Effect of Agraz (Vaccinium meridionale Swartz) on High-Density Lipoprotein Function and Inflammation in Women with Metabolic Syndrome

Effectiveness of anthocyanin-containing foods and nutraceuticals in mitigating oxidative stress, inflammation, and cardiovascular health-related biomarkers: a systematic review of animal and human interventions

Cardiovascular diseases (CVDs) are a group of chronic health disorders prevalent worldwide that claim millions of lives yearly. Inflammation and oxidative stress are intricately associated with myocardial tissue damage, endothelial dysfunction, and increased odds of heart failure. Thus, dietary strategies aimed at decreasing the odds of CVDs are paramount. In this regard, the consumption of anthocyanins, natural pigments found in edible flowers, fruits, and vegetables, has attracted attention due to their potential to promote cardiovascular health. The main mechanisms of action linked with their protective effects on antioxidant and anti-inflammatory activities, serum lipid profile modulation, and other cardiovascular health parameters are explained and exemplified. However, little is known about the dose-dependency nature of the effects, which anthocyanin has better efficiency, and whether anthocyanin-containing foods display better in vivo efficacy than nutraceuticals (i.e., concentrated extracts containing higher levels of anthocyanins than foods). Thus, this systematic review focused on determining the effects of anthocyanin-containing foods and nutraceuticals on biomarkers associated with CVDs using animal studies and human interventions supported by in vitro mechanistic insights. Overall, the results showed that the regular consumption of anthocyanin-containing foods and nutraceuticals improved vascular function, lipid profile, and antioxidant and anti-inflammatory effects. The daily dosage, the participants' health status, and the duration of the intervention also significantly influenced the results.

The Effect of Berry Consumption on Oxidative Stress Biomarkers: A Systematic Review of Randomized Controlled Trials in Humans

Bioactive compounds in berries may scavenge reactive oxygen and nitrogen species by donating electrons to free radicals, thereby protecting DNA, proteins, and lipids from oxidative damage. Evidence shows that berry consumption has beneficial health effects, though it remains unclear whether berries exert a significant impact on oxidative stress in humans. Thus, we performed a systematic review of randomized controlled trials (RCT) to examine the effects of non-acute (more than a single dose and ≥7 days) berry consumption on biomarkers of oxidative stress. Searches were conducted in PubMed, Cochrane Library, and Scopus; results were imported into Covidence for screening and data extraction. The literature search identified 622 studies that were screened, and 131 full-text studies assessed for eligibility. Ultimately, 28 RCTs met the eligibility criteria. Common biomarkers of oxidative stress (antioxidants, DNA damage, isoprostanes, malondialdehyde, and oxidized LDL) were systematically reviewed, and results were reported narratively. Of the approximate 56 oxidative stress biomarkers evaluated in the 28 RCTs, 32% of the biomarkers were reported to have statistically significant beneficial results and 68% of the biomarkers were reported as having no statistically significant differences. More well-designed and longer-term berry RCTs are needed to evaluate biomarkers of oxidative stress.

Effect of Dietary Berry Supplementation on Antioxidant Biomarkers in Adults with Cardiometabolic Risks: A Systematic Review of Clinical Trials

Cardiometabolic conditions are closely associated with inflammation and oxidative stress. Dietary berries may serve as a beneficial nutrition intervention to address the features of cardiometabolic dysfunction and associated oxidative stress. The high antioxidant status of dietary berries may increase antioxidant capacity and reduce biomarkers of oxidative stress. This systematic review was conducted to investigate these effects of dietary berries. The search was conducted using PubMed, Cochrane Library, Web of Science, and citation searching. Through this search we identified 6309 articles and 54 were included in the review. Each study's risk of bias was assessed using the 2019 Cochrane Methods' Risk of Bias 2 tool. Antioxidant and oxidative stress outcomes were evaluated, and the magnitude of effect was calculated using Cohen's d. A range of effectiveness was reported in the included studies and the quality of the studies differed between the parallel and crossover trials. Considering the inconsistency in reported effectiveness, future investigations are warranted to determine the acute and sustained reductions of oxidative stress biomarkers from dietary berry intake (PROSPERO registration# CRD42022374654).

Efficacy of Dietary Polyphenols from Whole Foods and Purified Food Polyphenol Extracts in Optimizing Cardiometabolic Health: A Meta-Analysis of Randomized Controlled Trials

The evidence from clinical trials concerning the efficacy of dietary polyphenols on cardiometabolic health is divergent. Therefore, this review aimed to determine the pooled effect of dietary polyphenols on cardiometabolic risk markers and compare the difference in efficacy between whole polyphenol-rich foods and purified food polyphenol extracts. We conducted a random-effect model meta-analysis of randomized controlled trials (RCTs) on the effect of polyphenols on blood pressure, lipid profile, flow-mediated dilation (FMD), fasting blood glucose (FBG), waist circumference, and markers of inflammation. Effect size was expressed as weighted mean difference and 95% CI. RCTs published in English between 2000 and 2021 involving adult participants with cardiometabolic risks were searched in electronic databases. Forty-six RCTs involving 2494 participants with a mean age of 53.3 ±10 y were included in this review. Whole polyphenol-rich food but not purified food polyphenol extracts significantly reduced systolic blood pressure (SBP, -3.69 mmHg; 95% CI: -4.24, -3.15 mmHg; P = 0.00001) and diastolic blood pressure (DBP, -1.44 mmHg; 95% CI: -2.56, -0.31 mmHg; P = 0.0002). Concerning waist circumference, purified food polyphenol extracts led to a larger effect (-3.04 cm; 95% CI: -7.06, -0.98 cm; P = 0.14). Significant effects on total cholesterol (-9.03 mg/dL; 95% CI: -16.46, -1.06 mg/dL; P = 0.02) and TGs (-13.43 mg/dL; 95% CI: -23.63, -3.23; P = 0.01) were observed when purified food polyphenol extracts were considered separately. None of the intervention materials significantly affected LDL-cholesterol, HDL-cholesterol, FBG, IL-6, and CRP. When both whole food and extracts were pooled together, there was a significant reduction in SBP, DBP, FMD, TGs, and total cholesterol. These findings suggest that polyphenols both as whole food and purified extracts can be efficacious in reducing cardiometabolic risks. However, these results must be interpreted with caution because of high heterogeneity and risk of bias among RCTs. This study was registered on PROSPERO as CRD42021241807.

Antioxidant properties of anthocyanins and their mechanism of action in atherosclerosis

Atherosclerosis develops due to lipid accumulation in the arterial wall and sclerosis as result of increased hyperlipidemia, oxidative stress, lipid oxidation, and protein oxidation. However, improving antioxidant status through diet may prevent the progression of atherosclerotic cardiovascular disease. It is believed that polyphenol-rich plants contribute to the inverse relationship between fruit and vegetable intake and chronic disease. Anthocyanins are flavonoid polyphenols with antioxidant properties that have been associated with reduced risk of cardiovascular disease. The consumption of anthocyanins increases total antioxidant capacity, antioxidant defense enzymes, and HDL antioxidant properties by several measures in preclinical and clinical populations. Anthocyanins appear to impart antioxidant actions via direct antioxidant properties, as well as indirectly via inducing intracellular Nrf2 activation and antioxidant gene expression. These actions counter oxidative stress and inflammatory signaling in cells present in atherosclerotic plaques, including macrophages and endothelial cells. Overall, anthocyanins may protect against atherosclerosis and cardiovascular disease through their effects on cellular antioxidant status, oxidative stress, and inflammation; however, their underlying mechanisms of action appear to be complex and require further elucidation.

Functional Food and Bioactive Compounds on the Modulation of the Functionality of HDL-C: A Narrative Review

Cardiovascular diseases (CVD) remain a serious public health problem and are the primary cause of death worldwide. High-density lipoprotein cholesterol (HDL-C) has been identified as one of the most important molecules in the prevention of CVD due to its multiple anti-inflammatories, anti-atherogenic, and antioxidant properties. Currently, it has been observed that maintaining healthy levels of HDL-C does not seem to be sufficient if the functionality of this particle is not adequate. Modifications in the structure and composition of HDL-C lead to a pro-inflammatory, pro-oxidant, and dysfunctional version of the molecule. Various assays have evaluated some HDL-C functions on risk populations, but they were not the main objective in some of these. Functional foods and dietary compounds such as extra virgin olive oil, nuts, whole grains, legumes, fresh fish, quercetin, curcumin, ginger, resveratrol, and other polyphenols could increase HDL functionality by improving the cholesterol efflux capacity (CEC), paraoxonase 1 (PON1), and cholesteryl ester transfer protein (CETP) activity. Nevertheless, additional rigorous research basic and applied is required in order to better understand the association between diet and HDL functionality. This will enable the development of nutritional precision management guidelines for healthy HDL to reduce cardiovascular risk in adults. The aim of the study was to increase the understanding of dietary compounds (functional foods and bioactive components) on the functionality of HDL.

Comparative Evaluation of the Effects of Consumption of Colombian Agraz (Vaccinium meridionale Swartz) on Insulin Resistance, Antioxidant Capacity, and Markers of Oxidation and Inflammation, Between Men and Women with Metabolic Syndrome

The metabolic syndrome (MS) is a constellation of related factors that increases the risk of developing cardiovascular diseases. Vaccinium meridionale Swartz contains polyphenols that could modulate some components of MS. Epidemiological and intervention studies have shown differences between men and women in MS components and antioxidant capacity. The objective of this study is to compare between men and women with MS the effects of agraz consumption on insulin resistance, antioxidant capacity, and markers of oxidation and inflammation. Men and women diagnosed with MS according to the Adult Treatment Panel III criteria were recruited in a double-blind, crossover study of 12 weeks. Participants were assigned to consume agraz nectar or placebo over 4 weeks. After 4 weeks of washout, they were switched to the alternative treatment. At the end of each period, the components of the MS, insulin resistance, antioxidant capacity, and some oxidative (oxidized low-density lipoprotein [oxLDL]; thiobarbituric acid reactive substances) and inflammatory (high-sensitive C-reactive protein [hs-CRP]) markers were evaluated. After consuming agraz, there was a tendency to increase the levels of antioxidants and to reduce the levels of hs-CRP in both genders. In addition, women who increased their serum phenols after consuming agraz had a significant reduction in insulin resistance, which was different from the results in men. Regarding men, those who increased their serum antioxidant capacity after consuming agraz had a better effect on the reduction of oxLDL levels that was significant compared to women. There are important differences between genders in the effects of agraz consumption in adults with MS.

Effect of Four Grape Varieties on the Physicochemical and Sensory Properties of Unripe Grape Verjuice

Verjuice is a sour-tasting juice obtained from the mechanical pressing of unripe grapes. The significance of verjuice as food product includes but not limited to its richness in antioxidant compounds, its usage as an alternative to lemon and vinegar, and also its production which can reduce the losses of lower quality grapes and waste from grape thinning. In this study, a survey for the common Lebanese traditional preparation methods for verjuice was done and physicochemical properties of four Lebanese verjuice varieties Tfayfihi, Baytamoni, Black, and Obeideh along with their sensory evaluation by consumers were studied. Results showed that "Black" grape verjuice has the highest density (1.01 ± 0.003 g/L), titratable acidity (4.51 g/L ± 0.03), total soluble solids (5.38°Brix ± 0.3), and polyphenol content (676.1 mg/L ± 6.8); verjuice processed from the Baytamoni grape variety has the highest browning index (0.432 ± 0.002) and color intensity (1.18 ± 0.007); "Obeideh" grape verjuice has the highest pH (2.55 ± 0.006); and "Tfayfihi" grape verjuice has the highest radical scavenging potential (91.76% ± 0.43) and moisture content (95.85% ± 0.19). Both "Tfayfihi" and "Black" grape verjuice has the highest total suspended solids (40 g/L ± 1.3 and 40 g/L ± 2.9, respectively) among all studied verjuice. There is no difference in taste between the four verjuice varieties which we studied, but there is a color preference for the "Tfayfihi" verjuice. The use of different varieties of grapes in the processing of verjuice affects the physicochemical and sensory properties and results in selection of grape varieties being favorable in the processing of verjuice with respect to factors such as polyphenol content and color of the final product.

Anthocyanin supplementation at different doses improves cholesterol efflux capacity in subjects with dyslipidemia-a randomized controlled trial

BACKGROUND/OBJECTIVES

Numerous clinical trials have confirmed that supplementation with purified anthocyanins has favorable effects on metabolic diseases, but the dose-response of dyslipidemia to anthocyanin supplementation remains unclear. This study aimed to investigate the effect of anthocyanin supplementation in different doses on lipid profile.

SUBJECTS/METHODS

We randomly assigned 176 dyslipidemic subjects aged 35-70 to three purified anthocyanin groups (40 mg/day, n = 45; 80 mg/day, n = 42; 320 mg/day, n = 43) and a placebo group (n = 46). Anthropometric parameters, serum lipid profiles, and cholesterol efflux capacity (CEC) were measured at baseline, and at the end of 6 and 12 weeks.

RESULTS

After 12 weeks of supplementation, significant differences in CEC (P = 0.033), high-density lipoprotein cholesterol (HDL-C) (P = 0.043), and apolipoprotein A-I (ApoA-I) (P = 0.022) were observed between four groups. Compared with placebo, 320 mg/day anthocyanin significantly increased CEC (35.8%, 95% CI: 11.5-60.2%; P = 0.004), HDL-C (0.07 mmol/L, 95% CI: 0.01-0.14; P = 0.003), and ApoA-I (0.07 g/L, 95% CI: 0.01-0.12; P = 0.008). Linear trend analysis showed that anthocyanin supplementation has a strong dose-response relationship with CEC (P = 0.002), HDL-C (P = 0.038), and ApoA-I (P = 0.023). Moreover, the enhancement of CEC showed positive correlations with the increase in HDL-C (r = 0.215, P < 0.01) and APOA-I (r = 0.327, P < 0.01).

CONCLUSIONS

Anthocyanin supplementation at 0-320 mg/day for 12 weeks enhances CEC in a dose-response manner in dyslipidemic subjects. Anthocyanin supplementation doses of 80-320 mg/day can improve serum HDL-C levels and HDL-induced CEC.

Impact of dietary anthocyanins on systemic and vascular inflammation: Systematic review and meta-analysis on randomised clinical trials

Anthocyanins are natural bioactive compounds that have several health benefits. This systematic review and meta-analysis assessed the impact of dietary anthocyanins on markers of systemic and vascular inflammation. Meta-analysis of 32 randomised controlled trials indicated that dietary anthocyanins significantly decreased levels of C-reactive protein (CRP; -0.33 mg/l, 95% CI: -0.55 to -0.11, P = 0.003), interleukin-6 (IL-6; -0.41 ρg/ml, 95% CI: -0.70 to -0.13, P = 0.004), tumor necrosis factor-alpha (TNF-α; -0.64 ρg/ml, 95% CI: -1.18 to -0.09, P = 0.023), intercellular adhesion molecule-1 (-52.4 ng/ml, 95% CI: -85.7 to -19.1, P = 0.002), and vascular adhesion molecule-1 (VCAM-1; -49.6 ng/ml, 95% CI: -72.7 to -26.5, P < 0.001) while adiponectin level was significantly increased (0.75 μg/ml, 95% CI: 0.23 to 1.26, P = 0.004). The levels of interleukin-1β (IL-1β; -0.45 ρg/ml, 95% CI: -3.77 to 2.88, P = 0.793) and P-selectin (-6.98 ng/ml, 95% CI: -18.1 to 4.15, P = 0.219) did not significantly change. Subgroup analyses showed that administration of higher doses of anthocyanins (>300 mg/day) significantly decreased levels of CRP, IL-6, TNF-α, and VCAM-1. The results indicate that dietary anthocyanins reduce the levels of systemic and vascular inflammation in the subjects.