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

Jaboticaba berry (Myrciaria jaboticaba) supplementation protects against micro- and macrovascular dysfunction induced by eccentric exercise: a randomized clinical trial

Physical activities that are unaccustomed and involve eccentric muscle contractions have been demonstrated to temporarily impair macrovascular and microvascular functions, which may be caused by exercise-induced oxidative stress. Jaboticaba (Myrciaria jaboticaba) is a famous Brazilian berry that has been described to exhibit high antioxidant activity. However, no human study has investigated the protective effects of jaboticaba consumption against the vascular damage induced by eccentric exercise. Therefore, the present study aimed to assess whether supplementation with jaboticaba berry juice could positively affect macro- and microvascular functions within 48 hours after eccentric exercise. This randomized, double-blind, placebo-controlled, parallel trial enrolled 24 healthy participants consuming 250 mL per day of jaboticaba berry juice (containing ∼1,300 mg of total polyphenols) or placebo for 6 days. At the baseline, pre-exercise, and 24 h and 48 h postexercise stages, blood samples were taken for analysis of reduced glutathione (GSH) levels. Also, brachial artery flow-mediated dilation (FMD), blood flow, and tissue oxygen saturation (StO2) responses to 5-minute cuff occlusion were assessed using Doppler ultrasound and near-infrared spectroscopy, respectively. Our findings revealed significant decreases in blood GSH (P < 0.001, ES = 0.76), FMD (P = 0.005, ES = 0.48), reperfusion slope of StO2 (P = 0.018, ES = 0.42) at 24 h and blood flow (P = 0.012, ES = 0.42) at 48 h following eccentric exercise in the control group as compared to the jaboticaba berry juice group. Our results demonstrated that jaboticaba berry juice prevented the exercise-induced increase in reactive oxygen species production and protected macro- and microvascular functions against the damage caused by eccentric exercise, suggesting that jaboticaba berry consumption could protect the vascular function under conditions of imbalance in redox homeostasis.

Vegetables, fruits, and berries - a scoping review for Nordic Nutrition Recommendations 2023

Vegetables, fruits, and berries comprise a large variety of foods and are recognised to play an important role in preventing chronic diseases. Many observational studies have been published during the last decade, and the aim of this scoping review is to describe the overall evidence for the role of vegetables, fruits, and berries for health-related outcomes as a basis for setting and updating food-based dietary guidelines. A scoping review was conducted according to the protocol developed within the Nordic Nutrition Recommendations 2023 project. Current available evidence strengthens the role of consuming vegetables, fruits, and berries in preventing chronic diseases. The most robust evidence is found for cancer in the gastric system and lung cancer, cardiovascular disease, and all-cause mortality. Steeper risk reductions are generally seen at the lower intake ranges, but further reductions have been seen for higher intakes for cardiovascular disease. Weaker associations are seen for type 2 diabetes. There is evidence that suggests a beneficial role also for outcomes such as osteoporosis, depression, cognitive disorders, and frailty in the elderly. The observed associations are supported by several mechanisms, indicting causal effects. Some subgroups of vegetables, fruits, and berries may have greater benefits than other subgroups, supporting a recommendation to consume a variety of these foods.

Acute effect of high-intensity interval exercise on vascular endothelial function and possible mechanisms of wall shear stress in young obese males

Objective: To investigate the mechanisms of wall shear stress (WSS) responsible for the effects of high-intensity interval exercise (HIIE) on vascular endothelial function in young obese males.

Methods: A within-subject study design was used. We examined the response of the reactive hyperemia index (RHI) to acute HIIE in young obese males (n = 20, age = 20.38 ± 1.40 years, body mass index [BMI] = 31.22 ± 3.57, body fat percentage [BF (%)] = 31.76 ± 3.57). WSS was manipulated using 100, 80, or 60 mmHg cuff inflation during the HIIE to determine the proper inflation capable of maintaining WSS near baseline levels. One-way repeated measures analysis of variance and LSD post hoc tests were performed to compare changes in WSS and vascular endothelial function at baseline HIIE and following HIIE using different cuff inflations.

Results: There were no significant differences in RHI and WSS between the three cuff inflation values (p > 0.05). WSS was significantly higher in obese male individuals after HIIE and HIIE with 100 mmHg cuff inflation (p = 0.018, p = 0.005) than that at baseline, with no significant differences observed comparing HIIE and HIIE with 100 mmHg inflation (p = 0.23). The RHI after HIIE was significantly higher (p = 0.012) than that at baseline, while no significant differences were detected after HIIE at 100 mmHg (p = 0.91). The RHI was significantly lower after HIIE with 100 mmHg than that after HIIE (p = 0.007). WSS (p = 0.004) and RHI (p = 0.017) were significantly higher after HIIE than that at baseline, while no significant differences were observed after HIIE with either 80 or 60 mmHg cuff inflation (baseline vs. HIIE + 80 mmHg: WSS: p = 0.33, RHI: p = 0.38; baseline vs. HIIE + 60 mmHg: WSS: p = 0.58, RHI: p = 0.45). WSS was similar to HIIE, after HIIE with either 80 or 60 mmHg inflation (p = 0.36, p = 0.40). However, RHI was significantly higher for HIIE than for HIIE with both 80 and 60 mmHg inflation (p = 0.011, p = 0.006).

Conclusion: HIIE could significantly improve WSS and vascular endothelial function. HIIE intervention with 60 or 80 mmHg inflation might enhance WSS near the baseline level. HIIE-induced acute changes in WSS may provide the primary physiological stimulus for vascular endothelial adaptation to HIIE in young obese males.

Systematic Review on the Potential Effect of Berry Intake in the Cognitive Functions of Healthy People

The increase in life expectancy poses health challenges, such as increasing the impairment of cognitive functions. Berries show a neuroprotective effect thanks to flavonoids, able to reduce neuroinflammatory and to increase neuronal connections. The aim of this systematic review is to explore the impact of berries supplementation on cognitive function in healthy adults and the elderly. Twelve studies were included for a total of 399 participants, aged 18–81 years (mean age: 41.8 ± 4.7 years). Six studies involved young adults (23.9 ± 3.7 years), and four studies involved the elderly (60.6 ± 6.4 years). Most studies investigated effects of a single berry product, but one used a mixture of 4 berries. Non-significant differences were detected across cognition domains and methodologies, but significant and positive effects were found for all cognitive domains (attention and concentration, executive functioning, memory, motor skills and construction, and processing speed), and in most cases they were present in more than one study and detected using different methodologies. Although some limitations should be taken into account to explain these results, the positive findings across studies and methodologies elicit further studies on this topic, to endorse the consumption of berries in healthy populations to prevent cognitive decline.

Plant-Based Foods and Vascular Function: A Systematic Review of Dietary Intervention Trials in Older Subjects and Hypothesized Mechanisms of Action

Cardiovascular diseases, still the leading cause of mortality in the world, are closely related to vascular function. Older subjects are more susceptible to endothelial dysfunction and therefore it is important to define possible preventive or support strategies, such as consumption of foods with health-promoting effects. This systematic review aims to summarize the currently available evidence on acute or chronic trials testing the effect of selected plant-based foods on vascular function parameters in older subjects, and consider plausible mechanisms that may support the main findings. A total of 15 trials were included and analyzed, testing the effects of beetroot, plum, blueberry, and vegetable oils. We found some interesting results regarding markers of vascular reactivity, in particular for beetroot, while no effects were found for markers of arterial stiffness. The amelioration of vascular function seems to be more related to the restoration of a condition of nitric oxide impairment, exacerbated by diseases or hypoxic condition, rather than the enhancement of a physiological situation, as indicated by the limited effects on healthy older subjects or in control groups with young subjects. However, the overall set of selected studies is, in any case, rather limited and heterogeneous in terms of characteristics of the studies, indicating the need for additional high-quality intervention trials to better clarify the role of vegetable foods in restoring and/or improving vascular function in order to better elucidate the mechanisms through which these foods may exert their vascular health benefits in older subjects.

Effectiveness of food concentrate phenolic compounds of apples in experimental membrane pathologies

Apple fruits are an available source of phenolic compounds that exhibit a wide range of biological activities (antioxidant, anti-inflammatory, membrane stabilizing, etc.). The antioxidant properties of food concentrate phenolic compounds of apples (Concentrate) were studied in vitro in models of spontaneous and ascorbate induced lipid peroxidation (LPO) in rat liver homogenate, and acute carbon tetrachloromethane hepatitis was chosen as in vivo model in rats. Membrane stabilizing activity was evaluated by the degree of hemolysis in blood samples from the tail vein. The effect of Concentrate on vascular permeability was studied considering the time of animal skin papules staining at the site of injection of phlogogenic substances. Hepatoprotective activity in the model of acute carbon tetrachloride hepatitis was assessed by changes in prooxidant-antioxidant status in liver homogenate and liver enzymes activity in serum. Significant antioxidant effect of Concentrate was fixed in models of spontaneous and ascorbate induced LPO (TBA reactants’ content was 3.12 times and 2.25 times lower than control for spontaneous LPO and ascorbate induced LPO, respectively) and under tetrachloride hepatitis (Concentrate antioxidant activity was 47.8%). The membrane-protective activity of the studied Concentrate was also high and reached 50.1%. Also, Concentrate demonstrated capillary-strengthening properties, reducing the permeability of the vascular wall, which was caused by three different chlorogens, most notably by zymosan (Concentrate significantly delayed the stain utilization from the bloodstream by 2.14 times compared to control). Newly developed concentrate showed complex hepatoprotective activity, improving the indices of antioxidant-prooxidant status and activity of liver cytolysis enzymes in rats with tetrachloromethane hepatitis. The transparent corrective effects of Concentrate are the result of synergism and additivity of its multiple components and indicate the prospects of its further research in order to develop medications for the prophylaxis and treatment of diseases associated with membrane damage.

Potential Relevance of Bioactive Peptides in Sports Nutrition

Bioactive peptides are physiologically active peptides mostly derived from proteins following gastrointestinal digestion, fermentation or hydrolysis by proteolytic enzymes. It has been shown that bioactive peptides can be resorbed in their intact form and have repeatedly been shown to have a positive effect on health-related parameters such as hypertension, dyslipoproteinemia, inflammation and oxidative stress. In recent years, there has been increasing evidence that biologically active peptides could also play an important role in sports nutrition. Current studies have shown that bioactive peptides could have a positive impact on changes in body composition and muscular performance, reduce muscle damage following exercise and induce beneficial adaptions within the connective tissue. In the following overview, potential mechanisms as well as possible limitations regarding the sports-related effect of bioactive peptides and their potential mechanisms are presented and discussed. In addition, practical applications will be discussed on how bioactive peptides can be integrated into a nutritional approach in sports to enhance athletic performance as well as prevent injuries and improve the rehabilitation process.

A mix of chlorogenic and caffeic acid reduces C/EBPß and PPAR-γ1 levels and counteracts lipid accumulation in macrophages

PURPOSE

Chlorogenic acid (CGA) and caffeic acid (CA) are bioactive compounds in whole grains, berries, apples, some citrus fruits and coffee, which are hypothesized to promote health-beneficial effects on the cardiovascular system. This study aimed to evaluate the capacity of CGA and CA to reduce lipid accumulation in macrophages, recognized as a critical stage in the progression of atherosclerosis. Furtherly, the modulation of CCAAT/enhancer-binding protein β (C/EBPβ) and peroxisome proliferator-activated receptor- γ1 (PPAR-γ1), as transcription factors involved in lipid metabolism, was evaluated.

METHODS

THP-1-derived macrophages were treated for 24 h with 0.03, 0.3, 3 and 30 μM of CGA and CA, tested alone or in combination, and a solution of oleic/palmitic acid (500 μM, 2:1 ratio). Lipid storage was assessed spectrophotometrically through fluorescent staining of cells with Nile red. C/EBPβ and PPAR-γ1 mRNA and protein levels were evaluated by RT-PCR and enzyme-linked immunosorbent assay, respectively.

RESULTS

The mix of CGA + CA (1:1 ratio) reduced lipid accumulation at all concentrations tested, except for the highest one. The greatest effect ( - 65%; p < 0.01) was observed at the concentration of 0.3 μM for each compound. The same concentration significantly (p < 0.01) downregulated C/EBPβ and PPAR-γ1 gene expression and reduced their protein levels at 2 h and 24 h, respectively.

CONCLUSION

The results indicate that the capacity of CGA + CA mix to reduce lipid storage in macrophages is mediated by a reduction in the expression of transcription factors C/EBPβ and PPAR-γ1.

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.

Effect of Freeze Crystallization on Quality Properties of Two Endemic Patagonian Berries Juices: Murta (Ugni molinae) and Arrayan (Luma apiculata)

This work studied the effects of centrifugal block freeze crystallization (CBFC) on physicochemical parameters, total phenolic compound content (TPCC), antioxidant activity (AA), and process parameters applied to fresh murta and arrayan juices. In the last cycle, for fresh murta and arrayan juices, the total soluble solids (TSS) showed values close to 48 and 54 Brix, and TPCC exhibited values of approximately 20 and 66 mg gallic acid equivalents/100 grams dry matter (d.m.) for total polyphenol content, 13 and 25 mg cyanidin-3-glucoside equivalents/100 grams d.m. for total anthocyanin content, and 9 and 17 mg quercetin equivalents/100 grams d.m. for total flavonoid content, respectively. Moreover, the TPCC retention indicated values over 78% for murta juice, and 82% for arrayan juice. Similarly, the AA presented an increase over 2.1 times in relation to the correspondent initial AA value. Thus, the process parameters values were between 69% and 85% for efficiency, 70% and 88% for percentage of concentrate, and 0.72% and 0.88 (kg solutes/kg initial solutes) for solute yield. Therefore, this work provides insight about CBFC on valuable properties in fresh Patagonian berries juices, for future applications in health and industrial scale.

Polyphenols and Cognition In Humans: An Overview of Current Evidence from Recent Systematic Reviews and Meta-Analyses

BACKGROUND

There is increasing interest in the impact of dietary influences on the brain throughout the lifespan, ranging from improving cognitive development in children through to attenuating ageing related cognitive decline and reducing risk of neurodegenerative diseases. Polyphenols, phytochemicals naturally present in a host of fruits, vegetables, tea, cocoa and other foods, have received particular attention in this regard, and there is now a substantial body of evidence from experimental and epidemiological studies examining whether their consumption is associated with cognitive benefits.

OBJECTIVE

The purpose of this overview is to synthesise and evaluate the best available evidence from two sources, namely meta-analyses and systematic reviews, in order to give an accurate reflection of the current evidence base for an association between polyphenols and cognitive benefits.

METHOD

Four meta-analyses and thirteen systematic reviews published between 2017-2020 were included, and were categorised according to whether they reviewed specific polyphenol-rich foods and classes or all polyphenols. A requirement for inclusion was assessment of a behavioural cognitive outcome in humans.

RESULTS

A clear and consistent theme emerged that whilst there is support for an association between polyphenol consumption and cognitive benefits, this conclusion is tentative, and by no means definitive. Considerable methodological heterogeneity was repeatedly highlighted as problematic such that the current evidence base does not support reliable conclusions relating to efficacy of specific doses, duration of treatment, or sensitivity in specific populations or certain cognitive domains. The complexity of multiple interactions between a range of direct and indirect mechanisms of action is discussed.

CONCLUSIONS

Further research is required to strengthen the reliability of the evidence base.

A Review of Registered Clinical Trials on Dietary (Poly)Phenols: Past Efforts and Possible Future Directions

In recent years, the increasing number of studies on polyphenol demonstrates the efforts in elucidating the potential role of these bioactives on human health. This study reviews the main topics and characteristics of clinical trials on polyphenols registered over the last 20 years, in order to track past and current efforts as well as to highlight the main research gaps in this field. The review was conducted by collecting trials registered in ClinicalTrials.gov and International Standard Randomised Controlled Trial Number (ISRCTN) registry. Overall, 750 clinical trials were selected and included in the final evaluation. Most of the trials were performed on extracts or pure compounds followed by studies conducted on polyphenol-rich foods, in particular berries. A total of 520 clinical trials focused on health effects, 55 on bioavailability, and 175 on both. Regarding outcomes, 139 registered intervention studies had the lipid profile and blood pressure as primary outcomes. The overview provided by this analysis also emphasizes the emerging interest in new outcomes related to polyphenols intervention such as microbiota composition and the evaluation of inter-individual variability in response to the intake of polyphenols. Our review underlines the need of further trials covering unexplored or debated research aspects and provides insights for the design and development of future intervention studies and related research areas.

Blueberries and cardiovascular disease prevention

Blueberries are a rich source of (poly)phenols, particularly anthocyanins. Epidemiological studies indicate that anthocyanin-rich foods including blueberries are associated with a reduction in the risk of cardiovascular disease. These observational findings are supported by a number of randomized-controlled trials showing improvements in biomarkers of cardiovascular disease risk. The beneficial effects of blueberry (poly)phenols are particularly clear when measuring flow-mediated dilation over various timeframes and study populations. However, other outcomes are less clear, such as effects on blood pressure, arterial stiffness and blood lipid profile. This may be due to the heterogeneity existing in study designs, such as duration of the intervention, and the health status of participants. Longer-term RCTs using gold standard methods in relevant populations which can be translated to the general public are needed to clarify and strengthen the evidence available. While circulating phenolic blueberry metabolites have been linked with improvements in vascular function, the biological activities and mechanisms of action of individual metabolites and their interaction in vivo are still unknown. Evaluating the bioactivities of metabolites alone and together, and analysing their structure-activity relationship in well-designed and physiologically relevant experimental and human studies are needed to understand the mechanisms of how these metabolites affect vascular function.

Modulation of Adhesion Process, E-Selectin and VEGF Production by Anthocyanins and Their Metabolites in an in vitro Model of Atherosclerosis

The present study aims to evaluate the ability of peonidin and petunidin-3-glucoside (Peo-3-glc and Pet-3-glc) and their metabolites (vanillic acid; VA and methyl-gallic acid; MetGA), to prevent monocyte (THP-1) adhesion to endothelial cells (HUVECs), and to reduce the production of vascular cell adhesion molecule (VCAM)-1, E-selectin and vascular endothelial growth factor (VEGF) in a stimulated pro-inflammatory environment, a pivotal step of atherogenesis. Tumor necrosis factor-α (TNF-α; 100 ng mL-1) was used to stimulate the adhesion of labelled monocytes (THP-1) to endothelial cells (HUVECs). Successively, different concentrations of Peo-3-glc and Pet-3-glc (0.02 µM, 0.2 µM, 2 µM and 20 µM), VA and MetGA (0.05 µM, 0.5 µM, 5 µM and 50 µM) were tested. After 24 h, VCAM-1, E-selectin and VEGF were quantified by ELISA, while the adhesion process was measured spectrophotometrically. Peo-3-glc and Pet-3-glc (from 0.02 µM to 20 µM) significantly (p < 0.0001) decreased THP-1 adhesion to HUVECs at all concentrations (-37%, -24%, -30% and -47% for Peo-3-glc; -37%, -33%, -33% and -45% for Pet-3-glc). VA, but not MetGA, reduced the adhesion process at 50 µM (-21%; p < 0.001). At the same concentrations, a significant (p < 0.0001) reduction of E-selectin, but not VCAM-1, was documented. In addition, anthocyanins and their metabolites significantly decreased (p < 0.001) VEGF production. The present findings suggest that while Peo-3-glc and Pet-3-glc (but not their metabolites) reduced monocyte adhesion to endothelial cells through suppression of E-selectin production, VEGF production was reduced by both anthocyanins and their metabolites, suggesting a role in the regulation of angiogenesis.