Bilberry Fruit

Bilberry Fruit

Common Names

  • Dwarf bilberry
  • European blueberry; whortleberry
  • Bog bilberry
  • Chinese blueberry

For Patients & Caregivers

How It Works

Bilberry is used in traditional medicine to treat eye disorders and support vision health, but clinical data for these purposes are mixed or lacking. There is insufficient evidence to support its other uses.

Compounds in bilberry called anthocyanins can regenerate rhodopsin, a pigment found in retinal cells responsible for eyesight. This is one of the reasons it has gained popularity in traditional medicine to support eye health.

In laboratory studies, bilberry reduces inflammation and fluid accumulation in tissues, acts as an antioxidant, inhibits blood clotting, and strengthens the walls of blood vessels. Bilberry extracts can inhibit the growth of cancer cells in the lab. Initial studies in humans also show that bilberry may have anti-cancer effects, relieve certain types of inflammation, or improve the biological profiles of those at higher risk for heart disease or diabetes. More clinical trials are needed to confirm these effects.

Purported Uses
  • To prevent cancer
    Laboratory studies and one clinical study suggest anti-cancer effects. More research is needed.
  • To treat eye disorders
    One small study suggests bilberry may improve visual function in some patients with normal tension glaucoma. But others produced mixed data.
  • To treat circulatory disorders
    Laboratory studies show that bilberry may protect blood vessels and decrease the risk of blood clots. Human data are needed.
  • To treat diabetic retinopathy
    Evidence is lacking to support this claim.
  • To treat diarrhea
    Evidence is lacking to support this claim.
  • To reduce chemo-induced mucositis
    Small studies have shown that formulas containing bilberry fruit help prevent chemo/radio-induced mucositis.
  • To improve visual acuity
    Clinical trial results are mixed on whether bilberry can help improve vision.
Do Not Take If
  • You use warfarin or other blood thinners: Bilberry may increase the risk of bleeding.
  • You use aspirin or aspirin products: Bilberry may increase the risk of bleeding. Clinical relevance is not known.
  • You use non-steroidal anti-inflammatory drugs (NSAIDs): Bilberry may increase the risk of bleeding. Clinical relevance is not known.
Side Effects
  • A case of excessive bleeding related to long-term consumption of bilberry along with a newly prescribed blood-thinning drug has been reported.
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For Healthcare Professionals

Scientific Name
Vaccinium myrtillus, Vaccinium uliginosum, Vaccinium smallii, Vaccinium arctostaphylos, Vaccinium cespitosum
Clinical Summary

Bilberry fruit grows on perennial fruit trees or shrubs, and is closely related to the huckleberry and blueberry. It is marketed as a dietary supplement to help improve eyesight and promote overall eye health, and is widely used in herbal therapy. The anthocyanins in bilberry are thought to regenerate rhodopsin, a pigment present in retinal photoreceptor cells.

In vitro, bilberry polyphenols appear to protect against neurodegenerative processes and eye disorders (1) (2). Animal models suggest that bilberry extract may help visual functioning (3) and protect against retinal diseases (4). A small clinical study indicates utility of bilberry for improving visual function in some individuals with normal tension glaucoma (8), but others produced mixed data on whether or not bilberry anthocyanosides improve visual acuity, night vision, or retinal function (5) (6); many of the positive studies are also poorly designed (7).  Further research is needed.

In other studies, a standardized bilberry extract was shown to reduce disease activity in patients with mild to moderate ulcerative colitis (10). Dietary bilberry produced beneficial changes in serum lipids and lipoproteins in women with higher metabolic risk, but had an unexpected opposite effect in those who were at low risk (11). Ingestion of bilberries in a diet that also included whole grain/low-insulin-response grain products and fatty fish altered lipid profiles and improved glucose metabolism in individuals at high risk for type 2 diabetes (13). Small studies suggest that bilberry fruit may help reduce risk of cardiovascular diseases (36); and that bilberry juice may be useful in decreasing biomarkers of inflammation and in improving cardiometabolic risk (14) (15). However, consumption of bilberry juice resulted in small to moderate increases in exercise-induced delayed onset muscle soreness and C-reactive Protein (37).

Bilberry has also been investigated for its anticancer potential. Preclinical findings indicate that it has anticancer effects (4) (16) (17) (18) (19) (20) (21); and exerts protective effects against chemo-induced oral mucositis (23). Small clinical studies found bilberry extract to affect reductions in proliferation of colorectal cancer cells (22); and a proprietary mixed herbal extract helped relieve chemo/radiotherapy-induced mucositis in pediatric (24) and adult cancer patients (25). However, the extent to which bilberry itself was responsible for such effects is unclear. 

Purported Uses
  • Cancer prevention
  • Ocular disorders
  • Circulatory disorders
  • Diabetic retinopathy
  • Diarrhea
  • Mucositis
  • Visual acuity
Mechanism of Action

In vitro, bilberry polyphenols inhibited amyloid fibril formation and dissolved preformed toxic aggregates and mature fibrils, suggesting a role in controlling fibril formations of various proteins that occur with neurodegenerative diseases (1). Bilberry anthocyanins modulated oxidative stress defense enzymes heme oxygenase-1 (HO-1) and glutathione S-transferase-pi (GST-pi) in human retinal pigment epithelial cells (2). In vitro and in vivo, bilberry inhibited angiogenesis through inhibition of ERK 1/2 and Akt phosphorylation (4). In an animal model of uveitis and retinal inflammation, pretreatment with a bilberry extract prevented photoreceptor impairment, relieved intracellular ROS elevation, activated retinal NF-ĸB in the inflamed retina, and suppressed the decrease of rhodopsin via inhibition of IL-6, which activates STAT3, thereby protecting outer segment length in photoreceptor cells (3). In a monocytic cell line, quercetin, epicatechin, and resveratrol inhibited lipopolysaccharide (LPS)-induced NF-kappaB activation (14).

In individuals with hypercholesterolemia, anthocyanins may improve endothelium-dependent vasodilation by activating the NO-cGMP signaling pathway (28). The polyphenols in bilberry juice can modulate inflammation by decreasing plasma C-reactive protein, interleukin (IL)-6, -15, and monokine induced by INFγ (MIG) (14).

In human colon and liver cancer cell lines, bilberry anthocyanins demonstrated intracellular antioxidant activity even though concentrations applied were very low (29). Bilberry extract inhibited human leukemia, colon, and breast cancer cells through apoptotic induction and/or inhibition of cell proliferation (17) (30). Delphinidin and other anthocyanidins synergistically enhanced cell-cycle arrest and apoptotic induction in aggressive non-small-cell lung cancer cells by modulating Notch, WNT, and NF-ĸB signaling pathways (16).

Adverse Reactions
  • Rectal bleeding:  In a 77-year-old man on warfarin therapy, following long-term over consumption of bilberry that required two emergency room visits, treatment with fresh plasma infusions, and hospitalization to evaluate inconsistent international normalized ratio (INR) values (34).
Herb-Drug Interactions

Anticoagulants / Antiplatelets: Bilberry was shown to potentiate the risk of bleeding (34).
Aspirin and aspirin products: Bilberry can have added or synergistic antiplatelet effects, and increase the risk of bleeding (35). Clinical relevance is not known.
Non-steroidal anti-inflammatory drugs (NSAIDs): Bilberry may have added or synergistic antiplatelet effects, and increase the risk of bleeding (35). Clinical relevance is not known.

Herb Lab Interactions

Bilberry may increase prothrombin time and partial thromboplastin time (PT/PTT) and inhibit platelet activity (33) (34) (35).

Dosage (OneMSK Only)
  1. Iwasa H, Kameda H, Fukui N, et al. Bilberry anthocyanins neutralize the cytotoxicity of co-chaperonin GroES fibrillation intermediates. Biochemistry. Dec 23 2013;52(51):9202-9211.

  2. Milbury PE, Graf B, Curran-Celentano JM, et al. Bilberry (Vaccinium myrtillus) anthocyanins modulate heme oxygenase-1 and glutathione S-transferase-pi expression in ARPE-19 cells. Invest Ophthalmol Vis Sci. May 2007;48(5):2343-2349.

  3. Matsunaga N, Chikaraishi Y, Shimazawa M, et al. Vaccinium myrtillus (Bilberry) Extracts Reduce Angiogenesis In Vitro and In Vivo. Evid Based Complement Alternat Med. Mar 2010;7(1):47-56.

  4. Muth ER, Laurent JM, Jasper P. The effect of bilberry nutritional supplementation on night visual acuity and contrast sensitivity. Altern Med Rev. Apr 2000;5(2):164-173.

  5. Zadok D, Levy Y, Glovinsky Y. The effect of anthocyanosides in a multiple oral dose on night vision. Eye (Lond). Dec 1999;13 ( Pt 6):734-736.

  6. Gerding H. [Primary or Secondary Prophylaxis of AMD with Anthocyanins?]. Klin Monbl Augenheilkd. Apr 2009;226(4):216-219.

  7. Biedermann L, Mwinyi J, Scharl M, et al. Bilberry ingestion improves disease activity in mild to moderate ulcerative colitis - an open pilot study. J Crohns Colitis. May 2013;7(4):271-279.

  8. Kianbakht S, Abasi B, Dabaghian FH. Anti-hyperglycemic effect of Vaccinium arctostaphylos in type 2 diabetic patients: a randomized controlled trial. Forsch Komplementmed. 2013;20(1):17-22.

  9. Kolehmainen M, Mykkanen O, Kirjavainen PV, et al. Bilberries reduce low-grade inflammation in individuals with features of metabolic syndrome. Mol Nutr Food Res. Oct 2012;56(10):1501-1510.

  10. Katsube N, Iwashita K, Tsushida T, et al. Induction of apoptosis in cancer cells by Bilberry (Vaccinium myrtillus) and the anthocyanins. J Agric Food Chem. Jan 1 2003;51(1):68-75.

  11. Bagchi D, Sen CK, Bagchi M, et al. Anti-angiogenic, antioxidant, and anti-carcinogenic properties of a novel anthocyanin-rich berry extract formula. Biochemistry (Mosc). Jan 2004;69(1):75-80, 71 p preceding 75.

  12. 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.

  13. 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. Apr 22 2009;57(8):3094-3101.

  14. Thomasset S, Berry DP, Cai H, et al. Pilot study of oral anthocyanins for colorectal cancer chemoprevention. Cancer Prev Res (Phila). Jul 2009;2(7):625-633.

  15. Davarmanesh M, Miri R, Haghnegahdar S, et al. Protective effect of bilberry extract as a pretreatment on induced oral mucositis in hamsters. Oral Surg Oral Med Oral Pathol Oral Radiol. Dec 2013;116(6):702-708.

  16. Bertoglio JC, Folatre I, Bombardelli E, et al. Management of gastrointestinal mucositis due to cancer therapies in pediatric patients: results of a case series with SAMITAL((R)). Future Oncol. Nov 2012;8(11):1481-1486.

  17. Yamamoto M, Yamaura K, Ishiwatari M, et al. Difficulty for consumers in choosing commercial bilberry supplements by relying only on product label information. Pharmacognosy Res. Jul 2013;5(3):212-215.

  18. Bornsek SM, Ziberna L, Polak T, et al. Bilberry and blueberry anthocyanins act as powerful intracellular antioxidants in mammalian cells. Food Chem. Oct 15 2012;134(4):1878-1884.

  19. Nguyen V, Tang J, Oroudjev E, et al. Cytotoxic effects of bilberry extract on MCF7-GFP-tubulin breast cancer cells. J Med Food. Apr 2010;13(2):278-285.

  20. Morazzoni P, Livio S, Scilingo A, et al. Vaccinium myrtillus anthocyanosides pharmacokinetics in rats. Arzneimittelforschung. Feb 1991;41(2):128-131.

  21. Aktas CSV, Sarikaya S, Karit S. Bilberry potentiates warfarin effect? Turk J Geriatr 2011;14:79-81.

  22. Lynn A, Garner S, Nelson N, Simper TN, Hall AC, Ranchordas MK. Effect of bilberry juice on indices of muscle damage and inflammation in runners completing a half-marathon: a randomised, placebo-controlled trial. J Int Soc Sports Nutr. 2018 May 2;15:22.

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