Bilberry

• Eye health protection
• Vascular integrity support
• Antioxidant defense
• Neuroprotection

• Night vision support
• Retinal health
• Blood vessel strength
• Microcirculation enhancement
• Blood glucose regulation
• Cognitive function
• Digestive health
• Anti-inflammatory effects

Bilberry extract exerts its diverse biological effects primarily through its rich anthocyanin content, which comprises up to 15 different anthocyanidin glycosides that give the berries their characteristic deep purple-blue color. These anthocyanins, particularly delphinidin and cyanidin glycosides, function as powerful antioxidants with multiple cellular targets and signaling pathways. In ocular tissues, bilberry anthocyanins accumulate in the retina and choroid after oral administration, where they enhance rhodopsin regeneration in rod photoreceptors, potentially improving night vision and visual adaptation to darkness. This effect is mediated through enhanced production of retinal pigments and stabilization of collagen structures in the eye.

Bilberry anthocyanins also protect retinal cells from light-induced damage by absorbing blue light radiation and neutralizing reactive oxygen species that would otherwise damage photoreceptors and retinal pigment epithelium. They upregulate antioxidant enzymes including superoxide dismutase, catalase, and glutathione peroxidase through activation of the Nrf2 pathway, providing comprehensive protection against oxidative stress in ocular tissues. For vascular health, bilberry anthocyanins strengthen blood vessel walls by stabilizing collagen in vascular structures, inhibiting collagenase and elastase enzymes that degrade connective tissue, and improving the integrity of tight junctions between endothelial cells. They enhance microcirculation by reducing capillary permeability, preventing abnormal leakage, and improving blood flow through small vessels, particularly in the extremities and ocular tissues.

Bilberry’s anti-inflammatory effects stem from inhibition of pro-inflammatory enzymes (cyclooxygenase-2, lipoxygenase) and reduction of inflammatory cytokines (IL-1β, IL-6, TNF-α) through suppression of NF-κB signaling pathways. In the context of metabolic health, bilberry anthocyanins improve insulin sensitivity by enhancing GLUT4 translocation to cell membranes, activating AMPK pathways, and reducing oxidative stress in pancreatic β-cells. They also inhibit intestinal α-glucosidase, potentially reducing postprandial glucose spikes. Bilberry’s neuroprotective effects involve multiple mechanisms: reduction of oxidative stress in neural tissues; inhibition of acetylcholinesterase, potentially enhancing cholinergic neurotransmission; protection of the blood-brain barrier integrity; and modulation of neuroinflammation through microglial regulation.

Additionally, bilberry anthocyanins may influence gene expression through epigenetic mechanisms, including histone modifications and DNA methylation patterns, potentially contributing to their long-term health effects. The extract also contains other bioactive compounds including quercetin, catechins, tannins, and resveratrol that work synergistically with anthocyanins to provide comprehensive health benefits through complementary mechanisms.

80-480 mg per day of standardized extract (containing 25-36% anthocyanins), typically divided into 1-3 doses. For whole dried bilberries (not extract), 1-3 grams daily. Dosage varies based on the specific condition being addressed and the standardization level of the extract.

Bilberry anthocyanins have relatively low oral bioavailability, with approximately 1-5% of the ingested dose reaching systemic circulation in intact form. Peak plasma concentrations are typically reached within 1-2 hours after ingestion. Despite this low systemic bioavailability, anthocyanins and their metabolites have been detected in various tissues, including the eyes, brain, and vascular endothelium, suggesting targeted tissue distribution. Anthocyanins undergo significant metabolism in the intestine and liver, producing various phenolic acid metabolites that may contribute to the overall biological effects.

Additionally, unabsorbed anthocyanins reaching the colon interact with gut microbiota, producing secondary metabolites that may have systemic effects.

Taking with a small amount of healthy fat may enhance absorption of certain bilberry compounds, Consuming with vitamin C may help stabilize anthocyanins and improve their absorption, Liposomal delivery systems can increase bioavailability by 2-3 fold, Phospholipid complexes improve stability and enhance cellular uptake, Micronized powder forms increase surface area for better absorption, Cyclodextrin complexes can protect anthocyanins from degradation in the GI tract, Consuming whole berries may provide synergistic compounds that enhance anthocyanin absorption, Fermented bilberry products may improve bioavailability through pre-metabolization, Avoiding simultaneous consumption of dairy products, which may bind to anthocyanins

Bilberry extract can be taken with or without food, though taking with a small meal containing some fat may enhance absorption of certain compounds. For eye health and vision support, consistent daily dosing is more important than specific timing. For blood glucose management, taking 15-30 minutes before meals may help moderate postprandial glucose spikes. For vascular conditions, dividing the daily dose into 2-3 administrations throughout the day provides more consistent blood levels.

For night vision support, some practitioners recommend taking a dose approximately 2-3 hours before anticipated need for enhanced night vision, though clinical evidence for timing-specific effects is limited. For general preventive health benefits, morning administration establishes a baseline of antioxidant protection throughout the day. When used alongside medications, no specific timing interactions are generally necessary, as bilberry has minimal known drug interactions.

• Mild gastrointestinal discomfort (rare)
• Mild allergic reactions in sensitive individuals (very rare)
• Temporary darkening of stool or urine color due to anthocyanin content
• Mild dizziness (very rare)
• Skin rash (very rare)
• Headache (very rare)

• Known allergy to bilberry or related plants in the Ericaceae family
• Caution in pregnancy and breastfeeding (insufficient safety data, though no specific concerns have been identified)
• Caution in bleeding disorders (theoretical concern due to potential antiplatelet effects at very high doses)
• Caution before surgery (discontinue 2 weeks before scheduled surgery due to theoretical anticoagulant effects at high doses)

• Anticoagulant/antiplatelet medications – theoretical potential for additive effects at very high doses, though clinical significance appears minimal at standard doses
• Diabetes medications – may enhance blood sugar-lowering effects, potentially requiring monitoring and adjustment
• Iron supplements – anthocyanins may bind to iron, potentially reducing absorption if taken simultaneously
• Herbs with anticoagulant properties (ginkgo, garlic, etc.) – theoretical additive effects, though clinical significance appears minimal at standard doses

No official upper limit has been established. Clinical studies have used doses up to 480 mg of standardized extract daily without significant adverse effects. For whole berries, consumption of up to 150g (approximately 1 cup) of fresh bilberries daily is considered very safe. The leaf of the bilberry plant (as opposed to the fruit or fruit extract) contains tannins that may be toxic at high doses and should be avoided except in specific formulations under professional guidance.

As with any supplement, it’s prudent to use the lowest effective dose for the intended purpose.

In the United States, bilberry extract is regulated as a dietary supplement under the Dietary Supplement Health and Education Act (DSHEA) of 1994.

It has not been approved as a drug for any specific indication. As a supplement, manufacturers cannot make claims about treating, curing, or preventing specific diseases, but can make structure/function claims about supporting normal bodily functions (e.g., ‘supports healthy vision’). The FDA has granted bilberry fruit Generally Recognized as Safe (GRAS) status for use as a food ingredient.

Eu: In the European Union, bilberry fruit is recognized as a traditional herbal medicinal product under Directive 2004/24/EC for specific indications including minor venous circulation disorders and eye fatigue. The European Medicines Agency (EMA) has published a community herbal monograph for bilberry fruit, recognizing its traditional medicinal use. Standardized bilberry extracts are available as registered herbal medicines in several European countries. Bilberry is also approved as a food and food supplement ingredient.

Germany: The German Commission E (similar to the FDA for herbal medicines) has approved bilberry fruit for acute, non-specific diarrhea and mild inflammation of the mouth and throat mucosa. Standardized extracts are approved for various vascular and ophthalmological indications.

France: Bilberry extract is available as a prescription medication for vascular disorders and ophthalmological conditions. It is also widely used in over-the-counter eye health products.

Uk: The Medicines and Healthcare products Regulatory Agency (MHRA) has registered several traditional herbal medicinal products containing bilberry for minor venous circulation disorders.

Australia: The Therapeutic Goods Administration (TGA) regulates bilberry as a listed complementary medicine ingredient. Several bilberry products are included in the Australian Register of Therapeutic Goods (ARTG) with permitted indications related to antioxidant activity, eye health, and vascular function.

Canada: Health Canada regulates bilberry as a Natural Health Product (NHP) ingredient. Several bilberry products have received Natural Product Numbers (NPNs) with approved claims related to eye health, antioxidant effects, and vascular integrity.

Japan: Bilberry extract is recognized as a functional food ingredient under the Foods for Specified Health Uses (FOSHU) system, particularly for eye health applications.

Medium

Standard extract (80-160 mg daily with 25% anthocyanins): $0.30-$0.70 per day. Higher potency extract (240-480 mg daily with 36% anthocyanins): $0.80-$2.00 per day. Premium European-sourced extracts: Add 30-50% to above costs. Specialized eye health formulations with additional synergistic compounds: $1.00-$3.00 per day.

Bilberry extract offers moderate cost efficiency compared to other eye health supplements. When comparing bilberry products, cost per milligram of anthocyanins provides the most accurate value comparison, as potency varies significantly between products. Products standardized only by weight without specifying anthocyanin percentage may contain minimal active compounds and represent poor value regardless of price. European-sourced extracts (particularly from Scandinavian countries) typically command premium prices (30-50% higher) compared to products from other regions, based on traditionally higher anthocyanin content and stricter quality control.

This premium may be justified for therapeutic applications but less necessary for general preventive use. Generic and store-brand bilberry products have become more available in recent years, offering 20-30% cost savings over premium brands, though quality can be variable. Bulk purchases and subscription services typically offer 10-20% savings over one-time purchases. For general eye health maintenance, lower doses (80-160 mg standardized extract) provide good value, while higher doses for therapeutic effects naturally increase costs.

Combination products with synergistic compounds like lutein, zeaxanthin, and omega-3s may provide better overall value for comprehensive eye health than bilberry alone, despite higher upfront costs. For vascular health applications, bilberry extract is typically more cost-effective than many specialized circulation supplements while offering comparable benefits. The relatively long shelf life (18-24 months) allows for bulk purchasing without significant waste risk. Compared to pharmaceutical treatments for early eye conditions, bilberry offers significant cost savings and fewer side effects, though may not be as effective for advanced conditions.

Fresh or frozen whole bilberries, while not as concentrated as extracts, offer excellent nutritional value and moderate anthocyanin content at lower cost, making them a cost-effective complementary approach to supplements.

Properly manufactured and stored bilberry extract supplements typically maintain acceptable anthocyanin content for 18-24 months. Capsules and tablets generally have longer stability than powder forms due to reduced exposure to environmental factors. Liquid extracts have the shortest shelf life, typically 6-12 months after opening. Fresh bilberries are highly perishable and maintain optimal anthocyanin content for only 1-2 weeks under refrigeration.

Store in a cool, dry place away from direct sunlight. Optimal temperature range is 15-25°C (59-77°F). Refrigeration can extend shelf life but is not necessary for most formulations. Avoid freezing and thawing cycles, as this can accelerate degradation of anthocyanins.

Keep containers tightly closed to prevent moisture absorption, as moisture significantly accelerates anthocyanin degradation. The original container typically provides appropriate protection from light and moisture. Dark glass or opaque containers are preferred for liquid extracts to protect from light degradation. For powder forms, use a dry measuring tool to prevent introducing moisture.

Once opened, use within the timeframe recommended by the manufacturer (typically 6-12 months) for optimal anthocyanin content. Fresh or frozen whole bilberries should be stored in the freezer for long-term preservation of anthocyanins.

Light exposure (particularly UV light) rapidly degrades anthocyanins, Heat accelerates chemical degradation of anthocyanins, Oxygen exposure leads to oxidation of anthocyanins and other polyphenols, Moisture causes hydrolysis and accelerates degradation, Alkaline pH conditions rapidly degrade anthocyanins (they are most stable in acidic conditions), Metal ions, particularly iron and copper, catalyze anthocyanin degradation, Enzymes (polyphenol oxidases) can degrade anthocyanins if activated by moisture, Freeze-thaw cycles disrupt cellular structures and release degradative enzymes, Microbial contamination if exposed to moisture, Time gradually reduces anthocyanin content even under optimal storage conditions

Synthesis Methods

Natural Sources

Quality Considerations

Bilberry has a rich history of traditional use spanning centuries, particularly in European folk medicine. The berries have been consumed as food since prehistoric times, with archaeological evidence suggesting human consumption dating back to the Mesolithic period (around 10,000 BCE). Native to Northern and Central Europe, bilberries were highly valued by indigenous peoples for both nutritional and medicinal purposes. In medieval Europe, bilberry was commonly used for digestive ailments, particularly diarrhea and dysentery, due to its astringent properties from the tannin content.

The 12th-century German abbess and herbalist Hildegard of Bingen documented bilberry’s use for menstrual disorders and as a blood purifier. Traditional herbalists throughout Europe used bilberry tea made from dried berries for various conditions including urinary tract infections, kidney stones, and gout. The leaves of the bilberry plant were also used medicinally, primarily for diabetes and urinary tract conditions, though modern usage focuses primarily on the fruit. Bilberry’s association with vision improvement has a particularly interesting historical origin.

During World War II, British Royal Air Force pilots reportedly consumed bilberry jam before night missions, claiming it improved their night vision for bombing raids. This anecdotal evidence sparked scientific interest in bilberry’s effects on visual function, though the story itself may be partially apocryphal. In traditional Russian and Scandinavian medicine, bilberry was used to treat eye fatigue and various vision problems. The berries were also traditionally applied topically as a poultice for skin inflammations, minor wounds, and mouth ulcers.

In Eastern European folk medicine, bilberry was used to improve circulation and treat vascular conditions. Throughout Northern Europe, bilberry was traditionally consumed during the autumn to prepare for winter and strengthen the body against colds and infections. The first scientific investigations into bilberry’s medicinal properties began in the 1960s, with French researchers identifying anthocyanosides (now called anthocyanins) as the primary active compounds. By the 1970s, standardized bilberry extracts became available in Europe as registered medicines for vascular and ophthalmological conditions.

In modern times, bilberry has transitioned from traditional food and folk remedy to standardized extract used in evidence-based complementary medicine, with particular focus on its benefits for eye health, vascular integrity, and antioxidant properties.

Zhu Y, et al. Anti-diabetic and cardiovascular protective effects of anthocyanins: A comprehensive review of experimental and clinical studies. Nutrients. 2021;13(5):1479., Huang W, et al. Anthocyanins and metabolites from berries: Bioavailability, food matrix, and health benefits. Molecules. 2021;26(10):2915., Riva A, et al. The effect of standardized bilberry extract on vascular endothelial function: A systematic review. Phytotherapy Research. 2017;31(5):732-739.

Bilberry Extract for Age-Related Macular Degeneration (NCT04761822), Effects of Bilberry on Retinal Blood Flow in Diabetic Retinopathy (NCT03877614), Bilberry Extract for Computer Vision Syndrome (NCT04523389), Anthocyanins for Cognitive Function in Aging (NCT03419039), Bilberry Extract for Dry Eye Syndrome (NCT04677089)