Bilberry Fruit

Purported Benefits, Side Effects & More

Bilberry Fruit

Purported Benefits, Side Effects & More
Bilberry Fruit

Common Names

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

For Patients & Caregivers

Tell your healthcare providers about any dietary supplements you’re taking, such as herbs, vitamins, minerals, and natural or home remedies. This will help them manage your care and keep you safe.

What is it?

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.

What are the potential uses and benefits?
  • 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.
What are the 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.
What else do I need to know?

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.

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 widely used in herbal therapy and promoted as a dietary supplement to help improve eyesight and promote overall eye health. The anthocyanins in bilberry are thought to regenerate rhodopsin, a pigment present in retinal photoreceptor cells. Preclinical studies suggest bilberry polyphenols protect against neurodegenerative processes and eye disorders (1) (2), as well as help visual functioning (3) and protect against retinal diseases (4).

Small studies indicate that bilberry fruit improves visual function in individuals with normal tension glaucoma (8) and relieves tonic accommodation of the ciliary muscle caused by visual display terminal and near-vision tasks (38), but others produced mixed data (5) (6) with a systematic review citing the need for well-designed trials (7).

Additional studies found a standardized bilberry extract reduced disease activity in patients with mild to moderate ulcerative colitis (10) and a bilberry formulation was effective against hemorrhoidal disease (39). Dietary bilberry also altered lipid profiles and improved glucose metabolism in individuals at high risk for type 2 diabetes (13) and produced beneficial changes in serum lipids and lipoproteins in women with higher metabolic risk, but had an unexpected opposite effect in women at low risk (11). Bilberry fruit may decrease biomarkers of inflammation indicative of reduced cardiometabolic risk in the long term (14) (15), but whether it lowers the risk of cardiovascular disease is not clear (36) (40) (41). Bilberry consumption resulted in small to moderate increases in exercise-induced delayed onset muscle soreness and C-reactive Protein (37).

Bilberry showed anticancer effects (4) (16) (17) (18) (19) (20) (21) in preclinical models and protected against chemo-induced oral mucositis (23). Preliminary findings suggest bilberry extract reduces proliferation of colorectal cancer cells (22) and a proprietary mixed herbal extract relieves 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 and Benefits
  • 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).

Herb-Drug Interactions

Anticoagulants / Antiplatelets: Concomitant bilberry use was associated with rectal bleeding and hematuria in a 77-year-old man with a history of hypertension and stroke (34).
Aspirin and aspirin products: Bilberry can have synergistic effects and increase the risk of bleeding (35). Clinical relevance is not known.
Non-steroidal anti-inflammatory drugs (NSAIDs): Bilberry may have synergistic 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. Miyake S, Takahashi N, Sasaki M, et al. Vision preservation during retinal inflammation by anthocyanin-rich bilberry extract: cellular and molecular mechanism. Lab Invest. Jan 2012;92(1):102-109.
  4. 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.
  5. 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.
  6. 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.
  7. Canter PH, Ernst E. Anthocyanosides of Vaccinium myrtillus (bilberry) for night vision—a systematic review of placebo-controlled trials. Surv Ophthalmol. Jan-Feb 2004;49(1):38-50.
  8. Shim SH, Kim JM, Choi CY, et al. Ginkgo biloba extract and bilberry anthocyanins improve visual function in patients with normal tension glaucoma. J Med Food. Sep 2012;15(9):818-823.
  9. Gerding H. [Primary or Secondary Prophylaxis of AMD with Anthocyanins?]. Klin Monbl Augenheilkd. Apr 2009;226(4):216-219.
  10. 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.
  11. Larmo PS, Kangas AJ, Soininen P, et al. Effects of sea buckthorn and bilberry on serum metabolites differ according to baseline metabolic profiles in overweight women: a randomized crossover trial. Am J Clin Nutr. Oct 2013;98(4):941-951.
  12. 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.
  13. Lankinen M, Schwab U, Kolehmainen M, et al. Whole grain products, fish and bilberries alter glucose and lipid metabolism in a randomized, controlled trial: the Sysdimet study. PLoS One. 2011;6(8):e22646.
  14. Karlsen A, Paur I, Bohn SK, et al. Bilberry juice modulates plasma concentration of NF-kappaB related inflammatory markers in subjects at increased risk of CVD. Eur J Nutr. Sep 2010;49(6):345-355.
  15. 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.
  16. Kausar H, Jeyabalan J, Aqil F, et al. Berry anthocyanidins synergistically suppress growth and invasive potential of human non-small-cell lung cancer cells. Cancer Lett. Dec 1 2012;325(1):54-62.
  17. 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.
  18. 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.
  19. 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.
  20. Misikangas M, Pajari AM, Paivarinta 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. Oct 2007;137(10):2285-2290.
  21. 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.
  22. 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.
  23. 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.
  24. 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.
  25. Pawar D, Neve RS, Kalgane S, et al. SAMITAL(R) improves chemo/radiotherapy-induced oral mucositis in patients with head and neck cancer: results of a randomized, placebo-controlled, single-blind Phase II study. Support Care Cancer. Mar 2013;21(3):827-834.
  26. 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.
  27. Ehala S, Vaher M, Kaljurand M. Characterization of phenolic profiles of Northern European berries by capillary electrophoresis and determination of their antioxidant activity. J Agric Food Chem. Aug 10 2005;53(16):6484-6490.
  28. Zhu Y, Xia M, Yang Y, et al. Purified anthocyanin supplementation improves endothelial function via NO-cGMP activation in hypercholesterolemic individuals. Clin Chem. Nov 2011;57(11):1524-1533.
  29. 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.
  30. 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.
  31. Cai H, Thomasset SC, D PB, et al. Determination of anthocyanins in the urine of patients with colorectal liver metastases after administration of bilberry extract. Biomed Chromatogr. Jun 2011;25(6):660-663.
  32. Morazzoni P, Livio S, Scilingo A, et al. Vaccinium myrtillus anthocyanosides pharmacokinetics in rats. Arzneimittelforschung. Feb 1991;41(2):128-131.
  33. Djuv A, Nilsen OG, Steinsbekk A. The co-use of conventional drugs and herbs among patients in Norwegian general practice: a cross-sectional study. BMC Complement Altern Med. 2013;13:295.
  34. Aktas CSV, Sarikaya S, Karit S. Bilberry potentiates warfarin effect? Turk J Geriatr 2011;14:79-81.
  35. Abebe W. Herbal medication: potential for adverse interactions with analgesic drugs. J Clin Pharm Ther. Dec 2002;27(6):391-401.
  36. Habanova M, Saraiva JA, Haban M, et al. Intake of bilberries (Vaccinium myrtillus L.) reduced risk factors for cardiovascular disease by inducing favorable changes in lipoprotein profiles. Nutr Res. 2016 Dec;36(12):1415-1422.
  37. 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.
  38. Kosehira M, Machida N, Kitaichi N. A 12-Week-Long Intake of Bilberry Extract (Vaccinium myrtillus L.) Improved Objective Findings of Ciliary Muscle Contraction of the Eye: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Comparison Trial. Nutrients. 2020 Feb 25;12(3):600.
  39. Gravina AG, Pellegrino R, Facchiano A, et al. Evaluation of the Efficacy and Safety of a Compound of Micronized Flavonoids in Combination With Vitamin C and Extracts of Centella asiatica, Vaccinium myrtillus, and Vitis vinifera for the Reduction of Hemorrhoidal Symptoms in Patients With Grade II and III Hemorrhoidal Disease: A Retrospective Real-Life Study. Front Pharmacol. 2021 Dec 14;12:773320.
  40. Aboufarrag H, Hollands WJ, Percival J, et al. No Effect of Isolated Anthocyanins from Bilberry Fruit and Black Rice on LDL Cholesterol or other Biomarkers of Cardiovascular Disease in Adults with Elevated Cholesterol: A Randomized, Placebo-Controlled, Cross-Over Trial. Mol Nutr Food Res. 2022 Nov;66(21):e2101157.
  41. Chan SW, Chu TTW, Choi SW, Benzie IFF, Tomlinson B. Impact of short-term bilberry supplementation on glycemic control, cardiovascular disease risk factors, and antioxidant status in Chinese patients with type 2 diabetes. Phytother Res. 2021 Jun;35(6):3236-3245.
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