Research - Cranberries
Consumption of a cranberry juice beverage lowered the number of clinical urinary tract infection episodes in women with a recent history of urinary tract infection
- Kevin C Maki2,3,*,
- Kerrie L Kaspar4,
- Christina Khoo4,
- Linda H Derrig2,
- Arianne L Schild2, and
- Kalpana Gupta5,6
Background: Urinary tract infections (UTIs) are among the most common bacterial infections and are often treated with antibiotics. Concerns about multidrug-resistant uropathogens have pointed to the need for safe and effective UTI-prevention strategies such as cranberry consumption.
Objective: We assessed the effects of the consumption of a cranberry beverage on episodes of clinical UTIs.
Design: In this randomized, double-blind, placebo-controlled, multicenter clinical trial, women with a history of a recent UTI were assigned to consume one 240-mL serving of cranberry beverage/d (n = 185) or a placebo (n = 188) beverage for 24 wk. The primary outcome was the clinical UTI incidence density, which was defined as the total number of clinical UTI events (including multiple events per subject when applicable) per unit of observation time.
Results: The dates of the random assignment of the first subject and the last subject’s final visit were February 2013 and March 2015, respectively. The mean age was 40.9 y, and characteristics were similar in both groups. Compliance with study product consumption was 98%, and 86% of subjects completed the treatment period in both groups. There were 39 investigator-diagnosed episodes of clinical UTI in the cranberry group compared with 67 episodes in the placebo group (antibiotic use–adjusted incidence rate ratio: 0.61; 95% CI: 0.41, 0.91; P = 0.016). Clinical UTI with pyuria was also significantly reduced (incidence rate ratio: 0.63; 95% CI: 0.40, 0.97; P = 0.037). One clinical UTI event was prevented for every 3.2 woman-years (95% CI: 2.0, 13.1 woman-years) of the cranberry intervention. The time to UTI with culture positivity did not differ significantly between groups (HR: 0.97; 95% CI: 0.56, 1.67; P = 0.914).
Conclusion: The consumption of a cranberry juice beverage lowered the number of clinical UTI episodes in women with a recent history of UTI.
Source : American Journal of Clinical Nutrition
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Cranberry fruit powder (Flowens™) improves lower urinary tract symptoms in men: a double-blind, randomized, placebo-controlled study.
Vidlar A1, Student V Jr, Vostalova J, Fromentin E, Roller M, Simanek V, Student V.
BACKGROUND:Lower urinary tract symptoms (LUTS) and benign prostatic hyperplasia increase with age. To date, several medications are available to treat LUTS, including herbal remedies which offer less side effects but lack robust efficacy studies.
METHODS:This 6-month, randomized, double-blind, placebo-controlled study aimed at evaluating the dose effect of 250 or 500 mg cranberry powder (Flowens™) on LUTS and uroflowmetry in men over the age of 45. A total of 124 volunteers with PSA levels <2.5 ng/mL and an international prostate symptoms score (IPSS) score ≥8 were recruited and randomized. The primary outcome measure was the IPSS, evaluated at 3 and 6 months. Secondary outcome measures included quality of life, bladder volume (Vol), maximum urinary flow rate (Q max), average urinary flow rate (Q ave), ultrasound-estimated post-void residual urine volume (PVR), serum prostate-specific antigen, selenium, interleukin 6, and C-reactive protein at 6 months.
RESULTS:After 6 months, subjects in both Flowens™ groups had a lower IPSS (-3.1 and -4.1 in the 250- and 500-mg groups, p = 0.05 and p < 0.001, respectively) versus the placebo group (-1.5), and a dose-response effect was observed. There were significant differences in Q max, Qave, PVR, and Vol in the Flowens™ 500-mg group versus baseline (p < 0.05). A dose-dependent effect on Vol was observed, as well as on PVR, for participants with a nonzero PVR. There was no effect on clinical chemistry or hematology markers.
CONCLUSIONS:Flowens™ showed a clinically relevant, dose-dependent, and significant reduction in LUTS in men over 45.
Source : World J Urol.
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Cranberry Supplements May Reduce the Severity of Radiation-induced Cystitis
Hamilton K, Bennett NC, Purdie G, Herst PM. Standardized cranberry capsules for radiation cystitis in prostate cancer patients in New Zealand: a randomized double blinded, placebo controlled pilot study. Support Care Cancer. July 2014; [epub ahead of print]. doi: 10.1007/s00520-014-2335-8.
Patients with prostate cancer undergoing radiation therapy often experience acute radiation-induced cystitis (inflammation of the bladder). Although the symptoms of this condition can be treated, there are no preventative therapies available. Cranberry (Vaccinium macrocarpon) supplements have been associated with urinary tract health and therefore may beneficial for patients with radiation-induced cystitis. The aim of this double-blinded, randomized, placebo-controlled pilot trial was to evaluate the effects of a standardized cranberry supplement on the incidence and severity of radiation cystitis in patients with prostate cancer.
The men participating in this study received radiation therapy for their prostate and regional lymph nodes at theSouthern Blood and Cancer Centre in Dunedin, New Zealand. Eligible patients were identified from planning computed tomography (CT) scans that assessed the prostate, bladder, and bowel. Excluded patients included men who had previous radiation therapy, metastatic disease, consumed warfarin, had a Karnofsky performance status score <70 (required at least some assistance for personal care), had kidney stones, or an allergy to cranberries.
In terms of radiation treatment, the patients were prescribed a dose of 74 Gy in 37 fractions or 64 Gy in 32 fractions to the prostate and prostate bed, respectively. The patients all received intensity-modulated radiation therapy (6MV photon beam). Radiation treatment was directed to the prostate, prostate bed, and/or regional lymph nodes. There was a 9-week radiation treatment period for prostate bed and 10-week treatment for prostate and prostate nodes. Patients (n=41) were randomly assigned to take a capsule a day (during breakfast) of either a cranberry extract (n=20) or a placebo (n=21) (Naturo Pharm LTD; Rotorua, New Zealand) during the entire radiation treatment period and 2 weeks post-treatment. The cranberry capsules contained 72 mg proanthocyanidins (PACs), determined by UV-VISEP/CN standard method, and the placebo capsules were nearly identical in taste, color, and smell to the capsules with the cranberry extracts.
Patients were advised not to consume or limit the consumption of wine, grapes (Vitis vinifera), cranberries, or other berries during the study. Treatment effects were evaluated by assessing the Modified Expanded Prostate Index Composite (EPIC) scores both at the beginning and the end of the study. In particular, this study focused on 5 urinary symptoms and the degree that 7 urinary tract symptoms bothered the patients.
The results of this study were analyzed on an intent-to-treat basis for 40 patients (20 in both groups). A total of 2 patients did not comply with the study, including 1 that left the study after 2 weeks. Most of the men (mean age: 68 years) in this study were of European descent (93%) and had a mid-range Gleason score (grading system for prostate cancer) of 6 or 7. In addition, nearly half of the patients had stage T1 disease (beginning of disease). Furthermore, all patient-related factors were evenly distributed between the 2 groups.
Based on symptom scoring, the researchers found that the incidence of cystitis was 65% for the patients in the cranberry treatment group and 90% for the patients in the placebo group (P=0.058). Moreover, 30% of the patients in the cranberry group and 45% of the patients in the placebo group had severe cystitis (P=0.30). There were no men in the study that developed a urinary tract infection (UTI). All EPIC scores were consistently lower for the cranberry cohort. In particular, the cranberry cohort had significantly lower mean (P=0.045) and maximum (P=0.019) scores for pain/burning urination symptoms. The cranberry cohort also had better mean scores for urine stream, although this was not significant when accounting for baseline symptoms (P=0.14).
Patients that presented with baseline urinary symptoms had worse EPIC scores for most symptoms. Less pain/burning (P=0.042), better control (P=0.034), stronger urine stream (P=0.036), and less leaking/dribbling (P=0.024), in comparison to the placebo group, were found to be significant only in the cranberry treatment group with baseline urinary symptoms. Additionally, patients in the cranberry cohort that followed the low hydration regimen had significant effects on symptoms for pain/burning (P=0.038), stronger urine stream (P=0.038), and less use of pad/liners (P=0.042). There were no significant differences found in the high hydration regimen.
The authors conclude, "Men receiving radiation therapy for prostate cancer may benefit from using cranberry capsules, particularly those on low hydration regimens or presenting with urinary symptoms before radiation treatment." Although the results are promising, one of the limitations of this study was that the improvements were based only on a questionnaire. This study could also have evaluated inflammation markers or any other diagnostic features of cystitis. Despite this shortcoming, the interesting results of this pilot study warrant further investigations on the use of cranberry supplements for radiation-induced cystitis.
--Laura M. Bystrom, PhD
Source : American Botanical Council
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Flavonoids and Phenolic Acids in Cranberry Juice Are Bioavailable and Increase Antioxidant Activity in Older, Healthy Subjects
McKay DL, Chen CY, Zampariello CA, Blumberg JB.
Flavonoids and phenolic acids from cranberry juice are bioavailable and bioactive in healthy older adults. Food Chem. February 1, 2015;168:233-240.
Cranberries (Vaccinium macrocarpon), which are rich in phenolic phytochemicals, have been associated with antibacterial, antimutagenic, anticarcinogenic, antiangiogenic, and antioxidant activities. Phenolic compounds have antioxidant and anti-inflammatory properties and can modulate enzyme activity and gene expression. However, most of the evidence supporting these activities was determined from in vitro studies and animal models. Furthermore, more research is needed to understand the bioavailability and metabolism of cranberry phenolics in humans. The authors have expanded on their earlier study which examined the pharmacokinetics of cranberry anthocyanins which showed most anthocyanins appeared in plasma within 1 to 2 hours after consumption.1 In the study reported here, the authors conducted a single-dose pharmacokinetic trial to examine the bioavailability and bioactivity of a broader array of phenolics from cranberry juice.
The study evaluated the acute (24-hour) bioavailability of flavonoids and phenolic acids from a single dose (237 mL) of a double-strength (54% juice), low-calorie, low-sugar cranberry juice cocktail (CJC) (Ocean Spray; Lakeville-Middleboro, Massachusetts). The principal phenolics in the beverage were the anthocyanins peonidin-3-galactoside and -arabinoside, the anthocyanins cyanidin-3-arabinoside and -galactoside, and the flavonols hyperoside and quercetin. Total phenolic content of the single dose of CJC was 188.5 mg.
The study involved 10 healthy, nonsmoking men and postmenopausal women aged 50 to 70 years. The subjects were asked to consume foods low in phenolics for 48 hours before the trial. The day before the trial, the subjects were fed the same meal low in phenols and refrained from food and beverages except for water for the next 12 hours to provide baseline values.
After administration of CJC, blood samples were collected periodically for 10 hours and at 24 hours. Blood samples were assessed for phenolic acids, flavonoids, and total antioxidant capacity: oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), and total antioxidant performance (TAP). Susceptibility of low-density lipoprotein (LDL) to Cu2+-induced lipid oxidation (LDL oxidation) was also measured.
The authors found the concentration of total phenolics detected in plasma reached a peak of 34.2 µg/mL between 8 and 10 hours after CJC consumption; in urine, the peak was 269.8 µg/mg creatinine, occurring 2 to 4 hours earlier. In plasma, protocatechuic acid, quercetin, and vanillic acid were the most predominant contributors to this total. In urine, protocatechuic acid and 4-OH-phenylacetic acid were the most predominant. Anthocyanins were detected in the urine samples of all subjects at widely varying concentrations. The predominant anthocyanin detected in both plasma and urine was peonidin-3-galactoside.
The authors "provide here the first observation that PAC-A2 [proanthocyanidin-A2] can be quantified in the urine of healthy volunteers following an acute dose of CJC." This finding suggests that PAC-A2 in urine could be a biomarker of cranberry intake and compliance since it does not occur in other plant foods.
Among the 3 assays measuring antioxidant capacity, the mean TAP values increased the most after CJC consumption. Correlations were observed between ORAC and protocatechuic acid (P=0.00), quercetin (P=0.00), epicatechin (P=0.001), 4-OH-3-methoxy-phenylacetic acid (P=0.018), gentisic acid (P=0.045), and 3,4-OH-phenylacetic acid (P=0.03), and between TAP and gentisic acid (P=0.01) and protocatechuic acid (P=0.036). No correlations were observed between FRAP and plasma phenolics. According to the authors, "This is the first study to correlate changes in individual cranberry metabolites, e.g., protocatechuic acid, with an array of measures of antioxidant capacity over time."
Consistent with earlier studies, the authors detected cranberry anthocyanins in plasma and urine and a marked inter-individual variation in anthocyanin pharmacokinetics. "The considerable inter-individual variability in the pharmacokinetics of these phytochemicals appears likely due to individual differences in phase II enzyme polymorphisms as well as composition of gastrointestinal microbiota," the authors write.
"In conclusion, we have demonstrated that phenolic acids and flavonoids, in CJC, are bioavailable and increase antioxidant capacity in healthy older adults. We also found that PAC-A2 is detectable in plasma and quantifiable in urine after an acute dose of cranberry juice," the authors state.
Source : American Botanical council
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Cranberry Products Prevent Urinary Tract Infections in Women: Clinical Evidence
Michael Tempesta and Marilyn Barrett
Conclusion : Further studies are required to establish optimal daily dosing of the cranberry-derived total phenols/PACs for efficient prevention of recurrent UTIs. In vitro and ex vivo studies indicate that these compounds prevent adhesion of E. coli to the epithelium of the urinary tract and thus prevent infection. Although in vitro studies indicate a clear dose- response effect with PACs, the clinical picture may be more complicated. There may be interference by high- and low- molecular- weight sugars naturally present in cranberry, reducing the effect of the PACs in prevention of UTIs via this mechanism. Other phenolics, including the anthocyanins, may also play a role in the clinical benefits observed.
Source : Botanical Medicine from Bench to Bedside
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Cranberry Juice Consumption May Reduce Arterial Stiffness in Overweight Men
Ruel G, Lapointe A, Pomerleau S, et al. Evidence that cranberry juice may improve augmentation index in overweight men. Nutr Res. 2013;33(1):41-49.
Endothelial dysfunction, the impairment of the normal functions of the inner lining of the blood vessels, is associated with cardiovascular disease (CVD) risk factors that can lead to arterial stiffness. The augmentation index (AIx) is an index of arterial stiffness measured by peripheral pulse wave analysis. Healthy nutritional habits, including increasing the consumption of fruits and vegetables and reducing dietary fat intake, are important in helping to prevent and treat CVD through improved lipoprotein-lipid and inflammatory profiles and endothelial function. The cardioprotective potential of fruits and vegetables is due to their high content of polyphenolic compounds such as flavonoids, which play a beneficial role in protecting against inflammation and oxidative stress. Cranberries (Vaccinium macrocarpon) are rich in polyphenols such as phenolic acids, flavonols, anthocyanins, and proanthocyanidins. The authors conducted a short-term, placebo-controlled, double-blind, crossover study at Université Laval in Quebec, Canada to examine the effect of consuming a low-calorie cranberry juice cocktail (CJC) on the AIx and cardiometabolic profile of overweight men.
The authors recruited 35 sedentary, otherwise healthy, overweight men (mean age = 45 ± 10 years) with a body mass index (BMI) of ≥ 25 kg/m2 and a waist circumference of ≥ 90 cm (35.4 inches). The men were nonsmokers and were not taking medications that affected lipid or insulin metabolism or blood pressure.
After a 4-week run-in period during which the subjects drank 500 mL of water daily to get used to that amount of liquid in their usual diet, they were randomly assigned to drink 500 mL daily of either a low-calorie CJC (27% juice) or placebo juice (PJ) for 4 weeks (2 boxes of 125 mL of juice in the morning and 2 in the evening). Then, after a 4-week washout period, the subjects began the other treatment for another 4 weeks.
The CJC and PJ (Ocean Spray Cranberries, Inc.; Lakeville-Middleboro, Massachusetts) had a similar taste, color, texture, and vitamin C content, but no cranberries were in the PJ. Each daily serving of the CJC contained 500 mg of total polyphenols, 20.8 mg of anthocyanins, and 21.84 g of carbohydrates.
At baseline and after week 4, body weight, height, waist and hip circumferences, and blood pressure were measured; BMI and waist-to-hip ratio values were calculated; and fasting blood samples were drawn. The subjects also completed a food frequency questionnaire at those 2 visits.
At baseline and at 4 weeks, the resting AIx was measured by applanation tonometry, during which peripheral artery waveforms were recorded on the subjects' radial artery. Waveforms were recorded again at 5, 10, 15, and 20 minutes after the subjects inhaled 400 μg of salbutamol, which elicits the synthesis of nitric oxide (NO) and a vascular response used as a proxy measure of endothelium-dependent vasodilation. The same technique was used to measure arterial stiffness during endothelium-independent radial artery vasodilation at 3, 5, 10, 15, 20, and 30 minutes following sublingual administration of 400 μg of glyceryl trinitrate (GTN), an NO donor used to treat angina and heart failure. The cardiometabolic profile, which assesses risks associated with type 2 diabetes mellitus and CVD, was determined for each subject before and after each phase of the study.
The subjects were separated into groups made up of those with metabolic syndrome (MetS+) (n = 13) and those without metabolic syndrome (MetS-) (n = 22), using the criteria for metabolic syndrome as defined by the National Cholesterol Education Program.
At baseline, although at the high end for total fat intake and the low end for carbohydrate intake, the daily energy and nutrient intakes of the subjects fell within the nutritional recommendations for Canadian adults. The MetS+ subjects had a higher BMI, higher circulating triglycerides (TG), and lower high-density lipoprotein cholesterol (HDL-C) levels compared with the MetS- subjects.
The authors report that the salbutamol reduced the AIx by 10.8% ± 6.4% compared with resting values (P < 0.0001). GTN further decreased the values by 2.1% ± 6.0% compared with salbutamol (P < 0.05). However, these changes in the AIx responses to salbutamol and GTN did not significantly differ between subjects who consumed the CJC or PJ.
Although no significant difference was noted in the AIx changes between the subjects who consumed the CJC or PJ, a statistically significant within-group decrease was noted in the AIx (P < 0.05 compared with baseline) in subjects who consumed the CJC.
No significant differences were noted in other cardiometabolic variables between those subjects drinking the CJC or PJ.
Comparing the AIx values in the MetS+ and MetS- subjects, the authors report no significant differences in the responses to salbutamol and GTN after supplementation; however, they noted a significant within-group decrease in the resting AIx values in MetS- subjects who drank CJC (P < 0.05 compared with baseline). In those same subjects, significant increases in the AIx responses to salbutamol and GTN were observed (P < 0.05 compared with baseline). Although these results may seem contradictory, say the authors, earlier studies have shown that, "Vascular tone is positively correlated with flow-mediated dilation in healthy individuals, and thus, a more relaxed (and possibly wider) artery at rest has a lower endothelium-dependent vasodilation response."
The authors previously reported that CJC supplementation was associated with reductions in circulating oxidized low-density lipoprotein (OxLDL) and adhesion molecule concentrations (inflammation and oxidative stress markers) in men.1,2 This was not supported, however, in the present study, where no significant changes in those markers were reported after the CJC supplementation. Although the differences in the design of the studies may explain the discrepancies, say the authors, the lack of effect of the CJC on plasma OxLDL and adhesion molecule levels in the current study agrees with previous reports showing that CJC consumption for 2 weeks had no effect on oxidative stress markers3 and that supplementing men and women with a 54% CJC for 4 weeks did not reduce cell adhesion molecule concentrations.4
These authors found that although CJC consumption did reduce the resting AIx in overweight men, the decrease was not significantly different from those drinking the PJ. The significant within-group decrease in the AIx following the CJC consumption, however, warrants further investigation.
1Ruel G, Pomerleau S, Couture P, Lamarche B, Couillard C. Changes in plasma antioxidant capacity and oxidized low-density lipoprotein levels in men after short-term cranberry juice consumption. Metabolism. 2005;54(7):856-861.
2Ruel G, Pomerleau S, Couture P, Lemieux S, Lamarche B, Couillard C. Low-calorie cranberry juice supplementation reduces plasma oxidized LDL and cell adhesion molecule concentrations in men. Br J Nutr. 2008;99(2):352-359.
3Duthie SJ, Jenkinson AM, Crozier A, et al. The effects of cranberry juice consumption on antioxidant status and biomarkers relating to heart disease and cancer in healthy human volunteers. Eur J Nutr. 2006;45(2):113-122.
4Dohadwala MM, Holbrook M, Hamburg NM, et al. Effects of cranberry juice consumption on vascular function in patients with coronary artery disease. Am J Clin Nutr. 2011;93(5):934-940.
Source : American Botanical Council
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Cranberry for UTI More Than Folk Remedy?
Drinking cranberry juice or taking cranberry capsules or tablets was associated with a protective effect against urinary tract infection, a systematic review found.
The pooled data from 10 studies comparing cranberry-product consumers against nonusers showed cranberry consumption had a risk ratio protective against UTI at 0.62 (95% CI 0.49 to 0.80), according to Chien-Chang Lee, MD, of the National Taiwan University Hospital, and colleagues.
A subgroup analysis found the cranberry products were more effective in women with recurrent UTI, female populations, children, regular cranberry juice drinkers, and those who used cranberry products more than twice daily, Lee and co-authors wrote in the July 9 issue of Archives of Internal Medicine.
"Cranberry-containing products have long been used as a folk remedy to prevent UTIs," the authors explained. Cranberry is thought to interfere with the attachment of bacteria to uroepithelial cells, potentially preventing infection.
The meta-analysis evaluated randomized controlled trials that compared the effectiveness of cranberry containing products, such as juices and pills, with placebo and non-placebo control groups at preventing UTIs. The review included data from 10 trials of 1,494 patients, with 794 in the cranberry group versus 700 in the control group.
In pooled trials, there was an association with protective effects for the cranberry group and significant heterogeneity between the trials (RR 0.68, 95% CI 0.47 to 1.00), but the results were nonsignificant, Lee and colleagues wrote.
They added that sensitivity analyses "showed that the protective effect of cranberry containing products was stronger in nonplacebo-controlled trials" and suggested that expectations of efficacy had an effect on outcomes.
When broken down by subgroup, there was a nonsignificant trend for protection in certain groups consuming cranberries, including:
- Women with recurrent UTI (RR 0.53, 95% CI 0.33 to 0.83)
- Female patients (RR 0.49, 95% CI 0.34 to 0.73)
- Children (RR 0.33, 95% CI 0.16 to 0.69)
- Cranberry juice drinkers (RR 0.47, 95% CI 0.30 to 0.72)
- Patients consuming cranberry products more than twice daily (RR 0.58, 95% CI 0.40 to 0.84)
However, the high sugar content in most cranberry drink products may cause gastrointestinal problems or raise concerns about sugar control in diabetic patients, the authors warned.
They concluded that although their meta-analysis showed an association between cranberry product consumption and protection against UTI, "this conclusion should be interpreted with great caution" due to the "substantial heterogeneity across trials."
The authors said that their review was limited by absent searches for conferences, proceedings, and clinical trial registries; inability to reach some study authors to acquire missing data; and missing proanthocyanidin content for cranberry products in several trials. Proanthocyanidins are compounds that may potentially inhibit the adherence of Escherichia coli to urological mucosa, they wrote.
Primary source: Archives of Internal Medicine
Lee CC, et al "Cranberry-containing products for prevention of urinary tract infections in susceptible populations" Arch Intern Med 2012; 172: 988-996.
Source : Medical News Today
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Cranberry shows heart health benefits: Study
Polyphenol-rich cranberry juice may boost heart health by alleviating arterial stiffness, says a new study from the Boston and Tufts Universities.
Double-strength cranberry containing 835 milligrams of total polyphenols and 94 mg of anthocyanins was associated with improvements in a measure of arterial stiffness called carotid femoral pulse wave velocity, according to findings published in the American Journal of Clinical Nutrition.
On the other hand, the Boston-based scientists report no benefits from cranberry juice consumption were observed for other measures of vascular or cardiovascular function, including blood pressure or brachial artery flow-mediated dilation, a measure of endothelial dysfunction since a low value is indicative of a blood vessel's inability to relax.
“We did observe a highly significant effect of cranberry juice on stiffness of the central aorta, which is increasingly recognized as an important measure of vascular function with relevance to cardiovascular disease,” wrote the researchers, led by Boston University’s Joe Vita, MD.
“Overall, our results may provide further support for the American Heart Association recommendation that cardiovascular disease risk may be reduced by a diet rich in fruit and vegetables, including cranberries,” they added.
Established and emerging health benefits
Cranberry is most famous for its ability to fight urinary tract infections, something that has led to almost one third of parents in the US giving it to their children, according to a recent study.
In 2004 France became the first country to approve a health claim for the North American cranberry species Vaccinium macrocarpon, which states that it can 'help reduce the adhesion of certain E.coli bacteria to the urinary tract walls'.
Other health conditions that may benefit from cranberry include stomach health, with several reports indicating that the berry’s constituents may inhibit the adhesion of Helicobacter pylori in the stomach. H. pylori is the only bacteria that can survive in the acidic environment of the stomach and known to cause peptic ulcers and gastritis.
In addition studies have suggested that proanthocyanidin-rich cranberry extracts may inhibit the growth and spread of human oesophageal adenocarcinoma (a cancer in glandular tissue), or may prevent colon cancer via an anti-inflammatory mechanism.
The researchers performed two studies: The first was an acute pilot study with no placebo involving 15 participants; the second was a chronic placebo-controlled crossover study with 44 participants with coronary artery disease.
In the acute, non-placebo controlled, pilot study, the researchers reported that cranberry juice (480 mL) was associated with improvements in both brachial artery flow-mediated dilation, from 7.7 percent before ingestion to 8.7 percent four hours after ingestion, as well as digital pulse amplitude tonometry ratio from to 0.10 to 0.23.
However, in the placebo-controlled, cross-over study, no such changes were observed. Dr Vita and his researchers did record a reduction in carotid-femoral pulse wave velocity from 8.3 to 7.8 m/s.
“We emphasize that the research beverage contained twice the amount of cranberry juice in commercially available cranberry juice and that the amount of anthocyanins consumed during the study greatly exceeded the average daily intake in the United States,” noted the researchers.
“Additional studies will be needed to determine how cranberry juice reduces central aortic stiffness, but our finding of improved pulse wave velocity without a change in endothelial function may be consistent with an effect at the level of the arterial wall or a change in sympathetic tone,” they added.
The study was funded by cranberry giant Ocean Spray and the National Institutes of Health (NIH).
Source NutraIngredients via American Journal of Clinical Nutrition
Published online ahead of print, doi: 10.3945/ajcn.110.004242
“Effects of cranberry juice consumption on vascular function in patients with coronary artery disease”
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