A close relative of the American blueberry, bilberry (also known as European blueberry, whortleberry, wineberry, huckleberry, or trackleberry), is a shrubby perennial that grows in forests and meadows throughout much of Europe. Growing up to 50 cm in height, bilberry flowers from April to June, with greenish-pink, bell-shaped blossoms. The fruit is a blue-black or purple berry with multiple seeds. The meat of the bilberry is also purple, unlike the American blueberry, which has cream-colored pulp. The ripe berries are used to promote vision and circulatory health.
The primary active constituents in bilberries are flavonoid compounds known as anthocyanidins, which exhibit powerful antioxidant activity. Bilberry extracts are commonly standardized to 25% anthocyanidin content, and this is the concentration used in most scientific studies.
Much of the European research on bilberry has focused on the herb's potential eye health benefits. Although bilberry extracts have become very popular for promoting nighttime vision and helping "night blindness," the herb's effectiveness in these areas has not been demonstrated conclusively in scientific studies.
Dosage of bilberry should be based upon its anthocyanidin content. Most bilberry extracts are standardized to 25% anthocyanidin content, and are commonly taken in 60-120 mg doses, three times daily. Bilberry is well tolerated in this dosage range and devoid of adverse effects. Excess anthocyanidin is excreted in the urine and does not accumulate in the body in toxic levels.