Blueberries improve endothelial function, but not blood pressure, in adults with metabolic syndrome: a randomized, double-blind, placebo-controlled clinical trial

Herbal drugs in chronic venous disease treatment: An update

The prevalence of chronic venous disease (CVD) is relatively high, it affects 20-80 % of the population worldwide. CVD may affect any veins in the human body, however, the veins of the lower extremities are the most susceptible to this condition. Among therapeutic possibilities for CVD, mainly chronic venous insufficiency, some medicinal plants (Ruscus aculeatus L., Aesculus hippocastanum L., Centella asiatica (L.) Urb.) and their active compounds (ruscoside, aescin, asiaticoside) or close derivatives also have important places. This review describes shortly the updated knowledge on pathophysiology, clinical manifestations, evaluation, and diagnostics of CVD as well as treatment modalities. The primary focus of this review is on the existing knowledge about botanical medications for treating chronic venous disease (CVD). It covers the chemical makeup of these plant drugs, their pharmacological effects, results from clinical trials involving humans, and any associated safety concerns.

Antioxidant activity of the main phenolics found in red fruits: An in vitro and in silico study

The current study analysed the antioxidant capacity of the main phenolics found in red fruits. In total, there were analysed the antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl radical, nitric oxide and superoxide radicals (DPPH, NO and O2-, respectively) of 23 phenolics. Regarding DPPH, anthocyanins, (-)-epicatechin and kaempferol 3-O-rutinoside were the most active, while isorhamnetin 3-O-glucoside was the least active. Anthocyanins, (-)-epicatechin, quercetin 3-O-glucoside and caffeic acid showed the strongest potential against NO, while ρ-hydroxybenzoic acid was the less efficient. Regarding the O2- assay, quercetin aglycone and their derivatives were the best ones, while cyanidin aglycone did not show any potential to quench this radical. To deeper explore the biological potential of the most promising compounds, docking molecular and ADME studies were also done. The obtained data is another support regarding the biological potential of phenolics and might be useful in encouraging their use and incorporation in new products.

Effects of Ellagic Acid on Glucose and Lipid Metabolism: A Systematic Review and Meta-Analysis

Background

Abnormal glucose and lipid metabolism (GALM) serve as both a cause and an inducer for the development of the disease. Improvement and treatment of GALM are an important stage to prevent the occurrence and development of the disease. However, current clinical treatment for GALM is limited. Ellagic acid (EA), a common polyphenol present in foods, has been shown to improve abnormalities in GALM observed in patients suffering from metabolic diseases.

Objective

This study used a meta-analysis method to systematically assess the effects of EA on GALM.

Method

As of November 8, 2023, a comprehensive search was conducted across 5 databases, namely, PubMed, Embase, Web of Science, Cochrane Library, and Google Scholar to identify randomized controlled trials (RCTs) in which EA served as the primary intervention for diseases related to GALM. The risk of bias within the included studies was assessed according to the Cochrane Handbook. All statistical analyzes were performed using RevMan 5.4 software.

Results

In this study, a total of 482 articles were retrieved, resulting in the inclusion of 10 RCTs in the meta-analysis. The results showed that EA could reduce fasting blood glucose (FBG) (p = 0.008), increase insulin secretion (p = 0.01), improve insulin resistance index (HOMA-IR) (p = 0.003), decrease triglyceride (TG) (p = 0.004), and reduce cholesterol (Chol) (p = 0.04) and low-density lipoprotein (LDL-c) (p = 0.0004). EA had no significant effect on waist circumference (WC), body weight (BW), body mass index (BMI), 2 hours after prandial blood glucose (2 h-PG), total cholesterol (TC), and high-density lipoprotein (HDL-c).

Conclusions

The effect of improvement in glucose and lipids of EA was closely related to the dose and the intervention time. EA can improve GALM caused by diseases. To corroborate the findings of this study and improve the reliability of the results, EA is imperative to refine the research methodology and increase the sample size in future investigations.

The state of the science on the health benefits of blueberries: a perspective

Mounting evidence indicates that blueberry consumption is associated with a variety of health benefits. It has been suggested that regular consumption of blueberries can support and/or protect against cardiovascular disease and function, pre-diabetes and type 2 diabetes, and brain and cognitive function in individuals with health conditions and age-related decline. Further, mechanistic investigations highlight the role of blueberry anthocyanins in mediating these health benefits, in part through interactions with gut microbiota. Also, nutritional interventions with blueberries have demonstrated the ability to improve recovery following exercise-induced muscle damage, attributable to anti-inflammatory effects. Despite these advancements in blueberry health research, research gaps persist which affects the generalizability of findings from clinical trials. To evaluate the current state of knowledge and research gaps, a blueberry health roundtable with scientific experts convened in Washington, DC (December 6-7, 2022). Discussions centered around five research domains: cardiovascular health, pre-diabetes and diabetes, brain health and cognitive function, gut health, and exercise recovery. This article synthesizes the outcomes of a blueberry research roundtable discussion among researchers in these domains, offering insights into the health benefits of blueberries and delineating research gaps and future research directions.

Effect of blueberry intervention on endothelial function: a systematic review and meta-analysis

Introduction: Endothelial dysfunction indicates blood vessel injury and is a risk factor for cardiovascular diseases. Blueberry has been approved for its benefits on human health, especially on cardiovascular function. However, its effect on endothelial function remains unclear. We conducted a systematic review and meta-analysis to explore the impact of blueberries on endothelial function in adults. Methods: We searched PubMed, Web of Science, Embase, and the Cochrane Library, 16 studies were included in the systematic review, and 11 were used for the meta-analysis. Data associated with endothelial function were extracted and pooled as mean differences (MD) with 95% confidence intervals (CI). Results: Blueberry consumption significantly improved flow-mediated dilation (FMD) by 1.50% (95% CI: 0.81, 2.20; I2 = 87%) and reactive hyperemia index (RHI) by 0.26 (95% CI: 0.09, 0.42; I2 = 72%). A significant decrease in diastolic blood pressure (DBP) was also observed (MD: -2.20 mm Hg; 95% CI: -4.13, -0.27; I2 = 11%). Subgroup analysis indicated a significant decrease in blood pressure (Systolic blood pressure [SBP]: -3.92 mmHg; 95% CI: -6.88, -0.97; I2 = 20% and DBP: -2.20 mmHg; 95% CI: -4.13, -0.27; I2 = 11%) in the smoking population. However, SBP levels (MD: -1.43 mm Hg; 95% CI: -3.11, 0.26; I2 = 20%) and lipid status (high-density lipoprotein cholesterol [HDL-C]: 0.06; 95% CI: -0.04, 0.16; I2 = 77%; low-density lipoprotein cholesterol [LDL-C]: 0.05; 95% CI: -0.14, 0.24; I2 = 0%) did not significantly improve. Conclusion: Blueberry intervention improved endothelial function and DBP. Subgroup analysis revealed a notable improvement in blood pressure among the smoking population. However, no significant effects were observed on SBP, HDL-C, and LDL-C levels. Future research should delve into the mechanisms of endothelial improvement and verify blood pressure reduction in specific subpopulations through large-scale trials. Clinical Trial Registration: https://www.crd.york.ac.uk/PROSPERO/, Identifier CRD42023491277.

Phenolic Compounds from Cherries and Berries for Chronic Disease Management and Cardiovascular Risk Reduction

Cardiovascular diseases (CVDs) are a leading cause of mortality worldwide. Therefore, there is increasing interest in dietary interventions to reduce risk factors associated with these conditions. Cherries and berries are rich sources of bioactive compounds and have attracted attention for their potential cardiovascular benefits. This review summarises the current research on the effects of cherry and berry consumption on cardiovascular health, including in vivo studies and clinical trials. These red fruits are rich in phenolic compounds, such as anthocyanins and flavonoids, which have multiple bioactive properties. These properties include antioxidant, anti-inflammatory, and vasodilatory effects. Studies suggest that regular consumption of these fruits may reduce inflammation and oxidative stress, leading to lower blood pressure, improved lipid profiles, and enhanced endothelial function. However, interpreting findings and establishing optimal dosages is a challenge due to the variability in fruit composition, processing methods, and study design. Despite these limitations, the evidence highlights the potential of cherries and berries as components of preventive strategies against CVD. Further research is needed to maximise their health benefits and improve clinical practice.

Polyphenols: immunonutrients tipping the balance of immunometabolism in chronic diseases

Mounting evidence progressively appreciates the vital interplay between immunity and metabolism in a wide array of immunometabolic chronic disorders, both autoimmune and non-autoimmune mediated. The immune system regulates the functioning of cellular metabolism within organs like the brain, pancreas and/or adipose tissue by sensing and adapting to fluctuations in the microenvironment's nutrients, thereby reshaping metabolic pathways that greatly impact a pro- or anti-inflammatory immunophenotype. While it is agreed that the immune system relies on an adequate nutritional status to function properly, we are only just starting to understand how the supply of single or combined nutrients, all of them termed immunonutrients, can steer immune cells towards a less inflamed, tolerogenic immunophenotype. Polyphenols, a class of secondary metabolites abundant in Mediterranean foods, are pharmacologically active natural products with outstanding immunomodulatory actions. Upon binding to a range of receptors highly expressed in immune cells (e.g. AhR, RAR, RLR), they act in immunometabolic pathways through a mitochondria-centered multi-modal approach. First, polyphenols activate nutrient sensing via stress-response pathways, essential for immune responses. Second, they regulate mammalian target of rapamycin (mTOR)/AMP-activated protein kinase (AMPK) balance in immune cells and are well-tolerated caloric restriction mimetics. Third, polyphenols interfere with the assembly of NLR family pyrin domain containing 3 (NLRP3) in endoplasmic reticulum-mitochondria contact sites, inhibiting its activation while improving mitochondrial biogenesis and autophagosome-lysosome fusion. Finally, polyphenols impact chromatin remodeling and coordinates both epigenetic and metabolic reprogramming. This work moves beyond the well-documented antioxidant properties of polyphenols, offering new insights into the multifaceted nature of these compounds. It proposes a mechanistical appraisal on the regulatory pathways through which polyphenols modulate the immune response, thereby alleviating chronic low-grade inflammation. Furthermore, it draws parallels between pharmacological interventions and polyphenol-based immunonutrition in their modes of immunomodulation across a wide spectrum of socioeconomically impactful immunometabolic diseases such as Multiple Sclerosis, Diabetes (type 1 and 2) or even Alzheimer's disease. Lastly, it discusses the existing challenges that thwart the translation of polyphenols-based immunonutritional interventions into long-term clinical studies. Overcoming these limitations will undoubtedly pave the way for improving precision nutrition protocols and provide personalized guidance on tailored polyphenol-based immunonutrition plans.

The effects of blueberry and cranberry supplementation on blood pressure in patients with cardiovascular diseases: A systematic review and meta-analysis of randomized clinical trials

Blueberries and cranberries are berry fruits with the highest number of randomized clinical trials (RCTs) focusing on blood pressure (BP). This systematic review and meta-analysis of RCTs analyzed the effects of blueberry and cranberry supplementation alone and in concert with systolic BP (SBP) and diastolic BP (DBP) in patients with cardiometabolic diseases. The searches were performed until August 2023 in the following databases: PubMed, Scopus, Web of Science, Cochrane, and Embase. Studies that examined the effects of blueberry or cranberry intake/supplementation were included. The risk of bias was evaluated using the Rob 2 scale. A meta-analysis was performed to estimate the effects of blueberry and cranberry supplementation on BP levels in patients with cardiometabolic diseases. A total of 17 articles were included, from which two found significant results from blueberry and/or cranberry supplementation in reducing BP. Pooled results revealed statistically non-significant reductions of -0.81 mm Hg for SBP (95% confidence interval [CI]: -2.26, 0.63; I2  = 0%) and -0.15 mm Hg for DBP (95% CI: -1.36, 1.05; I2  = 27%). Blueberry and/or cranberry supplementation had neutral effects on SBP and DBP in patients with cardiometabolic diseases, regardless of duration or age. Further high-quality studies are needed to firmly establish clinical efficacy.

Protective effects of blueberries on vascular function: A narrative review of preclinical and clinical evidence

Blueberries are rich in nutrients and (poly)phenols, popular with consumers, and a major agricultural crop with year-round availability supporting their use in food-based strategies to promote human health. Accumulating evidence indicates blueberry consumption has protective effects on cardiovascular health including vascular dysfunction (i.e., endothelial dysfunction and arterial stiffening). This narrative review synthesizes evidence on blueberries and vascular function and provides insight into underlying mechanisms with a focus on oxidative stress, inflammation, and gut microbiota. Evidence from animal studies supports beneficial impacts on vascular function. Human studies indicate acute and chronic blueberry consumption can improve endothelial function in healthy and at-risk populations and may modulate arterial stiffness, but that evidence is less certain. Results from cell, animal, and human studies suggest blueberry consumption improves vascular function through improving nitric oxide bioavailability, oxidative stress, and inflammation. Limited data in animals suggest the gut microbiome mediates beneficial effects of blueberries on vascular function; however, there is a paucity of studies evaluating the gut microbiome in humans. Translational evidence indicates anthocyanin metabolites mediate effects of blueberries on endothelial function, though this does not exclude potential synergistic and/or additive effects of other blueberry components. Further research is needed to establish the clinical efficacy of blueberries to improve vascular function in diverse human populations in a manner that provides mechanistic information. Translation of clinical research to the community/public should consider feasibility, social determinants of health, culture, community needs, assets, and desires, barriers, and drivers to consumption, among other factors to establish real-world impacts of blueberry consumption.

Anthocyanin Effects on Vascular and Endothelial Health: Evidence from Clinical Trials and Role of Gut Microbiota Metabolites

Hypertension and derived cardiovascular disease (CVD) are among the leading causes of death worldwide. Increased oxidative stress and inflammatory state are involved in different alterations in endothelial functions that contribute to the onset of CVD. Polyphenols, and in particular anthocyanins, have aroused great interest for their antioxidant effects and their cardioprotective role. However, anthocyanins are rarely detected in blood serum because they are primarily metabolized by the gut microbiota. This review presents studies published to date that report the main results from clinical studies on the cardioprotective effects of anthocyanins and the role of the gut microbiota in the metabolism and bioavailability of anthocyanins and their influence on the composition of the microbiota. Even if it seems that anthocyanins have a significant effect on vascular health, more studies are required to better clarify which molecules and doses show vascular benefits without forgetting the crucial role of the microbiota.

Effects of anthocyanin supplementation on blood lipid levels: a systematic review and meta-analysis

Introduction

Dyslipidemia is a major cardiovascular disease risk factor associated with increased mortality. The intake of plant food-derived bioactive compounds is associated with beneficial cardiovascular effects, including decreased blood lipid levels and cardiovascular risk. We aimed to evaluate the effects of anthocyanin intake on blood lipid levels by analyzing relevant randomized controlled trials.

Methods

We searched the PubMed and Embase databases using the "Patient/Population, Intervention, Comparison, and Outcomes" format to determine whether anthocyanin supplementation intervention affected blood lipid levels compared with placebo supplementation in human participants.

Results

A total of 41 studies with 2,788 participants were included in the meta-analysis. Anthocyanin supplementation significantly reduced triglyceride [standardized mean difference (SMD) = -0.10; 95% confidence interval [CI], -0.18, -0.01) and low-density lipoprotein-cholesterol (SMD = -0.16; 95% CI -0.26, -0.07) levels and increased high-density lipoprotein-cholesterol levels (SMD = 0.42; 95% CI 0.20, 0.65).

Discussion

Anthocyanin supplementation significantly improved blood lipid component levels in the included studies. Larger, well-designed clinical trials are needed to further investigate the effects of anthocyanin intake on blood lipid levels and the safety of anthocyanin supplementation for treating dyslipidemia.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021257087, identifier: CRD42021257087.

How effective are anthocyanins on healthy modification of cardiometabolic risk factors: a systematic review and meta-analysis

BACKGROUND

In this meta-analysis, findings from recent studies on the preventive properties of anthocyanins (ACN) against cardiovascular disease are summarized.

METHODS

MEDLINE, PubMed, Embase, Cochrane Library, and Google Scholar were searched and 2512 studies were found in a preliminary search. After screening of titles and abstracts, 47 studies met the inclusion criteria (randomized clinical trial design and sufficient data of outcomes). Studies were excluded based on the following criteria: incomplete data; obscurely reported outcomes, or lack of control groups; and animal studies.

RESULTS

The results showed that intervention with ACNs resulted in a significant decrease in body mass index ((MD),- 0.21; 95% CI, - 0.38, - 0.04; P < 0.001) and body fat mass (MD: - 0.3%, 95% CI - 0.42 to - 0.18%, p < 0.001). Pooled data comparing ACN with control showed statistically significant effect on fasting blood sugar and HbA1c. However, the reductions were significantly more in the subjects with type 2 diabetes and in those who used ACN as supplement/extract. The subgroup analysis test showed that there was a significant effect of ACN on triglyceride concentrations, total cholesterol, LDL-C and HDL-C concentrations in all subgroups of participants (with vs. without dyslipidemia at baseline) and intervention type (supplement/extract vs. food). However, we did not observe any significant effect on apo A and apo B concentrations.

CONCLUSIONS

ACN intake in the forms of natural foods and supplements can induce healthy changes in body fat mass, glycemic and lipidemic status and these effects are more prominent in the subjects with above-normal values. This meta-analysis was registered at http://www.crd.york.ac.uk/Prospero (Registration no. CRD42021286466).

The Research Progress of Extraction, Purification and Analysis Methods of Phenolic Compounds from Blueberry: A Comprehensive Review

Blueberry is the source of a variety of bioactive substances, including phenolic compounds, such as anthocyanins, pterostilbene, phenolic acids, etc. Several studies have revealed that polyphenols in blueberry have important bioactivities in maintaining health, such as antioxidant and anti-tumor activities, immune regulation, the prevention of chronic diseases, etc. Therefore, these phenolic compounds in blueberries have been widely used in the field of healthcare, and the extraction, isolation, and purification of phenolic compounds are the prerequisites for their utilization. It is imperative to systematically review the research progress and prospects of phenolic compounds present in blueberries. Herein, the latest progress in the extraction, purification, and analysis of phenolic compounds from blueberries is reviewed, which can in turn provide a foundation for further research and usage of blueberries.

Berry Dietary Interventions in Metabolic Syndrome: New Insights

Metabolic Syndrome (MetS) is characterized by a group of dysmetabolic conditions, including abdominal obesity, dyslipidemia, glucose intolerance and/or insulin resistance, and hypertension. Generally, MetS is accompanied by an exacerbation of oxidative stress, inflammation, and vascular dysfunction. Increasing evidence suggests that berries and berry bioactives could play a potential role in the prevention and mitigation of the risk factors associated with MetS. The present systematic review summarizes the more recently available evidence deriving from human intervention studies investigating the effect of berries in subjects with at least three out of five MetS parameters. The PubMed, Scopus, and Embase databases were systematically searched from January 2010 until December 2022. A total of 17 human intervention trials met the inclusion criteria. Most of them were focused on blueberry (n = 6), cranberry (n = 3), and chokeberry (n = 3), while very few or none were available for the other berries. If considering MetS features, the main positive effects were related to lipid profile (low and high-density lipoproteins, cholesterol, and triglycerides) following blueberries and chokeberries, while conflicting results were documented for anthropometric parameters, blood pressure, and fasting blood glucose levels. Other markers analyzed within the studies included vascular function, oxidative stress, and inflammation. Here, the main positive effects were related to inflammation with a reduction in interleukin 6 and tumor necrosis factor-alpha following the intake of different berries. In conclusion, although limited, the evidence seems to support a potential role for berries in the modulation of lipid profile and inflammation in subjects with MetS. Furthermore, high-quality intervention trials are mandatory to demonstrate the role of berries in reducing risk factors for MetS and related conditions. In the future, such a demonstration could bring the adoption of berries as a potential dietary strategy to prevent/counteract MetS and related risk factors.

Effectiveness of anthocyanins rich foods on cardiometabolic factors in individuals with metabolic syndrome: a systematic review and meta-analysis

PURPOSE

The aim of this systematic review with meta-analysis was to determine whether anthocyanin-rich foods are effective to improve cardiometabolic markers in individuals with metabolic syndrome (MetS), compared with placebo or control interventions.

METHODS

We searched MEDLINE, CENTRAL, Embase, LILACS, CINAHL, and Web of Science from their inception up to March 2022. We include clinical trials (randomized clinical trials, controlled clinical trials, and cross-over trials) with anthocyanin-rich foods versus placebo or control intervention that assessment cardiometabolic factors.

RESULTS

We found 14 clinical trials that met the eligibility criteria, and we included 10 studies for the quantitative synthesis. For anthocyanin-rich foods versus control interventions, the mean difference (MD) for low-density lipoprotein (LDL) was - 7.98 mg/dL (CI = - 15.20 to - 0.77, GRADE: Very low). For homeostatic model assessment for insulin resistance (HOMA-IR), the MD was 0.04 (CI = 0.08 to 0.16, GRADE: Moderate). The MD for interleukin 6 was 0.00 pg/mL (CI = - 0.01 to 0.00, GRADE: Low). For tumor necrosis factor alpha (TNF-α), the standardized mean difference (SMD) was - 0.52 pg/mL (CI = 0.85 to 0.19 GRADE: Very low) when compared with the control interventions. The certainty of the evidence for the other outcomes it is very low.

CONCLUSION

Our findings suggest that anthocyanin-rich foods could improve certain cardiometabolic markers (e.g., TC, TG, LDL, and TNF-α) among individuals with MetS (with very low quality evidence according to GRADE), compared with placebo or other control interventions.

PROSPERO REGISTRATION NUMBER

CRD42020187287.

Cardiovascular disease protective properties of blueberry polyphenols (Vaccinium corymbosum): a concise review

Increasing epidemiological evidence suggests inverse association between consumption of diets rich in fruits and vegetables and the incidence of cardiovascular diseases (CVD), metabolic syndrome disorders, certain types of cancer, neurodegenerative disorders, and other forms of human chronic diseases. This may be due to the contents of some bioactive phytochemicals, especially polyphenols, which are abundant in fruits and vegetables and have antioxidant effects. Berry fruits are reported to have the highest total antioxidant capacity (TAC) among fruits. They may protect against CVD and hypertension either directly or in tandem with other cellular mechanisms. Blueberry anthocyanins have been reported to exhibit cardiovascular protective health effects by preventing cholesterol-induced atherosclerosis, and reduction of oxidative and inflammatory damages to the endothelium through several mechanisms. Such mechanisms may involve suppressing the release of inflammatory mediators, protection against ischemic damage of the heart as well as cardiomyocyte survival, lower systolic and mean arterial pressures and renal nitrite content in addition to multiple other beneficial effects. However, several limitations in existing studies make it difficult to draw conclusions regarding the preventive effects of blueberries and other polyphenols-rich foods, especially as data supporting a causal relationship between direct antioxidant capacity and CVD are insufficient or limited. It is also unclear, which molecules exert this effect since few studies with isolated polyphenols have been conducted in addition to a lack of proper understanding of other mechanisms that may be involved. This review is, therefore aimed at discussing some of the current literature information on the cardiovascular protective effects of blueberries with suggestions for future research directions.

Graphical Abstract

Graphical abstract demonstrating the overall mechanisms of CVD protection by blueberry and blueberry polyphenols and anthocyanins. Blueberry consumption leads to reduced CVD complications due to the modulation of several mechanisms associated with CVD.

Daily blueberry consumption for 12 weeks improves endothelial function in postmenopausal women with above-normal blood pressure through reductions in oxidative stress: a randomized controlled trial

Estrogen-deficient postmenopausal women have oxidative stress-mediated suppression of endothelial function that is exacerbated by high blood pressure. Previous research suggests blueberries may improve endothelial function through reductions in oxidative stress, while also exerting other cardiovascular benefits. The objective of this study was to examine the efficacy of blueberries to improve endothelial function and blood pressure in postmenopausal women with above-normal blood pressure, and to identify potential mechanisms for improvements in endothelial function. A randomized, double-blind, placebo-controlled, parallel-arm clinical trial was performed, where postmenopausal women aged 45-65 years with elevated blood pressure or stage 1-hypertension (total n = 43, endothelial function n = 32) consumed 22 g day^-1 of freeze-dried highbush blueberry powder or placebo powder for 12 weeks. Endothelial function was assessed at baseline and 12 weeks through ultrasound measurement of brachial artery flow-mediated dilation (FMD) normalized to shear rate area under the curve (FMD/SR_AUC) before and after intravenous infusion of a supraphysiologic dose of ascorbic acid to evaluate whether FMD improvements were mediated by reduced oxidative stress. Hemodynamics, arterial stiffness, cardiometabolic blood biomarkers, and plasma (poly)phenol metabolites were assessed at baseline and 4, 8, and 12 weeks, and venous endothelial cell protein expression was assessed at baseline and 12 weeks. Absolute FMD/SR_AUC was 96% higher following blueberry consumption compared to baseline (p < 0.05) but unchanged in the placebo group (p > 0.05), and changes from baseline to 12 weeks were greater in the blueberry group than placebo (+1.09 × 10^-4 ± 4.12 × 10^-5vs. +3.82 × 10^-6 ± 1.59 × 10^-5, p < 0.03, respectively). The FMD/SR_AUC response to ascorbic acid infusion was lower (p < 0.05) at 12 weeks compared to baseline in the blueberry group with no change in the placebo group (p > 0.05). The sum of plasma (poly)phenol metabolites increased at 4, 8, and 12 weeks in the blueberry group compared to baseline, and were higher than the placebo group (all p < 0.05). Increases in several plasma flavonoid and microbial metabolites were also noted. No major differences were found for blood pressure, arterial stiffness, blood biomarkers, or endothelial cell protein expression following blueberry consumption. These findings suggest daily consumption of freeze-dried blueberry powder for 12 weeks improves endothelial function through reduced oxidative stress in postmenopausal women with above-normal blood pressure. The clinical trial registry number is NCT03370991 (https://clinicaltrials.gov).

Wild Blueberry (Poly)phenols can Improve Vascular Function And Cognitive Performance In Healthy Older Males And Females: A Double-Blind Randomized Controlled Trial

BACKGROUND

Evidence suggests that intake of blueberry (poly)phenols is associated with improvements in vascular function and cognitive performance. Whether these cognitive effects are linked to increases in cerebral and vascular blood flow or changes in the gut microbiota is currently unknown.

METHODS

A double-blind, parallel randomized controlled trial was conducted in 61 healthy older individuals aged 65-80 y. Participants received either 26g of freeze-dried wild blueberry (WBB) powder (302 mg anthocyanins) or a matched placebo (0 mg anthocyanins). Endothelial function measured by flow-mediated dilation (FMD), cognitive function, arterial stiffness, blood pressure (BP), cerebral blood flow (CBF), gut microbiome and blood parameters were measured at baseline and 12 weeks following daily consumption. Plasma and urinary (poly)phenol metabolites were analyzed using micro-elution solid phase-extraction coupled with LC-MS.

RESULTS

A significant increase in FMD and reduction in 24 h ambulatory systolic BP were found in the WBB group compared to placebo (0.86%; 95% CI 0.56, 1.17, p<0.001; -3.59 mmHg; 95% CI -6.95, -0.23, p=0.037; respectively). Enhanced immediate recall on the auditory verbal learning task, alongside better accuracy on a task-switch task were also found following WBB treatment compared to placebo (p<0.05). Total 24 h urinary (poly)phenol excretion increased significantly in the WBB group compared to placebo. No changes in CBF or gut microbiota composition were found.

CONCLUSIONS

Daily intake of WBB powder, equivalent to 178 g fresh weight, improves vascular and cognitive function, and decreases 24h ambulatory systolic BP in healthy older individuals. This suggests that WBB (poly)phenols may reduce future cardiovascular disease (CVD) disease risk in an older population, and may improve episodic memory processes and executive functioning in older adults at risk of cognitive decline. CLINICAL TRIAL REGISTRATION NUMBER IN CLINICALTRIALS.GOV: NCT04084457.

Blueberries and their bioactives in the modulation of oxidative stress, inflammation and cardio/vascular function markers: a systematic review of human intervention studies

Blueberries represent a rich source of (poly)phenols and other bioactive compounds. Numerous in vitro and animal model studies documented the potential health-promoting properties of blueberries and blueberry-bioactives, while little is still known about their effects in humans. The objective of the present systematic review is to provide main evidence and the potential mechanisms of action of blueberry and its (poly)phenols in the regulation of markers related to oxidative stress, inflammation, vascular and cardiometabolic function in health and disease states. A total of 45 human intervention studies were included in this review. Overall, the evidence suggests that blueberries may play a role in the improvement of markers of vascular function. Their effects were observed following both post-prandial and long-term consumption, particularly in subjects with risk factors and/or disease conditions. Conversely, the conflicting results on inflammation, oxidative stress and cardiometabolic risk markers were most likely due to differences among studies in terms of study design, subject characteristics, duration of intervention, dosage, and type of biomarkers analyzed. For these reasons, high-quality, well-designed, human intervention studies are warranted to strengthen the current findings on vascular function and provide more evidence about the impact of blueberries on the different markers considered. In addition, studies focusing on the relationship between the structure and the function of (poly)phenols will be fundamental for a better comprehension of the mechanisms behind the health effects observed.

Blueberry Consumption and Changes in Obesity and Diabetes Mellitus Outcomes: A Systematic Review

Low-grade inflammation and oxidative stress are key mechanisms involved in obesity and related disorders. Polyphenols from blueberry (BB) and bilberries (BiB) might protect against oxidative damage and inflammation. To summarize the effects of BiB or BB consumption in parameters related to obesity and its comorbidities, a search of the literature was performed in PubMed, Embase, and Cochrane Library repositories to identify all studies that evaluated associations of whole BB or BiB with obesity and associated disorders. Thirty-one studies were eligible for inclusion in this review: eight clinical trials and 23 animal studies. In humans, BB consumption only consistently decreased oxidative stress and improved endothelial function. In rodents, BB or BiB consumption caused positive effects on glucose tolerance, nuclear factor-kappa B (Nf-κb) activity, oxidative stress, and triglyceride (TG) content in the liver and hepatic steatosis. The high content of anthocyanins present in BB and BiB seems to attenuate oxidative stress. The decrease in oxidative stress may have a positive impact on glucose tolerance and endothelial function. Moreover, in rodents, these berries seem to protect against hepatic steatosis, through the decreased accumulation of hepatic TGs. BB and BiB might also attenuate inflammation by decreasing Nf-κb activity and immune cell recruitment into the adipose tissue.

Acute effect of blueberry intake on vascular function in older subjects: Study protocol for a randomized, controlled, crossover trial

Aging is associated with an increased risk of developing cardiovascular disease which is often accompanied by a decline in vascular health and function. Current evidence suggests that berries may have a potential role in the modulation of vascular function, but dietary interventions are still needed to confirm findings, especially in older subjects. In the context of the MIND FoodS HUB project, this study aims to investigate the effect of a single serving of blueberry (250 g of blueberry versus a control product) in a group of older subjects (≥ 60y) through a randomized, controlled, cross-over dietary intervention trial. Specifically, the study evaluates the absorption kinetics of bioactives following the blueberries intake and the effects on markers related to oxidative stress, inflammation, and vascular function analyzed at different time points. By considering a drop-out rate estimate of 25%, at least 20 subjects will be recruited in the study. The study will provide evidence to support the potential beneficial effects of blueberry and its bioactive compounds on vascular function in a group of population more susceptible to vascular dysfunction and to the development of cardiovascular diseases. Moreover, the study will contribute the analysis of several metabolic and functional markers that can support the biological plausibility of the results obtained. Finally, the trial will provide data on the absorption and metabolism of blueberry bioactives which will be used to study their association with the different markers under study. Trail registration: The trial is registered at ISRCTN (http://isrctn.com/ISRCTN18262533); May 7, 2021.

Elderberries as a potential supplement to improve vascular function in a SARS-CoV-2 environment

Coronavirus disease 2019 (COVID-19) pandemic has been triggered by the severe acute respiratory syndrome coronavirus (SARS-CoV-2). Although recent studies demonstrate that SARS-CoV-2 possibly does not directly infect endothelial cells (EC), the endothelium may be affected as a secondary response due to the damage of neighboring cells, circulating pro-inflammatory cytokines, and/or other mechanisms. Long-term COVID-19 symptoms specifically nonrespiratory symptoms are due to the persistence of endothelial dysfunction (ED). Based on the literature, anthocyanins a major subgroup of flavonoid polyphenols found in berries, have been well researched for their vascular protective properties as well as the prevention of cardiovascular disease (CVD)-related deaths. Elderberries have been previously used as a natural remedy for treating influenza, cold, and consequently cardiovascular health due to a high content of cyanidin-3-glucoside (C3G) a major anthocyanin found in the human diet. The literature reported many studies demonstrating that EE has both antiviral and vascular protective properties that should be further investigated as a nutritional component used against the (in)direct effect of SARS-CoV-2 in vascular function. PRACTICAL APPLICATIONS: While previous work among the literature looks promising and builds a suggestion for investigating elderberry extract (EE) against COVID-19, further in vitro and in vivo research is required to fully evaluate EE mechanisms of action and its use as a supplement to aid current therapies.

Ellagic Acid Effect on the Components of Metabolic Syndrome, Insulin Sensitivity and Insulin Secretion: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Metabolic syndrome (MetS) is a cluster of cardiovascular risk factors, usually with a common pathophysiological origin in insulin resistance and abdominal obesity. Considering the reported effects of ellagic acid (EA) on insulin resistance and abdominal obesity, the aim of this study was to evaluate the effect of EA on the components of MetS, insulin sensitivity and insulin secretion by conducting a randomized, double-blind, placebo-controlled, clinical trial with 32 volunteers diagnosed with MetS. Sixteen patients were randomly allocated, received 500 mg of EA orally twice a day for 12 weeks, and the other 16 received a placebo. Clinical and laboratory determinations were obtained at baseline and at the end of the study. After EA administration, patients reduced their waist circumference (females: 102.2 ± 4.2 to 99.5 ± 3.2 cm (p < 0.05); males: 99.8 ± 6.7 to 96.0 ± 4.7 cm (p < 0.01)), systolic blood pressure (118.1 ± 10.1 to 113.7 ± 7.8 mmHg (p < 0.01)), diastolic blood pressure (118.1 ± 10.1 to 113.7 ± 7.8 mmHg (p < 0.01)), triglycerides (2.8 ± 1.1 to 2.1 ± 0.7 mmol/L (p < 0.01)), fasting plasma glucose (6.5 ± 0.5 to 5.7 ± 0.6 mmol/L (p < 0.01)), fasting plasma insulin (p < 0.01), and insulin secretion (p < 0.05), with an increase of insulin sensitivity (p < 0.01). In male patients, high-density lipoprotein cholesterol increased (p < 0.05). In conclusion, EA improved the components of MetS, reduced hyperinsulinemia, and improved insulin sensitivity.

The Role of Berry Consumption on Blood Pressure Regulation and Hypertension: An Overview of the Clinical Evidence

The existence of a relationship between the consumption of dietary berries and blood pressure reduction in humans has been repeatedly hypothesized and documented by an increasing body of epidemiological and clinical evidence that has accumulated in recent years. However, results are mixed and complicated by a number of potentially confounding factors. The objective of this article is to review and summarize the available clinical evidence examining the effects of berry consumption on blood pressure regulation as well as the prevention or treatment of hypertension in humans, providing an overview of the potential contribution of distinctive berry polyphenols (anthocyanins, condensed tannins and ellagic acid), and results of dietary interventions with blueberries, bilberries, cranberries, raspberries, strawberries, chokeberries, cherries, blackcurrants and açai berries. We conclude that, while there is insufficient evidence supporting the existence of a direct blood pressure lowering effect, there is stronger evidence for specific types of berries acting indirectly to normalize blood pressure in subjects that are already hypertensive.

Effects of Blueberry Consumption on Cardiovascular Health in Healthy Adults: A Cross-Over Randomised Controlled Trial

Blueberries are rich in polyphenols, and their effect on cardiovascular health, including risk factors for endothelial dysfunction and hypertension, has been investigated in interventional studies. However, the difference between blueberry treatments in varied forms for their cardiovascular-protective effect remains poorly understood. The current study assessed the effects of whole blueberry and freeze-dried blueberry powder compared to a control on cardiovascular health in young adults. A cross-over randomised controlled trial (RCT) was implemented with 1 week of treatment for three treatment groups, each followed by 1 week of wash out period. Systolic (SBP) and diastolic blood pressure (DBP), pulse wave velocity (PWV), plasma cholesterol (low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and total cholesterol) and triglyceride levels (TAG), and glucose and nitrite (NO2-) concentrations were compared following fresh blueberry, freeze-dried blueberry powder, and control treatments. Thirty-seven participants with a mean age of 25.86 ± 6.81 completed the study. No significant difference was observed among fresh blueberry, blueberry powder, and the control arm. Plasma NO2- levels were improved by 68.66% and 4.34% separately following whole blueberry and blueberry powder supplementations compared to the baseline, whereas the control supplementation reported a decrease (−9.10%), although it was not statistically significant. There were no other effects shown for SBP, DBP, total cholesterol, HDL-C, LDL-C, TAG, or glucose. No difference was shown between whole blueberry and freeze-dried blueberry powder consumption for improving cardiovascular health.

Recent advances in nuclear receptors-mediated health benefits of blueberry

BACKGROUND

Blueberry is rich in bioactive substances and has anti-oxidant, anti-inflammatory, anti-obesity, anti-cancer, neuroprotective, and other activities. Blueberry has been shown to treat diseases by mediating the transcription of nuclear receptors. However, evidence for nuclear receptor-mediated health benefits of blueberry has not been systematically reviewed.

PURPOSE

This review aims to summarize the nuclear receptor-mediated health benefits of blueberry.

METHODS

This study reviews all relevant literature published in NCBI PubMed, Scopus, Web of Science, and Google Scholar by January 2022. The relevant literature was extracted from the databases with the following keyword combinations: "biological activities" OR "nuclear receptors" OR "phytochemicals" AND "blueberry" OR "Vaccinium corymbosum" as well as free-text words.

RESULTS

In vivo and in vitro experimental results and clinical evidence have demonstrated that blueberry has health-promoting effects. Supplementing blueberry is beneficial to the treatment of cancer, the alleviation of metabolic syndrome, and liver protection. Blueberry can regulate the transcription of PPARs, ERs, AR, GR, MR, LXRs, and FXR and mediate the expressions of Akt, CYP 1Al, p53, and Bcl-2.

CONCLUSION

Blueberry can be targeted to treat various diseases by mediating the transcription of nuclear receptors. Nevertheless, further human research is needed.

The Effects of Berry Polyphenols on the Gut Microbiota and Blood Pressure: A Systematic Review of Randomized Clinical Trials in Humans

Berry consumption has beneficial effects on blood pressure. Intestinal microbiota transform berry phytochemicals into more bioactive forms. Thus, we performed a systematic review of randomized clinical trials to determine whether berry polyphenols in foods, extracts or supplements have effects on both the profile of gut microbiota and systolic and diastolic blood pressure in humans. PubMed, Cochrane Library, Scopus, and CAB Abstracts (EBSCOhost) were searched for randomized clinical trials in humans published from 1 January 2011 to 29 October 2021. Search results were imported into Covidence for screening and data extraction by two blinded reviewers, who also performed bias assessment independently. The literature search identified 216 publications; after duplicates were removed, 168 publications were screened with 12 full-text publications assessed for eligibility. Ultimately three randomized clinical trials in humans met the eligibility criteria. One randomized clinical trial showed a low risk of bias while the other two randomized clinical trials included low, high or unclear risk of bias. Together the randomized clinical trials showed that berry consumption (Aronia berry, strawberries, raspberries, cloudberries and bilberries) for 8–12 weeks had no significant effect on both blood pressure and the gut microbiota. More randomized clinical trials are needed to determine the effects of berry consumption on the profile of gut microbiota and blood pressure in humans.

Effects of blueberry and cranberry on type 2 diabetes parameters in individuals with or without diabetes: A systematic review and meta-analysis of randomized clinical trials

AIMS

Blueberry and cranberry are rich in polyphenols that are associated with diabetes reduction. This study aimed: 1) to systematically review the literature on the effects of blueberry and cranberry consumption and type 2 diabetes parameters in individuals with or without type 2 diabetes and 2) to quantify these effects by carrying out a meta-analysis.

DATA SYNTHESIS

A systematic review and meta-analysis were performed using articles present in seven databases (PubMed, LILACS, Scielo, Scopus, Web of Science, Cochrane, and Embase), including publications until May 2021. We included randomized clinical trials that compared blueberry or cranberry effects on type 2 diabetes parameters, such as fasting blood glucose, insulin resistance, and glycated hemoglobin. Quality of the studies was performed using the Cochrane scale, while the Egger test assessed the publication bias and meta-regression the estimated effect sizes with potential moderator variables. From the 2034 studies identified, 39 were read in full and 22 were included in meta-analysis. In individuals with diabetes, the consumption of blueberry or cranberry significantly reduced fasting blood glucose [MD: -17.72 mg/dl; 95% CI: -29.62, -5.82; p = 0.03; I2 = 57%] and glycated hemoglobin [MD: -0.32%; 95% CI: -0.57, -0.07; p = 0.15; I2 = 39%], whereas for insulin resistance the effects were null. Results were not significant for the general population, except in the sensitivity analysis for fasting blood glucose.

CONCLUSIONS

The consumption of blueberry and cranberry significantly reduced fasting blood glucose and glycated hemoglobin levels in individuals with diabetes, with high credibility of the evidence.

Blueberry Polyphenols Increase Nitric Oxide and Attenuate Angiotensin II-Induced Oxidative Stress and Inflammatory Signaling in Human Aortic Endothelial Cells

Accumulating evidence indicate that blueberries have anti-hypertensive properties, which may be mainly due to its rich polyphenol content and their high antioxidant capacity. Thus, we aimed to investigate the mechanisms by which blueberry polyphenols exert these effects. Human aortic endothelial cells (HAECs) were incubated with 200 µg/mL blueberry polyphenol extract (BPE) for 1 h prior to a 12 h treatment with angiotensin (Ang) II, a potent vasoconstrictor. Our results indicate that Ang II increased levels of superoxide anions and decreased NO levels in HAECs. These effects were attenuated by pre-treatment with BPE. Ang II increased the expression of the pro-oxidant enzyme NOX1, which was not attenuated by BPE. Pre-treatment with BPE attenuated the Ang II-induced increase in the phosphorylation of the redox-sensitive MAPK kinases, SAPK/JNK and p38. BPE increased the expression of the redox-transcription factor NRF2 as well as detoxifying and antioxidant enzymes it transcribes including HO-1, NQO1, and SOD1. We also show that BPE attenuates the Ang II-induced phosphorylation of the NF-κB p65 subunit. Further, we show that inhibition of NRF2 leads to a decrease in the expression of HO-1 and increased phosphorylation of the NF-κB p65 subunit in HAECs treated with BPE and Ang II. These findings indicate that BPE acts through a NRF2-dependent mechanism to reduce oxidative stress and increase NO levels in Ang II-treated HAECs.

Beneficial effects of blueberry supplementation on the components of metabolic syndrome: a systematic review and meta-analysis

Metabolic syndrome (MetS) is a combination of interconnected disorders that puts a heavy burden on societies. This study investigated the impact of blueberry (BB) supplementation on components of MetS. A...

Blueberry anthocyanin intake attenuates the postprandial cardiometabolic effect of an energy-dense food challenge: Results from a double blind, randomized controlled trial in metabolic syndrome participants

Background & aims

Whilst the cardioprotective effects of blueberry intake have been shown in prospective studies and short-term randomized controlled trials (RCTs), it is unknown whether anthocyanin-rich blueberries can attenuate the postprandial, cardiometabolic dysfunction which follows energy-dense food intakes; especially in at-risk populations. We therefore examined whether adding blueberries to a high-fat/high-sugar meal affected the postprandial cardiometabolic response over 24 h.

Methods

A parallel, double-blind RCT (n = 45; age 63.4 ± 7.4 years; 64% male; BMI 31.4 ± 3.1 kg/m²) was conducted in participants with metabolic syndrome. After baseline assessments, an energy-dense drink (969 Kcals, 64.5 g fat, 84.5 g carbohydrate, 17.9 g protein) was consumed with either 26 g (freeze-dried) blueberries (equivalent to 1 cup/150 g fresh blueberries) or 26 g isocaloric matched placebo. Repeat blood samples (30, 60, 90, 120, 180, 360 min and 24 h), a 24 h urine collection and vascular measures (at 3, 6, and 24 h) were performed. Insulin and glucose, lipoprotein levels, endothelial function (flow mediated dilatation (FMD)), aortic and systemic arterial stiffness (pulse wave velocity (PWV), Augmentation Index (AIx) respectively), blood pressure (BP), and anthocyanin metabolism (serum and 24 h urine) were assessed.

Results

Blueberries favorably affected postprandial (0–24 h) concentrations of glucose (p < 0.001), insulin (p < 0.01), total cholesterol (p = 0.04), HDL-C, large HDL particles (L-HDL-P) (both p < 0.01), extra-large HDL particles (XL-HDL-P; p = 0.04) and Apo-A1 (p = 0.01), but not LDL-C, TG, or Apo-B. After a transient higher peak glucose concentration at 1 h after blueberry intake ([8.2 mmol/L, 95%CI: 7.7, 8.8] vs placebo [6.9 mmol/L, 95%CI: 6.4, 7.4]; p = 0.001), blueberries significantly attenuated 3 h glucose ([4.3 mmol/L, 95%CI: 3.8, 4.8] vs placebo [5.1 mmol/L, 95%CI: 4.6, 5.6]; p = 0.03) and insulin concentrations (blueberry: [23.4 pmol/L, 95%CI: 15.4, 31.3] vs placebo [52.9 pmol/L, 95%CI: 41.0, 64.8]; p = 0.0001). Blueberries also improved HDL-C ([1.12 mmol/L, 95%CI: 1.06, 1.19] vs placebo [1.08 mmol/L, 95%CI: 1.02, 1.14]; p = 0.04) at 90 min and XL-HDLP levels ([0.38 × 10-6, 95%CI: 0.35, 0.42] vs placebo [0.35 × 10-6, 95%CI: 0.32, 0.39]; p = 0.02) at 3 h. Likewise, significant improvements were observed 6 h after blueberries for HDL-C ([1.17 mmol/L, 95%CI: 1.11, 1.24] vs placebo [1.10 mmol/L, 95%CI: 1.03, 1.16]; p < 0.001), Apo-A1 ([1.37 mmol/L, 95%CI: 1.32, 1.41] vs placebo [1.31 mmol/L, 95%CI: 1.27, 1.35]; p = 0.003), L-HDLP ([0.70 × 10-6, 95%CI: 0.60, 0.81] vs placebo [0.59 × 10-6, 95%CI: 0.50, 0.68]; p = 0.003) and XL-HDLP ([0.44 × 10-6, 95%CI: 0.40, 0.48] vs placebo [0.40 × 10-6, 95%CI: 0.36, 0.44]; p < 0.001). Similarly, total cholesterol levels were significantly lower 24 h after blueberries ([4.9 mmol/L, 95%CI: 4.6, 5.1] vs placebo [5.0 mmol/L, 95%CI: 4.8, 5.3]; p = 0.04). Conversely, no effects were observed for FMD, PWV, AIx and BP. As anticipated, total anthocyanin-derived phenolic acid metabolite concentrations significantly increased in the 24 h after blueberry intake; especially hippuric acid (6-7-fold serum increase, 10-fold urinary increase). In exploratory analysis, a range of serum/urine metabolites were associated with favorable changes in total cholesterol, HDL-C, XL-HDLP and Apo-A1 (R = 0.43 to 0.50).

Conclusions

For the first time, in an at-risk population, we show that single-exposure to the equivalent of 1 cup blueberries (provided as freeze-dried powder) attenuates the deleterious postprandial effects of consuming an energy-dense high-fat/high-sugar meal over 24 h; reducing insulinaemia and glucose levels, lowering cholesterol, and improving HDL-C, fractions of HDL-P and Apo-A1. Consequently, intake of anthocyanin-rich blueberries may reduce the acute cardiometabolic burden of energy-dense meals.

Clinical trial registry

NCT02035592 at www.clinicaltrials.gov.

Potential Benefits of Berry Anthocyanins on Vascular Function

Cardiovascular disease (CVD), such as hypertension and atherosclerosis, is the leading cause of global death. Endothelial dysfunction (ED) is a strong predictor for most CVD making it a therapeutic target for both drug and nutrition interventions. It has been previously shown that polyphenols from wine and grape extracts possess vasodilator activities, due to the increased expression and phosphorylation of the endothelial nitric oxide synthase (eNOS), and consequent vasodilator nitric oxide (NO) production. This is vital in the prevention of ED, as NO production contributes to the maintenance of endothelial homeostasis. Moreover, polyphenols have the ability to inhibit reactive oxygen species (ROS), which can cause oxidative stress, as well as suppress the upregulation of inflammatory markers within the endothelium. However, while the majority of the research has focused on red wine, this has overshadowed the potential of other nutritional components for targeting ED, such as the use of berries. Berries are high in anthocyanin flavonoids a subtype of polyphenols with studies suggesting improved vascular function as a result of inducing NO production and reducing oxidative stress and inflammation. This review focuses on the protective effects of berries within the vasculature.

Vaccinium Species (Ericaceae): From Chemical Composition to Bio-Functional Activities

The genus Vaccinium L. (Ericaceae) includes more than 450 species, which mainly grow in cooler areas of the northern hemisphere. Vaccinium species have been used in traditional medicine of different cultures and the berries are widely consumed as food. Indeed, Vaccinium supplement-based herbal medicine and functional food, mainly from V. myrtillus and V. macrocarpon, are used in Europe and North America. Biological studies support traditional uses since, for many Vaccinium components, important biological functions have been described, including antioxidant, antitumor, anti-inflammatory, antidiabetic and endothelium protective activities. Vaccinium components, such as polyphenols, anthocyanins and flavonoids, are widely recognized as modulators of cellular pathways involved in pathological conditions, thus indicating that Vaccinium may be an important source of bioactive molecules. This review aims to better describe the bioactivity of Vaccinium species, focusing on anti-inflammatory and endothelial protective cellular pathways, modulated by their components, to better understand their importance for public health.

Effects of Berry Anthocyanins on Cognitive Performance, Vascular Function and Cardiometabolic Risk Markers: A Systematic Review of Randomized Placebo-Controlled Intervention Studies in Humans

Supplementation with anthocyanins, which are a type of flavonoids mainly found in various berries, is hypothesized to be a promising approach to lower the risk of developing cognitive decline. The aim of this systematic review was to provide a comprehensive overview of dietary intervention trials describing effects of berry anthocyanins on cognitive performance in humans, while also addressing potential underlying mechanisms. A total of 1197 articles were identified through a systematic search, and 49 studies reporting effects on cognitive performance (n = 18), vascular function (n = 22), or cardiometabolic risk markers (n = 32) were included. Significant improvements were observed on memory, while some of the studies also reported effects on attention and psychomotor speed or executive function. Vascular function markers such as brachial artery flow-mediated vasodilation were also affected and consistent evidence was provided for the beneficial effects of berry anthocyanins on endothelial function. Finally, studies reported improvements in blood pressure, but effects on metabolic risk markers (e.g. carbohydrate and lipid metabolism) were less consistent. In conclusion, this review provides evidence for the beneficial effects of berry anthocyanins on cognitive performance as memory improved. Whether observed anthocyanin-induced improvements in vascular function and blood pressure underlie beneficial effects on cognitive performance warrants further study.

Blueberry intervention improves metabolic syndrome risk factors: systematic review and meta-analysis

Recent studies have found that blueberry supplementation can improve parameters related to metabolic syndrome (MetS); however, there is no definitive consensus. Analysis of several randomized controlled trials can demonstrate whether a reduced effect of MetS risk factors is more pronounced in individuals who received supplementation with blueberry than in individuals who did not receive this supplementation. This systematic review and meta-analysis aimed to investigate the effect of blueberry intervention on MetS risk factors, including blood pressure, anthropometric measurements, and glycemic and lipid profiles. PubMed, Scopus, Web of Science, and SciELO were systematically searched to identify relevant studies published before July 2020. To compare the effects of blueberry supplements (powder, extract, fruit, juice, or frozen) with placebo, the mean differences with 95 % confidence intervals (CI) were pooled based on the random-effects model. We classified the quality of evidence according to the GRADE approach. In total, 18 randomized controlled trials (RCTs) were included in this systematic review, and 12 studies were selected for meta-analysis. Based on the Cochrane Collaboration risk-of-bias tool, all studies were of good quality. These trials differed with regards to blueberry dosage and forms, recruited subjects, and trial duration. Meta-analyses of the data showed that blueberry intervention had a significant effect on lipid levels, decreasing total cholesterol and low-density lipoprotein (LDL) levels. We found no significant differences in the glycemic status markers and anthropometric measurements. Blueberry supplementation significantly decreased diastolic blood pressure. In conclusion, the meta-analysis showed that blueberry may be efficacious in the treatment of MetS, due to its beneficial effects on lipid and blood pressure markers.

An 8-week freeze-dried blueberry supplement impacts immune-related pathways: a randomized, double-blind placebo-controlled trial

Background

Blueberries contain high levels of polyphenolic compounds with high in vitro antioxidant capacities. Their consumption has been associated with improved vascular and metabolic health.

Purpose

The objective was to examine the effects of blueberry supplement consumption on metabolic syndrome (MetS) parameters and potential underlying mechanisms of action.

Methods

A randomized double-blind placebo-controlled intervention trial was conducted in adults at risk of developing MetS. Participants consumed 50 g daily of either a freeze-dried highbush blueberry powder (BBP) or a placebo powder for 8 weeks (n = 49). MetS phenotypes were assessed at weeks 0, 4 and 8. Fasting blood gene expression profiles and plasma metabolomic profiles were examined at baseline and week 8 to assess metabolic changes occurring in response to the BBP. A per-protocol analysis was used.

Results

A significant treatment effect was observed for plasma triglyceride levels that was no longer significant after further adjustments for age, sex, BMI and baseline values. In addition, the treatment*time interactions were non-significant therefore suggesting that compared with the placebo, BBP had no statistically significant effect on body weight, blood pressure, fasting plasma lipid, insulin and glucose levels, insulin resistance (or sensitivity) or glycated hemoglobin concentrations. There were significant changes in the expression of 49 genes and in the abundance of 35 metabolites following BBP consumption. Differentially regulated genes were clustered in immune-related pathways.

Conclusion

An 8-week BBP intervention did not significantly improve traditional markers of cardiometabolic health in adults at risk of developing MetS. However, changes in gene expression and metabolite abundance suggest that clinically significant cardiometabolic changes could take longer than 8 weeks to present and/or could result from whole blueberry consumption or a higher dosage. BBP may also have an effect on factors such as immunity even within a shorter 8-week timeframe.

Clinical trial registration

clinicaltrials.gov, NCT03266055, 2017

Supplementary Information

The online version contains supplementary material available at 10.1186/s12263-021-00688-2.

The effect of barberry (Berberis vulgaris) consumption on flow-mediated dilation and inflammatory biomarkers in patients with hypertension: A randomized controlled trial

Hypertension is considered as an important cardiovascular risk factor and evidence suggests that hypertension and endothelial dysfunction reinforce each other. Polyphenol-rich foods, such as barberry can reduce the risk of cardiovascular disease. Our aim was to investigate the effects of barberry consumption on vascular function and inflammatory markers in hypertensive subject. In this randomized controlled parallel trial, 84 hypertensive subjects of both genders (aged 54.06 ± 10.19 years; body mass index 28.02 ± 2.18 kg/m2 ) were randomly allocated to consume barberry (10 g/day dried barberry) or placebo for 8 weeks. Before and after the intervention, changes in brachial flow-mediated dilation (FMD) and plasma macrophage/monocyte chemo-attractant protein-1 (MCP-1), vascular cellular adhesion molecule-1, and intracellular adhesion molecule-1 (ICAM-1) were measured. An intention-to-treat analysis was performed. Compared to placebo (n = 42), barberry consumption (n = 42) improved FMD (B [95% CI] was 6.54% [4.39, 8.70]; p < .001) and decreased plasma ICAM-1 (B [95% CI] was -1.61 ng/ml [-2.74, -0.48]; p = .006). MCP-1 was significantly lower in the barberry group compared with the placebo group (B [95% CI] was -37.62 pg/ml [-72.07, -3.17]; p = .033). Our results indicate that barberry consumption improves FMD and has a beneficial effect on plasma ICAM-1 and MCP-1 in hypertensive patients. This trial was registered at the Iranian Registry of Clinical Trial (IRCT) with number IRCT20160702028742N8.

Berries and Their Polyphenols as a Potential Therapy for Coronary Microvascular Dysfunction: A Mini-Review

Ischemia with no obstructive coronary artery disease (INOCA) is a common diagnosis with a higher prevalence in women compared to men. Despite the absence of obstructive coronary artery disease and no structural heart disease, INOCA is associated with major adverse cardiovascular outcomes as well a significant contributor to angina and related disability. A major feature of INOCA is coronary microvascular dysfunction (CMD), which can be detected by non-invasive imaging and invasive coronary physiology assessments in humans. CMD is associated with epicardial endothelial-dependent and -independent dysfunction, diffuse atherosclerosis, and left-ventricular hypertrophy, all of which lead to insufficient blood flow to the myocardium. Inflammatory and oxidative stress signaling, upregulation of the renin-angiotensin-aldosterone system and adrenergic receptor signaling are major drivers of CMD. Treatment of CMD centers around addressing cardiovascular risk factors; however, there are limited treatment options for those who do not respond to traditional anti-anginal therapies. In this review, we highlight the ability of berry-derived polyphenols to modulate those pathways. The evidence supports the need for future clinical trials to investigate the effectiveness of berries and their polyphenols in the treatment of CMD in INOCA patients.

Sex May Modulate the Effects of Combined Polyphenol Extract and L-citrulline Supplementation on Ambulatory Blood Pressure in Adults with Prehypertension: A Randomized Controlled Trial

Increased blood pressure (BP), vascular dysfunction and inflammation are involved in the etiology of cardiovascular disease (CVD). Although several dietary components such as polyphenols and L-citrulline may help to control BP, their combined impact on ambulatory BP in individuals at risk of CVD remains unknown. The objective of this research was to investigate the short-term impact of supplementation with a combination of polyphenol extract and L-citrulline on ambulatory BP, endothelial function and inflammation. In a randomized double-blind parallel trial, 73 men and women with prehypertension were supplemented with a placebo (cellulose, n = 34, Plac) or 548 mg/day of polyphenols and 2 g/day of L-citrulline (n = 35, Suppl) for 6 weeks. The primary outcome of this study was the difference between groups in 24-h ambulatory diastolic BP (DBP) at week six. Secondary outcomes were a difference between groups at week six in ambulatory systolic BP (SBP), casual BP, serum lipids and high-sensitivity C-reactive protein (hs-CRP) concentrations and skin advanced glycation end products (AGEs). Potential interaction of treatment with sex was examined. Suppl had no impact on mean ambulatory SBP and DBP (p > 0.10 vs. placebo). Daytime and 24-h SBP were reduced with Suppl in women (p ≤ 0.01), but not in men (p ≥ 0.27). A non-significant reduction in AGEs was observed after Suppl compared to Plac among all participants (p = 0.07) and there was no difference in the concentrations of blood lipids (p > 0.20) or CRP (p = 0.36) between treatments at week six. Therefore, supplementation with polyphenol extract and L-citrulline for 6 weeks has no impact on ambulatory BP, blood lipids and CRP in adults with prehypertension. However, the polyphenol extract/L-citrulline supplement may reduce ambulatory SBP in women, but not in men. These preliminary results need further research efforts towards further documenting this sex-dependent BP response to supplementation with polyphenols and L-citrulline.

Blueberry Supplementation in Neuronal Health and Protective Technologies for Efficient Delivery of Blueberry Anthocyanins

Blueberries are consumed as healthy fruits that provide a variety of benefits to the nervous system. Scientists have found that blueberries can be used as a daily edible source for supplementation to prevent and minimize complexities of age-related diseases as well as to improve learning and memory in children. Anthocyanins are the most mentioned compounds among the components in blueberries, as they play a major role in providing the health benefits of this fruit. However, while they are highly active in impeding biological impairment in neuronal functions, they have poor bioavailability. This review focuses on neurological investigations of blueberries from in vitro cell studies to in vivo studies, including animal and human studies, with respect to their positive outcomes of neuroprotection and intervention in neurodegenerative conditions. Readers will also find information on the bioavailability of anthocyanins and the considerable factors affecting them so that they can make informed decisions regarding the daily consumption of blueberries. In this context, the ways in which blueberries or blueberry supplementation forms are consumed and which of these forms is best for maximizing the health benefits of blueberries should be considered important decision-making factors in the consumption of blueberries; all of these aspects are covered in this review. Finally, we discuss recent technologies that have been employed to improve the bioavailability of blueberry anthocyanins in the development of effective delivery vehicles supporting brain health.

Effects of Montmorency Tart Cherry Juice Consumption on Cardiometabolic Biomarkers in Adults with Metabolic Syndrome: A Randomized Controlled Pilot Trial

Greater than one-third of adults in the United States have metabolic syndrome (MetS), a cluster of risk factors highly associated with the development of cardiovascular diseases. Premature vascular dysfunction in MetS may lead to accelerated age-related atherogenesis and arterial stiffening, thereby increasing cardiovascular risk. Montmorency tart cherries (Prunus cerasus L.) are rich in bioactive compounds, such as anthocyanins, known to exert cardiovascular protective effects. Previous research suggests that tart cherry juice consumption may improve cardiovascular health. The objective of this study was to evaluate the effects of daily consumption of tart cherry juice on hemodynamics, arterial stiffness, and blood biomarkers of cardiovascular and metabolic health in men and women with MetS. In a randomized, single-blind, placebo-controlled, parallel-arm pilot clinical trial, 19 men and women 20 to 60 years of age with MetS consumed 240 mL of tart cherry juice (Tart Cherry; n = 5 males, 4 females) or an isocaloric placebo-control drink (Control; n = 5 males, 5 females) twice daily for 12 weeks. Arterial stiffness (pulse wave velocity), brachial and aortic blood pressures, wave reflection (augmentation index), and blood biomarkers of cardiovascular and metabolic health were assessed at baseline and 6 and 12 weeks. Oxidized low-density lipoprotein and soluble vascular cell adhesion molecule-1 were significantly lower (P = .047 and P = .036, respectively) in Tart Cherry than Control at 12 weeks, but were not significantly lower than baseline values. There was a trend for total cholesterol to be lower (P = .08) in Tart Cherry than Control at 12 weeks. No significant changes were observed in hemodynamics, arterial stiffness, or other blood biomarkers assessed. These results suggest that daily tart cherry consumption may attenuate processes involved in accelerated atherogenesis without affecting hemodynamics or arterial stiffness parameters in this population. The pilot nature of this study warrants interpreting these findings with caution, and future clinical trials with a larger sample size are needed to confirm these findings.

Anthocyanin Bioactivity in Obesity and Diabetes: The Essential Role of Glucose Transporters in the Gut and Periphery

Obesity and type-2 diabetes trends continue to worsen in the United States. Dietary anthocyanins (typically provided by berries and other fruits) are reported to have protective effects against both conditions using a variety of experimental research models including animal and human feeding studies. This review highlights studies that explore the biochemical pathways in both tissue and rodent models which could explain clinical improvements noted with anthocyanin consumption. First, the primary mode of intestinal absorption of anthocyanins is through both sGLT1 and GLUT2 glucose transporters. Stronger binding affinities may allow anthocyanins to be more inhibitive to glucose absorption compared to the reverse, where GLUT2 expression may also be affected. Genetic or chemical inhibition of sGLT1 or GLUT2 demonstrate their essential function in anthocyanin absorption across the enterocyte, where the former interacts with a greater variety of anthocyanins but the latter is the major transporter for specific anthocyanin-glycosides. Once absorbed, anthocyanins positively modulate GLUT4 density and function in both skeletal muscle and adipose tissues via the upregulation of AMPK and restoration of insulin sensitivity. Antioxidant properties and phosphodiesterase inhibition by anthocyanins promote both mitochondrial function and density which could be novel targets for dietary management of obesity and its complications.

Blueberry Consumption Challenges Hepatic Mitochondrial Bioenergetics and Elicits Transcriptomics Reprogramming in Healthy Wistar Rats

An emergent trend of blueberries’ (BB) “prophylactic” consumption, due to their phytochemicals’ richness and well-known health-promoting claims, is widely scaled-up. However, the benefits arising from BB indiscriminate intake remains puzzling based on incongruent preclinical and human data. To provide a more in-depth elucidation and support towards a healthier and safer consumption, we conducted a translation-minded experimental study in healthy Wistar rats that consumed BB in a juice form (25 g/kg body weight (BW)/day; 14 weeks’ protocol). Particular attention was paid to the physiological adaptations succeeding in the gut and liver tissues regarding the acknowledged BB-induced metabolic benefits. Systemically, BB boosted serum antioxidant activity and repressed the circulating levels of 3-hydroxybutyrate (3-HB) ketone bodies and 3-HB/acetoacetate ratio. Moreover, BB elicited increased fecal succinic acid levels without major changes on gut microbiota (GM) composition and gut ultra-structural organization. Remarkably, an accentuated hepatic mitochondrial bioenergetic challenge, ensuing metabolic transcriptomic reprogramming along with a concerted anti-inflammatory pre-conditioning, was clearly detected upon long-term consumption of BB phytochemicals. Altogether, the results disclosed herein portray a quiescent mitochondrial-related metabolomics and hint for a unified adaptive response to this nutritional challenge. The beneficial or noxious consequences arising from this dietary trend should be carefully interpreted and necessarily claims future research.

Comprehensive characterisation of phenolics from Nitraria sibirica leaf extracts by UHPLC-quadrupole-orbitrap- MS and evaluation of their anti-hypertensive activity

ETHNOPHARMACOLOGICAL RELEVANCE

For more than ten scores years, the leaves and fruits of Nitraria sibirica have been used as a natural remedy for indigestion, irregular manes, and hypertension in the Middle East and Central Asia, especially, are recommended for hypertension treatment in the northwest region, China.

AIM OF THE STUDY

we aimed to support the traditional usage of N. sibirica leaves as pharmaceuticals or dietary supplements in treatment of hypertension by investigating their chemical constituents and anti-hypertensive activity. 
 METHODS: We identified the chemical composition of N. sibirica leaves ethanolic purified extract (NSL-EPE) using UHPLC-quadrupole-orbitrap-MS, and quantified the main chemical constituents by an analytical method established and validated. We also evaluated anti-hypertensive activity of NSL-EPE using spontaneously hypertensive rats (SHR): blood pressure was measured weekly by non-invasive blood pressure (NIBP) measurements; hemodynamic parameters, biochemical and clinical chemistry variables in plasma, serum and kidney tissue were measured after 10 weeks of treatment with NSL-EPE as well.
 RESULTS: UHPLC-quadrupole-orbitrap-MS analysis identified 52 compounds, of which 40 compounds were reported for the first time in N. sibirica. 11 phenolic compounds further quantitatively analyzed, among which the most abundant compound was found to be clovin (8.8%). Systolic blood pressure decreased progressively from the second treatment week compared to that in non-treated SHRs. The plasma endothelin, aldosterone, angiotensin II levels were significantly increased, while the level of NO_X was significantly decreased; glutathione to oxidized glutathione ratio, superoxide dismutase and total catalase levels in the kidney tissue were markedly accelerated, while malondialdehyde level was significantly reduced in NSL-EPE treated SHRs. Moreover, the serum cholesterol, triglyceride, blood uria nitrogen and creatinine were attenuated in NSL-EPE treated SHRs (P < 0.05), but in sharp contrast to those values in the water-treated SHRs.

CONCLUSION

This study screened out leading compounds from N. sibirica and offered a new understanding of the antihypertensive properties of N. sibirica leaves, by which inhibit oxidative stress-induced endothelial dysfunction and improve lipid profiles.

Bilberry Supplementation after Myocardial Infarction Decreases Microvesicles in Blood and Affects Endothelial Vesiculation

SCOPE

Diet rich in bilberries is considered cardioprotective, but the mechanisms of action are poorly understood. Cardiovascular disease is characterized by increased proatherogenic status and high levels of circulating microvesicles (MVs). In an open-label study patients with myocardial infarction receive an 8 week dietary supplementation with bilberry extract (BE). The effect of BE on patient MV levels and its influence on endothelial vesiculation in vitro is investigated.

METHODS AND RESULTS

MVs are captured with acoustic trapping and platelet-derived MVs (PMVs), as well as endothelial-derived MVs (EMVs) are quantified with flow cytometry. The in vitro effect of BE on endothelial extracellular vesicle (EV) release is examined using endothelial cells and calcein staining. The mechanisms of BE influence on vesiculation pathways are studied by Western blot and qRT-PCR. Supplementation with BE decreased both PMVs and EMVs. Furthermore, BE reduced endothelial EV release, Akt phosphorylation, and vesiculation-related gene transcription. It also protects the cells from P2X7 -induced EV release and increase in vesiculation-related gene expression.

CONCLUSION

BE supplementation improves the MV profile in patient blood and reduces endothelial vesiculation through several molecular mechanisms related to the P2X7 receptor. The findings provide new insight into the cardioprotective effects of bilberries.

Role of berries in vascular function: a systematic review of human intervention studies

CONTEXT

Berries are a source of polyphenols with recognized health-promoting activities. Several studies suggest that consumption of berries may improve vascular function.

OBJECTIVE

The aim of this systematic review is to provide evidence of short- and long-term benefits of berries on outcomes of vascular function.

DATA SOURCES

Human intervention studies were collected from PubMed and Scopus databases.

STUDY SELECTION

Studies were eligible if they investigated the effects of acute or chronic berry consumption on one or more markers of vascular function in humans and provided a characterization of the berry polyphenolic content. Only randomized controlled trials were included, and studies were excluded if berries were combined with other foods.

DATA EXTRACTION

After selection, 22 randomized controlled trials were included and analyzed, most of which were performed in healthy individuals or patients with cardiovascular risk factors.

RESULTS

The overall results seem to suggest a protective role of berries in vascular function, likely dependent on the time of exposure, the type and dose of berry, and the biomarkers analyzed. Flow-mediated dilation and reactive hyperemia index (markers of vascular reactivity) improved following short-term interventions, while pulse wave velocity and augmentation index (markers of arterial stiffness) improved only after medium- to long-term intervention.

CONCLUSIONS

Current evidence suggests that berries, at physiological relevant doses, may have a role in the modulation of vascular function and stiffness. High-quality human intervention trials are encouraged in order to strengthen these findings and to better elucidate the mechanisms involved in such modulation.