies were also screened to obtain further eligible publications. RESULTS: From the 111 records which were identified during the literature search, 5 meta-analyses met the selection criteria. Total sample size was 2703 subjects (1009 subjects with type 2 diabetes mellitus (T2DM)), aged 12-75 years from both sexes. Results of meta-analyses have been shown a moderate effect of probiotics on BP in hypertensive adults with/without T2DM; from 3.10 to 5.04 mmHg for systolic blood pressure (SBP) and from 0.39 to 3.84 mmHg for diastolic blood pressure (DBP) after 3-24 weeks consumption. These effects were greater in adults with BP ≥ 130/85, by dairy products, by Asian fermented products with multiple species and higher dose of probiotics (≥ 1011 colony forming units (CFU)). CONCLUSION: It seems probiotic foods and supplements which were contained high dose multiple species of probiotic bacteria could be more effective in BP control.

Effect of probiotics supplementation on glucose and oxidative stress in type 2 diabetes mellitus: a meta-analysis of randomized trials.

PURPOSE: The role of oxidative stress in pathogenesis of diabetes is well established. In addition, an association between gut microbiota and type 2 diabetes mellitus (T2DM) is widely observed in previously published reports. This meta-analysis critically examines the association between gut microbiota, and oxidative stress in T2DM. METHODS: A systematic search for clinical trials was performed in PubMed, Web of Science and Scopus web databases up to 1 Jan 2019. Primary search terms include "microbiota", "diabetes", and "oxidative stress". Study was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guideline. All clinical trials that compared the effects of probiotic supplementations with a control group using end points serum levels of fasting blood sugar (FBS), hemoglobin A1C (HbA1C) and oxidative stress biomarkers were included. Two independent researchers screened the data extracted from the relevant studies. The pooled standardized mean difference (SMD) was estimated using the random or fixed effects model. Heterogeneity among the studies was assessed using Q-test. RESULTS: Overall, 13 randomized clinical trials (RCTs) involving 840 subjects with T2DM were included in the meta-analysis. The analysis showed that probiotics intake resulted in significant improvement in serum levels of FBS [SMD: -0.35, 95% CI: (-0.59, -0.12)], total antioxidant status (TAS) [SMD: 0.33, 95% CI: (0.11, 0.55)], total glutathione (GSH) [SMD: 0.41, 95% CI: (0.26, 0.56)] and malondialdehyde (MDA) [SMD: -0.54, 95% CI: (-0.83, -0.26)]. No significant improvement was found in HbA1C [SMD: -0.06, 95% CI:(-0.82, 0.69)], and nitric oxide (NO) [SMD:-0.24, 95% CI:(-1.10, 0.62)] levels. CONCLUSION: It seems that gut microbiota can exert beneficial effects in diabetic patients via altering oxidative stress' biomarkers. The beneficial effect of gut microbiota however was modest on FBS and non-significant on HbA1C. These results need to be confirmed by conducting more reliable RCTs. PROSPERO REGISTRATION NUMBER: CRD42019134905. Graphical abstract Flow diagram of the study selection process.

Correction to: Dietary antioxidative supplements and diabetic retinopathy; a systematic review.

[This corrects the article DOI: 10.1007/s40200-019-00434-x.].

The link between breakfast skipping and overweigh/obesity in children and adolescents: a meta-analysis of observational studies.

PURPOSE: Childhood overweight/ obesity is one of critical public health concern. It has been suggested that there is a link between breakfast skipping and obesity. However, results are conflicting. The aim of the present study was to summarize the association between breakfast skipping and overweight/obesity in children and adolescent. METHODS: We performed a literature search using Pubmed/Medline, Scopus, Web of Science and EMBASE electronic databases from 2000 through 28 February 2018 without language limitation. Observational studies in which risk measures were reported regarding the link between breakfast skipping and obesity in children and adolescent were included. Studies with at least the score of 5 from Newcastle-Ottawa Scale were considered as low risk of bias. Random effect model was used for data synthesis. RESULTS: Of 3276 publications, finally 16 studies (14 cross-sectional studies, 2 cohort studies) were included for meta-analysis. Based on cross-sectional studies, we found a positive association between breakfast skipping and obesity (Odd ratio (OR) trim & fill: 1.43; 95%CI: 1.32, 1.54), while cohort studies showed no significant link (OR:1.01, 95%CI: 0.93, 1.11; I2: 48%, p = 0.14). Subgroup analysis in cross-sectional studies showed that the association between breakfast skipping and the risk of obesity in boys was OR: 1.64; 95% CI: 1.38, 1.95; I2: 38.3%, p = 0.18, while it was 1.56 (95% CI: 1.38, 1.77, I2: 0.0%, p = 0.49) in girls. CONCLUSION: The risk of obesity in children and adolescents who skipped breakfast was 43% greater than those who ate breakfast regularly in cross-sectional studies, while no significant link was found in cohort studies. However, due to high heterogeneity and limited cohort studies, findings should be interpreted by caution.

Dietary antioxidative supplements and diabetic retinopathy; a systematic review.

PURPOSE: There is controversial data regarding the effects of dietary antioxidative supplements on diabetic retinopathy (DR). We conducted a systematic review of both observational and randomized controlled clinical trials (RCTs) to clarify whether they are effective or not. METHODS: All observational and RCTs conducted by antioxidative supplements on DR published up to 1 January 2018 in PubMed, Web of Sciences, Scopus and Cochrane Library databases were included. Exclusion criteria were animal studies, and studies conducted in Type 1 diabetes mellitus (T1DM), children or pregnant women. Main outcome measures were reporting the incidence or progression of DR in T2DM by assessment of visual fields, and measurements of oxidative and antioxidative biomarkers. The quality of reporting of included articles and risk of bias were assessed. RESULTS: Finally, we reached 14 observational studies and 7 RCTs that conducted on 256,259 subjects. Due to severe methodological heterogeneity, only qualitative synthesis was carried. All studies were reported a significantly lower level of antioxidants and higher level of oxidative stress biomarkers in DR compared with others. There was an inverse significant correlation between vitamin C and malondialdehyde (MDA) (r = -0.81) or DNA damage (r = -0.41). These figures were statistically significant between vitamin E and MDA (r = 0.77) or superoxide dismutase (r = 0.44). Coefficient of correlation between MDA and zinc (-0.82), coenzyme Q10 (0.56), and magnesium (-0.73) was significant. Multi-oxidants trials were shown non-significant beneficial effects on DR. CONCLUSIONS: Although our study supports the positive effects of antioxidative supplements on DR, more high quality studies are needed to confirm.