Bilberry Introduction

Bilberry is also called huckleberry, whortleberry, dyeberry, trackleberry, wineberry, and European blueberry. It is a member of the Ericaceae family. This perennial shrub grows to an average height of 1-2 feet. It has small, bright green leaves with a bell shaped flower that can be pink or white, and makes a fruit in the end of spring (into summer) that is dark blue or purple, similar to a blueberry. [1]

The bilberry has been prized as a food source for many years. It was first used in the Middle ages, and was then popularized by herbalists in the 1500’s. Traditionally, bilberry was used to treat scurvy, cough, tuberculosis, stones, and biliary disease. Other medicinal applications including diarrhea, pharyngitis, and infections of the oral mucosa were also treated with bilberry. Currently, bilberry is recognized as a venotonic, anti-oxidant, and astringent. [2]

Although the fruit contains less than 1% of the flavonoid anthocyanins, it remains bilberry’s most recognizable and, quite possible, its most beneficial constituent. Bilberry also contains several other flavonoids, including catechin, quercitin, epicatechin, and OCPs. The leaves of bilberry also contain tannins, at a concentration of 7-20%. Other less recognized constituents are; caffeic acids, phenolic acids, pectins, and quinolizidine alkaloids. [3]

The majority of treatment recommendations for bilberry today focus on its most active constituent, anthocyanins. These flavonoids are considered to be highly potent antioxidants, effective in preventing oxidation, reducing capillary permeability, and inhibiting platelet aggregation. Anthocyanins have been applied for various vascular disorders, cardiovascular conditions, and opthamalogical conditions. In study, they have also been shown to exhibit effects on collagen integrity and production. [4, 5]

Tannins are the other primary acting constituents in bilberry. They act as an astringent and are also anti-inflammatory in nature. The leaf tannins make bilberry useful for diarrhea and inflammation of the mucous membranes of the mouth and throat. [6]

Parts Used

Several parts of the bilberry plant can be used for medicinal purpose. The berry and flowers are used for their anthocyanin content, while the leaves are used for the high tannin content. Many solid extracts of the berries and flowers are standardized to contain high levels of anthocyanins, sometimes as high as 25%.

Bilberry Uses

• Bilberry has been labeled a venotonic, meaning that it is protective against capillary damage and increased permeability. Increases in capillary permeability can cause edema in the extremities (hands and feet).

• Bilberry supports proper function of capillaries and reduces the leakage of fluid out into the tissue space, which causes edema. [7] Edema is a common occurrence in pregnancy, individuals on bed rest, and those with congestive heart failure, high blood pressure, and diabetes. Bilberry has the potential to be anti-edema for all these conditions.

• Bilberry has been specifically indicated for vision and as a nutrient for the overall health of the eyes. This is due to its high antioxidant content from anthocyanins. The eyes need long-term antioxidant protection to limit the damage caused by exposure to sunlight (UVs) everyday. Anthocyanins are a flavonoid that has a specific affinity for the eyes, especially the retina. [8]

• Bilberry was shown to protect against age-related macular degeneration. [9] This condition is common in elderly individuals, particularly those living in the 5th and 6th decade of their lives. This condition is due to oxidative damage from the sun.

• Bilberry has also been shown to improve night vision. Research suggests that bilberry may increase visual acuity, as well as improve the contrast between colors at night. [10]

• Bilberry is a potent antioxidant due to its diverse flavonoid content. It is useful in cardiovascular disease, namely, atherosclerosis. In clinical applications, bilberry has been shown to reduce the oxidation of LDL cholesterol levels. [11] Oxidized LDL is implicated as one of the initial steps towards the development of atherosclerosis.

• Bilberry has also been shown to inhibit platelet aggregation. [12] Platelet aggregation is another contributing factor in the formation of arterial plaques witnessed in atherosclerosis. It is also part of the disease process in thrombus formation and deep vein thrombosis. Because it supports the structure and integrity of the blood vessels and limits platelet aggregation, bilberry may be helpful for cases of deep vein thrombosis and thrombophlebitis.

• Bilberry may be an effective treatment for certain types of cancers. In study, bilberry extract was shown to inhibit angiogenesis, or new blood vessel formation. [13] The antioxidants contained in bilberry were shown to inhibit vascular endothelial growth factor, the molecule that signals new growth. Invasive cancers use the process of angiogenesis to increase blood supply, thereby supplying specific nutrients needed for tumor growth and subsequent invasion of surrounding tissue.

• Bilberry was also shown to inhibit the growth of colon cancer cells in vitro. [14] This activity is believed to be due to the antioxidant flavonoid anthocyanin. Bilberry did not inhibit growth of normal healthy colon cells.

Bilberry Contraindications

There are no contraindications to the use of bilberry. It has been found safe in all populations, including women who are pregnant and nursing. Theoretically, bilberry may be contraindicated in persons with a bleeding or hemorrhagic disorder because of the ability of bilberry to inhibit platelet aggregation. Although this is a relative contraindication, no case studies or research trials have determined this effect to exist. [15]

Bilberry Interactions

Bilberry may interact with blood thinning medications such as aspirin or coumadin, again, largely due to its ability to inhibit platelet aggregation. Therefore, individuals on blood thinning medications should have their bleeding time and PT and PTT checked regularly. The dosage of the medication may also need to be altered. [16, 17]

Another possible interaction could be with oral hypoglycemics. Because bilberry may exert some effect on lowering blood sugar levels, individuals who are taking medications for lowering blood sugar should be monitored by monitored by physician. The greatest fear is that hypoglycemia will result in coma.

Standard dosages range from 60 - 160 milligrams, taken two to three times daily, of an extract standardized to contain 25% anthocyanins. 3 - 6 milliliters per day of a 1:1 liquid extract may also be used. The fresh berries of the bilberry shrub can also be eaten. However, it is not recommended to exceed 12 ounces daily. These doses will provide for certain anti-oxidant and venotonic properties.

For astringent properties, leaves can be made into a tea with three tablespoons of herb in 1/2 liter of water, and may be consumed throughout the day.

No side effects have been reported after the use of bilberry fruit or flowers. However, mild upset of the digestive tract may occur due to the tannins found within the leaves. In addition, the overdose of constituents found in the leaves of bilberry can cause malnutrition, anemia, and jaundice. This is attributed to the an astringent action on the GI tract. [18]

[1] Mills S, Bone K. Principles and Practice of Phytotherapy, Churchill Livingstone, London UK. 2000: 297-302.

[2] Vaccinium myrtillus: Monograph. Altern Med Rev. 2001; 6(5): 500-504.

[3] Mills S, Bone K. Principles and Practice of Phytotherapy, Churchill Livingstone, London UK. 2000: 297-302.

[4] Mills S, Bone K. Principles and Practice of Phytotherapy, Churchill Livingstone, London UK. 2000: 297-302.

[5] Vaccinium myrtillus: Monograph. Altern Med Rev. 2001; 6(5): 500-504.

[6] Vaccinium myrtillus: Monograph. Altern Med Rev. 2001; 6(5): 500-504.

[7] Mills S, Bone K. Principles and Practice of Phytotherapy, Churchill Livingstone, London UK. 2000: 297-302.

[8] Mills S, Bone K. Principles and Practice of Phytotherapy, Churchill Livingstone, London UK. 2000: 297-302.

[9] Blodi BA. Nutritional supplements in the prevention of age related macular degeneration. Insight. 2004 Jan-Mar; 29(1): 15-16.

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

[11] Laplara PM, Lelubre A, Chapman MJ. Antioxidant activity of Vaccinium myrtillus on human low-density lipoproteins in vitro: initial observation. Fundam Clin Pharmacol. 1997; 11(1): 35-40.

[12] Mills S, Bone K. Principles and Practice of Phytotherapy, Churchill Livingstone, London UK. 2000: 297-302.

[13] Roy S et al. Anti-angiogenic properties of edible berries. Free Rad Res. 2002 Sep; 36(9): 1023-1031.

[14] Zhao C, Giusti MM, Malik M, Moyer MP, Magnuson BA. Effects of commercial anthocyanidin rich extracts on colonic cancer and non-tumorgenic colonic cell growth. J Agric Food Chem. 2004 Oct 6; 52(20): 6122-6128.

[15] www.pdrhealth.com Bilberry. January 2005.

[16] www.pdrhealth.com Bilberry. January 2005.

[17] Mills S, Bone K. Principles and Practice of Phytotherapy, Churchill Livingstone, London UK. 2000: 297-302.

[18] www.pdrhealth.com Bilberry. January 2005.