Six weeks daily ingestion of whole blueberry powder increases natural killer cell counts and reduces arterial stiffness in sedentary males and females

Anthocyanins in Vascular Health and Disease: Mechanisms of Action and Therapeutic Potential

ABSTRACT

Unhealthy lifestyles have placed a significant burden on individuals' cardiovascular health. Anthocyanins are water-soluble flavonoid pigments found in a wide array of common foods and fruits. Anthocyanins have the potential to contribute to the prevention and treatment of cardiovascular disease by improving lipid profiles and vascular function, reducing blood glucose levels and blood pressure, and inhibiting inflammation. These actions have been demonstrated in numerous clinical and preclinical studies. At the cellular and molecular level, anthocyanins and their metabolites could protect endothelial cells from senescence, apoptosis, and inflammation by activating the phosphoinositide 3-kinase/protein kinase B/endothelial nitric oxide synthases, silent information regulator 1 (SIRT1), or nuclear factor erythroid2-related factor 2 pathways and inhibiting the nuclear factor kappa B, Bax, or P38 mitogen-activated protein kinase pathways. Furthermore, anthocyanins prevent vascular smooth muscle cell from platelet-derived growth factor -induced or tumor necrosis factor-α-induced proliferation and migration by inhibiting the focal adhesion kinase and extracellular regulated protein kinases signaling pathways. Anthocyanins could also attenuate vascular inflammation by reducing the formation of oxidized lipids, preventing leukocyte adhesion and infiltration of the vessel wall, and macrophage phagocytosis of deposited lipids through reducing the expression of cluster of differentiation 36 and increasing the expression of ATP-binding cassette subfamily A member 1 and ATP-binding cassette subfamily G member 1. At the same time, anthocyanins could lower the risk of thrombosis by inhibiting platelet activation and aggregation through down-regulating P-selectin, transforming growth factor-1, and CD40L. Thus, the development of anthocyanin-based supplements or derivative drugs could provide new therapeutic approaches to the prevention and treatment of vascular diseases.

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.

The effects of raspberry consumption on lipid profile and blood pressure in adults: A systematic review and meta-analysis

Research into the effects of raspberry on blood pressure and lipid profiles is inconclusive. This meta-analysis was aimed to determine whether raspberry has beneficial effects in clinical practice and to what extent these effects are associated with blood pressure and lipid profiles. A systematic literature search up to September 2023 was completed in PubMed/Medline, Scopus, and Web of Science, to identify eligible RCTs. Heterogeneity tests of the selected trials were performed using the I 2 statistic. Random effects models were evaluated based on the heterogeneity tests, and pooled data were determined as weighted mean differences with a 95% confidence interval. Eleven randomized controlled trials (with 13 arms) were eligible for this meta-analysis. Our findings revealed that Raspberry consumption had no significant effects on the blood pressure and lipid profile markers, including systolic blood pressure (SBP) (WMD, -0.37 mm Hg; 95%CI: -2.19 to 1.44; p = .68), diastolic blood pressure (DBP) (WMD, -2.14 mm Hg; 95%CI: -4.27 to 0.00; p = .05), total cholesterol (TC) (WMD, -6.83 mg/dL; 95%CI: -15.11 to 1.44; p = .10), triglycerides (TG) (WMD, -5.19 mg/dL: 95%CI: -11.76 to 1.37; p = .12), low-density lipoprotein-cholesterol (LDL-C) (WMD, -5.19 mg/dL; 95%CI: -11.58 to 1.18; p = .11), and high-density lipoprotein-cholesterol (HDL-C) (WMD, 0.82 mg/dL; 95%CI: -1.67 to 3.32; p = .51), compared to control groups. Subgroup analysis showed that raspberry consumption significantly decreased total cholesterol and LDL-C levels in people with elevated TC levels, metabolic syndrome, and andropause symptoms, as well as those older than 35, while the consumption of raspberries led to a significant increase in HDL-C levels in females, obese, under 35, and healthy individuals. Raspberry can improve lipid profile and blood pressure, but it is important to keep in mind that further research is necessary to fully understand the exact mechanism of action and a definite conclusion in this regard.

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.

Natural Immunomodulatory Agents as a Complementary Therapy for Poxviruses

Poxviruses target innate immunity mediators such as tumor necrosis factors, interleukins, interferons, complement, and chemokines. It also targets adaptive immunity such as CD4+ T cells, CD4+ T cells, and B cells. Emerging of the recent epidemic of monkeypox virus (MPXV), a zoonotic disease native to Central and Western Africa, besides the lack of permitted treatments for poxviruses infections, encouraged researchers to identify effective inhibitors to help in preventing and treating poxviruses infections. Natural bioactive components, particularly polyphenolics, are promising for creating powerful antioxidants, anti-inflammatory, immune-stimulating, and antiviral agents. As a result, they are potentially effective therapies for preventing and treating viral diseases, such as infections caused by poxviruses including the recent pandemic MPXV. Polyphenolics: rosmarinic acid, caffeic acid, resveratrol, quercitrin, myricitrin, gingerol, gallotannin, and propolis-benzofuran A, as well as isoquinoline alkaloids: galanthamine and thalimonine represent prospective antiviral agents against MPXV, they can inhibit MPXV and other poxviruses via targeting different viral elements including DNA Topoisomerase I (TOP1), Thymidine Kinase (TK), serine/threonine protein kinase (Ser/Thr kinase), and protein A48R. The bioactive extracts of different traditional plants including Guiera senegalensis, Larrea tridentata, Sarracenia purpurea, Kalanchoe pinnata (Lam.) Pers., Zingiber officinale Roscoe, Quercus infectoria, Rhus chinensis, Prunella vulgaris L., Salvia rosmarinus, and Origanum vulgare also can inhibit the growth of different poxviruses including MPXV, vaccinia virus (VACV), variola virus, buffalopox virus, fowlpox virus, and cowpox virus. There is an urgent need for additional molecular studies to identify and confirm the anti-poxviruses properties of various natural bioactive components, especially those that showed potent antiviral activity against other viruses.

Natural killer cells immunosenescence and the impact of lifestyle management

Natural killer cells (NKs) are lymphocytes of the innate immune system that quickly respond to viruses, infections, and tumors during their short cell life cycle. However, it was recently found that NKs undergo quantitative, distributional, structural, and functional phenotypic changes during aging that suppress immune responses, which is known as immunosenescence. The aging host environment, cytokine regulation, cytomegalovirus status, and hypothalamic‒pituitary‒adrenal axis have significant effects on NK function. Different lifestyle management interventions modulate the number and cytotoxic activity of NKs, which are essential for rebuilding the immune barrier against pathogens in elderly individuals. Based on recent studies, we review the phenotypic changes of and potential threats of NKs during aging and explore the underlying mechanisms. By summarizing the effects of lifestyle management on NKs and their application prospects, we aim to provide evidence for enhancing immune system function against immune diseases in elderly individuals.

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.

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

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

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

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

Association between dietary intake of anthocyanidins and heart failure among American adults: NHANES (2007–2010 and 2017–2018)

Background

Despite anthocyanidins have anti-inflammatory and antioxidant properties, no studies have researched association between dietary intake of anthocyanidins and heart failure.

Methods

We enrolled 15,869 participants from the National Health and Nutrition Examination Survey (NHANES) (2007–2010 and 2017–2018) in this cross-sectional study. We examined baseline data and prevalence of heart failure in different quartile groups of anthocyanin intake (Q1-4). Three models were established through logistic regression to evaluate the protective effect of Q4 (highest anthocyanidins intake) on heart failure. The protective effect of high anthocyanidins intake on heart failure was further evaluated in different subgroups.

Results

Participants with the highest anthocyanidins intake (Q4) had the lowest prevalence of heart failure (Q1:2.54%, Q2:2.33%, Q3:2.43%, Q4:1.57%, p = 0.02). After adjusting for possible confounding factors, compared with the Q1 group, the highest anthocyanidins intake (Q4) was independently related to lower presence of heart failure (Q4: OR 0.469, 95%CI [0.289, 0.732], p = 0.003). And this association was still stable in subgroups of female, ≥45 years, smoker, non-Hispanic White or without diabetes, stroke and renal failure.

Conclusion

Dietary intake of anthocyanidins had negative association with the presence of heart failure.

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).

Dried Fruits, Nuts, and Cancer Risk and Survival: A Review of the Evidence and Future Research Directions

Dried fruits and nuts contain high amounts of nutrients and phytochemicals-all of which may have anticarcinogenic, anti-inflammatory, and antioxidant properties. This narrative review summarizes the evidence for dried fruits and nuts and cancer incidence, mortality, and survival and their potential anticancer properties. The evidence for dried fruits in cancer outcomes is limited, but existing studies have suggested an inverse relationship between total dried fruit consumption and cancer risk. A higher consumption of nuts has been associated with a reduced risk of several site-specific cancers in prospective cohort studies, including cancers of the colon, lung, and pancreas, with relative risks per 5 g/day increment equal to 0.75 (95% CI 0.60, 0.94), 0.97 (95% CI 0.95, 0.98), and 0.94 (95% CI 0.89, 0.99), respectively. A daily intake of total nuts of 28 g/day has also been associated with a 21% reduction in the rate of cancer mortality. There is also some evidence that frequent nut consumption is associated with improved survival outcomes among patients with colorectal, breast, and prostate cancer; however, further studies are needed. Future research directions include the investigation of additional cancer types, including rare types of cancer. For cancer prognosis, additional studies with pre- and postdiagnosis dietary assessment are warranted.

Randomized Double-Blind Controlled Trial of Freeze-Dried Strawberry Powder Supplementation in Adults with Overweight or Obesity and Elevated Cholesterol

OBJECTIVE

Recommended dietary patterns improve cardiovascular disease (CVD) risk factors such as blood pressure and LDL-C, as well as emerging markers that confer residual risk. Strawberry consumption has been shown to improve CVD risk factors, but further research is needed to better understand these effects using a dose-response model that evaluates a standard serving and a higher (but still achievable) dose.

METHODS

A randomized, placebo-controlled, double-blinded crossover trial was conducted in middle-aged adults with overweight or obesity (n = 40; mean BMI = 29.4 ± 0.2 kg/m²; mean age = 50 ± 1.0 years) and moderately elevated LDL-C (mean LDL-C: 140 ± 3 mg/dL) to investigate the effect of two doses of strawberry supplementation on LDL-C and other CVD risk factors. Study interventions were: 0 g/d (control), 13 g/d (low-dose), and 40 g/d (high-dose) of freeze-dried strawberry powder (4-week supplementation periods separated by a 2-week compliance break).

RESULTS

There was a significant main effect of treatment for the primary outcome of LDL-C, with a 4.9% reduction following the low-dose strawberry supplement compared to the high-dose (P = 0.01), but not compared to the control. There was also a significant effect on total cholesterol (TC), with a 2.8% and 2.4% reduction following the low-dose compared to the control and high-dose, respectively (P ≤ 0.05 in post-hoc analyses). There was a near significant effect for direct LDL-C (P = 0.07). There were no significant treatment effects for other atherogenic lipoprotein characteristics, indices of vascular function, measures of inflammation, or HDL efflux.

CONCLUSION

Low-dose supplementation with freeze-dried strawberry powder, equivalent to ∼1 serving/day of fresh strawberries, improved cholesterol in adults with overweight or obesity, compared to both the high-dose (∼3 servings/day of fresh strawberries) and control, but did not alter other markers of CVD.

Supplemental data for this article is available online at.

The effect of dietary anthocyanins on biochemical, physiological, and subjective exercise recovery: a systematic review and meta-analysis

Anthocyanins (ACN), the sub-class of (poly)phenols responsible for the red-blue-purple pigmentation of fruit and vegetables, have gained considerable interest in sport and exercise research due to their potential to facilitate exercise recovery. A systematic literature search was performed using PubMed, The Cochrane Library, MEDLINE, SPORTDiscus and CINAHL. Thirty nine studies were included and the standardized mean difference (Hedges g) for creatine kinase (CK), anti-oxidative and inflammatory markers, strength, power and delayed onset muscle soreness (DOMS) indices were pooled in separate meta-analyses; meta-regression was also performed on reported ACN dose. Immediately post-exercise there was an increase in antioxidant capacity (g: 0.56) and reduced C reactive protein (g: -0.24) and tumor necrosis factor α (g: -40); p ≤ 0.02. Strength was improved with ACN at all time points (g: 0.45-0.67). DOMS (g: -0.23) was lower 24 hours post-exercise and power was improved 24 hours (g: 0.62) and 48 hours (g: 0.57) post exercise. The CK was lower 48 hours post-exercise (g: -0.31) and there was a trend for a positive association with ACN dose (p = 0.057). This systematic review provides new data showing ACN-rich foods promote functional and subjective recovery likely due to the antioxidant and anti-inflammatory properties of ACN.

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.

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.

Chemical Compounds of Berry-Derived Polyphenols and Their Effects on Gut Microbiota, Inflammation, and Cancer

Berry-derived polyphenols are bioactive compounds synthesized and secreted by several berry fruits. These polyphenols feature a diversity of chemical compounds, including phenolic acids and flavonoids. Here, we report the beneficial health effects of berry-derived polyphenols and their therapeutical application on gut-microbiota-related diseases, including inflammation and cancer. Pharmacokinetic investigations have confirmed the absorption, availability, and metabolism of berry-derived polyphenols. In vitro and in vivo tests, as well as clinical trials, showed that berry-derived polyphenols can positively modulate the gut microbiota, inhibiting inflammation and cancer development. Indeed, these compounds inhibit the growth of pathogenic bacteria and also promote beneficial bacteria. Moreover, berry-derived polyphenols exhibit therapeutic effects against different gut-microbiota-related disorders such as inflammation, cancer, and metabolic disorders. Moreover, these polyphenols can manage the inflammation via various mechanisms, in particular the inhibition of the transcriptional factor Nf-κB. Berry-derived polyphenols have also shown remarkable effects on different types of cancer, including colorectal, breast, esophageal, and prostate cancer. Moreover, certain metabolic disorders such as diabetes and atherosclerosis were also managed by berry-derived polyphenols through different mechanisms. These data showed that polyphenols from berries are a promising source of bioactive compounds capable of modulating the intestinal microbiota, and therefore managing cancer and associated metabolic diseases. However, further investigations should be carried out to determine the mechanisms of action of berry-derived polyphenol bioactive compounds to validate their safety and examinate their clinical uses.

Betalain-rich dragon fruit (pitaya) consumption improves vascular function in men and women: a double-blind, randomized controlled crossover trial

BACKGROUND

Betalains are natural red color pigments abundant in red-fleshed dragon fruit (Hylocereus polyrhizus). Recent research has shown that dragon fruit consumption may help improve blood glucose and lipid profile. However, investigations of its cardioprotective properties in human trials, especially in nutritionally achievable amounts, remain nonexistent.

OBJECTIVES

The aim of this study was to investigate the effects of acute and short-term consumption of dragon fruit on vascular function in a healthy population.

METHODS

A randomized, double-blind, placebo-controlled, crossover trial was conducted in 19 young, healthy, nonsmoking men and women assigned to consume 24 g whole dragon fruit powder (33 mg betalains) or a nutrient-matched placebo, daily for 14 d. Flow-mediated dilation (FMD), arterial stiffness, and blood pressure (BP) were measured at 0 h, 1 h, 2 h, 3 h, and 4 h and finally at 14 d after daily consumption.

RESULTS

A total of 18 participants completed the trial. Dragon fruit consumption significantly improved acute FMD at 2 h (+0.8 ± 0.3%, P = 0.01), 3 h (+1.0 ± 0.3%, P = 0.001), and 4 h (+1.3 ± 0.4%, P < 0.001) postconsumption compared with placebo. This effect was sustained up until 14 d (+1.3 ± 0.2%, P < 0.001). Pulse-wave velocity was acutely significantly reduced at 3 h (-0.5 ± 0.2 m/s, P = 0.003), whereas augmentation index (AIx) also improved after 14 d (-7.0 ± 3.3%, P = 0.02) when compared with placebo. No differences were found in either peripheral or central BP across all time points.

CONCLUSIONS

Acute and short-term consumption of dragon fruit in dietary achievable amounts improved endothelial function and arterial stiffness in healthy individuals. This implies that regular dragon fruit consumption may have a meaningful impact on cardiovascular disease risk likely due to the high betalain content. This trial was registered at ClinicalTrials.gov as NCT03995602.

Anthocyanins, Anthocyanin-Rich Berries, and Cardiovascular Risks: Systematic Review and Meta-Analysis of 44 Randomized Controlled Trials and 15 Prospective Cohort Studies

Objective: The associations between intake of anthocyanins and anthocyanin-rich berries and cardiovascular risks remained to be established. We aimed to quantitatively summarize the effects of purified anthocyanins and anthocyanin-rich berries on major surrogate markers of cardiovascular diseases (CVDs) and the longitudinal associations between dietary anthocyanins and CVD events.

Methods: Meta-analysis of randomized controlled trials (RCTs) and prospective cohort studies.

Results: We included 44 eligible RCTs and 15 prospective cohort studies in this study. Pooled analysis of RCTs showed that purified anthocyanin supplementation could significantly reduce blood LDL cholesterol (weighted mean difference (WMD): −5.43 mg/dL, 95% CI: −8.96, −1.90 mg/dL; p = 0.003) and triglyceride (WMD: −6.18 mg/dL, 95% CI: −11.67, −0.69 mg/dL; p = 0.027) while increase HDL cholesterol (WMD: 11.49 mg/dL, 95% CI: 7.43, 15.55 mg/dL; p < 0.001) concentrations. Purified anthocyanins also markedly decreased circulating tumor necrosis factor alpha (WMD: −1.62 pg/mL, 95% CI: −2.76, −0.48 pg/mL; p = 0.005) and C-reactive protein (WMD: −0.028 mg/dL, 95% CI: −0.050, −0.005 mg/dL; p = 0.014). Besides, administration of anthocyanin-rich berries could significantly lower blood total cholesterol (WMD: −4.48 mg/dL, 95% CI: −8.94, −0.02 mg/dL; p = 0.049) and C-reactive protein (WMD: −0.046 mg/dL, 95% CI: −0.070, −0.022 mg/dL; p < 0.001). Neither purified anthocyanins nor anthocyanin-rich berries could cause any substantial improvements in BMI, blood pressure, or flow-mediated dilation. In addition, meta-analysis of prospective cohort studies suggested that high dietary anthocyanins were related to lower risk of coronary heart disease (CHD) (relative risk (RR): 0.83, 95% CI: 0.72, 0.95; p = 0.009), total CVD incidence (RR: 0.73, 95% CI: 0.55, 0.97; p = 0.030), and total CVD deaths (RR: 0.91, 95% CI: 0.87, 0.96; p < 0.001).

Conclusion: Habitual intake of anthocyanins and anthocyanin-rich berries could protect against CVDs possibly via improving blood lipid profiles and decreasing circulating proinflammatory cytokines.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO, identifier: CRD42020208782.

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.

The Relationship Between Dietary Choices and Health and Premature Vascular Ageing

The paper aims to review the available data about the main mechanisms enabling improvement or accelerating vascular ageing due to food choices, considering recent experimental and clinical data, and emphasising potential implications for clinical practice and therapy. The main food choices which will be discussed are diets rich in fruits and vegetables, the Mediterranean diet, polyunsaturated fatty acids, cocoa, caffeine, tea, meat, dairy products, sodium, and potassium intake.

Effects of Cranberry Juice Supplementation on Cardiovascular Disease Risk Factors in Adults with Elevated Blood Pressure: A Randomized Controlled Trial

Emerging cardiovascular disease (CVD) risk factors, including central vascular function and HDL efflux, may be modifiable with food-based interventions such as cranberry juice. A randomized, placebo-controlled, crossover trial was conducted in middle-aged adults with overweight/obesity (n = 40; mean BMI: 28.7 ± 0.8 kg/m²; mean age: 47 ± 2 years) and elevated brachial blood pressure (mean systolic/diastolic BP: 124 ± 2/81 ± 1 mm Hg). Study participants consumed 500 mL/d of cranberry juice (~16 fl oz; 27% cranberry juice) or a matched placebo juice in a randomized order (8-week supplementation periods; 8-week compliance break), with blood samples and vascular measurements obtained at study entry and following each supplementation period. There was no significant treatment effect of cranberry juice supplementation on the primary endpoint of central systolic blood pressure or central or brachial diastolic pressure. Cranberry juice significantly reduced 24-h diastolic ambulatory BP by ~2 mm Hg compared to the placebo (p = 0.05) during daytime hours. Cranberry juice supplementation did not alter LDL-C but significantly changed the composition of the lipoprotein profile compared to the placebo, increasing the concentration of large LDL-C particles (+29.5 vs. −6.7 nmol/L; p = 0.02) and LDL size (+0.073 vs. −0.068 nm; p = 0.001). There was no effect of treatment on ex vivo HDL efflux in the total population, but exploratory subgroup analyses identified an interaction between BMI and global HDL efflux (p = 0.02), with greater effect of cranberry juice in participants who were overweight. Exploratory analyses indicate that baseline C-reactive protein (CRP) values may moderate treatment effects. In this population of adults with elevated blood pressure, cranberry juice supplementation had no significant effect on central systolic blood pressure but did have modest effects on 24-h diastolic ambulatory BP and the lipoprotein profile. Future studies are needed to verify these findings and the results of our exploratory analyses related to baseline health moderators.

Dietary Effects of Anthocyanins in Human Health: A Comprehensive Review

In recent years, the consumption of natural-based foods, including beans, fruits, legumes, nuts, oils, vegetables, spices, and whole grains, has been encouraged. This fact is essentially due to their content in bioactive phytochemicals, with the phenolic compounds standing out. Among them, anthocyanins have been a target of many studies due to the presence of catechol, pyrogallol, and methoxy groups in their chemical structure, which confer notable scavenging, anti-apoptotic, and anti-inflammatory activities, being already recommended as supplementation to mitigate or even attenuate certain disorders, such as diabetes, cancer, and cardiovascular and neurological pathologies. The most well-known anthocyanins are cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside. They are widespread in nature, being present in considerable amounts in red fruits and red vegetables. Overall, the present review intends to discuss the most recent findings on the potential health benefits from the daily intake of anthocyanin-rich foods, as well as their possible pharmacological mechanisms of action. However, before that, some emphasis regarding their chemical structure, dietary sources, and bioavailability was done.

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.

Effects of Anthocyanins on Vascular Health

Cardiovascular disorders are leading mortality causes worldwide, often with a latent evolution. Vascular health depends on endothelial function, arterial stiffness, and the presence of atherosclerotic plaques. Preventive medicine deserves special attention, focusing on modifiable cardiovascular risk factors, including diet. A diet rich in fruits and vegetables has well-known health benefits, especially due to its polyphenolic components. Anthocyanins, water-soluble flavonoid species, responsible for the red-blue color in plants and commonly found in berries, exert favorable effects on the endothelial function, oxidative stress, inhibit COX-1, and COX-2 enzymes, exert antiatherogenic, antihypertensive, antiglycation, antithrombotic, and anti-inflammatory activity, ameliorate dyslipidemia and arterial stiffness. The present review aims to give a current overview of the mechanisms involved in the vascular protective effect of anthocyanins from the human diet, considering epidemiological data, in vitro and in vivo preclinical research, clinical observational, retrospective, intervention and randomized studies, dietary and biomarker studies, and discussing preventive benefits of anthocyanins and future research directions.

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.

Immunomodulatory Effects of Dietary Polyphenols

Functional and nutraceutical foods provide an alternative way to improve immune function to aid in the management of various diseases. Traditionally, many medicinal products have been derived from natural compounds with healing properties. With the development of research into nutraceuticals, it is becoming apparent that many of the beneficial properties of these compounds are at least partly due to the presence of polyphenols. There is evidence that dietary polyphenols can influence dendritic cells, have an immunomodulatory effect on macrophages, increase proliferation of B cells, T cells and suppress Type 1 T helper (Th1), Th2, Th17 and Th9 cells. Polyphenols reduce inflammation by suppressing the pro-inflammatory cytokines in inflammatory bowel disease by inducing Treg cells in the intestine, inhibition of tumor necrosis factor-alpha (TNF-α) and induction of apoptosis, decreasing DNA damage. Polyphenols have a potential role in prevention/treatment of auto-immune diseases like type 1 diabetes, rheumatoid arthritis and multiple sclerosis by regulating signaling pathways, suppressing inflammation and limiting demyelination. In addition, polyphenols cause immunomodulatory effects against allergic reaction and autoimmune disease by inhibition of autoimmune T cell proliferation and downregulation of pro-inflammatory cytokines (interleukin-6 (IL-6), IL-1, interferon-γ (IFN-γ)). Herein, we summarize the immunomodulatory effects of polyphenols and the underlying mechanisms involved in the stimulation of immune responses.

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.

Insights to potential antihypertensive activity of berry fruits

Hypertension is one of the main risk factors for cardiovascular disease and causes widespread morbidity and mortality worldwide. Although several antihypertensive drugs have been proposed for management of high blood pressure, changing lifestyle, including diet, has attracted interest recently. In this sense, consumption of fruits and vegetables, which are rich in vitamins, minerals, and phytochemicals, has been assigned as an efficient therapeutics. Berry fruits contain various bioactive compounds with potential health implications such as antioxidant, antimicrobial, anticancer, and anti-inflammatory properties. The main mechanisms responsible for antihypertensive activity mainly arise from the activity of flavonoids, minerals, and vitamins, as well as fibers. The objective of this review is to provide a summary of studies regarding the effect of berry fruits on the hypertensive animals and humans. The mechanisms involved in reducing blood pressure by each group of compounds have been highlighted. It can be concluded that berries' bioactive compounds are efficient in mitigation of hypertension through improvement of vascular function, angiotensin-converting enzyme's (ACE) inhibitory activity, increasing endothelial nitric oxide synthase (eNOS) activity, and nitric oxide (NO) production, besides anti-oxidative and anti-inflammatory activities. These fruits can be considered as potential sources of invaluable compounds for development of antihypertensive foods and pharmaceuticals.

Potential health benefits of (poly)phenols derived from fruit and 100% fruit juice

(Poly)phenol-rich diets have been associated with reduced risk of various diseases. Coffee and tea are typically identified as dietary sources of chlorogenic acid and flavan-3-ols; however, 100% fruit juice greatly contributes to anthocyanin, flavonol, flavan-3-ols, and flavanone intake, making them complementary sources of dietary (poly)phenols. Thus, the aim of this narrative review was to provide an overview of fruit (poly)phenols and their potential health benefits. Fruit (poly)phenols have been associated with several health benefits (eg, reduced risk of cardiovascular disease and neurocognitive benefits). Although perspectives on 100% fruit juice consumption are controversial due to the perception of sugar content, growing evidence supports the role of fruit in whole and 100% juice forms to provide consumer benefits in alignment with dietary guidance. However, differences in (poly)phenol profiles and bioavailability likely exist between whole fruit and 100% fruit juice due to processing and the presence/absence of fiber. Ongoing studies are better defining similarities and differences between whole fruit and 100% fruit juice to elucidate protective mechanisms and align with processing and consumer products.

Effects of chronic consumption of specific fruit (berries, citrus and cherries) on CVD risk factors: a systematic review and meta-analysis of randomised controlled trials

Purpose

This review aims to compare the magnitude of the effects of chronic consumption of fruits; specifically berries, citrus and cherries on cardiovascular disease (CVD) risk factors.

Methods

PubMed, Web of Science, Scopus, and psycARTICLES were searched from inception until January 2020. Forty-five chronic (≥ 1 week) randomised controlled trials assessing CVD risk factors including endothelial (dys)function, blood pressure (BP), blood lipids and inflammatory biomarkers were included.

Results

Investigated interventions reported improvements in endothelial function (n = 8), inflammatory biomarkers and lipid status (n = 14), and BP (n = 10). Berries including juice of barberry, cranberry, grape, pomegranate, powder of blueberry, grape, raspberry and freeze-dried strawberry significantly reduced SBP by 3.68 mmHg (95% CI − 6.79 to − 0.58; P = 0.02) and DBP by 1.52 mmHg (95% CI − 2.87 to − 0.18, P = 0.04). In subgroup analysis, these associations were limited to cranberry juice (SBP by 1.52 mmHg [95% CI − 2.97 to − 0.07; P = 0.05], DBP by 1.78 mmHg [95% CI − 3.43 to − 0.12, P = 0.04] and cherry juice (SBP by 3.11 mmHg [95% CI − 4.06 to − 2.15; P = 0.02]). Berries also significantly elevated sVCAM-1 levels by 14.57 ng/mL (85% CI 4.22 to 24.93; P = 0.02).

Conclusion

These findings suggest that supplementing cranberry or cherry juice might contribute to an improvement in blood pressure. No other significant improvements were observed for other specified fruits. More research is warranted comparing different classes of fruit and exploring the importance of fruit processing on their cardiovascular-protective effects.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02299-w) contains supplementary material, which is available to authorized users.

Blueberry and cardiovascular disease risk factors: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Cardiovascular disease (CVD) remains an important cause of mortality and morbidity that can be prevented by the consumption of healthy foods. These include blueberry, a dark coloured berry containing extremely high amounts of functional ingredients. We therefore examined the extent to which supplementation with blueberry effects on CVD risk indices.

METHODS

We searched the ISI Web of Science, Scopus, PubMed and Cochrane Library on March 2020 and checked reference lists from primary studies and review articles for any additional studies. No language restrictions were applied. All randomized and controlled clinical trials (RCTs) using blueberry supplements to modify CVD risk factors were included in our analysis.

RESULTS

Mean Difference (MD) was pooled using a random effects model and 11 studies were included in the final analysis. Pooled effect size showed that supplementation with blueberry had a small insignificant effect in reducing plasma triglycerides (MD = -0.27 mmol/l; 95 % CI: -0.57, 0.17, p = 0.06). Although current study found no differences between blueberry and control groups for any other outcomes, subgroup analysis suggested a favourable impact of blueberry on reducing body weight. Significant weight loss was indicated from studies longer with a follow up of more than 6 weeks or with blueberry powder or freeze-dried blueberry.

CONCLUSION

Current evidence is insufficient to show a benefit of blueberry supplements in modifying CVD risk factors across a variety of adult populations. Robust data and larger studies are required to assess potential effects.

Recent Research on the Health Benefits of Blueberries and Their Anthocyanins

Awareness of the human health benefits of blueberries is underpinned by a growing body of positive scientific evidence from human observational and clinical research, plus mechanistic research using animal and in vitro models. Blueberries contain a large number of phytochemicals, including abundant anthocyanin pigments. Of their various phytochemicals, anthocyanins probably make the greatest impact on blueberry health functionality. Epidemiological studies associate regular, moderate intake of blueberries and/or anthocyanins with reduced risk of cardiovascular disease, death, and type 2 diabetes, and with improved weight maintenance and neuroprotection. These findings are supported by biomarker-based evidence from human clinical studies. Among the more important healthful aspects of blueberries are their anti-inflammatory and antioxidant actions and their beneficial effects on vascular and glucoregulatory function. Blueberry phytochemicals may affect gastrointestinal microflora and contribute to host health. These aspects have implications in degenerative diseases and conditions as well as the aging process. More evidence, and particularly human clinical evidence, is needed to better understand the potential for anthocyanin-rich blueberries to benefit public health. However, it is widely agreed that the regular consumption of tasty, ripe blueberries can be unconditionally recommended.

Fruits

Fruits come in a wide variety of colors, shapes, and flavors. This chapter will cover selected fruits that are known to be healthy and highly nutritious. These fruits were chosen due to their common usage and availability. Since it is not possible to cover all health benefits or essential nutrients and important phytochemicals of the fruit composition, this chapter will focus on the key valuable constituents and their potential health effects.

Plant-Derived Bioactives and Oxidative Stress-Related Disorders: A Key Trend towards Healthy Aging and Longevity Promotion

Plants and their corresponding botanical preparations have been used for centuries due to their remarkable potential in both the treatment and prevention of oxidative stress-related disorders. Aging and aging-related diseases, like cardiovascular disease, cancer, diabetes, and neurodegenerative disorders, which have increased exponentially, are intrinsically related with redox imbalance and oxidative stress. Hundreds of biologically active constituents are present in each whole plant matrix, providing promissory bioactive effects for human beings. Indeed, the worldwide population has devoted increased attention and preference for the use of medicinal plants for healthy aging and longevity promotion. In fact, plant-derived bioactives present a broad spectrum of biological effects, and their antioxidant, anti-inflammatory, and, more recently, anti-aging effects, are considered to be a hot topic among the medical and scientific communities. Nonetheless, despite the numerous biological effects, it should not be forgotten that some bioactive molecules are prone to oxidation and can even exert pro-oxidant effects. In this sense, the objective of the present review is to provide a detailed overview of plant-derived bioactives in age-related disorders. Specifically, the role of phytochemicals as antioxidants and pro-oxidant agents is carefully addressed, as is their therapeutic relevance in longevity, aging-related disorders, and healthy-aging promotion. Finally, an eye-opening look into the overall evidence of plant compounds related to longevity is presented.

Potential Factors Influencing the Effects of Anthocyanins on Blood Pressure Regulation in Humans: A Review

Dietary intake of anthocyanins (ACNs) is associated with a reduced risk of cardiovascular and coronary heart disease. While the anti-inflammatory, antioxidant, and lipid-lowering effects of ACN consumption have been consistently reported, their effect(s) on blood pressure regulation is less consistent and results from human studies are mixed. The objective of this review is attempting to identify potential patterns which may explain the variability in results related to blood pressure. To do so, we review 66 human intervention trials testing the effects on blood pressure of purified ACN or ACN-rich extracts, or whole berries, berry juices, powders, purees and whole phenolic extracts, from berries that are rich in ACN and have ACNs as predominant bioactives. Several factors appear to be involved on the mixed results reported. In particular, the baseline characteristics of the population in terms of blood pressure and total flavonoid intake, the dose and duration of the intervention, the differential effects of individual ACN and their synergistic effects with other phytochemicals, the ACN content and bioavailability from the food matrix, and individual differences in ACN absorption and metabolism related to genotype and microbiota enterotypes.

Blueberries improve biomarkers of cardiometabolic function in participants with metabolic syndrome-results from a 6-month, double-blind, randomized controlled trial

BACKGROUND

Anthocyanin-rich blueberry intake is associated with reduced type 2 diabetes and cardiovascular disease (CVD) risk in prospective studies, although long-term randomized controlled trials (RCTs) have not been conducted in at-risk populations.

OBJECTIVE

In the longest-duration RCT to date, we examined the effect of 6-mo blueberry intake on insulin resistance and cardiometabolic function in metabolic syndrome.

METHODS

A double-blind, parallel RCT (n = 115; age 63 ± 7 y; 68% male; body mass index 31.2 ± 3.0 kg/m2) was conducted, which fed 2 dietarily achievable blueberry intakes [equivalent to 1/2 and 1 cup/d (75/150 g)] compared with matched placebo. Insulin resistance was assessed via the homeostasis model assessment of insulin resistance (primary endpoint) and confirmed by [6-6-2H2]-glucose-labeled, 2-step hyperinsulinemic clamp (n = 20). Clinically relevant cardiometabolic endpoints [including flow-mediated dilatation, augmentation index, lipoprotein status (by nuclear magnetic resonance spectroscopy), and nitric oxide (NO)-related metabolite assay] and anthocyanin metabolism were assessed.

RESULTS

A daily intake of 1 cup of blueberries improved endothelial function (flow-mediated dilatation: +1.45%; 95% CI: 0.83%, 2.1%; P = 0.003), systemic arterial stiffness (augmentation index: -2.24%; 95% CI: -3.97%, -0.61%; P = 0.04) and attenuated cyclic guanosine monophosphate concentrations. In statin nonusers (n = 71), elevated high-density lipoprotein cholesterol (+0.08 mmol/L; P = 0.03), high-density lipoprotein particle density (+0.48n, ×10-6; P = 0.002) and apolipoprotein A-I (+0.05 g/L; P = 0.01) concentrations were observed following the 1-cup/d intervention. Treatment compliance was 94.1% (wrapper returns) and total concentrations of anthocyanin-derived phenolic acid metabolites significantly increased, dose-dependently, in serum and 24-h urine (P < 0.01 and P < 0.001, respectively). Insulin resistance, pulse wave velocity, blood pressure, NO, and overall plasma thiol status were unaffected. Likewise, a half cup per day had no effect on any biomarkers.

CONCLUSIONS

Despite insulin resistance remaining unchanged we show, to our knowledge, the first sustained improvements in vascular function, lipid status, and underlying NO bioactivity following 1 cup blueberries/d. With effect sizes predictive of 12-15% reductions in CVD risk, blueberries should be included in dietary strategies to reduce individual and population CVD risk. This study was registered at clinicaltrials.gov as NCT02035592.

Effects of superfoods on risk factors of metabolic syndrome: a systematic review of human intervention trials

Functional foods can be effective in the prevention of metabolic syndrome and subsequently the onset of cardiovascular diseases and type II diabetes mellitus. More recently, however, another term was introduced to describe foods with additional health benefits: "superfoods", for which, to date, no generally accepted definition exists. Nonetheless, their consumption might contribute to the prevention of metabolic syndrome, for example due to the presence of potentially bioactive compounds. This review provides an overview of controlled human intervention studies with foods described as "superfoods" and their effects on metabolic syndrome parameters. First, an Internet search was performed to identify foods described as superfoods. For these superfoods, controlled human intervention trials were identified until April 2017 investigating the effects of superfood consumption on metabolic syndrome parameters: waist circumference or BMI, blood pressure, or concentrations of HDL cholesterol, triacylglycerol or glucose. Seventeen superfoods were identified, including a total of 113 intervention trials: blueberries (8 studies), cranberries (8), goji berries (3), strawberries (7), chili peppers (3), garlic (21), ginger (10), chia seed (5), flaxseed (22), quinoa (1), cocoa (16), maca (1), spirulina (7), wheatgrass (1), acai berries (0), hemp seed (0) and bee pollen (0). Overall, only limited evidence was found for the effects of the foods described as superfoods on metabolic syndrome parameters, since results were not consistent or the number of controlled intervention trials was limited. The inconsistencies might have been related to intervention-related factors, such as duration or dose. Furthermore, conclusions may be different if other health benefits are considered.

Molecular Mechanism and Health Role of Functional Ingredients in Blueberry for Chronic Disease in Human Beings

Functional ingredients in blueberry have the best health benefits. To obtain a better understanding of the health role of blueberry in chronic disease, we conducted systematic preventive strategies for functional ingredients in blueberry, based on comprehensive databases, especially PubMed, ISI Web of Science, and CNKI for the period 2008⁻2018. Blueberry is rich in flavonoids (mainly anthocyanidins), polyphenols (procyanidin), phenolic acids, pyruvic acid, chlorogenic acid, and others, which have anticancer, anti-obesity, prevent degenerative diseases, anti-inflammation, protective properties for vision and liver, prevent heart diseases, antidiabetes, improve brain function, protective lung properties, strong bones, enhance immunity, prevent cardiovascular diseases, and improve cognitive decline. The anthocyanins and polyphenols in blueberry are major functional ingredients for preventive chronic disease. These results support findings that blueberry may be one of the best functional fruits, and further reveals the mechanisms of anthocyanins and polyphenols in the health role of blueberry for chronic disease. This paper may be used as scientific evidence for developing functional foods, nutraceuticals, and novel drugs of blueberry for preventive chronic diseases.

Efficacy of an Anthocyanin and Prebiotic Blend on Intestinal Environment in Obese Male and Female Subjects

Background

Anthocyanins and prebiotics impact overall health and wellness, likely through modulation of the microbiota and the intestinal ecosystem.

Objectives

An 8-week open-label study in male and female volunteers with uncomplicated obesity was designed to study the efficacy of an anthocyanin and prebiotic blend in modulating intestinal microbiota and intestinal inflammation.

Results

After 8 weeks of daily supplementation, participants had a significant decrease in Firmicutes (p < 0.001) and Actinobacteria (p < 0.001) and a significant increase in Bacteroidetes (p < 0.001). Bowel habits were improved as evidenced by reductions in the severity of bloating (p < 0.05), gas (p=0.035), and abdominal pain (p=0.015) as well as significant improvements in stool consistency (p < 0.05). Finally, a nonsignificant decrease in the inflammatory marker fecal calprotectin was seen (p=0.107). The supplement was safe and well tolerated.

Conclusions

The results suggest that regular consumption of the anthocyanin-prebiotic blend positively modulated the intestinal ecosystem and provided insights into the mechanisms of action and its impact on health benefits.

Association between berries intake and cardiovascular diseases risk factors: a systematic review with meta-analysis and trial sequential analysis of randomized controlled trials

The main goal of this work was to clarify the effects of the consumption of berries on cardiovascular disease (CVD) risk factors by performing a systematic review according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) statement, followed by a meta-analysis and a trial sequential analysis (TSA) of randomized controlled trials (RCTs). The electronic search was conducted in PubMed, Scopus, SciELO, Web of Science and Cochrane Library between April and June 2016. To be included, RCTs had to report 1 or more of the following outcomes: total cholesterol (TC), HDL-cholesterol (HDL), LDL-cholesterol (LDL), triglycerides (TG), blood pressure (BP), C-reactive protein (CRP), tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), vascular cell adhesion molecule-1 (VCAM), intercellular adhesion molecule-1 (ICAM), glucose, insulin, apolipoprotein A-I (Apo A-I) or apolipoprotein B (Apo B). It was observed that the intake of berries reduces TC, LDL, TG, and BP while increasing the level of HDL, suggesting a beneficial effect on the control of CVDs' risk factors. Thus, the intake of berries as nutraceuticals or functional foods could be suggested for the prevention and control of CVDs.

Effects of fruit and vegetable consumption on inflammatory biomarkers and immune cell populations: a systematic literature review and meta-analysis

BACKGROUND

Inflammation is associated with an increased risk of a range of chronic diseases. A diet high in fruit and vegetables may help to reduce inflammation, as fruit and vegetables are rich sources of antioxidants and other biologically active substances, which may improve immune function.

OBJECTIVE

To summarize the evidence, we executed a systematic review and meta-analysis examining the effects of fruit and/or vegetable intake on inflammatory biomarkers and immune cells in humans with different diseases and conditions.

Design

Electronic databases including PubMed, Cochrane, CINAHL, and EMBASE were systematically searched up to March 2018.

RESULTS

Eighty-three studies were included. Of these, 71 (86%) were clinical trials, and 12 were observational studies (n = 10 cross-sectional and n = 2 cohort). Amongst the observational research, n = 10 studies found an inverse association between intakes of fruit or vegetables and inflammatory biomarkers. Similarly, the majority of the intervention studies (68%, n = 48) reported beneficial effects of fruit or vegetable intake on ≥1 biomarker of systemic or airway inflammation. A meta-analysis of included studies showed that fruit or vegetable intake decreased circulating levels of C-reactive protein and tumor necrosis factor-α (P < 0.05) and increased the γδ-T cell population (P < 0.05).

Conclusions

In conclusion, this review suggests that higher intakes of fruit and vegetables lead to both a reduction in proinflammatory mediators and an enhanced immune cell profile.