Thearubigins
Research reviewed: Up until 03/2026
Thearubigins (Thearubigins (heterogeneous black tea polyphenols)) is a dietary supplement with 8 published peer-reviewed studies involving 5,942 participants, researched for Cardiovascular Health & Cholesterol, Antioxidant Properties, Gut Health & Microbiome Effects and 1 more areas.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Cardiovascular Health & Cholesterol
ModerateAntioxidant Properties
ModerateGut Health & Microbiome Effects
ModerateAnti-inflammatory & Reviews
ModerateResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Cardiovascular Health & Cholesterol
To evaluate black tea consumption (thearubigin-rich) on cardiovascular risk biomarkers.
Study Type
RCT
Purpose
To evaluate black tea consumption (thearubigin-rich) on cardiovascular risk biomarkers.
Dose
5 cups black tea daily (600 mg thearubigins estimated)
Participants
50 adults with borderline high cholesterol
Duration
4 weeks
Results
Black tea consumption produced significant reductions in LDL-C (-7%) and improvements in FMD; platelet aggregation decreased vs water control.
How They Measured It
Serum lipids, CRP, fibrinogen, platelet aggregation
To investigate black tea consumption and stroke risk in a Dutch cohort.
Study Type
Prospective cohort
Purpose
To investigate black tea consumption and stroke risk in a Dutch cohort.
Dose
Tea consumption (observational)
Participants
4807 Dutch adults in Rotterdam Study
Duration
15 years follow-up
Results
Highest black tea intake associated with 29% lower stroke risk; association stronger for ischaemic stroke; thearubigins cited as likely bioactive.
How They Measured It
Tea intake FFQ; stroke incidence from national registry
Antioxidant Properties
To characterise the antioxidant capacity of thearubigins relative to theaflavins and catechins.
Study Type
In vitro comparative study
Purpose
To characterise the antioxidant capacity of thearubigins relative to theaflavins and catechins.
Dose
0.05-1 mg/mL thearubigins
Participants
Cell-free assay
Duration
Acute
Results
Thearubigins showed high aggregate ORAC values and potent lipid peroxidation inhibition; lower per-molecule potency than theaflavins but substantially higher in mass terms due to complex polymerisation.
How They Measured It
DPPH, ORAC, iron chelation, lipid peroxidation inhibition
To assess plasma antioxidant status after black tea vs black tea polyphenol extract consumption.
Study Type
RCT
Purpose
To assess plasma antioxidant status after black tea vs black tea polyphenol extract consumption.
Dose
4 cups black tea daily vs thearubigin-enriched extract
Participants
40 healthy adults
Duration
4-week crossover
Results
Both black tea and thearubigin extract significantly increased plasma antioxidant capacity vs water; extract showed slightly higher and more sustained peak.
How They Measured It
Plasma ORAC, FRAP, ascorbate, uric acid over 4 hours
Gut Health & Microbiome Effects
To evaluate black tea polyphenol (thearubigin-rich) supplementation on gut microbiota composition.
Study Type
RCT
Purpose
To evaluate black tea polyphenol (thearubigin-rich) supplementation on gut microbiota composition.
Dose
700 mg black tea polyphenols daily
Participants
45 healthy adults
Duration
8 weeks
Results
Black tea polyphenols significantly increased Bifidobacterium and Lactobacillus spp. while reducing Clostridium perfringens; SCFA production enhanced.
How They Measured It
16S rRNA sequencing of faecal samples; short-chain fatty acid analysis
To investigate the fermentation of thearubigins by human gut microbiota and metabolite production.
Study Type
In vitro colonic fermentation study
Purpose
To investigate the fermentation of thearubigins by human gut microbiota and metabolite production.
Dose
Thearubigins at physiological concentrations
Participants
Human faecal batch fermentation model
Duration
24-48 hours
Results
Thearubigins were extensively fermented; produced numerous bioactive metabolites including hydroxyphenylpropionic acids with anti-inflammatory properties.
How They Measured It
HPLC metabolite profiling; microbiota composition by 16S; SCFA quantification
Anti-inflammatory & Reviews
To investigate black tea intake and markers of systemic inflammation in an elderly cohort.
Study Type
Observational study
Purpose
To investigate black tea intake and markers of systemic inflammation in an elderly cohort.
Dose
Tea consumption (observational)
Participants
1000+ adults aged 65+ in ESTHER cohort
Duration
Cross-sectional
Results
Regular black tea drinkers had significantly lower serum CRP and IL-6; thearubigin content linked to anti-inflammatory benefit.
How They Measured It
Serum CRP, IL-6, fibrinogen by FFQ and biobank
To review the health effects of thearubigins and their role in black tea's bioactivity.
Study Type
Systematic review
Purpose
To review the health effects of thearubigins and their role in black tea's bioactivity.
Dose
Varied
Participants
Multiple studies reviewed
Duration
Review
Results
Thearubigins constitute ~60-70% of black tea solids and contribute substantially to cardiovascular, antioxidant, and gut microbiome benefits; their chemical complexity makes isolation and standardisation challenging.
How They Measured It
Literature synthesis
Frequently Asked Questions
Common questions about Thearubigins research
There are currently 8 peer-reviewed studies on Thearubigins (Thearubigins (heterogeneous black tea polyphenols)), involving 5,942 total participants. Research covers Cardiovascular health, Antioxidant protection, Gut health and 1 more areas. The overall evidence strength is rated as Strong.
The evidence is currently rated as "Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (5 human studies), and reported outcomes.
Thearubigins has been researched for: Cardiovascular health, Antioxidant protection, Gut health, Anti-inflammatory. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 5 out of 8 studies are human trials. Human trials carry more weight in our evidence scoring system.
