- How It Works
- Purported Uses
- Research Evidence
- Patient Warnings
- Do Not Take If
- Side Effects
- Dosage (Inside MSKCC Only)
Scientific Name
Vaccinium myrtillus
Common Name
Dwarf bilberry, bog bilberry, European blueberry, huckleberry, and whortleberry
Clinical Summary
Bilberry is derived from the fruit of the tree. It is available as a dietary supplement to help improve eyesight. Several human studies suggest that bilberry anthocyanosides prevent diabetic retinopathy and improve visual acuity and retinal function (1) (2) (3) (4) . One human study also suggested that bilberry extract may significantly reduce the proliferation of colorectal cancer tumor tissue (5). In vitro studies have also indicated that bilberry may have anticancer activities(6) (7) (8) (9) (10). Coumarins present in bilberry may interact with platelets and have an additive effect with blood thinners (11). Bilberry fruit should not be confused with bilberry leaf, which may have hypoglycemic effect.
Purported Uses
- Cancer prevention
- Cataracts
- Circulatory disorders
- Diabetic retinopathy
- Diarrhea
- Glaucoma
- Hemorrhoids
- Macular degeneration
- Mucositis
- Varicose veins
- Visual acuity
Constituents
- Tannins: 5-10% catechin tannins
- Carbohydrates: 30% invert sugar and pectins
- Flavonols: Flavonol glycosides including astragalin, hyperoside, isoquercitrin and quercetin
- Phenolic acids
- Anthocyanosides
(12)
Mechanism of Action
The anthocyanins in bilberry contribute to most of its pharmacological activities. Anthocyanin has anti-inflammatory, vasoprotective (13), and antioxidant effects (14). It has demonstrated free radical scavenging and inhibition of cAMP phosphodiesterase actions. Extract of bilberry can inhibit human leukemia cells and human colon carcinoma cells growth through the induction of apoptosis (6). Another in vitro study investigated the effect of bilberry extract on MCF-7 human breast cancer cells and also found that it inhibited cell proliferation and induced apoptosis (15). In vitro and in vivo clinical studies show inhibition of platelet aggregation and stimulation of vascular prostacyclin. Bilberry anthocyanins regenerate rhodopsin and are indicated in treatment of poor night vision, macular degeneration, glaucoma and cataracts (1) (2) (3) (4) (16) (17)
Pharmacokinetics
Pharmacokinetic studies in humans have found that the anthocyanins in bilberry extract are excreted in the urine either Intact or as methylated or glucuronidated metabolites (5) (8). One of these studies suggested that the stomach is the primary site for anthocyanin absorption (16). Intravenous and oral studies of bilberry anthocyanosides have also been performed in male rats (19). Oral administration showed moderate GI absorption with bioavailability less than 2%. Peak levels were achieved within 15 minutes with a three-compartment distribution and elimination shown. Elimination was primarily through urine and bile.
Adverse Reactions
None reported.
Herb-Drug Interactions
Anticoagulants / Antiplatelets:Bilberry may potentiate the risk of bleeding if used concurrently due to platelet aggregation inhibition and prostaglandin modulation.
Herb Lab Interactions
Coumarin content in bilberry may increase PT/PTT and inhibit platelet activity (11).
Literature Summary and Critique
Thomasset S, et al. Pilot study of oral anthocyanins for colorectal cancer chemoprevention. Cancer Prev Res (Phila). 2009 Jul;2(7):625-33.
This unblinded study enrolled 25 patients with colorectal cancer (n=15) or colorectal liver metastases (n=10) who were scheduled to undergo resection of the primary tumor. The patients were randomized to receive a daily dose of mirtocyan, an anthocyanin rich bilberry extract, until 7 days before surgery. Immunohistochemical observations were made in biopsy samples preintervention and compared to resection tissue post-intervention. Plasma concentrations of insulin-like growth factor (IGF-1) were also measured pre- and post-intervention. The proliferation index reflected by Ki-67 staining of colorectal tissue significantly decreased by 7% (p=00.003) in all patients receiving mirtocyan extract, and was as high as 9% (p=0.021) in one dosage group. After receiving mirtocyan, the patients in this study also experienced a small, but nonsignificant (p=0.06) reduction in circulating IGF-I concentrations. The investigators also found mirtocyan to be safe and well-tolerated.
Muth ER, Laurent JM, Jasper P. The effect of bilberry nutritional supplementation on night visual acuity and contrast sensitivity. Altern Med Rev 2000;5:164-73.
A prospective, randomized, placebo-controlled crossover evaluation of bilberry supplementation in 15 healthy male Air Force personnel. All subjects had visual acuity of 20/20 or better at baseline. Two 3-week treatment periods with a 1-month washout period between evaluated effects of bilberry or placebo on night visual acuity and night contrast sensitivity. No change was detected in either outcome. Bilberry did not augment night visual acuity or contrast sensitivity in subjects with no prior deficiencies.
References
- Muth ER, et al. The effect of bilberry nutritional supplementation on night visual acuity and contrast sensitivity. Altern Med Rev 2000;5:164-73.
- Zadok D, et al. The effect of anthocyanosides on night vision tests. Invest Ophthalmol Vis Sci 1997;38(suppl):633.
- Boniface R,et al. Pharmacological properties of mytillus anthocyanosides: correlation with results of treatment of diabetic microangiopathy. Flavonoids Bioflavonoids. Ireland: Elsevier; 1985, 293-301.
- Perossini M, et al. Diabetic and hypertensive retinopathy therapy with anthocyanosides double blind placebo-controlled clinical trial. Ann Ottal Clin Ocul 1987;113:1173-90.
- Thomasset S, Berry DP, Cai H, et al. Pilot study of oral anthocyanins for colorectal cancer chemoprevention. Cancer Prev Res (Phila). 2009 Jul;2(7):625-33.
- Katsube N, et al. Induction of apoptosis in cancer cells by Bilberry (Vaccinium myrtillus) and the anthocyanins. J Agric Food Chem. 2003 Jan 1;51(1):68-75.
- Bagchi D, Sen CK, Bagchi M, Atalay M. Anti-angiogenic, antioxidant, and anti-carcinogenic properties of a novel anthocyanin-rich berry extract formula. Biochemistry (Mosc). 2004 Jan;69(1):75-80
- Lala G, Malik M, Zhao C, et al. Anthocyanin-rich extracts inhibit multiple biomarkers of colon cancer in rats. Nutr Cancer. 2006;54(1):84-93.
- Misikangas M, Pajari AM, Päivärinta E, et al. Three Nordic berries inhibit intestinal tumorigenesis in multiple intestinal neoplasia/+ mice by modulating beta-catenin signaling in the tumor and transcription in the mucosa. J Nutr. 2007 Oct;137(10):2285-90.
- Teller N, Thiele W, Marczylo TH, et al. Suppression of the kinase activity of receptor tyrosine kinases by anthocyanin-rich mixtures extracted from bilberries and grapes. J Agric Food Chem. 2009 Apr 22;57(8):3094-101.
- Brinker F. Herb Contraindications and Drug Interactions 3rd ed. Sandy (OR): Eclectic Medical; 2001.
- Bisset NG, et al. Herbal Drugs and Phytopharmaceuticals, 2nd ed. Boca Raton: Medpharm CRC Press; 1994.
- Lietti A, et al. Studies on Vaccinium myrtillus anthocyanosides. I. Vasoprotective and antiinflammatory activity. Arzneimittelforschung. 1976;26(5):829-32.
- Laplaud PM, et al. Antioxidant action of Vaccinium myrtillus extract on human low density lipoproteins in vitro: initial observations. Fundam Clin Pharmacol. 1997;11(1):35-40.
- Nguyen V, Tang J, Oroudjev E, et al. Cytotoxic effects of bilberry extract on MCF7-GFP-tubulin breast cancer cells. J Med Food. 2010 Apr;13(2):278-85.
- Blumenthal, et al. Herbal Medicine Expanded Commission E Monographs, 1st ed. Austin: American Botanical Council; 2000.
- Bruneton, J. Pharmacognosy, Phytochemistry, Medicinal Plants. Paris: Lavoisier Publishing; 1995.
- Cai H, Thomasset SC, Berry DP, et al. Determination of anthocyanins in the urine of patients with colorectal liver metastases after administration of bilberry extract. Biomed Chromatogr. 2010 Aug 31.
- Morazzoni P, et al. Vaccinium myrtillus anthocyanosides pharmacokinetics in rats. Arzneimittel-Forschung 1991;41:128-31.
How It Works
Bottom Line: Bilberry may help improve vision in people with cataracts and macular degeneration. There is insufficient evidence to support its other uses.
In laboratory studies, bilberry reduces inflammation and edema (accumulation of fluid in the tissues), acts as an antioxidant, inhibits blood clotting, and strengthens the walls of the blood vessels. The extracts of bilberry can inhibit the growth of cancer cells in the lab. Preliminary clinical trials indicate that bilberry strengthens and protects the walls of the blood vessels in humans. More clinical trials are needed to confirm these effects in humans.
In addition, compounds isolated from bilberry called anthocyanins are able to regenerate rhodopsin, the pigment found in retina cells responsible for eyesight. This finding explains bilberry’s success in improving vision in patients with macular degeneration, glaucoma and cataracts.
Purported Uses
- To prevent cancer
Laboratory studies and one clinical study suggest some anti-cancer effects. However, further study is needed to confirm these effects. - To treat cataracts
Several clinical trials support this use. - To treat diabetic retinopathy (degeneration of the retina due to diabetes)
Several clinical trials support this use. - To treat glaucoma
Several clinical trials support this use. - To prevent the progression of macular degeneration
Several clinical trials support this use. - To reduce inflammation in conditions such as hemorrhoids or mucositis
Laboratory studies suggest anti-inflammatory effects, but there is no proof from clinical trials that bilberry can reduce inflammation in humans. - To improve vision, especially at night
Clinical trials show that bilberry improves eyesight in patients with certain disorders, but do not support this use in individuals with good vision. - To treat diarrhea
No scientific evidence supports this use. - To treat circulatory disorders
Laboratory studies show that bilberry may protect blood vessels and decrease the risk of blood clots, but there is no proof from clinical trials that bilberry can effectively treat circulatory disorders. - To improve the appearance of varicose veins
No scientific evidence supports this use.
Research Evidence
Vision and Diabetic Retinopathy
Researchers have performed several clinical trials with bilberry and have found no short- or long-term improvements in night vision. Numerous clinical studies have shown that bilberry (in standardized extract form of 25% anthocyanosides) is effective in preventing diabetic retinopathy and improving both vision and retina function.
A small crossover clinical trial assessed the ability of bilberry to improve night vision in 15 healthy male Air Force personnel with 20/20 vision. Eight men took bilberry extract (standardized to 25% anthocyanosides) and seven men took a placebo pill for the first three-week period. After one month of “washout” (no treatment), the men switched to the other treatment: the eight took placebo and the other seven took bilberry extract. No change was detected in night vision in either group of men. This study does not support the use of bilberry for night vision in people with no prior sight problems, but its results may not apply to those with retina dysfunction.
Colorectal Cancer
One study in humans suggests that bilberry extract may decrease tumor growth in colorectal cancer. However, additional study is needed to confirm this effect.
Patient Warnings
- Bilberry fruit should not be confused with bilberry leaf, which may lower blood sugar levels.
Do Not Take If
- You use warfarin or other blood thinners (bilberry may increase the risk of bleeding).
- You have a blood clotting disorder such as hemophilia (bilberry may increase the risk of bleeding).
Side Effects
None known
Dosage (Inside MSKCC Only)
This field is only visible to only Inside MSKCC users.
Aliases
Vaccinium Myrtillus
E-mail your questions and comments to aboutherbs@mskcc.org.
