Bilberry: Anthocyanins, Screen Time and the Research
Bilberries are small, dark berries that grow wild across the heaths and forests of northern Europe. They’re a close relative of the blueberry and have a long history in European kitchens and folk traditions. Today they’re popular with researchers because of their deep colour. This guide looks at what’s in bilberries and what the studies have found.
What is bilberry?
Bilberry is Vaccinium myrtillus, a low shrub in the heath family. Its cousins include the blueberry, cranberry and lingonberry. Bilberries look a lot like blueberries, but there are differences: bilberries are smaller, grow singly or in pairs rather than in clusters, and are dark purple all the way through, while most blueberries are pale inside.
In Scandinavia, the UK and central Europe, foraging bilberries is a summer tradition. They’re used in pies, jams and soups. In folk practice, both the berries and the leaves have been used.
What’s in it?
Bilberries are particularly rich in anthocyanins, the pigments that give them their deep blue-purple colour. Bilberries contain a wide range of different anthocyanins, and they’re found in both the skin and the flesh, which is part of why researchers are interested in them. They also contain other polyphenols, vitamin C, fibre and natural fruit sugars.
A 2020 review in Current Pharmaceutical Design summarised the phenolic compounds found in bilberry fruit and the research on their possible health effects (Pires et al., 2020). It described antioxidant and other effects seen largely in lab and animal studies, and the berry’s uses in food and other industries. As always, lab results don’t automatically translate into effects in people.
The screen-time study
Bilberry has a long-standing link with eyesight. A popular story claims that British pilots in World War II ate bilberry jam to improve their night vision. It’s a good tale, but there’s little evidence that it happened, and early studies on night vision didn’t support it.
More recently, a Japanese trial looked at a different question: eye fatigue in people who spend long hours at screens (Ozawa et al., 2015). In the study, 281 office workers who used computer screens took either a bilberry extract (480 mg a day) or a placebo for eight weeks.
The bilberry group showed improvements in some eye fatigue measures, including some symptoms people reported and an objective measure of the eye’s focusing. Not every measure changed, and the study used a concentrated extract, not whole berries or tea. It’s one trial, and more research would be needed to confirm the findings.
A small heart study, for context
Researchers have also looked at bilberry in other settings. In a 2019 Swedish study published in Nutrition Research, 50 people who had recently had a heart attack were randomly assigned to take freeze-dried bilberry powder or nothing extra for eight weeks, alongside their usual treatment (Arevström et al., 2019). The authors reported changes in some measures, including walking distance and blood lipids.
However, this was an open-label pilot study: everyone knew who was taking bilberry, and there was no placebo. Studies like this are designed to see whether a bigger trial is worth doing, not to show that something works. We mention it only to show where research is heading. Bilberry is not a treatment for heart disease, and anyone with a heart condition should follow their cardiologist’s advice.
Enjoying bilberries
Fresh bilberries are hard to find in Australia, but dried and frozen bilberries and bilberry tea are available:
- As a tea: steep about 1–2 teaspoons of dried berries in just-boiled water for 8–10 minutes. Crushing the berries lightly first helps release colour and flavour.
- In cooking: add dried bilberries to porridge, muesli, muffins or yoghurt, as you would blueberries.
- Flavour: bilberries are more intense and tart than blueberries, with a deep, jammy taste.
Who should take care?
Bilberry fruit is a food and is generally considered safe in food amounts. Concentrated extracts may affect blood clotting or blood sugar, so take care if you take blood-thinning or diabetes medicines. Bilberry leaf is not the same as the fruit and isn’t recommended in large amounts. If you’re pregnant or breastfeeding, or take regular medication, check with your pharmacist.
The bottom line
Bilberries are a flavourful wild berry rich in anthocyanins, with a long place in European food traditions. Research is exploring their effects, including a trial on eye fatigue in screen workers, but most of the evidence comes from extracts, lab studies and small trials. Enjoy them for their taste and colour as part of a varied diet.
This article is general information only and is not medical advice. It is not about any specific product. Talk to your GP or pharmacist about your own health.
References
- Ozawa Y, et al. Bilberry extract supplementation for preventing eye fatigue in video display terminal workers. J Nutr Health Aging. 2015. https://pubmed.ncbi.nlm.nih.gov/25923485/
- Pires TCSP, et al. Vaccinium myrtillus L. fruits as a novel source of phenolic compounds with health benefits and industrial applications: a review. Curr Pharm Des. 2020. https://pubmed.ncbi.nlm.nih.gov/32183662/
- Arevström L, et al. Freeze-dried bilberry (Vaccinium myrtillus) dietary supplement improves walking distance and lipids after myocardial infarction: an open-label randomized clinical trial. Nutr Res. 2019. https://pubmed.ncbi.nlm.nih.gov/30803503/
