What Are the Most Common Bilberry Side Effects?

Bilberry is a relative of the cranberry and the blueberry that has been used medicinally for centuries to treat vision problems and diarrhea. Reported bilberry side effects have been few, and its use is considered relatively safe. Some bilberry side effects can occur that may require consulting a medical professional, including allergic reactions that can result in hives or breathing problems. An extract made from the plant as well as the plant’s leaves can cause spasms and severe weight loss, and in some instances can even lead to death if taken in large doses over a long period.

Bilberry side effects are rare but they can occur. It is recommended that bilberry not be taken except under the care of a doctor or other medical professional because it can interact with other types of supplements, including herbs and vitamins. Bilberry side effects also can include a drop in blood sugar levels, which is of particular importance to diabetics and makes a physician’s oversight especially important. Bilberry interactions also can occur with anticoagulant medications.

Vitamin C is present in abundance in bilberry. Other beneficial chemicals that are found in the plant are called anthocyanosides, which are antioxidant-rich pigments. These substances help protect the body from developing cancer, macular degeneration and heart disease. Research performed on animals has led to a belief that bilberry’s anthocyanosides could bolster the body’s blood vessels, keep cholesterol levels in check, and help circulation. Few research studies have been performed to learn exactly how bilberry affects people, but many have been performed on related kinds of antioxidants.

Anthocyanosides are believed to be beneficial for vision and protection of the retina. Despite the lack of human studies, the benefits of bilberry are believed to include protection against the loss of night vision. This is based in part on firsthand accounts of British pilots who ate bilberry jam during World War II. Some people also believe that beneficial uses of bilberry include cataract prevention. The tannins in bilberry are thought to be a good remedy for diarrhea because they are astringent and anti-inflammatory.

Bilberry, also known as Vaccinium corymbosum and Vaccinium myrtillus, is a perennial plant that can reach about 16 inches (40.64 centimeters)tall. The berries are black and reach maturity in summer. They are similar in taste to the blueberry.