Bilberry

The dried, ripe fruit is the traditional remedy. It is taken as a decoction for diarrhoea and used as a gargle and mouthwash for mild inflammation of the mouth and throat ^{38Reference 38Committee on Herbal Medicinal Products · 2015ReviewAssessment report on Vaccinium myrtillus L., fructus recens and Vaccinium myrtillus L., fructus siccus — regulatory reviewView study →}.

The dried fruit contains at least 1% tannins. Their astringent action is the accepted basis for both uses, which the European Medicines Agency recognises as traditional herbal medicine ^{37,38Reference 37Committee on Herbal Medicinal Products · 2015ReviewEuropean Union herbal monograph on Vaccinium myrtillus L., fructus siccus (dried bilberry fruit) — regulatory monographView study →Reference 38Committee on Herbal Medicinal Products · 2015ReviewAssessment report on Vaccinium myrtillus L., fructus recens and Vaccinium myrtillus L., fructus siccus — regulatory reviewView study →}.

Fresh-fruit preparations are used for heavy, uncomfortable legs caused by minor venous circulation problems and for fragile skin capillaries ^{36Reference 36Committee on Herbal Medicinal Products · 2015ReviewEuropean Union herbal monograph on Vaccinium myrtillus L., fructus recens (fresh bilberry fruit) — regulatory monographView study →}.

Older herbal handbooks also list the dried fruit for dysentery, haemorrhoids, gastrointestinal inflammation, mouth infections, scurvy and urinary complaints ^{38Reference 38Committee on Herbal Medicinal Products · 2015ReviewAssessment report on Vaccinium myrtillus L., fructus recens and Vaccinium myrtillus L., fructus siccus — regulatory reviewView study →}.

Across its range the berry is a food first. It is gathered in quantity for preserves, pies and cordials.

Bilberry leaf has its own tradition. Infusions of the leaf have been used for centuries in several European countries as a folk treatment for diabetes ^{28,33Reference 28Cignarella A et al et al. · 1996AnimalNovel lipid-lowering properties of Vaccinium myrtillus L. leaves, a traditional antidiabetic treatment, in rat dyslipidaemia — animal modelView study →Reference 33Ștefănescu R et al et al. · 2022Systematic reviewAn updated systematic review of Vaccinium myrtillus leaves: phytochemistry and pharmacology — systematic reviewView study →}.

In the same tradition, the leaf’s value for diabetes has been linked to its chromium content ^{33Reference 33Ștefănescu R et al et al. · 2022Systematic reviewAn updated systematic review of Vaccinium myrtillus leaves: phytochemistry and pharmacology — systematic reviewView study →}.

In a structure–activity study of 15 purified bilberry anthocyanins, superoxide scavenging ran in the order delphinidin > petunidin > malvidin ≈ cyanidin > peonidin. The mixture showed synergy between its anthocyanins ^{15Reference 15Rahman MM et al et al. · 2006In vitroSuperoxide radical- and peroxynitrite-scavenging activity of anthocyanins; structure-activity relationship and their synergism — in vitroView study →}.

Total phenolic content and antioxidant activity vary with season and plant part ^{34Reference 34Bujor OC et al et al. · 2016Seasonal variations of the phenolic constituents in bilberry (Vaccinium myrtillus L.) leaves, stems and fruits, and their antioxidant activity — analytical studyView study →}.

In people, anthocyanin bioavailability is low. They reach the circulation mainly as glucuronides, and more degradation products than intact anthocyanins appear in the blood ^{29Reference 29Mueller D et al et al. · 2017Clinical trialHuman intervention study to investigate the intestinal accessibility and bioavailability of anthocyanins from bilberries — clinical studyView study →}. About 30% of the ingested anthocyanins survived passage through the small intestine, and the colon is a significant site of absorption ^{29Reference 29Mueller D et al et al. · 2017Clinical trialHuman intervention study to investigate the intestinal accessibility and bioavailability of anthocyanins from bilberries — clinical studyView study →}.

Encapsulating bilberry extract in whey protein changed short-term bioavailability, and citrus-pectin encapsulation raised the amount reaching the end of the small intestine ^{30Reference 30Mueller D et al et al. · 2018Clinical trialEncapsulation of anthocyanins from bilberries — effects on bioavailability and intestinal accessibility in humans — clinical studyView study →}.

Gap: The measured antioxidant potency belongs to isolated anthocyanins at concentrations the whole fruit does not reach in blood ^{15,29,30Reference 15Rahman MM et al et al. · 2006In vitroSuperoxide radical- and peroxynitrite-scavenging activity of anthocyanins; structure-activity relationship and their synergism — in vitroView study →Reference 29Mueller D et al et al. · 2017Clinical trialHuman intervention study to investigate the intestinal accessibility and bioavailability of anthocyanins from bilberries — clinical studyView study →Reference 30Mueller D et al et al. · 2018Clinical trialEncapsulation of anthocyanins from bilberries — effects on bioavailability and intestinal accessibility in humans — clinical studyView study →}.

A standardised anthocyanoside preparation (25% anthocyanidins) reduced chemically induced skin-capillary permeability in rabbits and rats, by mouth and by injection. It was about twice as active as rutin and inhibited carrageenan paw oedema in a dose-dependent way ^{8Reference 8Lietti A et al. · 1976AnimalStudies on Vaccinium myrtillus anthocyanosidesView study →}.

In rats given 12 days of treatment before hypertension was induced, the anthocyanosides kept the blood–brain barrier normal and limited permeability rises in the skin and aortic wall. The authors linked this to interaction with vascular-wall collagen ^{9Reference 9Detre Z et al et al. · 1986AnimalStudies on vascular permeability in hypertension: action of anthocyanosides — rat modelView study →}.

Injected anthocyanosides promoted arteriolar vasomotion in hamsters ^{10Reference 10Colantuoni A et al et al. · 1991AnimalEffects of Vaccinium myrtillus anthocyanosides on arterial vasomotion — hamster in vivoView study →}. An extract added to the diet protected hamster pial microcirculation during hypoperfusion and reperfusion ^{11Reference 11Mastantuono T et al et al. · 2016AnimalThe effects of Vaccinium myrtillus extract on hamster pial microcirculation during hypoperfusion-reperfusion injury — in vivo animal modelView study →}.

Human data come from multi-ingredient products. A venotonic formula containing bilberry improved chronic venous insufficiency signs against compression stockings ^{12Reference 12Cesarone MR et al et al. · 2008Clinical trialLinfavenix: improvement of signs and symptoms of chronic venous insufficiency and microangiopathy — controlled clinical studyView study →}, and a diosmin, hesperidin, Centella, grape and bilberry compound was studied retrospectively in grade II–III haemorrhoids ^{13Reference 13Gravina AG et al et al. · 2021Efficacy and safety of a compound of micronized flavonoids with vitamin C and extracts of Centella asiatica, Vaccinium myrtillus and Vitis vinifera in hemorrhoidal disease — retrospective studyView study →}.

The European Medicines Agency accepts fresh-fruit extract for minor venous circulatory problems and capillary fragility on the basis of long-standing use ^{36Reference 36Committee on Herbal Medicinal Products · 2015ReviewEuropean Union herbal monograph on Vaccinium myrtillus L., fructus recens (fresh bilberry fruit) — regulatory monographView study →}.

Gap: The human venous and capillary data test bilberry only inside combination products, so its standalone effect in people is not measured ^{12,13Reference 12Cesarone MR et al et al. · 2008Clinical trialLinfavenix: improvement of signs and symptoms of chronic venous insufficiency and microangiopathy — controlled clinical studyView study →Reference 13Gravina AG et al et al. · 2021Efficacy and safety of a compound of micronized flavonoids with vitamin C and extracts of Centella asiatica, Vaccinium myrtillus and Vitis vinifera in hemorrhoidal disease — retrospective studyView study →}.

Bilberry anthocyanins suppress inflammatory signalling in cell and animal models, lowering TNF-α, IL-6 and IL-1β and modulating NF-κB and COX ^{14Reference 14Sharma A et al. · 2022ReviewAnti-inflammatory activity of bilberry (Vaccinium myrtillus L.) — reviewView study →}. A review of clinical studies in metabolic disorders reported lower inflammatory markers with bilberry in most of them ^{14Reference 14Sharma A et al. · 2022ReviewAnti-inflammatory activity of bilberry (Vaccinium myrtillus L.) — reviewView study →}.

In dextran-sulfate colitis in mice, dried bilberries and their anthocyanins reduced disease severity and IFN-γ and TNF secretion ^{7Reference 7Piberger H et al et al. · 2011AnimalBilberries and their anthocyanins ameliorate experimental colitis — mouse modelView study →}. In people, a 2025 meta-analysis found no significant change in hs-CRP or IL-6 ^{2Reference 2Talebi S et al et al. · 2025Meta-analysisInvestigating the effects of Vaccinium myrtillus supplementation on cardiometabolic indices — systematic review and meta-analysis of randomised controlled trialsView study →}.

Gap: The clearest anti-inflammatory results are local to the gut, where anthocyanin concentrations are high. A systemic effect in people has not been shown ^{2,29Reference 2Talebi S et al et al. · 2025Meta-analysisInvestigating the effects of Vaccinium myrtillus supplementation on cardiometabolic indices — systematic review and meta-analysis of randomised controlled trialsView study →Reference 29Mueller D et al et al. · 2017Clinical trialHuman intervention study to investigate the intestinal accessibility and bioavailability of anthocyanins from bilberries — clinical studyView study →}.

A 2025 meta-analysis of randomised trials (11 trials with 409 participants, 8 of them pooled) found a non-significant fall in fasting glucose. HbA1c fell by a borderline amount across three trials (WMD −1.63%, 95% CI −3.36 to +0.11, p = 0.06) ^{2Reference 2Talebi S et al et al. · 2025Meta-analysisInvestigating the effects of Vaccinium myrtillus supplementation on cardiometabolic indices — systematic review and meta-analysis of randomised controlled trialsView study →}.

Total cholesterol and triglycerides did not change significantly overall, though triglycerides fell in crossover trials and trials of four weeks or less. LDL cholesterol rose slightly (WMD +0.07 mmol/L) ^{2Reference 2Talebi S et al et al. · 2025Meta-analysisInvestigating the effects of Vaccinium myrtillus supplementation on cardiometabolic indices — systematic review and meta-analysis of randomised controlled trialsView study →}.

An earlier review of four bilberry-and-blackcurrant trials reported lower HbA1c, at least in Chinese participants, and lower total and LDL cholesterol after four weeks ^{3Reference 3Grohmann T et al et al. · 2021Systematic reviewEfficacy of bilberry and grape seed extract supplement interventions to improve glucose and cholesterol metabolism and blood pressure in different populations — systematic reviewView study →}.

A single 0.47 g dose of extract (36% anthocyanins, about 50 g of fresh berries) lowered the post-load glucose and insulin response in eight men with diet-controlled type 2 diabetes. Incretin hormones did not change, and the authors attributed the effect to slower carbohydrate digestion or absorption ^{4Reference 4Hoggard N et al et al. · 2013RCTA single supplement of a standardised bilberry (Vaccinium myrtillus L.) extract (36% wet-weight anthocyanins) modifies glycaemic response in individuals with type 2 diabetes — randomised crossover trialView study →}.

In people with features of the metabolic syndrome, a bilberry-rich diet raised fasting hippuric acid 3.5-fold, and the rise tracked better fasting glucose ^{5Reference 5de Mello VD et al et al. · 2017RCTFasting serum hippuric acid is elevated after bilberry consumption and associates with improvement of fasting glucose and insulin secretion in persons at high risk of type 2 diabetes — randomised controlled trialView study →}.

The traditional antidiabetic preparation is the leaf. A leaf extract lowered plasma glucose by about 26% and triglycerides by 39% in diabetic rats ^{28Reference 28Cignarella A et al et al. · 1996AnimalNovel lipid-lowering properties of Vaccinium myrtillus L. leaves, a traditional antidiabetic treatment, in rat dyslipidaemia — animal modelView study →}.

Gap: The pooled effect on glucose is not significant, the HbA1c signal is borderline, and the LDL result in the 2025 meta-analysis runs the wrong way ^{2,3Reference 2Talebi S et al et al. · 2025Meta-analysisInvestigating the effects of Vaccinium myrtillus supplementation on cardiometabolic indices — systematic review and meta-analysis of randomised controlled trialsView study →Reference 3Grohmann T et al et al. · 2021Systematic reviewEfficacy of bilberry and grape seed extract supplement interventions to improve glucose and cholesterol metabolism and blood pressure in different populations — systematic reviewView study →}.

A multicentre, randomised, double-blind, placebo-controlled trial tested an anthocyanin-rich bilberry extract in moderate-to-severe ulcerative colitis. It stopped early during the COVID-19 pandemic, randomising 34 of a planned 100 patients ^{6Reference 6Biedermann L et al et al. · 2024RCTEfficacy and safety of anthocyanin-rich extract in patients with ulcerative colitis — randomised controlled trialView study →}.

⚠ The primary endpoint was missed. Clinical response at week 8 was 9 of 18 on the extract and 3 of 8 on placebo (p = 0.278), and the authors reported an unusually high placebo response ^{6Reference 6Biedermann L et al et al. · 2024RCTEfficacy and safety of anthocyanin-rich extract in patients with ulcerative colitis — randomised controlled trialView study →}.

Faecal calprotectin fell on the extract (from 1,049 to 557 μg/g) but not on placebo (p = 0.035). Serious adverse events were rare ^{6Reference 6Biedermann L et al et al. · 2024RCTEfficacy and safety of anthocyanin-rich extract in patients with ulcerative colitis — randomised controlled trialView study →}.

This builds on work in mice, where dried bilberries and their anthocyanins improved acute and chronic DSS colitis ^{7Reference 7Piberger H et al et al. · 2011AnimalBilberries and their anthocyanins ameliorate experimental colitis — mouse modelView study →}.

Gap: The one controlled trial was underpowered and did not show clinical superiority over placebo, so the effect in ulcerative colitis is not established ^{6Reference 6Biedermann L et al et al. · 2024RCTEfficacy and safety of anthocyanin-rich extract in patients with ulcerative colitis — randomised controlled trialView study →}.

The night-vision claim has been tested directly. A systematic review found 12 placebo-controlled trials; the four most recent were randomised and all negative in people with normal or above-average eyesight ^{1Reference 1Canter PH et al. · 2004Systematic reviewAnthocyanosides of Vaccinium myrtillus (bilberry) for night vision — a systematic review of placebo-controlled trials — systematic reviewView study →}. The same review found no rigorous research in people whose night vision is impaired by eye disease ^{1Reference 1Canter PH et al. · 2004Systematic reviewAnthocyanosides of Vaccinium myrtillus (bilberry) for night vision — a systematic review of placebo-controlled trials — systematic reviewView study →}.

The positive human data address a different outcome, eye fatigue. Extract at 480 mg/day for 8 weeks reduced screen-induced fatigue symptoms and one objective measure in office workers ^{16Reference 16Ozawa Y et al et al. · 2015RCTBilberry extract supplementation for preventing eye fatigue in video display terminal workers — randomised controlled trialView study →}. Extract at 240 mg/day for 12 weeks improved ciliary-muscle accommodation after screen work ^{17Reference 17Kosehira M et al. · 2020RCTA 12-week intake of standardised bilberry extract improved objective ciliary-muscle contraction — randomised controlled trialView study →}.

Retinal-protection data are preclinical. Extract preserved photoreceptor function in endotoxin-induced uveitis in mice ^{21Reference 21Miyake S et al et al. · 2012AnimalVision preservation during retinal inflammation by anthocyanin-rich bilberry extract: cellular and molecular mechanism — mouse modelView study →}, and reduced blood–retinal-barrier breakdown and VEGF in diabetic rats ^{20Reference 20Kim J et al et al. · 2015AnimalVaccinium myrtillus extract prevents or delays the onset of diabetes-induced blood-retinal barrier breakdown — rat modelView study →}.

Trials in age-related macular degeneration ^{19Reference 19Parravano M et al et al. · 2019RCTEffects of Macuprev supplementation in age-related macular degeneration — double-blind randomised studyView study →} and presbyopia ^{18Reference 18Szumny D et al et al. · 2026RCTStandardised berry extract improves selected visual-function outcomes in presbyopia — randomised controlled crossover trialView study →} used multi-ingredient formulas, so they cannot attribute benefit to bilberry.

Gap: Night vision is not supported by rigorous trials ^{1Reference 1Canter PH et al. · 2004Systematic reviewAnthocyanosides of Vaccinium myrtillus (bilberry) for night vision — a systematic review of placebo-controlled trials — systematic reviewView study →}, and the AMD and presbyopia trials test combination products ^{18,19Reference 18Szumny D et al et al. · 2026RCTStandardised berry extract improves selected visual-function outcomes in presbyopia — randomised controlled crossover trialView study →Reference 19Parravano M et al et al. · 2019RCTEffects of Macuprev supplementation in age-related macular degeneration — double-blind randomised studyView study →}.

In a Western-diet mouse model of non-alcoholic fatty liver disease, bilberry anthocyanins lowered ALT, AST, LDL cholesterol and liver fat. They also reduced the Firmicutes/Bacteroidetes ratio and increased Akkermansia ^{22Reference 22Nakano H et al et al. · 2020AnimalBilberry anthocyanins ameliorate NAFLD by improving dyslipidemia and gut-microbiome dysbiosis — mouse modelView study →}.

In rats fed a high-AGE diet for 80 weeks, European bilberry extract reduced steatohepatitis, with more short-chain-fatty-acid-producing bacteria and suppression of the HMGB1/RAGE/NF-κB pathway ^{23Reference 23Shen L et al et al. · 2025AnimalEuropean bilberry extract ameliorates dietary AGE-induced non-alcoholic steatohepatitis in rats via gut microbiota and its metabolites — rat modelView study →}.

Gap: No human data exist for any liver endpoint ^{22,23Reference 22Nakano H et al et al. · 2020AnimalBilberry anthocyanins ameliorate NAFLD by improving dyslipidemia and gut-microbiome dysbiosis — mouse modelView study →Reference 23Shen L et al et al. · 2025AnimalEuropean bilberry extract ameliorates dietary AGE-induced non-alcoholic steatohepatitis in rats via gut microbiota and its metabolites — rat modelView study →}.

A systematic review of Vaccinium berries and digestive-tract cancers found that 21 of 26 studies concerned bilberry and colorectal cancer. Experimental data showed inhibition of intestinal tumour formation and cancer-cell growth, and one uncontrolled human pilot suggested reduced colorectal cell proliferation ^{24Reference 24Onali T et al et al. · 2021Systematic reviewAnticancer effects of lingonberry and bilberry on digestive-tract cancers — systematic reviewView study →}.

In azoxymethane-treated rats, an anthocyanin-rich bilberry extract reduced aberrant crypt foci, colonic cell proliferation and COX-2 expression ^{25Reference 25Lala G et al et al. · 2006AnimalAnthocyanin-rich extracts inhibit multiple biomarkers of colon cancer in rats — animal modelView study →}.

Anthocyanins and their degradation products persist through the gut, so the colon is exposed to far higher concentrations than the blood ^{29Reference 29Mueller D et al et al. · 2017Clinical trialHuman intervention study to investigate the intestinal accessibility and bioavailability of anthocyanins from bilberries — clinical studyView study →}.

Gap: Human evidence is limited to one small uncontrolled pilot ^{24Reference 24Onali T et al et al. · 2021Systematic reviewAnticancer effects of lingonberry and bilberry on digestive-tract cancers — systematic reviewView study →}.

In a rat traumatic-brain-injury model, Vaccinium myrtillus anthocyanin lowered brain malondialdehyde and cleaved caspase-3, although tissue damage looked similar to untreated animals ^{26Reference 26Ozdemir A et al et al. · 2023AnimalNeuroprotective effects of Vaccinium myrtillus on damage-related brain injury — rat modelView study →}.

In Alzheimer’s-disease mice, a diet with 1% bilberry anthocyanoside prevented cognitive decline. It did not reduce amyloid deposits, which increased, apparently in a less toxic form ^{27Reference 27Yamakawa MY et al et al. · 2016In vitroAnthocyanin suppresses the toxicity of Aβ deposits in in vitro and in vivo models of Alzheimer’s disease — animal and cell modelView study →}.

Gap: No human data; the effect rests on isolated rodent and cell models ^{26,27Reference 26Ozdemir A et al et al. · 2023AnimalNeuroprotective effects of Vaccinium myrtillus on damage-related brain injury — rat modelView study →Reference 27Yamakawa MY et al et al. · 2016In vitroAnthocyanin suppresses the toxicity of Aβ deposits in in vitro and in vivo models of Alzheimer’s disease — animal and cell modelView study →}.

The fruit. Bilberries are eaten in quantity across northern Europe. The European Medicines Agency lists no known undesirable effects and no reported interactions for either the dried fruit or the fresh-fruit extract ^{36,37Reference 36Committee on Herbal Medicinal Products · 2015ReviewEuropean Union herbal monograph on Vaccinium myrtillus L., fructus recens (fresh bilberry fruit) — regulatory monographView study →Reference 37Committee on Herbal Medicinal Products · 2015ReviewEuropean Union herbal monograph on Vaccinium myrtillus L., fructus siccus (dried bilberry fruit) — regulatory monographView study →}. The ulcerative colitis trial reported serious adverse events as rare, and the eye-fatigue trial reported none that were severe ^{6,16Reference 6Biedermann L et al et al. · 2024RCTEfficacy and safety of anthocyanin-rich extract in patients with ulcerative colitis — randomised controlled trialView study →Reference 16Ozawa Y et al et al. · 2015RCTBilberry extract supplementation for preventing eye fatigue in video display terminal workers — randomised controlled trialView study →}.

Age limits. The EMA does not recommend dried-fruit products under 12 years, or the fresh-fruit extract under 18, for lack of data ^{36,37Reference 36Committee on Herbal Medicinal Products · 2015ReviewEuropean Union herbal monograph on Vaccinium myrtillus L., fructus recens (fresh bilberry fruit) — regulatory monographView study →Reference 37Committee on Herbal Medicinal Products · 2015ReviewEuropean Union herbal monograph on Vaccinium myrtillus L., fructus siccus (dried bilberry fruit) — regulatory monographView study →}.

When to see a doctor. For leg symptoms, the EMA advises seeing a doctor if there is skin inflammation, thrombophlebitis, hardening under the skin, severe pain, ulcers, sudden swelling of one or both legs, or heart or kidney failure ^{36Reference 36Committee on Herbal Medicinal Products · 2015ReviewEuropean Union herbal monograph on Vaccinium myrtillus L., fructus recens (fresh bilberry fruit) — regulatory monographView study →}. Diarrhoea lasting longer than 3 days also needs medical advice ^{37Reference 37Committee on Herbal Medicinal Products · 2015ReviewEuropean Union herbal monograph on Vaccinium myrtillus L., fructus siccus (dried bilberry fruit) — regulatory monographView study →}.

Blood thinners and glucose-lowering drugs. Bilberry anthocyanins have antiplatelet activity, so chronic high doses of concentrated extract taken with antiplatelet drugs call for monitoring for bleeding ^{32Reference 32Chan SW et al. · 2020ReviewEffects of bilberry supplementation on metabolic and cardiovascular disease risk — reviewView study →}. Extracts also lower post-meal glucose, which may add to glucose-lowering medication ^{4Reference 4Hoggard N et al et al. · 2013RCTA single supplement of a standardised bilberry (Vaccinium myrtillus L.) extract (36% wet-weight anthocyanins) modifies glycaemic response in individuals with type 2 diabetes — randomised crossover trialView study →}. Neither interaction has been tested directly.

The leaf. Bilberry leaves contain no toxic compounds as such. Their tannins can cause constipation and, with long-term use, reduce the absorption of iron and other nutrients, which matters most for children, the elderly and pregnant women ^{33Reference 33Ștefănescu R et al et al. · 2022Systematic reviewAn updated systematic review of Vaccinium myrtillus leaves: phytochemistry and pharmacology — systematic reviewView study →}. A leaf extract showed weak mutagenic activity in the Ames test ^{38Reference 38Committee on Herbal Medicinal Products · 2015ReviewAssessment report on Vaccinium myrtillus L., fructus recens and Vaccinium myrtillus L., fructus siccus — regulatory reviewView study →}. Near a copper-nickel smelter, bilberry leaves carried higher levels of toxic metals than the berries did ^{35Reference 35Eeva T et al et al. · 2018Leaves, berries and herbivorous larvae of bilberry Vaccinium myrtillus as sources of metals in food chains at a Cu-Ni smelter site — field studyView study →}.

Quality. Commercial extracts are frequently adulterated with other anthocyanin sources or synthetic dye, so a stated anthocyanin percentage does not confirm the plant ^{41,42Reference 41Gardana et al. · 2014Bilberry adulteration: identification and chemical profiling of anthocyanins by different analytical methods — analyticalView study →Reference 42Penman et al. · 2006Bilberry adulteration using the food dye amaranth — analyticalView study →}.