Dietary acid load, kidney function and risk of chronic kidney disease: A systematic review and meta-analysis of observational studies.

Aim: Study findings examining the association between dietary acid load (DAL), kidney function and risk of chronic kidney disease (CKD) are inconsistent and there has been no meta-analysis on the relationship between DAL, kidney function and risk of CKD, hence we investigated this association in this paper. Methods: PubMed, ISI web of science and Scopus were searched up to January 2018 to identify all relevant articles. Effect sizes of eligible studies were pooled in random- effect model using the Der Simonian-Laird method. The I2 index was used to assess the amount of heterogeneity. Result: Twenty three studies with 200092 subjects were included. Meta-analysis of 9 observational studies showed that DAL had a positive significant association with risk of CKD (1.31; 95% CI: 1.06, 1.62; P = 0.011). Furthermore, increased DAL can decrease urine pH (-0.47; 95% CI: -0.85, -0.08; P = 0.017) significantly. Subgroup analysis could not identify the sources of heterogeneity about the association of DAL and risk of CKD. However, it showed the method of measurement was the source of heterogeneity about the association of DAL and urine pH (24 h urine pH: -0.62; 95% CI: -0.70, -0.54; P < 0.0001; Fasting urine pH: -0.08; 95% CI: -0.18, 0.02; P = 0.111). Conclusion: Our study showed that DAL can increase the risk of CKD and have an inverse association with urine pH.

The effects of garlic supplementation on weight loss: A systematic review and meta-analysis of randomized controlled trials.

Obesity is related to increase in the incidence of morbidity and mortality. Studies have suggested anti-obesity properties of garlic; however, results are inconsistent. This systematic review and meta-analysis is done to summarize the data obtained from available randomized clinical trials on the effect of garlic supplementation on body weight, Body Mass Index (BMI), and Waist Circumference (WC). The online databases of Scopus, PubMed, Google Scholar and Cochrane library were searched until March 2018 for related publications using relevant keywords. Effect sizes of eligible studies were pooled using random-effects models. Cochran's Q-test and I2 index were used for assessing heterogeneity. We found 1241 records in our initial search, of which 13 randomized clinical trials (RCTs) with 15 treatment arms were included. Pooled analysis showed that garlic administration might significantly decrease WC (Weighed Mean Difference (WMD): -1.10 cm, 95% CI: -2.13, -0.07, P = 0.03, I2 = 0%). However, garlic intervention had no significant effect on body weight (WMD): -0.17 kg, 95% CI: -0.75 to 0.39, P = 0.54, I2 = 0%) and BMI (WMD: -0.17 kg/m2, 95% CI: -0.52, 0.16, P = 0.30, I2 = 44.5%) as compared to controls. From Subgroup analysis, it was ascertained that the effect of garlic supplementation on BMI was significant in trials with duration < 12 weeks (WMD: -0.58 kg/m2, 95% CI: -1.08, -0.08, I2 = 19.8%, P = 0.02) compared to those with higher duration (>12 weeks). The current meta-analysis results suggest that garlic supplementation seems to reduce waist circumference unlike body weight and BMI.

Correction to: The effect of zinc supplementation on blood pressure: a systematic review and dose-response meta-analysis of randomized-controlled trials.

The original version of this article unfortunately contained a mistake. The family name of "Israel Júnior Borges do Nascimento" was incorrect.

The effect of zinc supplementation on blood pressure: a systematic review and dose-response meta-analysis of randomized-controlled trials.

PURPOSE: Despite previous investigations on the effects of zinc supplementation on blood pressure, inconsistent findings are available in this regard. Therefore, we conducted a systematic review and meta-analysis of randomized clinical trials on the effects of zinc supplementation on blood pressure (BP) in adults. METHODS: Relevant studies published up to September 2019 were searched through PubMed/Medline, Scopus, ISI Web of Science, and Google Scholar using suitable keywords. All randomized clinical trials (RCTs) that examined the effect of oral zinc supplementation on systolic blood pressure (SBP) or diastolic blood pressure (DBP) in adults were included. RESULTS: Overall, nine trials were included in our study. Zinc supplementation significantly reduced SBP compared to the control [weighted mean differences (WMD) - 1.49 mmHg; 95% CI - 2.85 to - 0.13; P = 0.03]. However, zinc supplementation had no significant effects on DBP (WMD - 0.88 mmHg; 95% CI - 2.04 to 0.29; P = 0.14). Nonlinear analysis failed to indicate a significant influence of supplementation dosage or duration on both SBP and DBP. Sensitivity analysis showed that no individual study had a significant impact on our final results. In addition, we found no evidence for the presence of small-study effects among studies for both SBP and DBP. CONCLUSION: We found a significant reduction in SBP following zinc supplementation. However, zinc supplementation had no significant effect on DBP. In addition, no nonlinear association was found between supplementation dosage and duration with changes in both SBP and DBP. Further RCTs using different dosages of zinc in various durations are required to confirm our conclusion.

Blackcurrant Anthocyanins Improve Blood Lipids and Biomarkers of Inflammation and Oxidative Stress in Healthy Women in Menopause Transition without Changing Body Composition.

Recent cell and animal studies suggest the potential of blackcurrants (BCs; Ribes nigrum) as a dietary agent that may reduce the risk of cardiovascular disease (CVD) by improving dyslipidemia, oxidative stress, and inflammation. This study aimed to examine the effects of BC anthocyanin (ACN) extract supplementation on biomarkers of CVD risk in healthy adult women in menopause transition. The effects of BC ACN supplementation on body composition, fasting blood lipids and biomarkers of inflammation and oxidative stress were evaluated using anthropometric measures and blood samples collected from a pilot randomized controlled clinical trial in peri- and early postmenopausal women. Thirty-eight eligible peri- and early postmenopausal women aged 45-60 completed the entire trial, in which they were randomly assigned into one of three treatment groups: placebo (control group), 392 mg/day (low BC group), or 784 mg/day (high BC group) for six months. The significance of differences in outcomes was tested using repeated-measures ANOVA. Overall, following six-month BC consumption, significantly decreased triglyceride (TG) levels were observed between treatment groups (p < 0.05) in a dose-dependent manner. Plasma interleukin-1ß (IL-1ß) was significantly reduced in a dose and time dependent manner (p < 0.05). Significant decreases in thiobarbituric acid reactive substances (TBARS) levels were also observed between treatment groups (p < 0.05) in a dose-dependent manner. Six-month change in oxidized LDL was inversely correlated with changes in catalase (CAT) and total antioxidant capacity (TAC) (p < 0.05), while C-reactive protein (hs-CRP) change was positively correlated with changes in TG and IL-1ß (p < 0.01). Together, these findings suggest that daily BC consumption for six months effectively improved dyslipidemia, inflammation, and lipid peroxidation, thus potentially mitigating the risk of postmenopausal CVD development in study participants. Future studies with larger sample sizes and at-risk populations are warranted to confirm these findings.

Dietary Quality Index and Cardiometabolic Risk Factors among Adult Women.

BACKGROUND: The prevalence of cardiovascular disease is dramatically increasing particularly in developing countries. Among the different factors, diet has an important role in the pathogenesis of these diseases. This study aimed to assess the relationship between dietary quality index-international (DQI-I) and cardiovascular risk factors in adult Iranian women. METHODS: This was a cross-sectional study of 371 participants, aged 20-50 yr, and recruited from 10 health centers from health centers affiliated with Tehran University of Medical Sciences (TUMS), Tehran, Iran in 2018. Usual dietary intake was evaluated by a validated and reliable 168-items food frequency questionnaire (FFQ). To assess overall quality of diet, the Dietary Quality Index-International (DQI) was used. Anthropometric measurements, blood pressure, and fasting blood of samples were taken to assess biochemical parameters related to cardiovascular disease. RESULTS: The results of linear regression showed that DQI-I score was inversely and directly associated with serum level of total cholesterol (TC) (0.27, confidence interval (CI): 0.13-0.58; P<0.001) and high-density lipoprotein cholesterol (HDL-C) (2.53, CI: 1.42-4.52; P=0.001), respectively. However, there was no significant association between DQI-I and other cardiovascular risk factors. CONCLUSION: A greater DQI-I score was associated with preferable lipid profile including TC and HDL-C. Future large-scale, prospective cohort or clinical studies are required to confirm these findings.