top Clinical Studies References
Bilberry has been shown to be beneficial in vascular and blood disorders and shows positive effects when treating varicose veins, thrombosis and angina. Bilberry contains flavonoids and anthocyanidin, which serve to prevent capillary fragility, thin the blood and stimulate the release of vasodilators. (Anthocyanidin, a natural antioxidant, also lowers blood pressure, reduces clotting and improves blood supply to the nervous system.) Bilberry also contains glucoquinine that has the ability to lower blood sugar.
Flavonoids in Bilberry provide numerous benefits in diabetics. They have been shown to increase intracellular vitamin C levels, decrease the leakiness and breakage of small blood vessels, prevent bruising and have potent antioxidant effects, e.g. helping to prevent free radical damage to the eyes.
Anthocyanosides support and protect collagen structures in the blood vessels of the eyes, assuring strong, healthy capillaries that carry vital nutrients to eye muscles and nerves.
Bilberry has long been a remedy for poor vision and "night blindness". Clinical tests confirm that given orally it improves visual accuracy in healthy people and can help those with eye diseases such as cataracts, retinitis pigmentosa, glaucoma and myopia.
Bilberry may be beneficial in diabetes, diabetic retinopathy, macular degeneration, cataract, glaucoma, varicose veins, retinopathy, atherosclerosis, diarrhea and night blindness.
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Published Clinical Studiesclin
1 Consumption of black currants, lingonberries and bilberries increases serum quercetin concentrations.
Erlund I, Marniemi J, Hakala P, Alfthan G, Meririnne E, Aro A.
Biomarker Laboratory, National Public Health Institute, Helsinki, Finland. iris.erlund@ktl.fi
OBJECTIVE: To study serum quercetin concentrations of subjects consuming berries or habitual Finnish diets. DESIGN: Randomized parallel dietary intervention. SUBJECTS: Forty healthy men (age 60 y). INTERVENTION: Twenty subjects consumed 100 g/day of berries (black currants, lingonberries and bilberries) for 8 weeks. Twenty subjects consuming their habitual diets served as controls. Fasting blood samples were obtained 2 weeks prior to the study, at baseline, and at 2, 4 and 8 weeks. Intake of quercetin was assessed from 3 day food records collected at baseline and at 8 weeks. RESULTS: The serum quercetin concentrations were significantly higher in the subjects consuming berries compared to the control group (P=0.039 ANCOVA with repeated measures). During the berry consumption period the mean serum concentrations of quercetin ranged between 21.4 and 25.3 micro g/l in the berry group, which was 32-51% higher compared with the control group. According to 3 day food records, there was no difference in quercetin intake at baseline, but at 8 weeks the intake was 12.3+/-1.4 mg/day (mean+/-s.e.m.) in the berry group and 5.8+/-0.6 mg/day in the control group (P=0.001). CONCLUSIONS: The results indicate that the berries used in this study are a good source of bioavailable quercetin.
Publication Types:
PMID: 12548295 [PubMed - indexed for MEDLINE]
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2 Oxygen radical absorbing capacity of phenolics in blueberries, cranberries, chokeberries, and lingonberries.
Zheng W, Wang SY.
Fruit Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705, USA.
The antioxidant activity of phenolics in fruits of blueberry (Vaccinium corymbosum cv. Sierra), cranberry (Vaccinium macrocarpon cv. Ben Lear), wild chokeberry (Aronia melanocarpa), and lingonberry (Vaccinium vitis-idaea cv. Amberland) was determined in this study. The phenolic constituents and contents among the different berries varied considerably. Anthocyanins were found to be the main components in all these berries. Chlorogenic acid in blueberry, quercetin glycosides in cranberry and lingonberry, and caffeic acid and its derivative in chokeberry were also present in relatively high concentrations. Chlorogenic acid, peonidin 3-galactoside, cyanidin 3-galactoside, and cyanidin 3-galactoside were the most important antioxidants in blueberry, cranberry, wild chokeberry, and lingonberry, respectively. The contribution of individual phenolics to the total antioxidant capacity was generally dependent on their structure and content in the berries. Phenolics such as quercetin and cyanidin, with 3',4'-dihydroxy substituents in the B ring and conjugation between the A and B rings, had highly effective radical scavenging structures in blueberries, cranberries, chokeberries, and lingonberries. Phenolic acids such as caffeic acid also showed high antioxidant activity, probably due to its dihydroxylation in the 3,4 positions as hydrogen donors.
PMID: 12517117 [PubMed - indexed for MEDLINE]
Antioxidant and antiproliferative activities of common fruits.3
Sun J, Chu YF, Wu X, Liu RH.
Department of Food Science, Cornell University, Ithaca, New York 14853-7201, USA.
Consumption of fruits and vegetables has been associated with reduced risk of chronic diseases such as cardiovascular disease and cancer. Phytochemicals, especially phenolics, in fruits and vegetables are suggested to be the major bioactive compounds for the health benefits. However, the phenolic contents and their antioxidant activities in fruits and vegetables were underestimated in the literature, because bound phenolics were not included. This study was designed to investigate the profiles of total phenolics, including both soluble free and bound forms in common fruits, by applying solvent extraction, base digestion, and solid-phase extraction methods. Cranberry had the highest total phenolic content, followed by apple, red grape, strawberry, pineapple, banana, peach, lemon, orange, pear, and grapefruit. Total antioxidant activity was measured using the TOSC assay. Cranberry had the highest total antioxidant activity (177.0 +/- 4.3 micromol of vitamin C equiv/g of fruit), followed by apple, red grape, strawberry, peach, lemon, pear, banana, orange, grapefruit, and pineapple. Antiproliferation activities were also studied in vitro using HepG(2) human liver-cancer cells, and cranberry showed the highest inhibitory effect with an EC(50) of 14.5 +/- 0.5 mg/mL, followed by lemon, apple, strawberry, red grape, banana, grapefruit, and peach. A bioactivity index (BI) for dietary cancer prevention is proposed to provide a new alternative biomarker for future epidemiological studies in dietary cancer prevention and health promotion.
PMID: 12452674 [PubMed - indexed for MEDLINE]
[Anthocyanosides in the treatment of retinopathies (author's transl)]4
Scharrer A, Ober M.
Thirty-one patients with various types of retinopathy were investigated with regard to the effect of anthocyanosides on the retinal vessels. Especially in patients with diabetic retinopathy, a positive influence on the permeability and tendency to hemorrhage was observed. The importance of internal treatment of the primary disease is pointed out.
PMID: 7253530 [PubMed - indexed for MEDLINE]
The effect of anthocyanosides on night vision.5
Levy Y, Glovinsky Y.
Department of Ophthalmology, Assaf Harofeh Medical Center, Tel Aviv University, Israel.
PURPOSE: In view of research demonstrating the ability of anthocyanosides in a single oral dose to improve night vision in normal individuals, it was decided to evaluate their effect on three night vision tests: full-field scotopic retinal threshold (SRT), dark adaptation rate (DAR) and mesopic contrast sensitivity (MCS). METHODS: In a double-masked, placebo-controlled, cross-over study, 16 young normal volunteers were randomly assigned to one of four different regimens of single oral administrations of 12, 24 and 36 mg of anthocyanosides, and a placebo, with a 2 week washout period between doses. SRT, DAR and MCS were measured immediately before, and 4, 8 and 24 h after treatment. RESULTS: No significant effect was found on any of the three night vision tests during the 24 h following a single oral administration of 12, 24 or 36 mg anthocyanosides. The study had a power of 0.95 to detect a 0.1 log unit improvement in SRT and 0.5 log unit improvement in MCS. CONCLUSIONS: Single oral administration of 12-36 mg of anthocyanosides appears to lack significant effect on militarily relevant night vision tests.
PMID: 10325997 [PubMed - indexed for MEDLINE]
6 Loss of fimbrial adhesion with the addition of Vaccinum macrocarpon to the growth medium of P-fimbriated Escherichia coli.
Ahuja S, Kaack B, Roberts J.
Department of Urology and Tulane University Primate Center, Tulane University School of Medicine, New Orleans, Louisiana, USA.
PURPOSE: Vaccinium macrocarpon--the American cranberry--irreversibly inhibits the expression of P-fimbriae of E. coli. Further effects on the function and expression of P-fimbriae were studied by growing P-fimbriated E. coli in solid media laced with cranberry juice. METHODS: Cranberry concentrate at pH 7.0 was added to CFA medium to a final concentration of 25%. E. coli strains JR1 and DS17 were plated on this medium with a plain CFA control and incubated at 37C. Cultures were tested for ability to agglutinate P-receptor specific beads. Bacteria were washed in PBS and agglutination retested. Cultures were also replated on plain CFA agar and rechecked for their ability to agglutinate. Transmission electron micrographs were performed on positive control and test bacteria. RESULTS: For E. coli strain JR1, P-fimbrial agglutination was inhibited after the third plating. DS17 was fully inhibited after the second plating. Washing in PBS did not affect agglutination, but replating on CFA agar allowed agglutination to recur. Electron micrographic study of control populations confirmed fimbriae. Fully inhibited bacteria had a 100% reduction in expression of fimbriae. Additionally, inhibited bacteria showed cellular elongation. CONCLUSIONS: Cranberry juice irreversibly inhibits P-fimbriae. Electron micrographic evidence suggests that cranberry juice acts on the cell wall preventing proper attachment of the fimbrial subunits or as a genetic control preventing the expression of normal fimbrial subunits or both.
PMID: 9649291 [PubMed - indexed for MEDLINE]
7 Novel lipid-lowering properties of Vaccinium myrtillus L. leaves, a traditional antidiabetic treatment, in several models of rat dyslipidaemia: a comparison with ciprofibrate.
Cignarella A, Nastasi M, Cavalli E, Puglisi L.
Institute of Pharmacological Sciences, University of Milano, Italy.
Vaccinium myrtillus L. (blueberry) leaf infusions are traditionally used as a folk medicine treatment of diabetes. To further define this therapeutical action, a dried hydroalcoholic extract of the leaf was administered orally to streptozotocin-diabetic rats for 4 days. Plasma glucose levels were consistently found to drop by about 26% at two different stages of diabetes. Unexpectedly, plasma triglyceride (TG) were also decreased by 39% following treatment. Subsequent to the latter observation, possible lipid-lowering properties of the extract were investigated on other models of hyperlipidaemia and ciprofibrate, a well-established hypolipidaemic drug, was used as a reference compound. Both drug reduced TG levels of rats on hyperlipidaemic diet in a dose-dependent fashion. When administered at single doses over the same experimental period, blueberry and ciprofibrate were effective in lowering TG concentrations in ethanol-treated normolipidaemic animals and in genetically hyperlipidaemic Yoshida rats. Unlike ciprofibrate, however, blueberry failed to prevent the rise in plasma TG elicited by fructose and did not affect free fatty acid levels in any of the above experimental conditions. In rats treated with Triton WR-1339, blueberry feeding induced an hypolipidaemic activity one hour after injection but proved to be ineffective at later time points, thus suggesting that its hypolipidaemic action may reflect improved TG-rich lipoprotein catabolism. In addition, ciprofibrate and the extract were tested for antithrombotic activity using a collagen-triggered model of venous thrombosis in diabetic and Yoshida rats. Only ciprofibrate, however, significantly reduced thrombus formation in diabetics, possibly because of its effects on free fatty acid metabolism, whereas no effect was observed in Yoshida rats. In conclusion, the present findings indicate that active consituent(s) of Vaccinium myrtillus L. leaves may prove potentially useful for treatment of dyslipidaemiae associated with impaired TG-rich lipoprotein clearance.
PMID: 8948058 [PubMed - indexed for MEDLINE]
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