Bilberry has been used for centuries, both medicinally and as a food in jams and pies. It is related to the blueberry and is native to Northern Europe. Bilberry fruit contains chemicals known as anthocyanosides, plant pigments that have excellent antioxidant properties. They scavenge damaging particles in the body known as free radicals, helping prevent or reverse damage to cells. Antioxidants have been shown to help prevent a number of long-term illnesses, such as heart disease, cancer, and an eye disorder called macular degeneration. Bilberry also contains vitamin C, which is another antioxidant.

Not many studies have examined bilberry specifically. Even fewer studies have been done in humans. Recommendations about bilberry come from research on similar antioxidants, or from test tube and animal studies.

Chronic venous insufficiency

In Europe, health care professionals use bilberry extracts to treat this condition, which occurs when valves in veins in the legs that carry blood to the heart are damaged. Studies have reported improvements in symptoms, but most were poorly designed.

Diabetes

Traditionally, bilberry leaves have been used to control blood sugar levels in people with diabetes. Research shows that all berries help reduce the body's glucose response after eating a high sugar meal. Studies suggest bilberry may be effective for managing blood sugar levels, particularly when combined with oatmeal. More research is needed. At this time, bilberry is not recommended to help manage diabetes.

Atherosclerosis

Studies show that anthocyanosides may strengthen blood vessels, improve circulation, and prevent the oxidation of LDL ("bad") cholesterol, a major risk factor for atherosclerosis (plaque that blocks blood vessels, leading to heart attack and stroke). More research is needed.

Diarrhea and wounds

Bilberry has been used in European medicine for nearly one thousand years, primarily to treat diarrhea. The fruit contains tannins, substances that act as both an anti-inflammatory and an astringent (constricting and tightening tissues). Bilberry is believed to help people with diarrhea by reducing intestinal inflammation. No studies, however, have examined bilberry's use for diarrhea.

Vision

Anthocyanosides found in bilberry fruits may also be useful for people with vision problems. During World War II, British fighter pilots reported improved nighttime vision after eating bilberry jam. Studies have shown mixed results, however. Bilberry has been suggested as a treatment for retinopathy (damage to the retina) because anthocyanosides appear to help protect the retina. Bilberry has also exhibited protective effects against macular degeneration, glaucoma, and cataracts. However, studies are lacking.

Other Disorders

Preliminary studies suggest the anthocyanosides may help lower the risk of chronic diseases, including cancer and Alzheimer disease.

Bilberry is a perennial shrub that grows to about 16 inches in height. It has sharp-edged, green branches and black wrinkled berries, which are ripe for picking in late summer. Bilberry is a relative of blueberry, cranberry, and huckleberry, and its fruit looks and tastes much like the American blueberry.

The key compounds in bilberry fruit are called anthocyanosides. These compounds help build strong blood vessels and improve circulation to all areas of the body. They also prevent blood platelets from clumping together (helping to reduce the risk of blood clots), and they have antioxidant properties (preventing or reducing damage to cells from free radicals). Anthocyanidins boost the production of rhodopsin, a pigment that improves night vision and helps the eye adapt to light changes.

Bilberry fruit is also rich in tannins, a substance that acts as an astringent. The tannins have anti-inflammatory properties and may help control diarrhea.

You may eat bilberries fresh or dried, and you can make bilberry tea using fresh or dried berries. Bilberry extract should be standardized to contain 25% anthocyanidin. The extract contains the highest percentage of anthocyanosides, making it the strongest form of bilberry.

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, can trigger side effects and can interact with other herbs, supplements, or medications. For these reasons, you should take herbs under the supervision of a health care provider.

Pediatric

Bilberry may be used in children 2 years of age and older for the treatment of diarrhea, but only under the supervision of your doctor.

Adult

Speak with your doctor regarding dosing.

Bilberry fruit and extract are considered generally safe, with no known side effects. However, bilberry leaf and extract should not be taken in large quantities over an extended period of time because the tannins they contain may cause severe weight loss, muscle spasms, and even death. Taking bilberry may change the way other remedies, medicines, and even vitamins work, and using these products together may cause harmful effects. Pregnant and breastfeeding women should not use bilberry extracts unless the supervision of a knowledgeable herbal prescriber.

Anticoagulants (blood-thinning medication): In theory, because the anthocyanosides in bilberry may stop blood from clotting, there may be an increased risk of bleeding if you take bilberry with blood-thinning medication, including aspirin. The whole fruit may be safer in these instances. Ask your doctor before taking bilberry if you take blood-thinning medication.

Medication for diabetes: Because bilberry appears to lower blood sugar, it could make the effects of diabetes medication stronger. Also, taking bilberry with other herbs that also lower blood sugar may result in hypoglycemia (low blood sugar). Herbs that also lower blood sugar include ginger, ginseng, fenugreek, and garlic. DO NOT take bilberry if you take medications for diabetes.

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