Effect of Egg Consumption on Blood Pressure: a Systematic Review and Meta-analysis of Randomized Clinical Trials

PURPOSE OF REVIEW

We identified and quantified the results of randomized controlled trials (RCTs) that have assessed the impact of egg consumption on blood pressure in adults.

RECENT FINDINGS

We conducted a comprehensive search of medical bibliographic databases up to February 2019 for RCTs investigating the effect of egg consumption on blood pressure in adults. Fifteen RCTs were included with a total of 748 participants. Overall, egg consumption had no significant effect on systolic blood pressure (weighted mean difference (WMD) = 0.046 mmHg; 95% CI - 0.792, 0.884) and diastolic blood pressure (WMD = - 0.603 mmHg; 95% CI - 1.521, 0.315). Subgroup analyses had no effect on pooled results and no heterogeneity was found among included studies. Egg consumption has no significant effects on systolic and diastolic blood pressure in adults. Due to several limitations among existing studies, general conclusions cannot be drawn regarding the beneficial or neutral impact of egg consumption on blood pressure in adults.

Sodium status is associated with type 2 diabetes mellitus: a systematic review and meta-analysis of observational studies

PURPOSE

The relationship between sodium intake and the risk of developing type 2 diabetes mellitus (T2DM) is inconsistent. We, therefore, aimed to summarize the current evidence by conducting a systematic review and meta-analysis of observational studies.

METHODS

We retrieved studies which compared any marker of sodium status between individuals with T2DM and those without diabetes published in any language by searching online databases from inception up to June 2019. Summary effects were derived using random-effects model.

RESULTS

A total of 44 studies with 503,830 participants from 25 countries were included in this study. Sodium status was significantly different between individuals with and without T2DM (Hedges' g = 0.21; 95% CI 0.02, 0.40; P = 0.029). Individuals with T2DM had higher sodium intake compared to non-diabetic controls (WMD = 621.79 mg/day; 95% CI 321.53, 922.06; P < 0.001) and 24-h urinary excretion was associated with likelihood of developing T2DM (OR = 1.27, 95% CI 1.15, 1.41; P < 0.001). Furthermore, salivary, hair, and platelet sodium were higher in patients with T2DM compared to controls (P < 0.05).

CONCLUSION

The findings of the current meta-analysis suggest that sodium levels are higher in patients with T2DM compared to non-diabetic controls; however, given that these studies are observational, it is not possible to infer causality.

The responses of different dosages of egg consumption on blood lipid profile: An updated systematic review and meta-analysis of randomized clinical trials

Diverse notions exist regarding egg intake, which is one of the main sources of dietary cholesterol, and its effect on blood lipids. We conducted this study to update the previous meta-analysis for their flaw in calculated effect size. PubMed, Scopus, ISI, and Cochrane were searched up to April 2019, for relevant randomized controlled clinical trials. Mean changes in total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), triglyceride (TG), very low-density lipoprotein cholesterol (VLDL-C), LDL-C/HDL-C, TC/HDL-C, apolipoprotein (apo)A1, and apoB100 were assessed. Meta-analysis of 66 RCTs with 3,185 participants revealed that egg consumption can significantly increase TC, LDL-C, HDL-C, TC/HDL-C, apoA1/and B100, but there was no significant effect on other serum lipids. Dose-response analysis showed a linear effect for TC, HDL-C, ApoA1, ApoB100, and nonlinear for LDL-C, and TC/HDL-C. In conclusion, intake of more than one egg daily in less than 12 weeks may increase some blood lipids without any changes in the ratio of LDL-C/HDL-C. PRACTICAL APPLICATIONS: There are controversies reports for egg intake, which is one of the main sources of dietary cholesterol. This study provides comprehensive information about the effect of the number of eggs consumed per day (dietary cholesterol) on blood lipids for nutritionists, physicians, researchers, and the general population. In this regard, our results indicated that there is a linear correlation between consumption of greater than one egg per day in a short time (no long time) and increasing lipid profiles which may increase the risk of cardiovascular diseases. However, consumption of one egg daily can be safe and this can be a useful recommendation for prevention of cardiovascular disease and promotion of healthy life which indeed are the potential or actual uses of this research.

The effect of Vitamin C and Zn supplementation on the immune system and clinical outcomes in COVID-19 patients

SARS-CoV-2 (Severe Acute Respiratory Syndrome-Coronavirus-2) is the most dangerous form of the coronavirus, which causes COVID-19. In patients with severe COVID-19, the immune system becomes markedly overactive. There is evidence that supplementation with select micronutrients may play a role in maintaining immune system function in this patient population. Throughout the COVID-19 pandemic, significant emphasis has been placed on the importance of supplementing critical micronutrients such as Vitamin C and Zinc (Zn) due to their immunomodulatory effects. Viral infections, like COVID-19, increase physiological demand for these micronutrients. Therefore, the purpose of this review was to provide comprehensive information regarding the potential effectiveness of Vitamin C and Zn supplementation during viral infection and specifically COVID-19. This review demonstrated a relation between Vitamin C and Zn deficiency and a reduction in the innate immune response, which can ultimately make patients with COVID-19 more vulnerable to viral infection. As such, adequate intake of Vitamin C and Zn, as an adjunctive therapeutic approach with any necessary pharmacological treatment(s), may be necessary to mitigate the adverse physiological effects of COVID-19. To truly clarify the role of Vitamin C and Zn supplementation in the management of COVID-19, we must wait for the results of ongoing randomized controlled trials. The toxicity of Vitamin C and Zn should also be considered to prevent over-supplementation. Over-supplementation of Vitamin C can lead to oxalate toxicity, while increased Zn intake can reduce immune system function. In summary, Vitamin C and Zn supplementation may be useful in mitigating COVID-19 symptomology.

Effect of egg consumption on inflammatory markers: a systematic review and meta-analysis of randomized controlled clinical trials

There is little evidence about whether eggs affect inflammation. The aim of this meta-analysis was to explore the effects of egg consumption on inflammation. A systematic search of online databases (Institute for Scientific Information (ISI), Scopus, Ovid, PubMed, Cochrane) was used to gather clinical trials that assessed the effect of egg consumption on circulating inflammatory biomarkers. Using a random-effects model, pooled weighted mean differences (WMD) and corresponding standard deviations (SD) were calculated. Of the 21 eligible studies found, nine trials were eligible for analysis. Eight trials assessed high-sensitivity C-reactive protein (hs-CRP), four trials assessed interleukin-6 (IL-6), and five trials assessed tumor necrosis factor-alpha (TNF-α). Egg consumption did not affect hs-CRP (WMD 0.24 mg/L; 95% CI: -0.43, 0.90; I²  = 53.8; P = 0.48), IL-6 (WMD 0.20 pg/mL; 95% CI: -0.71, 1.11; I² = 69.3; P = 0.50), and TNF-α (WMD: -0.38 pg/mL; 95% CI: -0.87, 0.10; I² = 0.00; P = 0.12) relative to controls. Overall, this meta-analysis revealed that egg consumption had no significant effect on serum biomarkers of inflammation in adults. © 2019 Society of Chemical Industry.

Effects of probiotic/synbiotic supplementation on body weight in patients with diabetes: a systematic review and meta-analyses of randomized-controlled trials

OBJECTIVE

The aim of the present study was to assess the effect of probiotic/synbiotic supplementation on anthropometric measures in adults with diabetes, independent of body weight.

METHODS

PubMed, Scopus, Web of Sciences and the Cochrane Library were searched for randomized controlled trials (RCTs) up until December 14, 2022. The effect sizes were pooled using an inverse-variance random-effects model. The methodological quality of studies as well as the quality of evidence was assessed using standard tools.

RESULTS

Thirty-two RCTs met the established inclusion criteria. Overall, compared with the respective control groups, probiotic/synbiotic supplementation resulted in a significant reduction in body weight (weighted mean difference [WMD]: -0.50 kg; 95% CI: -0.83, -0.17; I² = 79.8%, n = 27 studies]), body mass index (WMD: -0.24 kg/m²; 95% CI: -0.39, -0.09; I² = 85.7%, n = 30 studies), and waist circumference (WMD: -0.90 cm; 95% CI: -1.13, -0.52; I² = 0%, n = 11 studies). However, hip circumference and waist to hip ratio were not significantly improved.

CONCLUSIONS

Our analysis revealed that probiotic/synbiotic supplementation may assist with weight management in patients with diabetes, especially when consumed at higher doses, in younger adults, and in participants with obesity. However, more studies are needed to elucidate the anti-obesity effects of specific strains of probiotics/synbiotics.

The effect of resveratrol supplementation on biomarkers of liver health: A systematic review and meta-analysis of randomized controlled trials

This study aimed to evaluate the effect of resveratrol on liver biomarkers in adult participants, using systematic review and meta-analysis of randomized controlled trials. PubMed, Scopus, Web of Science and Cochran Library was searched, up to October 2021. The pooled effects were calculated using a random-effects model and expressed as weighted mean difference and 95% confidence interval. The methodological quality of studies as well as certainty of evidence were assessed by standard tools. Thirty-seven relevant trials were found. Although overall analysis found no significant change, subgroup analysis showed a significant improvement in alanine aminotransferase (ALT; -7.79 U/L) and glutamyl transferase (-6.0 U/L) in patients with liver disorders, and ALT (-2.22 U/L) in younger adults; however, high-dose supplementation (>1,000 mg/day) appeared to increase alkaline phosphatase concentration (+5.07 U/L). ALT also increased in older adults (+2.33 U/L) following resveratrol supplementation. We found resveratrol did not have a significant effect on liver health in the general population. However, resveratrol could be effective in patients with liver disorders. Our findings also suggest that high-dose resveratrol administration and supplementation in older adults should be performed with caution. Further high-quality clinical trials are also needed to firmly establish the clinical efficacy of resveratrol.

The effect of whole grape products on blood pressure and vascular function: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Grape consumption-associated improvements in cardiovascular health have received significant attention over the last few years; however, major gaps have remained in the meta-evidence related to this topic. This systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to explore the effect of whole grapes and its products on blood pressure, endothelial function, heart rate, and pulse rate.

METHODS AND RESULTS

Four database (PubMed, Scopus, Web of Sciences, and the Cochrane Library) were searched until the 14th of January 2022. The pooled effect size of interested outcomes was calculated using the random-effects model. Thirty eligible RCTs were identified. Pooled results indicated that compared to the control group, consumption of grape products significantly decreased systolic blood pressure (SBP) (WMD = -3.17 mmHg; 95% CI: -5.36, -0.99 mmHg; P = 0.004; I2 = 64%; P-heterogeneity<0.001); while, vascular cell adhesion molecule-1 (VCAM-1) increased (WMD = 34.11 ng/ml; 95% CI: 0.98, 67.25 ng/ml; P = 0.04; I2 = 2%; P-heterogeneity = 0.4). Although, the certainty of evidence was low and very low, respectively. No significant effect was observed on diastolic blood pressure, endothelial function, heart rate, pulse rate, and soluble intercellular adhesion molecule-1 (sICAM-1). In a subgroup analysis, consumption of whole grape products (raisin and grape powder) induced a significant decrease in SBP (WMD = -2.69 mmHg; 95% CI: -4.81, -0.57; P = 0.01; I2 = 18.1%; P-heterogeneity < 0.001), while grape juice did not.

CONCLUSION

The low certainty of evidence from RCTs revealed that consumption of grape products, especially in whole forms, resulted in a small reduction of SBP but did not influence other markers of cardiovascular health.

PROSPERO REGISTRATION CODE

CRD42022379231.

Age-related Aortic Stiffness Can Be Transferred and Ameliorated via Fecal Microbiota Transplant in Mice

Age-related increases in aortic stiffness contribute to the development of cardiovascular diseases (CVD). To determine whether the gut microbiome (GM) modulates age-related aortic stiffening, we performed fecal microbiota transplants (FMT) between young (Y; 3 month) and older (O; 25 month) male C57BL/6N mice. Following antibiotic treatment (to suppress endogenous microbiota), mice received weekly FMT (fecal samples collected at baseline) via oral gavage for 8-16 weeks from their own (i.e., sham condition: Y-y, O-o [RECIPIENT-donor]) or opposite age group (Y-o, O-y) (N=8-12/group). In vivo aortic stiffness (pulse wave velocity [PWV]) was higher in older vs. young mice at baseline (382±8 vs. 328±7cm/sec, mean±SE, P<0.001). Arterial phenotypes were transferred such that old microbiota transplanted into young mice increased, while young into old decreased, PWV (Y-y: 325±10 vs. Y-o: 362±10cm/sec, P=0.022; O-o: 409±10 vs. O-y: 335±6cm/sec, P<0.001). Intrinsic mechanical stiffness of excised aortic rings (elastic modulus) increased after transplant of old into young (Y-y: 2141±223 vs. Y-o: 3218±394kPA, P=0.022), and decreased with young into old (O-O: 3263±217 vs. O-y: 2602±136kPA, P=0.016), indicating the GM mediates aortic stiffening by modulating structural changes in the arterial wall. Age-related increases in aortic abundance of advanced glycation end products (AGEs), which cross-link arterial structural proteins, tended to be transferred by the GM (Y-y: 0.022±0.001 vs. Y-o: 0.038±0.006 A.U., P=0.11; O-o: 0.120±0.029 vs. O-y: 0.038±0.009 A.U., P=0.06). The aging GM can induce aortic stiffening via promoting AGEs accumulation and crosslinking of arterial structural proteins, and thus might be a promising target for preventing/treating age-related aortic stiffening and CVD.

The Protective Effects of Apigenin on Cognitive Function and The Brain Transcriptome in Old Mice

CCG-1423 is a Rho A pathway inhibitor which has been reported to inhibit Rho/SRF-mediated transcriptional regulation. SRF and SRF cofactors, which include ternary complex factors (TCFs) and myocardin-related transcription factor (MRTF), regulate various cellular functions. The Rho/SRF signaling pathway also regulates the sirtuin 2 (SIRT2) gene that contains a classic serum response element (SRE) sequence. Current research on CCG-1423 focuses on gene expression levels of SRF in response to CCG-1423 and how SRF levels affect the cells; the studies are focused on cell morphology, migration, viability/reproduction, and overall function. The pathways of this inhibitor have yet to be fully elucidated, but several have been suggested with good evidence. Our goal is to study the effect of CCG-1423 on mitochondrial function and gene expression of cells. In this work C2C12 myoblast cells have been used as an in-vitro model to study cellular bioenergetics and variations in gene expressions induced by CCG-1423. The effect of CCG-1423 on mitochondrial function was determined by measuring the mitochondrial oxygen consumption rate and glycolysis rate after treating C2C12 cells with varying concentrations of CCG-1423 overnight. In C2C12 myoblast cells, CCG-1423 treatment significantly reduced mitochondrial oxygen consumption rate (OCR) in a dose-dependent manner. However, treatment of C2C12 cells with CCG-1423 overnight increased the extracellular acidification rate (ECAR) in a dose-dependent manner. By indicating that CCG-1423 represses mitochondrial respiration via the Rho-SRF signaling pathway, the results of this study may enable a better understanding of the bioenergetics of the cell in the aging body.