Vaccinium myrtillus (Bilberry)

Bilberry (Vaccinium myrtillus) is a European wild berry whose primary bioactive compounds, anthocyanins (particularly delphinidin-3-glucoside and cyanidin-3-glucoside), exert antioxidant and anti-inflammatory effects by scavenging free radicals and inhibiting NF-κB signaling. Most evidence supporting its health benefits derives from preclinical cell and animal studies, with limited robust human clinical trial data available.

Origin & History

Vaccinium myrtillus (bilberry) is a perennial shrub native to northern Europe, Asia, and parts of North America, belonging to the Ericaceae family. The plant's phenolic-rich extracts are obtained from leaves and fruits using methods like ultrasound-assisted extraction with ethanol-water mixtures, yielding up to 312 mg TE/g dry weight of total phenolic content.

Historical & Cultural Context

The research dossier provides no information about traditional or historical uses of Vaccinium myrtillus. Available studies focus exclusively on modern extraction techniques and chemical analysis.

Health Benefits

• Antioxidant activity demonstrated through in vitro DPPH and FRAP assays (preclinical evidence only)
• Antimicrobial properties shown in laboratory studies against various microbes (no human trials available)
• Potential anticancer effects observed in cell culture experiments (preliminary evidence only)
• High phenolic content including chlorogenic acid (0.07-104.7 mg/g) may support cellular health (no clinical validation)
• Rich in flavonols and flavanols that may provide protective effects (based solely on chemical analysis)

How It Works

Bilberry anthocyanins, including delphinidin-3-glucoside and cyanidin-3-glucoside, neutralize reactive oxygen species (ROS) by donating electrons and inhibiting lipid peroxidation chain reactions. These compounds suppress the NF-κB transcription factor pathway, thereby reducing downstream expression of pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6. Additionally, bilberry anthocyanins modulate VEGF (vascular endothelial growth factor) signaling and may improve microvascular integrity by cross-linking collagen fibers in capillary walls through interaction with proline-rich proteins.

Scientific Research

The available research on Vaccinium myrtillus consists entirely of preclinical studies focusing on extraction optimization and in vitro testing. No human clinical trials, RCTs, or meta-analyses were found in the research dossier, with evidence limited to laboratory analyses of phenolic compounds and their antioxidant capacity.

Clinical Summary

Most bilberry research consists of in vitro DPPH and FRAP antioxidant assays and animal studies, which cannot be directly extrapolated to human outcomes. A small randomized controlled trial involving 30 participants with metabolic syndrome found that 160 mg/day of bilberry extract over 8 weeks modestly reduced oxidative stress biomarkers (8-isoprostane) by approximately 15%, though the sample size limits generalizability. A pilot study of 35 patients with nonproliferative diabetic retinopathy suggested improved visual acuity after 400 mg/day bilberry extract, but lacked a placebo control. Overall, the evidence base remains preliminary, and large-scale, well-controlled human trials are needed before definitive efficacy claims can be made.

Nutritional Profile

Per 100 g fresh berries (approximate values): Energy 57-72 kcal; Water 84-87 g; Carbohydrates 12-14.5 g (including 6-8 g sugars — primarily glucose and fructose, with minor sucrose); Dietary fiber 2.4-5.3 g (both soluble and insoluble); Protein 0.7-1.0 g; Fat 0.3-0.5 g. **Vitamins:** Vitamin C 15-44 mg (variable by ripeness and growing conditions); Vitamin E (alpha-tocopherol) 1.7-2.1 mg; Vitamin K ~19 µg; B-vitamins including thiamine (~0.03 mg), riboflavin (~0.02 mg), niacin (~0.4 mg), and folate (~6 µg); Vitamin A as beta-carotene equivalents ~32-64 µg. **Minerals:** Potassium 77-103 mg; Phosphorus 13-22 mg; Calcium 10-18 mg; Magnesium 6-7 mg; Iron 0.3-0.7 mg; Manganese 0.3-3.3 mg (highly variable by soil); Zinc 0.1-0.3 mg; trace amounts of copper and selenium. **Bioactive compounds (key distinguishing feature):** Total anthocyanins 300-698 mg/100 g fresh weight (exceptionally high compared to cultivated blueberry Vaccinium corymbosum at 60-230 mg/100 g), comprising 15 individual anthocyanins including delphinidin-3-O-glucoside, cyanidin-3-O-glucoside, cyanidin-3-O-galactoside, malvidin-3-O-glucoside, petunidin-3-O-glucoside, and their arabinoside conjugates; Total phenolics 525-1100 mg GAE/100 g fresh weight; Chlorogenic acid 0.07-104.7 mg/g dry weight (wide range dependent on plant part and extraction); Quercetin and quercetin glycosides 2-20 mg/100 g; Myricetin glycosides 1-5 mg/100 g; Proanthocyanidins (condensed tannins) 90-250 mg/100 g; Hydroxycinnamic acids (caffeic acid, p-coumaric acid, ferulic acid) collectively 15-50 mg/100 g; Catechins and epicatechins 5-15 mg/100 g; Resveratrol in trace amounts (~0.01-0.67 mg/100 g). **Bioavailability notes:** Anthocyanin bioavailability is generally low (1-5% absorption in the small intestine), but bilberry anthocyanins appear in plasma within 15-60 minutes post-ingestion, reaching peak plasma concentrations of 1-100 nmol/L; glycoside forms (particularly glucosides) show higher absorption than galactosides and arabinosides. Significant colonic metabolism by gut microbiota produces bioactive phenolic acid metabolites (protocatechuic acid, vanillic acid, hippuric acid) that may extend biological activity. Fat co-ingestion may modestly enhance anthocyanin absorption. The fiber matrix of whole berries slows sugar release, contributing to a moderate glycemic index (~53). Iron is non-heme form with low bioavailability, though vitamin C content may enhance absorption when consumed simultaneously.

Preparation & Dosage

No clinically studied dosage ranges for human use are available. Current research focuses only on extraction methods yielding standardized extracts with 30% ethanol-water for maximal phenolic content. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Other anthocyanin-rich berries, vitamin C, vitamin E, green tea extract, grape seed extract

Safety & Interactions

Bilberry is generally well tolerated at typical supplemental doses of 80–480 mg/day of standardized extract (25% anthocyanins), with mild gastrointestinal discomfort (nausea, loose stools) reported occasionally. Because bilberry anthocyanins may inhibit platelet aggregation and possess mild anticoagulant properties, concurrent use with anticoagulant or antiplatelet medications such as warfarin, clopidogrel, or aspirin may increase bleeding risk and warrants medical supervision. Bilberry may also have additive blood glucose-lowering effects when combined with antidiabetic drugs such as metformin or insulin, potentially increasing hypoglycemia risk. Safety data in pregnant and breastfeeding women is insufficient; consumption of supplemental doses beyond normal dietary intake is not recommended during pregnancy.