Bilberry extract is derived from the dark purple berries of the bilberry plant, which is native to the northern regions of Europe. The small bilberry shrub, also known as Vaccinium myrtillus, generally reaches a height of 16 inches (40.64 cm) and features oval leaves and pinkish-white flowers. Bilberry extract is commonly used as a nutritional supplement to treat a variety of conditions, including diarrhea, heart disease and macular degeneration. Its effectiveness has not been determined scientifically, but the chemicals in bilberry extract generally have been found to have beneficial properties.
One chemical in bilberry extract is anthocyanidin, a flavonoid that causes the deep purple color of the bilberry. Its strong antioxidant properties protect the bilberry from the damaging effects of free radicals, and researchers have found that anthocyanidin can also protect human cells from free radical damage. In fact, anthocyanidin is a more potent antioxidant than vitamin C and vitamin E. An unique feature of anthocyanidins is that they are usually effective in both polar and non-polar environments.
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Potential medical applications of anthocyanidin rely on its ability to protect collagen from free radicals. Collagen is the material that makes capillary walls and joints. Over time, free radicals damage the collagen, reducing its integrity. Since anthocyanidin can protect collagen from free radical damage, researchers are studying possible ways to incorporate anthocyanidin into the treatment of atherosclerosis and arthritis.
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Another chemical in bilberry extract that has beneficial properties is tannin. It is an astringent, meaning it shrinks or constricts tissue to reduce inflammation. Tannins are a great first aid medicine, as they can help stop bleeding and reduce the risk of infection associated with cuts and burns. Tannins are also effective at reducing constipation and diarrhea. There is some evidence which suggests that tannins may help eliminate colon cancer cells as well.
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With these great benefits, come possible side effects, however. Individuals who are sensitive to tannins may experience pain in the stomach or irritation of the kidneys. Tannins can also inhibit the natural absorption of minerals, including iron, which may lead to anemia if tannins are consumed for an extended period of time.
Bilberry extract supplements contain a high concentration of anthocyanidins, typically between 25 and 35 percent. The bilberry fruit is less potent than the supplement, but it still provides the benefits of an antioxidant and an anti-inflammatory. Eating more bilberries generally increases the effectiveness of its properties. Another way to extract the anthocyanidins and tannins from bilberries is to brew bilberry tea from bilberries and bilberry leaves.