Effects of Vaccinium Berries on Serum Lipids: A Meta-Analysis of Randomized Controlled Trials

The Epidemiology of Berry Consumption and Association of Berry Consumption with Diet Quality and Cardiometabolic Risk Factors in United States Adults: The National Health and Nutrition Examination Survey, 2003-2018

BACKGROUND

Berries are rich in important nutrients and bioactive compounds, which could potentially contribute to maintenance of normal lipid and glucose profiles.

OBJECTIVE

We reported the epidemiology of berry consumption and examined associations of berry consumption with diet quality [measured by Healthy Eating Index (HEI-2015)] and levels of cardiometabolic risk factors, including body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure, total cholesterol, high-density lipoprotein cholesterol (HDL cholesterol), glycated hemoglobin, and fasting biomarkers: triglycerides, low-density lipoprotein cholesterol (LDL cholesterol), glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR).

METHODS

We evaluated 33,082 adults (aged ≥20 y) using two 24-h diet recalls from National Health and Nutrition Examination Survey (2003-2018). Multivariable linear regression models were applied to examine the associations of total and individual berry intake with diet quality and cardiometabolic risk factors using appropriate sample weights.

RESULTS

Approximately 25 % of the United States adults consumed berries (0.08 ± 0.003 cup-equivalents/d), representing ∼10 % of the daily mean total fruit intake. Among berry consumers, the mean intake of strawberries (0.31 ± 0.01 cup-equivalents) was higher than for other berries. Berry consumers had a significantly higher HEI-2015 score than nonconsumers (mean HEI-2015 score = 58.8 compared with 52.3, P < 0.0001). Berry consumers had significantly lower concentrations of cardiometabolic indices than nonconsumers, including BMI, WC, SBP, total cholesterol, LDL cholesterol, triglycerides, fasting insulin, HOMA-IR, and higher mean HDL cholesterol, after adjusting for sociodemographic, lifestyle, and dietary confounders (all P < 0.05).

CONCLUSIONS

United States adult berry consumers had a higher diet quality and lower concentrations of cardiometabolic risk factors, suggesting a favorable role for berries in diets and cardiometabolic disease prevention in United States adult population.

Nephroprotective effect of cranberry (Vaccinium oxycoccos) in streptozocin-induced diabetic nephropathy in mice

OBJECTIVES

Diabetic nephropathy is a chief reason of mortality particularly in individuals with renal dysfunction. The current research was aimed to assess the nephroprotective portion of Vaccinium oxycoccos toward mice diabetic nephropathy induced by streptozotocin (STZ). V. oxycoccos was purchased and used for hydroalcoholic extraction.

METHODS

Sixty male mice were subjected to STZ-intraperitoneal injection (45 mg/kg). After diabetes induction, mice were divided into five groups of diabetic control (received only STZ), non-diabetic control (received only citrate buffer), two V. oxycoccos treatment (received V. oxycoccos extract (200 and 400 mg/kg) oral daily by gavage), and metformin treatment (received metformin (500 mg/kg) oral daily by gavage). Glucose and weight of mice were checked weekly.

RESULTS

After 28 days, the effect of V. oxycoccos extract on serum and urine parameters were assessed. STZ caused significant decreased in the mice body weight. Mice treated with the V. oxycoccos (400 mg/kg) harbored the lowest weight loss at day 28 (70.2±1.38 g). STZ caused significant increase in the mice FBS. Mice treated with the V. oxycoccos (400 mg/kg) harbored the lowest FBS at day 28 (189.2±1.20 mg/dL). Treatment of mice with V. oxycoccos (400 mg/kg) caused the lowest increase in the levels of cholesterol, HbA1c and triglycerides compared to the diabetic control mice. Compared to the diabetic control group, mice treated with V. oxycoccos (400 mg/kg) had the highest HDL, insulin, SOD, and GSH (p<0.05). The lowest serum BUN, CR, and UR were found in mice treated with V. oxycoccos (400 mg/kg). Anti-inflammatory effects of V. oxycoccos (400 mg/kg) was shown by the lowest TNF-α, IL-6, and TGF-β1 concentration in mice treated with V. oxycoccos (400 mg/kg).

CONCLUSIONS

The current study disclosed that treatment with V. oxycoccos resulted in substantial development in the serum and urine parameters and also antioxidant and anti-inflammatory response of STZ-induced diabetic mice.

Evidence-Based Anti-Diabetic Properties of Plant from the Occitan Valleys of the Piedmont Alps

Data on urban and rural diabetes prevalence ratios show a significantly lower presence of diabetes in rural areas. Several bioactive compounds of plant origin are known to exert anti-diabetic properties. Interestingly, most of them naturally occur in different plants present in mountainous areas and are linked to traditions of herbal use. This review will aim to evaluate the last 10 years of evidence-based data on the potential anti-diabetic properties of 9 plants used in the Piedmont Alps (North-Western Italy) and identified through an ethnobotanical approach, based on the Occitan language minority of the Cuneo province (Sambucus nigra L., Achillea millefolium L., Cornus mas L., Vaccinium myrtillus L., Fragaria vesca L., Rosa canina L., Rubus idaeus L., Rubus fruticosus/ulmifolius L., Urtica dioica L.), where there is a long history of herbal remedies. The mechanism underlying the anti-hyperglycemic effects and the clinical evidence available are discussed. Overall, this review points to the possible use of these plants as preventive or add-on therapy in treating diabetes. However, studies of a single variety grown in the geographical area, with strict standardization and titration of all the active ingredients, are warranted before applying the WHO strategy 2014-2023.

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.

Efficacy of Bilberry and Grape Seed Extract Supplement Interventions to Improve Glucose and Cholesterol Metabolism and Blood Pressure in Different Populations-A Systematic Review of the Literature

Intervention with fruit extracts may lower glucose and lipid levels, as well as blood pressure. We reviewed the efficacy of bilberry and grape seed extracts to affect these outcomes across populations with varying health status, age and ethnicity, across intervention doses and durations, in 24 intervention studies with bilberry and blackcurrant (n = 4) and grape seed extract (n = 20). Bilberry and blackcurrant extract lowered average levels of glycated hemoglobin (HbA1c), at least in Chinese subjects, especially in those who were older, who were diagnosed with Type 2 Diabetes Mellitus (T2DM) and who were participating in longer-term studies. We also found good evidence that across studies and in subjects with hypercholesterolemia, T2DM or metabolic syndrome, intervention with bilberry and blackcurrant extract, and to some extent grape seed extract, significantly lowered total and low density lipoprotein (LDL) cholesterol levels after four weeks. Intervention with grape seed extract may reduce systolic and diastolic blood pressure in subjects with hypertension or metabolic syndrome. Differential responsiveness in cholesterol and blood pressure outcomes between stratified populations could not be explained by age, dose or study duration. In conclusion, bilberry and blackcurrant extract appears effective in lowering HbA1c and total and LDL cholesterol, whereas grape seed extract may lower total and LDL cholesterol, and blood pressure, in specific population groups.

Dietary Strawberries Improve Cardiometabolic Risks in Adults with Obesity and Elevated Serum LDL Cholesterol in a Randomized Controlled Crossover Trial

Background and aims: Dietary berries, such as strawberries, are rich in bioactive compounds and have been shown to lower cardiometabolic risk. We examined the effects of two dietary achievable doses of strawberries on glycemic control and lipid profiles in obese adults with elevated serum LDL cholesterol (LDL-C). Methods: In this 14-week randomized controlled crossover study, participants were assigned to one of the three arms for four weeks separated by a one-week washout period: control powder, one serving (low dose: 13 g strawberry powder/day), or two-and-a -half servings (high dose: 32 g strawberry powder/day). Participants were instructed to follow their usual diet and lifestyle while refraining from consuming other berries and related products throughout the study interval. Blood samples, anthropometric measures, blood pressure, and dietary and physical activity data were collected at baseline and at the end of each four-week phase of intervention. Results: In total, 33 participants completed all three phases of the trial [(mean ± SD): Age: 53 ± 13 y; BMI: 33 ± 3.0 kg/m2). Findings revealed significant reductions in fasting insulin (p = 0.0002) and homeostatic model of assessment of insulin resistance (p = 0.0003) following the high dose strawberry phase when compared to the low dose strawberry and control phases. Glucose and conventional lipid profiles did not differ among the phases. Nuclear magnetic resonance-determined particle concentrations of total VLDL and chylomicrons, small VLDL, and total and small LDL were significantly decreased after the high dose strawberry phase, compared to control and low dose phases (all p < 0.0001). Among the biomarkers of inflammation and adipokines measured, only serum PAI-1 showed a decrease after the high dose strawberry phase (p = 0.002). Conclusions: These data suggest that consuming strawberries at two-and-a-half servings for four weeks significantly improves insulin resistance, lipid particle profiles, and serum PAI-1 in obese adults with elevated serum LDL-C.

Vaccinium vitis-idaea L.: Chemical Contents, Pharmacological Activities

One of the most known species of the genus Vaccinium (Ericaceae) is Vaccinium vitis-idaea L. or lingonberry. Leaves are included in the State Pharmacopoeia of the Russian Federation (XIV-th edition) and the State Pharmacopoeia of the Republic of Belarus (II-nd edition). The aim of this review is an analysis of data about a chemical content and types of pharmacological activities of Vaccinium vitis-idaea L. to discuss the tendency of future investigations on this plant. The main parts of works describe researches of chemical contents of fruits as medicinal and edible plant material. The majority of researches describe results of in vitro experiments. A significant interest is the study of the neuroprotective activity of the Vaccinium vitis-idaea extracts as well as their anti-cytokine and antiapoptotic properties and metabolic effects. The main biologically active compounds are phenologlycosides, tannins, proanthocyanes, saponins etc. These results will be of great significance for the development of new drugs from this plant and use along with the fruits of other parts of the plant.

Role of Berry Bioactive Compounds on Lipids and Lipoproteins in Diabetes and Metabolic Syndrome

Blood lipids are an important biomarker of cardiovascular health and disease. Among the lipid biomarkers that have been widely used to monitor and predict cardiovascular diseases (CVD), elevated LDL and low HDL cholesterol (C), as well as elevated triglyceride-rich lipoproteins, deserve special attention in their predictive abilities, and thus have been the targets of several therapeutic and dietary approaches to improving lipid profiles. Among natural foods and nutraceuticals, dietary berries are a rich source of nutrients, fiber, and various types of phytochemicals. Berries as whole fruits, juices, and purified extracts have been shown to lower total and LDL-C, and increase HDL-C in clinical studies in participants with elevated blood lipids, type 2 diabetes or metabolic syndrome. This short review aimed to further discuss the mechanisms and magnitude of the lipid-lowering effects of dietary berries, with emphasis on reported clinical studies. Based on the emerging evidence, colorful berry fruits may thus be included in a healthy diet for the prevention and management of CVD.

Freeze-dried bilberry (Vaccinium myrtillus) dietary supplement improves walking distance and lipids after myocardial infarction: an open-label randomized clinical trial

Bilberries, Vaccinium myrtillus, have a high content of phenolic compounds including anthocyanins, which could provide cardiometabolic health benefits following acute myocardial infarction (AMI). We hypothesized that standard medical therapy supplemented with freeze-dried bilberry after AMI would have a more beneficial effect on cardiovascular risk markers and exercise capacity than medical therapy alone. Patients were allocated in a 1:1 ratio within 24 hours of percutaneous coronary intervention in an 8-week trial either to V myrtillus powder (40 g/d, equivalent to 480 g fresh bilberries) and standard medical therapy or to a control group receiving standard medical therapy alone. High-sensitivity C-reactive protein and exercise capacity measured with the 6-minute walk test were the primary biochemical and clinical end points, respectively. Fifty subjects completed the study. No statistically significant difference in high-sensitivity C-reactive protein was detected between groups. The mean 6-minute walk test distance increased significantly more in the bilberry group compared to the control group: mean difference 38 m at follow-up (95% confidence interval 14-62, P = .003). Ex vivo oxidized low-density lipoprotein was significantly lowered in the bilberry group compared to control, geometric mean ratio 0.80 (95% confidence interval 0.66-0.96, P = .017), whereas total cholesterol and low-density lipoprotein cholesterol did not differ significantly between groups. Anthocyanin-derived metabolites in blood increased significantly in the bilberry group during the intervention and were different after 8 weeks between the bilberry group and control. Findings in the present study suggest that bilberries may have clinically relevant beneficial effects following AMI; a larger, double-blind clinical trial is warranted to confirm this.

Meta-Analysis of the Effects of Foods and Derived Products Containing Ellagitannins and Anthocyanins on Cardiometabolic Biomarkers: Analysis of Factors Influencing Variability of the Individual Responses

Understanding interindividual variability in response to dietary polyphenols remains essential to elucidate their effects on cardiometabolic disease development. A meta-analysis of 128 randomized clinical trials was conducted to investigate the effects of berries and red grapes/wine as sources of anthocyanins and of nuts and pomegranate as sources of ellagitannins on a range of cardiometabolic risk biomarkers. The potential influence of various demographic and lifestyle factors on the variability in the response to these products were explored. Both anthocyanin- and ellagitannin-containing products reduced total-cholesterol with nuts and berries yielding more significant effects than pomegranate and grapes. Blood pressure was significantly reduced by the two main sources of anthocyanins, berries and red grapes/wine, whereas waist circumference, LDL-cholesterol, triglycerides, and glucose were most significantly lowered by the ellagitannin-products, particularly nuts. Additionally, we found an indication of a small increase in HDL-cholesterol most significant with nuts and, in flow-mediated dilation by nuts and berries. Most of these effects were detected in obese/overweight people but we found limited or non-evidence in normoweight individuals or of the influence of sex or smoking status. The effects of other factors, i.e., habitual diet, health status or country where the study was conducted, were inconsistent and require further investigation.

Current evidence on the health-beneficial effects of berry fruits in the prevention and treatment of metabolic syndrome

PURPOSE OF REVIEW

Berries belong to the best dietary sources of bioactive compounds, which exert a synergistic and cumulative effect on promotion of human health and prevention of diseases. The present review presents the most recent findings of animal and human studies regarding the health benefits of berries in terms of prevention and treatment of obesity, hypertension, type 2 diabetes, dyslipidemia, and nonalcoholic fatty liver disease.

RECENT FINDINGS

In the last years, there was a growing number of evidence from human epidemiological and interventional studies, which emphasized the role of berries in the management of metabolic diseases. Based on the results from recent clinical trials, it can be established that a berry diet rich in antioxidants and bioactive phytochemicals has beneficial effects on hepatic function, increase of insulin sensitivity and high-density lipoprotein-cholesterol, decrease of serum glucose and low-density lipoprotein-cholesterol, and finally is inversely associated with the incidence of type 2 diabetes.

SUMMARY

Numerous recent studies have shown that berries provide great benefits in preventing or mitigating metabolic disorders. The results of this review indicate that regular long-term consumption of different berries could potentially delay the progression of metabolic syndrome and comorbidities.