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Cranberries for preventing urinary tract infections

Posted
Authors
Williams G, Stothart CI, Hahn D, Stephens JH, Craig JC, Hodson EM
Journal
Cochrane Database Syst Rev. 2023 Nov 10;11(11):CD001321. doi: 10.1002/14651858.CD001321.pub7. PMID: 37947276; PMCID: PMC10636779
Abstract

Background: Cranberries contain proanthocyanidins (PACs), which inhibit the adherence of p-fimbriated Escherichia coli to the urothelial cells lining the bladder. Cranberry products have been used widely for several decades to prevent urinary tract infections (UTIs). This is the fifth update of a review first published in 1998 and updated in 2003, 2004, 2008, and 2012. 

Objectives: To assess the effectiveness of cranberry products in preventing UTIs in susceptible populations. 

Search methods: We searched the Cochrane Kidney and Transplant Specialised Register up to 13 March 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register Search Portal (ICTRP) and ClinicalTrials.gov. 

Selection criteria: All randomised controlled trials (RCTs) or quasi-RCTs of cranberry products compared with placebo, no specific treatment or other intervention (antibiotics, probiotics) for the prevention of UTIs were included. 

Data collection and analysis: Two authors independently assessed and extracted data. Information was collected on methods, participants, interventions and outcomes (incidence of symptomatic UTIs, positive culture results, side effects, adherence to therapy). Risk ratios (RR) with 95% confidence intervals (CI) were calculated where appropriate. Study quality was assessed using the Cochrane risk of bias assessment tool. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. 

Main results: For this update 26 new studies were added, bringing the total number of included studies to 50 (8857 randomised participants). The risk of bias for sequence generation and allocation concealment was low for 29 and 28 studies, respectively. Thirty-six studies were at low risk of performance bias, and 23 studies were at low risk of detection bias. Twenty-seven, 41, and 17 studies were at low risk of attrition bias, reporting bias and other bias, respectively. Forty-five studies compared cranberry products with placebo or no specific treatment in six different groups of participants. Twenty-six of these 45 studies could be meta-analysed for the outcome of symptomatic, culture-verified UTIs. In moderate certainty evidence, cranberry products reduced the risk of UTIs (6211 participants: RR 0.70, 95% CI 0.58 to 0.84; I² = 69%). When studies were divided into groups according to the treatment indication, cranberry products probably reduced the risk of symptomatic, culture-verified UTIs in women with recurrent UTIs (8 studies, 1555 participants: RR 0.74, 95% CI 0.55 to 0.99; I² = 54%), in children (5 studies, 504 participants: RR 0.46, 95% CI 0.32 to 0.68; I² = 21%) and in people with a susceptibility to UTIs due to an intervention (6 studies, 1434 participants: RR 0.47, 95% CI 0.37 to 0.61; I² = 0%). However, in low certainty evidence, there may be little or no benefit in elderly institutionalised men and women (3 studies, 1489 participants: RR 0.93, 95% CI 0.67 to 1.30; I² = 9%), pregnant women (3 studies, 765 participants: RR 1.06, 95% CI 0.75 to 1.50; I² = 3%), or adults with neuromuscular bladder dysfunction with incomplete bladder emptying (3 studies, 464 participants: RR 0.97, 95% CI 0.78 to 1.19; I² = 0%). Other comparisons were cranberry products with probiotics (three studies) or antibiotics (six studies), cranberry tablets with cranberry liquid (one study), and different doses of PACs (two studies). Compared to antibiotics, cranberry products may make little or no difference to the risk of symptomatic, culture-verified UTIs (2 studies, 385 participants: RR 1.03, 95% CI 0.80 to 1.33; I² = 0%) or the risk of clinical symptoms without culture (2 studies, 336 participants: RR 1.30, 95% CI 0.79 to 2.14; I² = 68%). Compared to probiotics, cranberry products may reduce the risk of symptomatic, culture-verified UTIs (3 studies, 215 participants: RR 0.39, 95% CI 0.27 to 0.56; I = 0%). It is unclear whether efficacy differs between cranberry juice and tablets or between different doses of PACs as the certainty of the evidence was very low. The number of participants with gastrointestinal side effects probably does not differ between those taking cranberry products and those receiving placebo or no specific treatment (10 studies, 2166 participants: RR 1.33, 95% CI 1.00 to 1.77; I² = 0%; moderate certainty evidence). There was no clear relationship between compliance with therapy and the risk for repeat UTIs. No difference in the risk for UTIs could be demonstrated between low, moderate and high doses of PACs. 

Authors' conclusions: This update adds a further 26 studies taking the total number of studies to 50 with 8857 participants. These data support the use of cranberry products to reduce the risk of symptomatic, culture-verified UTIs in women with recurrent UTIs, in children, and in people susceptible to UTIs following interventions. The evidence currently available does not support its use in the elderly, patients with bladder emptying problems, or pregnant women. 

Suppression of Helicobacter pylori infection by daily cranberry intake: A double-blind, randomized, placebo-controlled trial

Posted
Authors
Zhe-Xuan L, Jun-Ling M, Yang G, Wei-Dong L, Ming L, et al
Journal
J. Gastroenterol Hepatol. August 2020; doi: 10.1111/jgh.15212
Abstract

Background and aim: Dietary strategies that contribute to reducing incidence of Helicobacter pylori infection without negative side effects are highly desirable owing to worldwide bacterial prevalence and carcinogenesis potential. The aim of this study was to determine dosage effect of daily cranberry consumption on H. pylori suppression over time in infected adults to assess the potential of this complementary management strategy in a region with high gastric cancer risk and high prevalence of H. pylori infection. 

Methods: This double‐blind, randomized, placebo‐controlled trial on 522 H. pylori‐positive adults evaluated dose–response effects of proanthocyanidin‐standardized cranberry juice, cranberry powder, or their placebos on suppression of H. pylori at 2 and 8 weeks by 13C‐urea breath testing and eradication at 45 days post‐intervention. 

Results: H. pylori‐negative rates in placebo, low‐proanthocyanidin, medium‐proanthocyanidin, and high‐proanthocyanidin cranberry juice groups at week 2 were 13.24%, 7.58%, 1.49%, and 13.85% and at week 8 were 7.35%, 7.58%, 4.48%, and 20.00%, respectively. Consumption of high‐proanthocyanidin juice twice daily (44 mg proanthocyanidin/240‐mL serving) for 8 weeks resulted in decreased H. pylori infection rate by 20% as compared with other dosages and placebo (P < 0.05). Percentage of H. pylori‐negative participants increased from 2 to 8 weeks in subjects who consumed 44 mg proanthocyanidin/day juice once or twice daily, showing a statistically significant positive trend over time. Encapsulated cranberry powder doses were not significantly effective at either time point. Overall trial compliance was 94.25%. Cranberry juice and powder were well‐tolerated. 

Conclusions: Twice‐daily consumption of proanthocyanidin‐standardized cranberry juice may help potentiate suppression of H. pylori infection. Trial registration: ChiCTR1800017522, per WHO ICTRP. 

Identification of antiviral phytochemicals from cranberry as potential inhibitors of SARS-CoV-2 main protease (Mpro)

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Authors
Pillai U J, Cherian L, Taunk K, Iype E, Dutta M
Journal
Int J Biol Macromol. 2024 Mar;261(Pt 1):129655. doi: 10.1016/j.ijbiomac.2024.129655. Epub 2024 Jan 22. PMID: 38266830
Abstract

Cranberry phytochemicals are known to possess antiviral activities. In the current study, we explored the therapeutic potential of cranberry against SARS-CoV-2 by targeting its main protease (Mpro) enzyme. Firstly, phytochemicals of cranberry origin were identified from three independent databases. Subsequently, virtual screening, using molecular docking and molecular dynamics simulation approaches, led to the identification of three lead phytochemicals namely, cyanidin 3-O-galactoside, β-carotene and epicatechin. Furthermore, in vitro enzymatic assays revealed that cyanidin 3-O-galactoside had the highest inhibitory potential with IC50 of 9.98 μM compared to the other two phytochemicals. Cyanidin 3-O-galactoside belongs to the class of anthocyanins. Anthocyanins extracted from frozen cranberry also exhibited the highest inhibitory potential with IC50 of 23.58 μg/ml compared to the extracts of carotenoids and flavanols, the class for β-carotene and epicatechin, respectively. Finally, we confirm the presence of the phytochemicals in the cranberry extracts using targeted LC-MS/MS analysis. Our results, therefore, indicate that the identified cranberry-derived bioactive compounds as well as cranberry could be used for therapeutic interventions against SARS-CoV-2.

A polyphenol-rich cranberry supplement improves muscle oxidative capacity in healthy adults

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Authors
Parenteau F, Denis A, Roberts M, Comtois AS, Bergdahl A
Journal
Appl Physiol Nutr Metab. 2024 Aug 1;49(8):1047-1054. doi: 10.1139/apnm-2023-0633. Epub 2024 Apr 16. PMID: 38626462
Abstract

Cranberries are rich in polyphenols, have a high antioxidant capacity, and may protect against exercise-induced free radical production. Mitochondria are known producers of free radical in skeletal muscle, and preventing overproduction of radicals may be a viable approach to improve muscle health. This study aimed to investigate the effect of a polyphenol-rich cranberry extract (CE) on muscle oxidative capacity and oxygenation metrics in healthy active adults. 17 participants (9 males and 8 females) were tested at: (i) baseline, (ii) 2 h following an acute CE dose (0.7 g/kg of body mass), and (iii) after 4 weeks of daily supplement consumption (0.3 g/kg of body mass). At each time point, muscle oxidative capacity was determined using near-infrared spectroscopy to measure the recovery kinetics of muscle oxygen consumption following a 15-20 s contraction of the vastus lateralis. Cranberry supplementation over 28 days significantly improved muscle oxidative capacity (k-constant, 2.8 ± 1.8 vs. 3.9 ± 2.2; p = 0.02). This was supported by a greater rate of oxygen depletion during a sustained cuff occlusion (-0.04 ± 0.02 vs. -0.07 ± 0.03; p = 0.02). Resting muscle oxygen consumption was not affected by cranberry consumption. Our results suggest that cranberry supplementation may play a role in improving mitochondrial health, which could lead to better muscle oxidative capacity in healthy active adult populations. 

A Review with a Focus on Vaccinium-Berries-Derived Bioactive Compounds for the Treatment of Reproductive Cancers

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Authors
Alsharairi NA
Journal
Plants (Basel). 2024 Apr 8;13(7):1047. doi: 10.3390/plants13071047. PMID: 38611574; PMCID: PMC11013621
Abstract

Cancers of the reproductive organs, including prostate, bladder, ovarian, and cervical cancers, are considered the most common causes of death in both sexes worldwide. The genus Vaccinium L. (Ericaceae) comprises fleshy berry crop species, including cranberries, blueberries, lingonberries, bilberries, and bog bilberries, and are widely distributed in many countries. Flavonols, anthocyanins (ACNs), proanthocyanidins (PACs), and phenolic acids are the most bioactive compounds naturally found in Vaccinium berries and have been extensively used as anticancer agents. However, it remains uncertain whether Vaccinium bioactives have a therapeutic role in reproductive cancers (RCs), and how these bioactives could be effective in modulating RC-related signalling pathways/molecular genes. Therefore, this article aims to review existing evidence in the PubMed/MEDLINE database on Vaccinium berries’ major bioactive compounds in RC treatment and unravel the mechanisms underlying this process.

Acute Uncomplicated UTIs in Adults: Rapid Evidence Review

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Authors
Kurotschka PK, Gágyor I, Ebell MH
Journal
Am Fam Physician. 2024 Feb;109(2):167-174. PMID: 38393801
Abstract

An acute uncomplicated urinary tract infection (UTI) is a bacterial infection of the lower urinary tract with no sign of systemic illness or pyelonephritis in a noncatheterized, nonpregnant adult with no urologic abnormalities or immunocompromise. In women, a self-diagnosis of a UTI with the presence of typical symptoms (e.g., frequency, urgency, dysuria/burning sensation, nocturia, suprapubic pain), without vaginal discharge, is accurate enough to diagnose an uncomplicated UTI without further testing. Urine culture and susceptibility testing should be reserved for women with recurrent infection, treatment failure, history of resistant isolates, or atypical presentation to make a definitive diagnosis and guide antibiotic selection. First-line antibiotics include nitrofurantoin for five days, fosfomycin in a single dose, trimethoprim for three days, or trimethoprim/sulfamethoxazole for three days. Symptomatic treatment with nonsteroidal anti-inflammatory drugs and delayed antibiotics may be considered because the risk of complications is low. Increased fluids, intake of cranberry products, and methenamine hippurate can prevent recurrent infections. Antibiotic prophylaxis is also effective in preventing recurrence but has a risk of adverse effects and antimicrobial resistance. Men with lower UTI symptoms should always receive antibiotics, with urine culture and susceptibility results guiding the antibiotic choice. Clinicians should also consider the possibility of urethritis and prostatitis in men with UTI symptoms. First-line antibiotics for men with uncomplicated UTI include trimethoprim, trimethoprim/sulfamethoxazole, and nitrofurantoin for seven days. Uncomplicated UTIs in nonfrail women and men 65 years and older with no relevant comorbidities also necessitate a urine culture with susceptibility testing to adjust the antibiotic choice after initial empiric treatment; first-line antibiotics and treatment durations do not differ from those recommended for younger adults.

Anthocyanins: Molecular Aspects on Their Neuroprotective Activity

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Authors
Zaa CA, Marcelo ÁJ, An Z, Medina-Franco JL, Velasco-Velázquez MA
Journal
Biomolecules. 2023 Oct 31;13(11):1598. doi: 10.3390/biom13111598. PMID: 38002280; PMCID: PMC10669056
Abstract

Anthocyanins are a type of flavonoids that give plants and fruits their vibrant colors. They are known for their potent antioxidant properties and have been linked to various health benefits. Upon consumption, anthocyanins are quickly absorbed and can penetrate the blood–brain barrier (BBB). Research based on population studies suggests that including anthocyanin-rich sources in the diet lower the risk of neurodegenerative diseases. Anthocyanins exhibit neuroprotective effects that could potentially alleviate symptoms associated with such diseases. In this review, we compiled and discussed a large body of evidence supporting the neuroprotective role of anthocyanins. Our examination encompasses human studies, animal models, and cell cultures. We delve into the connection between anthocyanin bioactivities and the mechanisms underlying neurodegeneration. Our findings highlight how anthocyanins’ antioxidant, anti-inflammatory, and anti-apoptotic properties contribute to their neuroprotective effects. These effects are particularly relevant to key signaling pathways implicated in the development of Alzheimer’s and Parkinson’s diseases. In conclusion, the outcome of this review suggests that integrating anthocyanin-rich foods into human diets could potentially serve as a therapeutic approach for neurological conditions, and we identify promising avenues for further exploration in this area.

Anticaries properties of natural berries: systematic literature review

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Authors
García-Manríquez N, Lozano C, Muñoz A, Morales MF, Giacaman RA
Journal
Nutr Rev. 2024 Feb 12;82(3):302-317. doi: 10.1093/nutrit/nuad063. PMID: 37352393
Abstract

Context: Anticariogenic properties have been ascribed to polyphenolic compounds present in high concentrations in numerous fruits. Berries, in particular, have been reported as potentially having an inhibitory effect on the dental biofilm and subsequently on caries, but the evidence is unclear.

Objective: The objective of this review was to explore the literature and summarize the evidence for berries having an inhibitory effect on the dental biofilm and an anticariogenic effect.

Data sources: Following Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, the PubMed, Web of Science, and SCOPUS databases were scanned using predefined and accessible terms, with a search strategy based on a structured PICO question.

Data extraction: After article selection, 23 studies met the inclusion criteria, most of them being in vitro studies. A risk assessment was performed, and data were extracted and presented in a table for qualitative analysis.

Data analysis: Meta-analyses were conducted using standardized mean differences (SMDs) with a 95% confidence interval (CI) by Review manager 5.4.

Results: Only 3 types of berries were found to have a reported anticaries effect: grape seed extract (GSE), cranberry, and sour cherry. Nine studies that fulfilled the eligibility criteria were subjected to quantitative analysis. Meta-analyses showed GSE was associated with enhanced remineralization of dental enamel (SMD = .96 95% CI [.45, 1.46], P < .0002) and of dentin (SMD = .65 95% CI [.13, 1.17], P = .01). Cranberry extracts positively influenced the cariogenic dental biofilm by decreasing the biofilm biomass (SMD = -2.23 95% CI [-4.40, -.05], P = .04), and biovolume (SMD = -2.86 95% CI [-4.34, -1.37], P = .0002), and increasing the biofilm pH (SMD = 7.9 95% CI [3.49, 12.31], P < .0004).

Conclusion: Within the limitations of this systematic review and metaanalysis, GSE and cranberries or their active compounds could represent an alternative for caries management. Further clinical trials are needed to verify this effect in a clinical setting.

Berries in Microbiome-Mediated Gastrointestinal, Metabolic, and Immune Health

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Authors
Komarnytsky S, Wagner C, Gutierrez J, Shaw OM
Journal
Curr Nutr Rep. 2023 Mar;12(1):151-166. doi: 10.1007/s13668-023-00449-0. Epub 2023 Feb 4. PMID: 36738429
Abstract

Purpose of review: Current research has shown that berry-derived polymeric substrates that resist human digestion (dietary fibers and polyphenols) are extensively metabolized in the gastrointestinal tract dominated by microbiota. This review assesses current epidemiological, experimental, and clinical evidence of how berry (strawberry, blueberry, raspberry, blackberry, cranberry, black currant, and grapes) phytochemicals interact with the microbiome and shape health or metabolic risk factor outcomes.

Recent findings: There is a growing evidence that the compositional differences among complex carbohydrate fractions and classes of polyphenols define reversible shifts in microbial populations and human metabolome to promote gastrointestinal health. Interventions to prevent gastrointestinal inflammation and improve metabolic outcomes may be achieved with selection of berries that provide distinct polysaccharide substrates for selective multiplication of beneficial microbiota or oligomeric decoys for binding and elimination of the pathogens, as well as phenolic substrates that hold potential to modulate gastrointestinal mucins, reduce luminal oxygen, and release small phenolic metabolites signatures capable of ameliorating inflammatory and metabolic perturbations. These mechanisms may explain many of the differences in microbiota and host gastrointestinal responses associated with increased consumption of berries, and highlight potential opportunities to intentionally shift gut microbiome profiles or to modulate risk factors associated with better nutrition and health outcomes.

Clinical Potential of Fruit in Bladder Cancer Prevention and Treatment

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Authors
Wigner P, Bijak M, Saluk-Bijak J
Journal
Nutrients. 2022 Mar 8;14(6):1132. doi: 10.3390/nu14061132. PMID: 35334790; PMCID: PMC8951059
Abstract

Bladder cancer (BC) is the most common tumor of the urinary system in the world. Moreover, despite using anticancer therapies, BC is also characterized by a high recurrence risk. Among numerous risk factors, cigarette smoking, occupational exposure to certain aromatic compounds, and genetic factors contribute most strongly to BC development. However, the epidemiological data to date suggests that diet quality may influence some carcinogenic factors of BC and, therefore, might have a preventative effect. Adequate consumption of selected fruits with scientifically proven properties, including pomegranates and cranberries, can significantly reduce the risk of developing BC, even in those at risk. Therefore, in this article, we aim to elucidate, using available literature, the role of fruits, including pomegranates, cranberries, citrus fruits, cactus pears, and apples, in BC prevention and treatment. Previous data indicate the role of compounds in the above-mentioned fruits in the modulation of the signaling pathways, including cell proliferation, cell growth, cell survival, and cell death.