Cranberry Consumption Research Articles

Cranberry consumption improves survival in the spontaneously hypertensive stroke‐prone rat

Hypertension is a risk factor for stroke, a leading cause of death in North America. A reduction in systolic blood pressure of only 3 mm Hg reduces the incidence of cerebrovascular disease. Vascular integrity is altered in hypertension, characterized by arterial inflammation, oxidative stress and vasoconstriction. American cranberries (Vaccinium macrocarpon) contain polyphenols which have been shown to act as antioxidants and anti‐inflammatory agents in biological systems. We hypothesized that feeding cranberry‐enriched diets (CBD) to spontaneously hypertensive stroke prone rats (SHRSP) would reduce hypertension and incidence of stroke mortalities. Eight‐week‐old SHRSP and Wistar rats (n=10) were fed one of two diets: 3% cranberry + 4% NaCl or 4% NaCl, mixed into commercial chow. SHRSP eating CBD experienced a 10–20 mm Hg reduction in systolic blood pressure by week 6. This hypotensive effect may be due to a reduction in vasoconstriction as SHRSP eating CBD had significantly higher nitrite levels in their urine after 6 wks (p=0.034), suggestive of higher levels of NO release. SHRSP fed control diet had signs of oxidative stress, with elevated F2 isoprostane excretion in the urine. Feeding cranberry reduced urinary isoprostane excretion in SHRSP rats (p=0.01). Overall, SHRSP on CBD lived 40% longer than control rats (51.3 ± 3.8 days vs 70.5 ± 9.9 days, p= 0.039). These data suggest that cranberry supplementation reduces oxidative stress and vasoconstriction, resulting in lower blood pressure and increased longevity. Funded by NSERC & Atlantic Innovation Fund.

Evidences of the cardioprotective potential of fruits: The case of cranberries

Eating a healthy balanced diet, is one of the most important and relevant ways to delay and prevent various health complications including cardiovascular disease (CVD). Among the nutritional factors that have been investigated in recent years, dietary fat intake may be the one that has been most targeted. However, there is also clear epidemiological evidence that increased fruits and vegetables intake can significantly reduce the risk of CVD, an effect that has been suggested to be resulting to a significant extent, from the high polyphenol content of these foods. Numerous polyphenolic compounds such as flavonoids have been identified as having strong antioxidant properties. Most interesting is the fact that, in addition to being one of the largest groups of antioxidant phytochemicals, flavonoids are also an integral part of the human diet as they are found in most fruits and vegetables. Cranberries are one of the most important sources of flavonoids that have a strong antioxidant and anti-inflammatory capacities. Thus, consumption of cranberries or their related products could be of importance not only in the maintenance of health but also in preventing CVD. The following review will present evidences supported for the most part by clinical observations that cranberries can exert potentially healthy effects for your heart.

Changes in blood lipid parameters with chronic cranberry consumption in healthy human adults

Changes in blood lipid parameters with chronic cranberry consumption in healthy human adults

Reduction of Escherichia coli adherence to uroepithelial bladder cells after consumption of cranberry juice: a double-blind randomized placebo-controlled cross-over trial

To determine the efficacy of the consumption of cranberry juice versus placebo with regard to the presence of in vitro bacterial anti-adherence activity in the urine of healthy volunteers. Twenty healthy volunteers, 10 men and 10 women, were included. The study was a double-blind, randomized, placebo-controlled, and cross-over study. In addition to normal diet, each volunteer received at dinner a single dose of 750 ml of a total drink composed of: (1) 250 ml of the placebo and 500 ml of mineral water, or (2) 750 ml of the placebo, or (3) 250 ml of the cranberry juice and 500 ml of mineral water, or (4) 750 ml of the cranberry juice. Each volunteer took the four regimens successively in a randomly order, with a washout period of at least 6 days between every change in regimen. The first urine of the morning following cranberry or placebo consumption was collected and used to support bacterial growth. Six uropathogenic Escherichia coli strains (all expressing type 1 pili; three positive for the gene marker for P-fimbriae papC and three negative for papC), previously isolated from patients with symptomatic urinary tract infections, were grown in urine samples and tested for their ability to adhere to the T24 bladder cell line in vitro. There were no significant differences in the pH or specific gravity between the urine samples collected after cranberry or placebo consumption. We observed a dose dependent significant decrease in bacterial adherence associated with cranberry consumption. Adherence inhibition was observed independently from the presence of genes encoding type P pili and antibiotic resistance phenotypes. Cranberry juice consumption provides significant anti-adherence activity against different E. coli uropathogenic strains in the urine compared with placebo.

Consumption of Sweetened Dried Cranberries Versus Unsweetened Raisins for Inhibition of Uropathogenic Escherichia coli Adhesion in Human Urine: A Pilot Study

The aim of this study was to determine whether consumption of sweetened dried cranberries elicits urinary anti-adherence properties against Escherichia coli as previously demonstrated with cranberry juice and/or sweetened cranberry juice cocktail, compared to unsweetened raisins. Uropathogenic E. coli isolates were obtained from five women with culture-confirmed urinary tract infections (UTIs). Four urine samples were collected from each subject. The first urine sample was collected before any study intervention. The second urine sample was collected 2-5 hours after consumption of one box (42.5 g) of raisins. The third urine sample was collected 5-7 days later. The final urine sample was collected 2-5 hours after consumption of approximately 42.5 g of dried cranberries. E. coli isolates were incubated separately in each of the four urine samples collected from the five subjects. Bacteria were harvested from the urine and tested for the ability to prevent adhesion of P-fimbriated E. coli bacteria using a mannose-resistant hemagglutination assay with human red blood cells (A1, Rh+). Of the urine samples collected after dried cranberry consumption, one demonstrated 50% antiadherence activity, two demonstrated 25% activity, and two did not show any increased activity. None of the control urine samples and none of the postraisin consumption samples demonstrated any inhibitory activity. Data from this pilot study on only five subjects suggest that consumption of a single serving of sweetened dried cranberries may elicit bacterial antiadhesion activity in human urine, whereas consumption of a single serving of raisins does not. Further studies are needed to verify the antiadhesion effect of sweetened dried cranberries. In addition, dose-response and pharmacokinetics of the active compounds in the dried cranberries need to be determined. If clinical research is positive, dried cranberries could potentially be a viable alternative to cranberry juice consumption for prevention of UTIs.

Effect of cranberry juice on bacteriuria in children with neurogenic bladder receiving intermittent catheterization

Objective: To determine the effect of cranberry prophylaxis on rates of bacteriuria and symptomatic urinary tract infection in children with neurogenic bladder receiving clean intermittent catheterization. Design: Double-blind, placebo-controlled, crossover study of 15 children receiving cranberry concentrate or placebo concentrate for 6 months (3 months receiving one concentrate, followed by 3 months of the other). Weekly home visits were made. During each visit, a sample of bladder urine was obtained by intermittent catheterization. Signs and symptoms of urinary tract infection and all medications were recorded, and juice containers were counted. Results: During consumption of cranberry concentrate, the frequency of bacteriuria remained high. Cultures of 75% (114 of 151) of the 151 samples obtained during consumption of placebo were positive for a pathogen (≥10 4 colony-forming units/mL) compared with 75% (120 of 160) of the 160 samples obtained during consumption of cranberry concentrate. Escherichia coli remained the most common pathogen during placebo and cranberry periods. Three symptomatic infections each occurred during the placebo and cranberry periods. No significant difference was observed in the acidification of urine in the placebo group versus the cranberry group (median, 5.5 and 6.0, respectively). Conclusion: The frequency of bacteriuria in patients with neurogenic bladder receiving intermittent catheterization is 70%; cranberry concentrate had no effect on bacteriuria in this population. (J Pediatr 1999;135:698-702)