The effect of grape products containing polyphenols on C-reactive protein levels: a systematic review and meta-analysis of randomised controlled trials

Higher Dietary Polyphenol Intake Is Associated With Lower Blood Inflammatory Markers

BACKGROUND

Evidence suggests a link between polyphenol intake and reduced incidence of several chronic diseases. This could arise through associations between polyphenol intake and reduced systemic oxidative stress and subsequent inflammation. However, confirming this association is difficult, as few large cohorts allow for comprehensive assessments of both polyphenol intake and markers of systemic inflammation.

OBJECTIVES

To address this, polyphenol intake was assessed in the UK-based Airwave cohort using 7-d diet diaries and data from Phenol-Explorer to test for associations between polyphenol intake and blood biomarkers of inflammation.

METHODS

Participants included 9008 males and females aged 17-74 y (median age: 42 y) whose data was included in a cross-sectional analysis. Phenol-Explorer was used to estimate individuals' polyphenol intake from diet data describing the consumption of 4104 unique food items. C-reactive protein (CRP) and fibrinogen were used as blood biomarkers of inflammation.

RESULTS

There were 448 polyphenols found in reported diet items. Median total polyphenol intake was 1536 mg/d (1058-2092 mg/d). Phenolic acids and flavonoids were the main types of polyphenols, and nonalcoholic beverages, vegetables, and fruit were the primary sources. Variation in energy-adjusted polyphenol intake was explained by age, sex, salary, body mass index, education level, smoking, and alcohol consumption. Linear regressions showed inverse associations between total daily intake and both CRP (β: -0.00702; P < 0.001) and fibrinogen (β: -0.00221; P = 0.038). Associations with specific polyphenol compound groups were also found. Logistic regressions using total polyphenol intake quartiles showed stepwise reductions in the odds of elevated CRP with higher intake (6%, 23%, and 24% compared with quartile 1; P = 0.003), alongside 3% and 7% lower odds per unit of polyphenol consumption equivalent to 1 cup of tea or coffee per day.

CONCLUSIONS

This study describes polyphenol intake in a large, contemporary UK cohort. We observed associations between higher intake and lower CRP and fibrinogen. This contributes to evidence supporting the health benefits of dietary polyphenols.

The Effect of Grape Seed Extract on the Alveolar, Jaw, and Skeletal Bone Remodeling: A Scoping Review

Herbal medicine has an important part in promoting and maintaining human health. One of them was grape seed extract (GSE). Various potentials of GSE in human health have been explored, and its potential for maintaining bone health is promising. Some initial research has provided evidence that the GSE was able to affect bone remodeling (bone resorption and bone formation). This scoping review analyzed and discussed all the reports on the effect of GSE on bone healing and bone remodeling in animals in the alveolar bone, jaw bone, and skeletal bone. The further purpose is to give an opportunity to research and development of supplementation of GSE for humans.The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 guidelines were used to compose this scoping review through database on Scopus, PubMed, Science Direct, Web of Science, Embase, and manual search until December 2022. The inclusion criteria were a study that analyzed the effect of supplementation GSE on all bones.All included study was in vivo study with supplementation of GSE. The supplementation of GSE affects the alveolar bone, jaw bones, and skeletal bone by promoting bone formation and inhibiting bone resorption by suppressing inflammation, apoptosis pathways, and osteoclastogenesis. It not only supports bone remodeling in bone inflammation, osteonecrosis, osteoporosis, and arthritis but also the GSE increases bone health by increasing the density and mineral deposition in trabecula and cortical bone.The supplementation of GSE supports bone remodeling by interfering with the inflammation process and bone formation not only by preventing bone resorption but also by maintaining bone density.

Anthropometric and cardiometabolic effects of polyphenols in people with overweight and obesity: an umbrella review

CONTEXT

Polyphenols are plant-based compounds with potential anti-inflammatory, antioxidant, and anti-obesogenic properties. However, their effects on health outcomes remain unclear.

OBJECTIVE

To evaluate the effects of polyphenols on anthropometric and cardiometabolic markers.

DATA SOURCES

Six electronic databases-namely, EMBASE, CINAHL, PubMed, Scopus, The Cochrane Library (reviews only), and Web of Science-were searched for relevant systematic reviews with meta-analyses (SRMAs).

DATA EXTRACTION

Three reviewers performed the data extraction via a data-extraction Microsoft Excel spreadsheet.

DATA ANALYSIS

An umbrella review and meta-analysis of existing SRMAs was conducted. Eighteen SRMAs published from 2015 to 2023, representing 445 primary studies and 838 unique effect sizes, were identified. Meta-analyses were conducted using random-effects models with general inverse variance. Polyphenol-containing foods were found to significantly improve weight (-0.36 kg; 95% confidence interval [CI]: -0.62, 0.77 kg; P < 0.01, I2 = 64.9%), body mass index (-0.25 kg/m2; 95% CI: -0.34, -0.17 kg/m2; P < 0.001, I2 = 82.4%), waist circumference (-0.74 cm; 95% CI: -1.34, -0.15 cm; P < 0.01, I2 = 99.3%), low-density-lipoprotein cholesterol (-1.75 mg/dL; 95% CI: -2.56, -0.94; P < 0.001, I2 = 98.6%), total cholesterol (-1.23 mg/dL; 95% CI: -2.00, -0.46; P = 0.002, I2 = 94.6%), systolic blood pressure (-1.77 mmHg; 95% CI: -1.77, -0.93 mmHg; P < 0.001, I2 = 72.4%), diastolic blood pressure (-1.45 mmHg; 95% CI: -2.09, -0.80 mmHg; P < 0.001, I2 = 61.0%), fat percentage (-0.70%; 95% CI: -1.03, -0.36%; P < 0.001, I2 = 52.6%), fasting blood glucose (-0.18 mg/dL; 95% CI: -0.35, -0.01 mg/dL; P = 0.04, I2 = 62.0%), and C-reactive protein (CRP; including high-sensitivity-CRP [hs-CRP]) (-0.2972 mg/dL; 95% CI: -0.52, -0.08 mg/dL; P = 0.01, I2 = 87.9%). No significant changes were found for high-density-lipoprotein cholesterol (-0.12 mg/dL; 95% CI: -1.44, 0.69; P = 0.67, I2 = 89.4%) and triglycerides (-1.29 mg/dL; 95% CI: -2.74, 0.16; P = 0.08, I2 = 85.4%). Between-study heterogeneity could be explained by polyphenol subclass differences.

CONCLUSION

The findings of this umbrella review support the beneficial effects of polyphenols on anthropometric and metabolic markers, but discretion is warranted to determine the clinical significance of the magnitude of the biomarker improvements.

SYSTEMATIC REVIEW REGISTRATION

International Prospective Register of Systematic Reviews no. CRD42023420206.

C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians

The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.

Purple grape juice improves performance of recreational runners, but the effect is genotype dependent: a double blind, randomized, controlled trial

Background

We examined the influence of superoxide dismutase 3 (SOD3) Arg213Gly and Peroxisome Proliferator-Activated α-Receptor (PPARα) 7G/C polymorphisms to a single dose of purple grape juice supplementation on time-to-exhaustion running test, redox balance and muscle damage in recreational runners.

Methods

Forty-seven male recreational runners performed a running test until exhaustion after supplementation with grape juice or a control drink. Serum total antioxidant capacity (TAC), malondialdehyde (MDA), plasma nitrite (NO), creatine kinase (CK) and lactate dehydrogenase (LDH) were measured pre and post exercise. Also, polymorphisms were analyzed in DNA extracted from the oral mucosa.

Results

Grape juice improved the time-to-exhaustion. When analyzed by genotype, the recreational runners with GG+CG genotypes of the SOD3 gene had greater time-to-exhaustion than the CC genotype, but was no different for the PAPRα gene. A slight difference was noted in TAC, since the CC genotype of the SOD3 gene showed higher TAC values in the post-exercise compared to the baseline and with pre-exercise, but these values did not increase compared to the CG+GG group, respectively. The SOD3 and PPARα genes were similar at all times for the other biochemical variables.

Conclusion

The ergogenic effect of grape juice was genotype-dependent for SOD3 Arg213Gly. However, biochemical redox balance markers did not explain this difference.

Oxygen mediated oxidative couplings of flavones in alkaline water

Catalyzed oxidative C-C bond coupling reactions play an important role in the chemical synthesis of complex natural products of medicinal importance. However, the poor functional group tolerance renders them unfit for the synthesis of naturally occurring polyphenolic flavones. We find that molecular oxygen in alkaline water acts as a hydrogen atom acceptor and oxidant in catalyst-free (without added catalyst) oxidative coupling of luteolin and other flavones. By this facile method, we achieve the synthesis of a small collection of flavone dimers and trimers including naturally occurring dicranolomin, philonotisflavone, dehydrohegoflavone, distichumtriluteolin, and cyclodistichumtriluteolin. Mechanistic studies using both experimental and computational chemistry uncover the underlying reasons for optimal pH, oxygen availability, and counter-cations that define the success of the reaction. We expect our reaction opens up a green and sustainable way to synthesize flavonoid dimers and oligomers using the readily available monomeric flavonoids isolated from biomass and exploiting their use for health care products and treatment of diseases.

The effect of grape seed extract supplementation on oxidative stress and inflammation: A systematic review and meta-analysis of controlled trials

BACKGROUND

Grape seed extract (GSE) seems to have antioxidant and anti-inflammatory properties due to its high polyphenolic content. Nevertheless, the scientific literature in this field is controversial and inconclusive. Therefore, we aimed to conduct a systematic review and meta-analysis of controlled trials to evaluate the effect of supplementation with GSE on biomarkers of oxidative stress and inflammation.

METHODS

Medline, Scopus, Cochrane Library, Google Scholar and Web of Science databases were searched up to 10 September 2020 using appropriate keywords without restrictions. In the systematic review phase, all biomarkers of oxidative stress and inflammation were considered as outcomes. In the meta-analysis phase, six biomarkers were selected as outcomes, and weighted mean difference (WMD) or standardised mean difference (SMD) with 95% confidence interval (CI) was calculated for them using a random-effects model.

RESULTS

Twenty-three studies were included in the systematic review, and 19 studies were included in the meta-analysis. GSE supplementation caused a significant decrease in malondialdehyde (SMD: -1.04, 95% CI: -1.65, -0.42), oxidised low-density lipoprotein (SMD: -0.44, 95% CI: -0.75, -0.13) and high-sensitivity C-reactive protein (WMD: -0.48 mg/L, 95% CI: -0.94, -0.03) and a marginally significant increase in total antioxidant capacity (SMD: 0.49, 95% CI: -0.05, 1.04) but did not significantly influence C-reactive protein (WMD: -0.36 mg/L, 95% CI: -1.02, 0.30) and white blood cell count (WMD: 0.12 × 10⁹ /L, 95% CI: -0.25, 0.48).

CONCLUSION

It appears that GSE supplementation can remarkably modulate the body's redox system, particularly through the inhibition of lipid peroxidation, but has neutral or mildly beneficial effects on inflammatory responses.