A close relative of American blueberry, bilberry grows in northern Europe, Canada, and the United States. The ripe berries are primarily used in modern herbal extracts.
Historical or traditional use (may or may not be supported by scientific studies): The dried berries and leaves of bilberry have been recommended for a wide variety of conditions, including scurvy, urinary tract infections, kidney stones, and diabetes. Perhaps the most sound historical application is the use of the dried berries to treat diarrhea. Modern research of bilberry was partly based on its use by British World War II pilots, who noticed that their night vision improved when they ate bilberry jam prior to night bombing raids.1
Active constituents: Anthocyanosides, the flavonoid complex in bilberries, speed the regeneration of rhodopsin, the purple pigment that is used by the rods in the eye for night vision.2 While earlier trials suggested that taking bilberry could benefit people with night blindness,3 4 more recent trials with healthy volunteers have found no effect of bilberry on night vision.5 6 Preliminary human trials conducted in Europe show that bilberry may prevent cataracts,7 and may even help to treat people with mild retinopathies (such as macular degeneration and diabetic retinopathy).8 9 Anthocyanosides are potent antioxidants.10 They support normal formation of connective tissue and strengthen capillaries in the body. Anthocyanosides may also improve capillary and venous blood flow. Bilberry may also prevent blood vessel thickening due to diabetes.11
Bilberry protects cholesterol from oxidizing in test tubes.12 While this action is thought to help prevent atherosclerosis, no human trials have studied whether bilberry may be useful in the regard.
How much is usually taken? Bilberry herbal extract in capsules or tablets standardized to provide 25% anthocyanosides are typically recommended at 240-600 mg per day.13 Herbalists have traditionally recommended taking 1-2 ml two times per day in tincture form, or 20-60 grams of the fruit daily.
Are there any side effects or interactions? In recommended amounts, no side effects have been reported with bilberry extract.
At the time of writing, there were no well-known drug interactions with bilberry.
1. Brown DJ. Herbal Prescriptions for Health and Healing. Roseville, CA: Prima Health, 2000, 47�54.
2. Sala D, Rolando M, Rossi PL, et al. Effect of anthocyanosides on visual performance at low illumination. Minerva Oftalmol 1979;21:283�5.
3. Jayle GE, Aubry M, Gavini H, et al. Study concerning the action of anthocyanoside extracts of Vaccinium myrtillus on night vision. Ann Ocul 1965;198:556�62 [in French].
4. Belleoud L, Leluan D, Boyer YS. Study on the effects of anthocyanin glycosides on the nocturnal vision of air controllers. Rev Med Aeronaut Spatiale 1966;18:3�7.
5. Zadok D, Levy Y, Glovinsky Y. The effect of anthocyanosides in a multiple oral dose on night vision. Eye 1999;13:734�6.
6. 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.
7. Bravetti G. Preventive medical treatment of senile cataract with vitamin E and anthocyanosides: Clinical evaluation. Ann Ottalmol Clin Ocul 1989;115:109 [in Italian].
8. Perossini M, Guidi G, Chiellini S, Siravo D. Diabetic and hypertensive retinopathy therapy with Vaccinium myrtillus anthocyanosides (Tegens�): Double-blind placebo-controlled clinical trial. Ann Ottalmol Clin Ocul 1987;12:1173�90 [in Italian].
9. Scharrer A, Ober M. Anthocyanosides in the treatment of retinopathies. Klin Monatsbl Augenheikld Beih 1981;178:386�9.
10. Salvayre R, Braquet P, Perruchot T, DousteBlazy L. Comparison of the scavenger effect of bilberry anthocyanosides with various flavonoids. Proceed Intl Bioflavonoids Symposium, Munich, 1981, 437�42.
11. Boniface R, Miskulin M, Robert AM. Pharmacological properties of myrtillus anthocyanosides: Correlation with results of treatment of diabetic microangiopathy. In Flavonoids and Bioflavonoids, L Farkas, M Gabors, FL Kallay, eds. Ireland: Elsevier, 1985, 293�301.
12. Francesca Rasetti M, Caruso D, Galli G, et al. Extracts of Ginkgo biloba L. leaves and Vaccinium myrtillus L. fruits prevent photo induced oxidation of low density lipoprotein cholesterol. Phytomedicine 1997;3:335�8.
13. Brown DJ. Herbal Prescriptions for Health and Healing. Roseville, CA: Prima Health, 2000, 47�54.