Cross-referencing clinical data
A pairing appears on this page only when a trial gave both ingredients together and measured the result. Bog Bilberry has none that clears that bar.
Stitching two separate single-ingredient studies into a pairing is the one thing this engine will not do. When a study of the combination itself holds up at source, it lands here with its citation.
No invented synergy. Where actives were studied on their own rather than together, the record shows each on its own evidence, never a combined effect no trial measured.
Research strength. Research strength says how much work stands behind the combination. It is never a product score.
Independent record. Every finding is cited to a named trial, dated, and never written by the brand.
20 pairings are live across the library today. Checked 20 July 2026.
No study gave these as a pair, so they are not in the card above. But the reason they belong together is settled biochemistry, not a guess, so it is worth knowing.
Anthocyanins hold their coloured flavylium form only at acidic pH and shift to colourless or degraded species as pH rises. Ascorbate keeps a formulation acidic, which preserves the pigment in the product. The relationship is well established in food chemistry, though ascorbate can also accelerate anthocyanin loss in the presence of oxygen and copper.
Lutein concentrates in the macular pigment while anthocyanins circulate briefly and do not accumulate in the retina. Because they occupy different compartments, pairing them in an eye formula adds coverage rather than duplicating it. The rationale is anatomical and the combination has not been isolated in a controlled comparison.
Zeaxanthin, like lutein, deposits in the macula through a specific binding protein, which anthocyanins do not use. That difference is exactly why the two classes appear together in eye products. Regard the pairing as complementary chemistry rather than as a tested combination.
Berry polyphenols, including the tannins and anthocyanins in Vaccinium fruit, bind non-heme iron in the gut lumen and reduce the fraction absorbed. This is the same chemistry behind tea's effect on iron uptake. Anyone building iron status should separate a berry extract from an iron dose.
Quercetin glycosides occur naturally alongside anthocyanins in Vaccinium fruit, so a whole-fruit extract already contains both. Given together as supplements they compete for the same intestinal and hepatic conjugating enzymes, which raises circulating levels of each. That is a pharmacokinetic point, not an efficacy claim.
Tocopherol works within the lipid membrane while anthocyanins act in the aqueous phase, and aqueous phenolics can regenerate the tocopheroxyl radical back to tocopherol in vitro. The chemistry is well characterised in model systems. Whether it translates to a measurable effect in people has not been shown.
Most ingested anthocyanins reach the colon intact, where gut bacteria cleave them into phenolic acids such as protocatechuic acid that are absorbed far better than the parent pigments. Gut composition therefore shapes what a person actually gets from a berry extract. This is a mechanism, and no probiotic strain has been shown to change berry outcomes in people.
Both materials carry proanthocyanidins alongside their signature compounds, so a combined product duplicates part of the profile rather than extending it. The distinct part is the anthocyanin fraction in the berry. Formulators pairing them should count the total polyphenol load rather than assuming the two contributions are separate.
Anthocyanins and proanthocyanidins bind proline-rich proteins, which is why berry extracts lose colour and astringency when mixed into a protein shake. The bound complex changes what is available for absorption in the upper gut. This is a practical formulation limit rather than a safety issue.
Nothing specific on file for Bog Bilberry. Match the label to the daily amount above, and tell your doctor what you take.
Not medical advice. Show the label to your pharmacist.These are the studies our verdict leans on, chosen from the 3 we read for Bog Bilberry. The full linked list is below.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement regimen.