Higher dietary total antioxidant capacity (TAC) reduces the risk of cardio-metabolic risk factors among adults: An updated systematic review and meta-analysis

2021 ◽  
pp. 1-15
Author(s):  
Mahdieh Abbasalizad Farhangi ◽  
Ali Mohammad-Rezaei
Keyword(s):  
Systematic Review ◽  
Blood Pressure ◽  
Antioxidant Capacity ◽  
Total Antioxidant Capacity ◽  
Observational Studies ◽  
Meta Analysis ◽  
Dietary Antioxidants ◽  
Total Antioxidant ◽  
Dietary Total Antioxidant Capacity

Abstract. Background: Numerous studies have revealed the protective role of dietary antioxidants against hypertension and diabetes. In the current systematic review and meta-analysis, we evaluated the possible role of dietary total antioxidant capacity (TAC) against metabolic parameters in the adult population. Methods: A literature search of authentic electronic resources including PubMed, Scopus, Web of Sciences, and Cochrane had been performed to retrieve the qualified observational studies that reported the mean plus/minus the SD for the parameter in subjects of the highest versus lowest dietary TAC categories up to July 2020. Results: Totally, the number of included studies was 13 for fasting blood sugar (FBS), 12 for systolic blood pressure (SBP), and 12 for diastolic blood pressure (DBP), with the participants’ number of 26349. The results of the current study showed that being at highest category of TAC significantly reduces serum FBS (WMD: −2.381; CI: −3.445, −1.316; P<0.001), SBP (WMD: −1.080; CI: −1.458, −0.701; P<0.001) and DBP (WMD: −0.854; CI: −1.655, −0.052; P<0.001), while no significant difference in the serum insulin, HOMA-IR values, prevalence of type 2 diabetes (T2DM) (P=0.37) and hypertension (HTN) (P=0.09) was observed. Subgroup analysis revealed the geographical location, dietary assessment tool, sample size, and gender as possible sources of heterogeneity. Conclusion: Higher intake of dietary TAC was associated with reduced SBP, DBP, and FBS in the current observational studies of this meta-analysis. These findings further confirm the clinical importance of dietary antioxidants in the prevention of different metabolic disorders.

Dietary total antioxidant capacity (TAC), general and central obesity indices and serum lipids among adults: An updated systematic review and meta-analysis

2020 ◽  
pp. 1-17 ◽  
Author(s):  
Mahdieh Abbasalizad Farhangi ◽  
Mahdi Vajdi ◽  
Pourya Fathollahi
Keyword(s):  
Antioxidant Capacity ◽  
Total Antioxidant Capacity ◽  
Central Obesity ◽  
Meta Analysis ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Cochrane Library ◽  
Total Antioxidant ◽  
Obesity Indices ◽  
Dietary Total Antioxidant Capacity

Abstract. Background: In the present meta-analysis, we aimed to summarize the relationship between dietary total antioxidant capacity (TAC), general and central obesity indices and lipid profile in adult population. Methods: The electronic databases of Web of Sciences, PubMed, Scopus and Cochrane library were searched for relevant studies from inception to October 2019. The effect size was indicated as weighted mean difference (WMD) and 95% confidence intervals (CI) by using random effects model. The I2 index and Cochran’s Q-test were used for evaluating heterogeneity. Results: From 2,469 studies identified, thirty-four studies (nineteen cross-sectional studies, thirteen cohort studies, two case-control studies) were included in the meta-analysis. According to our results, higher categories of TAC were associated with significantly lower serum triglyceride concentartions (TG; WMD: −7.58; CI: −11.42, −3.75; P < 0.001) and waist circumference (WC; WMD: −1.17; 95% CI: −1.47, −0.87; P < 0.001); while no significant change in body mass index (BMI; WMD: −0.17; 95% CI: −0.35, 0.01; P = 0.12), high density lipoprotein cholesterol (HDL-C; WMD: 0.61; 95% CI: −0.16, 1.40; P = 0.12), low density lipoprotein cholesterol (LDL-C; WMD: 1.34; 95% CI: −0.61, 3.30; P = 0.17) and total cholesterol (TC; WMD: 1.19; 95% CI: −1.46, 3.855; P = 0.37) was reported. Conclusion: Higher dietary TAC was related to reduced prevalence of central obesity, reduced WC and TG concentrations in the current meta-analysis. Moreover, subgroup analysis showed that TAC measurement index, geographical area, dietary assessment tool, health status and gender were potential sources of heterogeneity.

Effects of Astaxanthin Supplementation on Oxidative Stress

2020 ◽  
Vol 90 (1-2) ◽  
pp. 179-194 ◽  
Author(s):  
Di Wu ◽  
Hao Xu ◽  
Jinyao Chen ◽  
Lishi Zhang
Keyword(s):  
Systematic Review ◽  
Superoxide Dismutase ◽  
Antioxidant Capacity ◽  
Subgroup Analysis ◽  
Total Antioxidant Capacity ◽  
Meta Analysis ◽  
Antioxidant Effect ◽  
High Dose ◽  
Standard Mean Difference ◽  
Total Antioxidant

Abstract. A systematic review and meta-analysis was conducted in six databases from 1948 to 2015 to assess the antioxidant activity of astaxanthin in humans. Nine randomized controlled trials were included in the systematic review. Results of meta-analysis revealed a borderline significant antioxidant effect of astaxanthin between the intervention and control groups, with a malondialdehyde-lowering effect for lipid peroxidation ( p = 0.050). However, the data included here are insufficient. When compared with the baseline in intervention groups, the meta-analysis suggested that astaxanthin supplements significantly decreased plasma malondialdehyde {Standard mean difference (SMD) −1.32 μmol/L [95% CI −1.92, −0.72]; p < 0.0001} and isoprostane (SMD −3.10 ng/mL [95% CI −4.69, −1.51]; p < 0.0001). However, they increased superoxide dismutase (SMD 1.57 U/mL [95% CI 0.57, 2.56]; p = 0.002) and total antioxidant capacity (SMD 0.77 mmol 95% CI [0.12, 1.43]; p = 0.018). For dosage subgroup analysis, high dose (≥20 mg/day) of astaxanthin showed significant antioxidant effect (on total antioxidant capacity, isoprostane, and superoxide dismutase, p < 0.05). However, low dose (<20 mg/day) showed no significant effect ( p > 0.05). Further duration subgroup analysis indicated that astaxanthin showed antioxidant effect after a 3-week intervention ( p < 0.001), whereas this effect was not observed after a 12-week or 3-month intervention (on isoprostane and superoxide dismutase, p > 0.05). This review suggested that the antioxidant effect of astaxanthin on humans is unclear.

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