Bilberry Extract Powder
Also known as: Bilberry, European blueberry, Bilberry extract powder, Vaccinium myrtillus
Overview
Bilberry extract powder is derived from the fruit of *Vaccinium myrtillus*, a plant rich in anthocyanins and other polyphenols. It is traditionally used to support vascular health, vision, and metabolic regulation. Primary applications include improving blood glucose control, lipid profiles, and microcirculation, as well as providing antioxidant and anti-inflammatory effects. Research on bilberry extract is moderately mature, with several randomized controlled trials (RCTs) and some systematic reviews and meta-analyses available. While some studies have small sample sizes or heterogeneous populations, systematic reviews provide aggregated data for more robust conclusions. The extract is often standardized to contain a specific percentage of anthocyanins, which are considered its primary active compounds. It is generally consumed as a dietary supplement in powder or capsule form.
Benefits
Bilberry extract offers several evidence-based benefits, particularly for individuals with metabolic disorders. It has shown potential in **glycemic control**, with some RCTs indicating a reduction in HbA1c and postprandial glucose levels, especially in type 2 diabetes mellitus (T2DM) patients, though effects on fasting glucose and insulin sensitivity are inconsistent. For **lipid profiles**, meta-analyses suggest bilberry extract may modestly lower total cholesterol and LDL cholesterol, with variable effects on HDL and triglycerides. The anthocyanins in bilberry exhibit significant **antioxidant properties**, potentially reducing oxidative stress markers, although effects on systemic inflammation markers are mixed. While human data are limited, animal studies suggest bilberry extract, especially when combined with docosahexaenoic acid (DHA), may protect against myopia progression and improve retinal function, indicating potential for **vision and ocular health**. The effect sizes are generally modest, and benefits tend to be more pronounced in populations with existing metabolic imbalances rather than in healthy individuals.
How it works
Bilberry's therapeutic effects are primarily attributed to its high concentration of anthocyanins. These compounds modulate glucose metabolism by potentially improving insulin sensitivity and reducing postprandial glucose spikes. They influence lipid metabolism by inhibiting cholesterol synthesis and enhancing the clearance of low-density lipoprotein (LDL). The antioxidant activity of bilberry anthocyanins stems from their ability to scavenge reactive oxygen species and upregulate endogenous antioxidant enzymes, thereby reducing oxidative stress. Anti-inflammatory effects may involve the downregulation of pro-inflammatory cytokines and modulation of the NF-κB signaling pathway. The bioavailability of anthocyanins is moderate, and saccharide-free extracts may show better efficacy due to higher concentrations of active compounds and reduced interference from sugars.
Side effects
Bilberry extract is generally well-tolerated and has a good safety profile. Common side effects are rare and typically mild, primarily involving gastrointestinal discomfort such as stomach upset or diarrhea. No significant drug interactions or contraindications have been consistently reported in clinical studies. While data on its use during pregnancy are limited, one study on pregnancy-induced edema reported no adverse effects. However, due to the lack of extensive research, pregnant and breastfeeding individuals should consult a healthcare professional before use. There are no known severe adverse reactions associated with bilberry extract when used within recommended dosages. Long-term safety has been demonstrated in trials lasting up to 24 weeks, with no major adverse effects observed. Individuals with known allergies to plants in the Ericaceae family (which includes blueberries and cranberries) should exercise caution.
Dosage
Effective dosages of standardized bilberry extract in clinical studies typically range from 140 mg to 1400 mg daily. The extract is often standardized to contain 25-36% anthocyanins, which is an important factor in determining the appropriate dose. The duration of supplementation in studies has varied from 4 weeks to 24 weeks or longer, with benefits often observed after several weeks of consistent use. Optimal dosing can depend on the specific extract standardization and the desired therapeutic outcome; higher doses may be required for more pronounced metabolic effects. The timing of supplementation relative to meals is not well-established, but it may influence absorption. There are no clearly defined upper limits or safety thresholds beyond the doses used in clinical trials, but adherence to recommended dosages is advised.
FAQs
Is bilberry extract effective for diabetes?
Evidence suggests potential modest benefits in lowering HbA1c and postprandial glucose, especially in type 2 diabetes, but results are mixed and not definitive across all studies.
Can bilberry improve cholesterol?
Meta-analyses support modest reductions in total and LDL cholesterol, indicating a potential benefit for lipid profiles, particularly in individuals with metabolic disorders.
Is it safe long term?
Current evidence indicates a good safety profile with no major adverse effects reported in trials lasting up to 24 weeks, suggesting it is safe for short to medium-term use.
Does it improve vision?
Animal studies show promise for improving retinal function and delaying myopia progression, but robust human clinical evidence specifically for vision improvement is currently lacking.
Research Sources
- https://academy.miloa.eu/wp-content/uploads/2020/06/C.-Ulbricht-G.-N.-Papaliodis-al-2009.pdf – This systematic review provides a comprehensive overview of bilberry's efficacy and safety. It concludes that bilberry is generally safe with no major adverse effects reported, but notes that the quality of included studies varies, with some being small or uncontrolled.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8156535/ – This critical review of randomized controlled trials (RCTs) suggests that bilberry extract can lower HbA1c, total cholesterol, and LDL cholesterol. It highlights that effects are stronger in populations with metabolic disorders and points to heterogeneity in study populations and doses as limitations.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC9277355/ – This narrative review focuses on clinical trials in type 2 diabetes patients, reporting mixed results on glycemic control. It suggests that saccharide-free extracts may be more effective and notes that some trials showed no significant effect, often due to small sample sizes or variability in extract types.
- https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2024.1502612/full – This animal RCT on guinea pigs found that a combination of DHA and bilberry extract was more effective than either alone in delaying myopia progression. While demonstrating high internal validity for an animal study, its direct applicability to humans is limited.
- https://onlinelibrary.wiley.com/doi/10.1002/ptr.70054 – This meta-analysis of multiple RCTs indicates that bilberry modestly improves lipid profiles and inflammatory markers. It provides a quantitative synthesis of data, acknowledging some heterogeneity among studies and the possibility of publication bias.