Bilberry (Vaccinium myrtillus) – Health Benefits of Fruits and Leaves and Their Application in Phytotherapy

Bilberry (Vaccinium myrtillus) is a deciduous dwarf shrub of the heath family (Ericaceae), reaching heights of 15 to 60 cm. It thrives natively throughout the acidic podzolic soils of Eurasian coniferous and mixed forests.

Its pharmacological value is concentrated in two distinct plant parts:

• Ripe Berries (Fructus Myrtilli) – exceptional reservoirs of monomeric anthocyanins (including delphinidin, cyanidin, malvidin, and petunidin glucosides), alongside condensed tannins, ascorbic acid, resveratrol, and pectin fibers;
• Leaves (Folium Myrtilli) – densely supplied with phenolic acids (chlorogenic, caffeic), flavonoids (quercetin, isoquercitrin), catechin tannins, and trace minerals like chromium and manganese.

While the dark berries capture consumer attention, bilberry foliage possesses potent pharmacological properties, particularly in urological antisepsis and carbohydrate metabolism.

Owing to arbutin and astringent tannins, foliar decoctions exert antibacterial and anti-inflammatory actions on the urinary tract. Concurrently, the synergy of chlorogenic acid and trace chromium aids peripheral insulin sensitivity, rendering bilberry leaf infusions a traditional adjunct for impaired fasting glucose and prediabetes. They should be cycled responsibly without substituting prescribed endocrinological therapies.

Bilberry fruit is universally celebrated as a flagship functional food. Its concentrated anthocyanin complex underpins significant microvascular and ocular benefits:

• Endothelial integrity – anthocyanins stabilize capillary basement membranes and downregulate vascular permeability, curtailing capillary fragility;
• Night vision adaptation – bilberry metabolites stimulate the enzymatic resynthesis of rhodopsin (retinal visual purple), enhancing scotopic vision acuity;
• Digital eye strain mitigation – standardized extracts alleviate asthenopia and ocular fatigue induced by prolonged display exposure;
• Neuroprotective shielding – polyphenol antioxidants defend retinal ganglion cells and cerebral neurons against oxidative degradation.

Preserving the therapeutic potency of bilberries requires gentle handling. Excessive thermal processing, such as prolonged boiling for commercial jams, degrades 40% to 60% of heat-sensitive anthocyanins.

The optimal preservation techniques are flash freezing and freeze-drying (lyophilization), retaining over 90% of native bioflavonoids. Incorporating fresh or thawed berries into smoothies alongside healthy lipid matrices (such as crushed flaxseed or walnuts) optimizes nutrient absorption. During off-season periods, clinically standardized pharmaceutical extracts standardized to 25% anthocyanosides offer reliable bioactivity.