Bilberry Extract in VisiVra: Night Vision Claims Checked

What is bilberry?

Bilberry (Vaccinium myrtillus) is a small, dark blue berry that grows wild across northern Europe. It is a close relative of the North American blueberry but has darker flesh, with more pigments throughout the fruit. Those pigments are anthocyanins, a group of flavonoids responsible for the deep blue-purple colour of many berries. Bilberry has been used in traditional European medicine for centuries, and today extracts standardised for anthocyanin content are sold as supplements, often for eye health.

The World War II pilot story

Bilberry’s fame in eye health largely comes from a popular story that British Royal Air Force pilots ate bilberry jam to improve their night vision during bombing raids. The U.S. National Center for Complementary and Integrative Health (NCCIH) notes that this story may have been a superstition or even a hoax, possibly spread to hide the use of radar technology. Either way, it led to decades of interest in bilberry and vision.

How bilberry might work

Several mechanisms have been proposed, mostly from laboratory and animal research:

• Antioxidant activity: anthocyanins neutralise free radicals in laboratory tests.
• Rhodopsin regeneration: Memorial Sloan Kettering notes anthocyanins are thought to help regenerate rhodopsin, the pigment needed for low-light vision, but describes this as a proposed mechanism rather than proven clinical benefit.
• Blood vessel support: some laboratory studies suggest effects on capillaries, which is likely the basis for “ocular circulation” claims.

What the research shows

This is where bilberry’s reputation runs ahead of the evidence. NCCIH summarises the research as follows:

• Bilberry has not been clearly shown to help any health condition.
• Results from studies of night vision are conflicting, and much of the research was of poor quality.
• The most rigorous studies did not find bilberry effective for improving night vision in healthy people.
• Many human studies used weak methods or too few participants to draw firm conclusions.

Memorial Sloan Kettering reports similar findings: trial results on night vision and visual acuity are mixed, one small study suggested improved visual function in some people with normal tension glaucoma, and evidence is lacking for diabetic retinopathy.

How much bilberry is studied?

According to NCCIH, bilberry fruit extracts at amounts up to 160 mg a day for up to six months were well tolerated in research studies. Many commercial extracts are standardised to about 25% anthocyanins. VisiVra lists bilberry fruit extract (Vaccinium myrtillus) within its 351 mg proprietary blend, without an individual amount or standardisation.

Safety and interactions

• Generally safe as food: NCCIH considers bilberry fruit safe in amounts typically found in food.
• Leaves are different: bilberry leaves may be unsafe in high doses or with long-term use. Supplements should use the fruit.
• Bleeding risk: Memorial Sloan Kettering warns bilberry may increase bleeding risk with anticoagulants such as warfarin, antiplatelet drugs, aspirin and NSAIDs, and reports a case of excessive bleeding in a patient combining bilberry with a blood thinner.
• Pregnancy: little is known about safety above food amounts in pregnancy or breastfeeding.
• Surgery: because of the bleeding concern, tell your surgeon if you take bilberry.

Bilberry in your diet

Fresh or frozen bilberries can be hard to find outside Europe, but blueberries, blackberries, blackcurrants and other dark berries also provide anthocyanins along with fibre and vitamin C. Eating a handful of berries regularly is an easy, low-risk way to get these compounds from food, and is considered safe even for people who should avoid concentrated extracts.

Bilberry’s role in VisiVra

Bilberry adds anthocyanin antioxidants and a traditional eye-health ingredient to the formula. It is unlikely to be harmful for most healthy adults, but it is one of the ingredients with the weakest evidence in VisiVra. Its main practical significance for buyers is the blood-thinner interaction, which it shares with two other blend ingredients, ginkgo and forskolin.

Bottom line

Bilberry is a nutritious berry with a famous but probably exaggerated reputation for night vision. Its antioxidant content is real, but rigorous studies have not confirmed eye benefits in healthy people. If you take blood thinners or regular aspirin or NSAIDs, speak with your doctor before taking VisiVra.