What is Bilberry?
Bilberry, also known as European blueberry, is an edible dark blue berry. It is rich in anthocyanins, polyphenolic compounds that give bilberries their blue/black color and high antioxidant content, making them a key bioactive substance.
While bilberries are most commonly known for improving vision, research reports suggest that they also have blood sugar-lowering effects, anti-inflammatory and lipid-lowering effects, and can promote antioxidation while reducing oxidative stress.
What are the Nutritional Components of Bilberry?
Bilberries contain various phenolic compounds, including flavonols, quercetin, catechins, tannins, ellagitannins, and phenolic acids, but anthocyanins contribute most to their phytochemical composition . These naturally occurring phenolic compounds act as both reactive oxygen species scavengers and iron chelators, present in red, blue, and purple flowers, fruits, and vegetables.
In addition, every 100 grams of fresh bilberries contain small amounts of other nutritional components such as vitamin C (3 mg), quercetin (3 mg), and catechins (20 mg) .
What are the Recommended Evidence-Based Effects and Benefits of Bilberry?
Due to anthocyanins, bilberries are widely used to enhance night vision or vision impairments in low light. It is reported that during World War II, British fighter pilots improved their night vision after consuming bilberry jam. However, more rigorous clinical trials are needed to confirm the effectiveness of bilberries in this regard . Additionally, bilberries are considered a therapeutic approach for retinal diseases, providing preventive protection against macular degeneration, glaucoma, and cataracts     .
Treatment of Circulatory Issues
In European traditional medicine, bilberry supplements are used to treat circulatory problems, also known as chronic venous insufficiency.
💡Research indicates that bilberry can improve venous blood flow in the legs with damaged valves . Other studies also suggest that daily consumption of bilberry for up to six months may improve swelling, pain, bruising, and burning associated with chronic venous insufficiency .
Improving Bad Cholesterol
The anthocyanins found in bilberries can strengthen blood vessels and prevent the oxidation of “bad cholesterol” (low-density lipoprotein LDL-cholesterol), a major risk factor for atherosclerosis, the plaque that blocks arteries leading to heart attacks and strokes    .
In vitro studies and animal carcinogenesis models have demonstrated that bilberry anthocyanins possess anti-cancer properties, antioxidant inhibitory activity, and anti-inflammatory effects. Anthocyanins can induce apoptosis in cancer cells, repair and protect genomic DNA integrity     . Extracts of bilberry anthocyanins demonstrate efficacy in inhibiting the growth of colon cancer cells.
💡In DNA research, the use of bilberry extracts in macrophages also observed anti-inflammatory effects, and since inflammation is a significant risk factor for cancer, bilberry may be very effective in cancer prevention      .
Treatment of Diarrhea
Bilberry has been used in European medicine to treat diarrhea for many years. This fruit contains tannins, which have both anti-inflammatory and astringent properties, helping to tighten and contract tissues. By reducing intestinal inflammation, it aids in alleviating symptoms of diarrhea  .
💡In a mouse experiment, oral administration of bilberry and its anthocyanins resulted in improvement of symptoms of acute and chronic colitis, demonstrating their therapeutic effects in patients with inflammatory bowel disease .
Reducing the Risk of Alzheimer’s Disease
💡A study found that treatment with myricetin and quercetin from bilberry significantly reduced symptoms of Alzheimer’s disease, alleviating some behavioral abnormalities  .
💡Another study also found that bilberry helps improve memory and learning abilities in a chemical-induced Alzheimer’s disease experimental animal model .
Are There Any Side Effects of Bilberry?
For most people, consuming dried ripe bilberry fruits is delicious, and consuming the whole fruit is likely safer than concentrated forms. However, high-dose use of bilberry supplements should generally be safe.
- Knowledge about the use of bilberry during pregnancy and breastfeeding is still insufficient, and caution should be exercised to avoid use.
- The anthocyanins in bilberries may inhibit blood clotting, and concurrent use with blood-thinning medications containing aspirin may increase the risk of bleeding.
- Bilberry’s potential side effects on blood glucose levels may interfere with blood sugar control during and after surgery, and its use should be discontinued at least 2 weeks before scheduled surgery .