Bilberry

What is bilberry?

Bilberry is a low shrub native to northern Europe and parts of North America. Its small dark berries look like blueberries and are rich in anthocyanins, the pigments that give them their color, along with tannins and other flavonoids. Both the fruit and the leaves have been used in folk medicine. Most supplements use a fruit extract standardized to a percentage of anthocyanosides.

What the research says

The US National Center for Complementary and Integrative Health summarizes the evidence plainly: bilberry has not been clearly shown to be helpful for any health condition, and many studies were too small or poorly designed to reach conclusions (NCCIH).

Vision

Bilberry’s reputation for eyesight is often traced to a wartime story about British pilots eating bilberry jam. A systematic review of placebo-controlled trials found that the four most recent randomized trials on night vision were all negative, and that the more rigorous the study, the less likely it was to find a benefit (Canter and Ernst, 2004). NCCIH also notes that the most rigorous studies have not found bilberry effective for night vision in healthy people.

Blood sugar and circulation

Bilberry fruit and leaf extracts have been used traditionally for blood sugar and circulation, and anthocyanins are of research interest for these uses. Human evidence remains limited and inconsistent, and no bilberry product has shown clear, reproducible benefits in well-designed trials for these uses.

Brain and focus

Bilberry is sometimes included in brain formulas because berries rich in anthocyanins are of general interest for healthy aging. We found no controlled trials of bilberry extract specifically on memory or attention, so any brain benefit is unproven.

How it’s used in supplements

Bilberry is sold mostly for eye health and appears in vision, blood sugar and antioxidant blends. NCCIH notes that fruit extracts have been used in studies at up to 160 mg a day for up to six months and appear well tolerated. Bilberry leaves are a different matter: they may be unsafe in high doses or with long-term use (NCCIH). A label should say whether it uses fruit or leaf, and how much.

People allergic to blueberries, cranberries or other Vaccinium berries should avoid bilberry products (LactMed). Little is known about safety in pregnancy or breastfeeding beyond food amounts. Because anthocyanin-rich extracts are sometimes discussed for blood sugar and clotting, people on diabetes medicines or blood thinners should ask their doctor before using concentrated extracts.