Airelle, anthocyanins, Bickbeere (German), bilberry leaf, black whortle, Blaubeere (Dutch), blaubessen, bleaberry, blueberry, bogberry, bog bilberry, burren myrtle, cranberry, dwarf bilberry, dyeberry, Ericaceae (family), European blueberry, Heidelbeere (Dutch), Heidelbeereblatter, heidelberry, huckleberry, hurtleberry, lingonberry, lowbush blueberry, Mirtillo nero (Italian), Myrtilli folium, Myrtilli fructus, Myrtilus niger Gilib., Optiberry, resveratrol, sambubiosides, trackleberry, Vaccinium angulosum Dulac, Vaccinium montanum Salibs., Vaccinium myrtillus anthocyanoside extract, VMA extract, VME, whortleberry, wineberry.
Bilberry, a close relative of blueberry, has a long history of medicinal use. The dried fruit has been popular for the symptomatic treatment of diarrhea, for topical relief of minor mucus membrane inflammation, and for a variety of eye disorders, including poor night vision, eyestrain, and myopia.
Bilberry fruit and its extracts contain a number of biologically active components, including a class of compounds called anthocyanosides. These have been the focus of recent research in Europe.
Bilberry extract has been evaluated for efficacy as an antioxidant, mucostimulant, hypoglycemic, anti-inflammatory, "vasoprotectant," and lipid-lowering agent. Although pre-clinical studies have been promising, human data are limited and largely of poor quality. At this time, there is not sufficient evidence in support of (or against) the use of bilberry for most indications. Notably, the evidence suggests a lack of benefit of bilberry for the improvement of night vision.
Bilberry is commonly used to make jams, pies, cobblers, syrups, and alcoholic/non-alcoholic beverages. Fruit extracts are used as a coloring agent in wines.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Atherosclerosis ("hardening" of the arteries), peripheral vascular disease
Bilberry has sometimes been used traditionally to treat heart disease and atherosclerosis. There is some laboratory research in this area, but there is a lack of clear information in humans.
Bilberry extract has been used for a number of eye problems, including the prevention of cataract worsening. At this time, there is limited scientific information in this area.
Chronic venous insufficiency
Chronic venous insufficiency is a condition that is more commonly diagnosed in Europe than in the United States, and it may include leg swelling, varicose veins, leg pain, itching, and skin ulcers. A standardized extract of bilberry called Vaccinium myrtillius anthocyanoside (VMA) is popular in Europe for the treatment chronic venous insufficiency. However, there is only preliminary research in this area, and more studies are needed before a recommendation can be made.
Bilberry has been used traditionally in the treatment of diabetes, and animal research suggests that bilberry leaf extract can lower blood sugar levels. Human research is needed in this area before a recommendation can be made.
Bilberry is used traditionally to treat diarrhea, but there is a lack of reliable research in this area.
Fibrocystic breast disease
There is limited research suggesting a possible benefit of bilberry in the treatment of fibrocystic disease of the breast. More study is needed before a strong recommendation can be made.
High intraocular pressure is considered a risk factor for developing glaucoma. Products containing bilberry may reduce the risk for developing glaucoma. Additional study is needed.
Painful menstruation (dysmenorrhea)
Preliminary evidence suggests that bilberry may be helpful for the relief of menstrual pain, although more research is necessary before a firm conclusion can be drawn.
Based on animal research and several small human studies, bilberry may be useful in the treatment of retinopathy in patients with diabetes or high blood pressure. However, this research is early, and it is still unclear if bilberry is beneficial for this condition.
Stomach ulcers (peptic ulcer disease)
Bilberry extract has been suggested as a treatment to help stomach ulcer healing. There is some support for this use from laboratory and animal studies, but there is a lack of reliable human evidence in this area.
Traditional use and several unclear studies from the 1960s and 1970s suggest possible benefits of bilberry on night vision. However, more recent well-designed studies report no benefits. Based on this evidence, it does not appear that bilberry is helpful for improving night vision.
*Key to grades:
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use (it may not work);
F: Strong scientific evidence against this use (it likely does not work).
The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below. Age-related macular degeneration, angina (chest pain), angiogenesis (blood vessel formation), antifungal, antimicrobial, antioxidant, antiseptic, antiviral, arthritis, bleeding gums, burns, cancer, cardiovascular disease, chemoprotectant, chronic fatigue syndrome, common cold, cough, dermatitis, dysentery (severe diarrhea), edema (swelling), encephalitis (tick-borne), eye disorders, fevers, gout (painful inflammation), heart disease, hematuria (blood in the urine), hemorrhoids, high blood pressure, high cholesterol, kidney disease, lactation suppression, laxative (fresh berries), leukemia, liver disease, macular degeneration, oral ulcers, pharyngitis, poor circulation, retinitis pigmentosa, scurvy, skin infections, sore throat, stomach upset, tonic, urine blood, urinary tract infection, varicose veins of pregnancy, vision improvement.
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (18 years and older)
Fresh berries 55 to 115 grams three times daily or 80 to 480 milligrams of aqueous extract three times daily by mouth (standardized to 25% anthocyanosides) have been used traditionally.
Dried fruit 4 to 8 grams by mouth with water two times per day has been used traditionally, or decoction of dried fruit by mouth three times per day (made by boiling 5 to 10 grams of crushed dried fruit in 150 milliliters of water for 10 minutes and straining while hot), or cold macerate of dried fruit by mouth three times per day (made by soaking dried crushed fruit in 150 milliliters of water for several hours). Experts have warned that patients should use dried bilberry preparations because the fresh fruit may actually worsen diarrhea.
Some experts recommend using a mouthwash gargle of 10% dried fruit decoction as needed for mucus membrane inflammation.
Children (younger than 18 years)
There is not enough scientific evidence to recommend the use of bilberry in children.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
People with allergies to plants in the Ericaceae family or to anthocyanosides may have reactions to bilberry. However, there is a lack of reliable published cases of serious allergic reactions to bilberry.
Side Effects and Warnings
Bilberry is generally believed to be safe in recommended doses for short periods of time, based on its history as a foodstuff. There is a lack of known reports of serious toxicity or side effects, although if taken in large doses, there is an increased risk of bleeding, upset stomach, or hydroquinone poisoning.
Based on human use, bilberry fresh fruit may cause diarrhea or have a laxative effect. Based on animal studies, bilberry may cause low blood sugar levels. Caution is therefore advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels may need to be monitored by a healthcare provider and medication adjustments may be necessary.
In theory, bilberry may decrease blood pressure, based on laboratory studies.
With the use of bilberry leaf extract, there is a theoretical increased bleeding risk, although there are no reliable published human reports of bleeding. Caution is advised in patients with bleeding disorders, taking drugs that may increase the risk of bleeding, or prior to some surgeries and dental procedures.
Pregnancy and Breastfeeding
There is not enough scientific evidence to recommend the safe use of bilberry in pregnancy or breastfeeding, although eating bilberry fruit is believed to be safe based on its history of use as a foodstuff. One study used bilberry extract to treat pregnancy-induced leg swelling (edema), and no adverse effects were reported.
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.
Interactions with Drugs
Bilberry may lower blood sugar levels, although there is a lack of reliable human studies in this area. Caution is advised when using medications that may also lower blood sugar. Patients taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare provider. Medication adjustments may be necessary.
Based on human use, bilberry may increase diarrhea when taken with drugs that cause or worsen diarrhea, such as laxatives or some antibiotics. Bilberry theoretically may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin©) or heparin, anti-platelet drugs such as clopidogrel (Plavix©), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin©, Advil©) or naproxen (Naprosyn©, Aleve©). There are no reliable published human reports of bleeding with the use of bilberry. Based on theory, bilberry may further lower blood pressure when taken with drugs that decrease blood pressure.
Based on early laboratory study, berry extracts have been shown to inhibit H. pylori, an ulcer-producing bacteria and enhance the effects of the prescription drug clarithromycin (Biaxin©).
Bilberry may also interact with anticancer agents, liver-damaging agents, and estrogen-containing medications. Consult with a qualified healthcare professional, including a pharmacist, to check for interactions.
Interactions with Herbs and Dietary Supplements
Based on animal research, bilberry may lower blood sugar levels. Although there is a lack of reliable human study in this area, caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.
Based on theory, bilberry may lower blood pressure further when taken with herbs or supplements that decrease blood pressure.
Based on theory, bilberry may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.
Based on traditional use, bilberry may increase diarrhea or laxative effects when taken with herbs and supplements that are also believed to have laxative effects.
Consuming bilberry with quercetin supplements may result in additive effects. Cooking bilberries with water and sugar to make soup may decrease the amount of quercetin by 40%. Berries contain resveratrol, which has been studied as an antioxidant, for cardiovascular disease, and for cancer and may have additive effects when taken with supplements like grape seed.
Bilberry may also interact with anticancer agents, antioxidants, liver-damaging agents, and herbs or supplement with hormonal properties. Consult with a qualified healthcare professional, including a pharmacist, to check for interactions.
This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
Natural Standard Bottom Line Monograph, Copyright © 2011 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.
While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.
The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.
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Copyright © 2011 Natural Standard (www.naturalstandard.com)
Copyright © 2011 Natural Standard (www.naturalstandard.com)