Supplement analysis backed by scientific evidence · PT

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Limited evidenceEye health

Bilberry

The famous "RAF pilots ate bilberry jam to see in the dark" story is wartime myth, and controlled trials have repeatedly failed to find a night-vision benefit. The modest real signal is for accommodation strain and eye fatigue in screen workers.

What the science says

  • Improves night vision Limited evidence

    This is the claim that sells bilberry and it does not hold up. Placebo-controlled trials in young adults with normal vision have found no improvement in night visual acuity or dark adaptation with bilberry anthocyanins. The origin story traces to British WWII cover for radar development, not to any experiment.

  • Relieves eye fatigue and accommodation strain from screen work Limited evidence

    In a 12-week randomized, double-blind, placebo-controlled trial (n = 109, ages 20–60), 240 mg/day of standardised bilberry extract significantly improved objective ciliary muscle accommodation (HFC-1) after visual display terminal tasks versus placebo at weeks 8 and 12. Other small trials report reduced subjective eye fatigue. Sample sizes are modest and several trials were run by extract manufacturers.

  • Improves dry eye Limited evidence

    Small randomized and pilot studies of standardised bilberry extract in dry eye report symptom improvement, but they are underpowered, short, and not consistently replicated. Not enough to recommend bilberry over established dry-eye management.

  • Improves cholesterol, glucose or blood pressure Limited evidence

    A systematic review of bilberry and grape seed extract interventions found inconsistent effects on glucose metabolism, cholesterol and blood pressure, with results depending heavily on the population studied. No reliable cardiometabolic benefit has been established.

Dosage & safety

Studied doseTrials used 160–480 mg/day of standardised bilberry extract, most commonly 240 mg/day for 8–12 weeks, typically standardised to about 36% anthocyanosides (e.g. Mirtoselect). Fresh bilberries, jams and juices do not realistically deliver these anthocyanin doses.
SafetyWell tolerated at trial doses; mild GI upset is the most common complaint. Bilberry anthocyanins have mild antiplatelet activity — a theoretical additive bleeding risk with anticoagulants and antiplatelets, and reason to stop before surgery. Bilberry leaf is a different material and has been linked to toxicity with high chronic intake; use fruit extract only. Product quality is a genuine problem: adulteration of "bilberry" extract with cheaper anthocyanin sources or with dyes is documented, so choose products with an identified standardised extract and third-party testing.

Scientific references

Where to buy

Vitacost, Bilberry Extract Including Elderberry, 90 Capsules

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