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Dietetics, Nutrition and Biological Sciences

Permanent URI for this collectionhttps://eresearch.qmu.ac.uk/handle/20.500.12289/23

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Author: search.filters.author.Jafarnejad, SadeghSubject: search.filters.subject.Meta-analysis

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    Effect of cinnamon (Cinnamomum Zeylanicum) supplementation on serum C-reactive protein concentrations: A meta-analysis and systematic review
    (Elsevier, 2018-12-07) Vallianou, Natalia; Tsang, Catherine; Taghizadeh, Mohsen; Davoodvandi, Amirhossein; Jafarnejad, Sadegh
    Objective: The effect of cinnamon (Cinnamomum Zeylanicum) on serum C-reactive protein (CRP), an acute phase protein commonly used as a marker of inflammation, is uncertain. Therefore, the objective of the present study was to conduct a systematic review and meta-analysis of published randomised controlled trials (RCTs) of cinnamon to determine the effect on levels of serum CRP, relative to controls. Design: Studies were identified by a search of electronic databases including PubMed, Cochrane Library, Google Scholar and Scopus before August 2018. Combined and stratified analyses were used. Weighted mean differences (WMD) and its 95% confidence interval were estimated for net change in serum CRP by using random-effects model. The heterogeneity of meta-analysis was assessed by χ2 and I2 test. Results: Six studies were identified, and data from 285 participants were included. Pooled analysis showed significant reductions in serum CRP (WMD: −0.81 mg/L, 95% CI: −1.36 to −0.26, p = 0.004), with significant heterogeneity between selected studies. Improvements in sub-group analysis were observed when baseline CRP levels were greater than 3 mg/dL, and in trials of >12 weeks duration. Doses <1500 mg/day and ≥1500 mg/day were effective in lowering serum CRP (WMD: −0.56 mg/dL, 95% CI: −1.01 to -0.10, p = 0.02 and WMD: −2.13 mg/dL, 95% CI: −4.08 to −0.19, p = 0.03), respectively, with significantly reduced heterogeneity in trials with lower doses of cinnamon <1500 mg/day (test for heterogeneity: P = 0.22 and I2 = 33%). No changes were found in controls. Conclusion: Cinnamon supplementation improves levels of serum CRP, particularly in chronic conditions, where basal CRP levels are raised. Further well-designed studies are warranted to confirm or not the above-mentioned findings.
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    Effect of N-Acetylcysteine on Positive and Negative Syndrome Scale associated with Schizophrenia: A Meta-Analysis
    (Mashhad University of Medical Sciences, 2020-10) Ghaderi, Amir; Bussu, Anna; Tsang, Catherine; Jafarnejad, Sadegh
    Background and objective: N-acetylcysteine (NAC), a precursor of L-cysteine with antioxidant, anti-inflammatory and neurotropic effects, is a promising agent in alleviating symptoms associated with schizophrenia. However, the role of NAC on parameters of Positive and Negative Syndrome Scale (PANSS) remain uncertain. This systematic review and meta-analysis explored the effect of NAC on parameters of PANSS in patients with chronic schizophrenia. Methods: We searchedPubmed/MEDLINE™, PsycNET™, PsycLIT™, Scopus™ and Google Scholar™ for studies on the effect of NAC on PANSS in patients with schizophrenia from inception to March 2019. We adopted medical and non-medical subjects headings (MeSH, non-MeSH) and several keywords, including “NAC”, “N-acetylcysteine”, “N-acetyl cysteine”, “Acetylcysteine”, “N-Acetyl-L-cysteine”, “schizophrenia”, “psychotic disorder”, “psychosis”, “schizoaffective” and “dementia praecox”. Results: We identified seven trials with274 patients meeting the inclusion criteria, with follow up between 8-52 weeks, and NAC supplementation between 1200-3600 mg/day. Significant improvements in PANSS were identified following NAC for total (SMD=-0.61, 95% CI = -0.91, -0.31 ; P<0.001), general (SMD = -0.58; 95% CI = -0.90, -0.26; P=0.0004); and negative (SMD = -0.56; 95% CI = -0.92, -0.21; P = 0.001) scores, respectively. No significant heterogeneity was found among studies. Significant reductions were observed following sub-group analysis in trials ≤ 24 weeks duration, with appreciable effect size for total (SMD= -0.83), general (SMD= -0.67) and negative (SMD=-1.09) scores. Conclusion: Supplementation of NAC was effective in alleviating PANSS symptoms associated with schizophrenia in trials ≤ 24 weeks duration. The use of NAC as an adjunct seems promising and further investigation is warranted to determine its precise role.
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    Potential blood pressure lowering effect of L-citrulline supplementation in at risk populations: a meta-analysis
    (Emerald, 2022-05-10) Jafarnejad, Sadegh; Tsang, Catherine; Amin, Negin
    Purpose This paper aims to investigate the effect of L-citrulline supplementation on blood pressure (BP) in middle-aged and elderly populations. Design/methodology/approach Three electronic databases, namely, Google Scholar, PubMed and Scopus, were searched from 1990 to November 2020. Random effects model analysis was applied for quantitative data synthesis, and 6 trials with 150 participants were identified and included in the analysis. Findings Results showed an overall non-significant effect of L-citrulline supplementation on both systolic BP (SBP) and diastolic BP (DBP) in middle-aged and elderly participants. However, stratified analysis indicated a significant reduction in SBP (SMD: −0.41, 95% CI: −0.84, 0.02; p = 0.06, heterogeneity p = 0.41; I2 = 10%) but not in DBP (SMD:−0.15, 95% CI: −0.57, 0.28; p = 0.51, heterogeneity p = 0.60; I2 = 0%), following longer-term (= 8 weeks) supplementation of L-citrulline. Additionally, higher doses of L-citrulline (= 6 grams) showed a marginally significant reduction in DBP (SMD: −0.38, 95% CI: −0.78, 0.02; p = 0.06, heterogeneity p = 0.50; I2 = 0%). Originality/value In conclusion, a higher dosage and longer duration of supplementation with L-citrulline may have potential BP lowering effects in populations at an increased risk of hypertension