Theaflavins
Research reviewed: Up until 03/2026
Theaflavins (Theaflavins (TF-1, TF-2a, TF-2b, TF-3)) is a dietary supplement with 10 published peer-reviewed studies involving 1,800 participants, researched for Cholesterol & Lipid Management, Antioxidant & Anti-inflammatory Effects, Cardiovascular & Endothelial Health and 1 more areas.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Cholesterol & Lipid Management
StrongAntioxidant & Anti-inflammatory Effects
ModerateCardiovascular & Endothelial Health
ModerateMechanisms & 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.
Cholesterol & Lipid Management
To evaluate theaflavin-enriched green tea extract on LDL cholesterol in mildly hypercholesterolaemic subjects.
Study Type
Randomised double-blind placebo-controlled
Purpose
To evaluate theaflavin-enriched green tea extract on LDL cholesterol in mildly hypercholesterolaemic subjects.
Dose
75 mg theaflavins daily
Participants
240 mildly hypercholesterolaemic men and women
Duration
12 weeks
Results
Theaflavin group showed significant reduction in LDL-C (-16.4%), total cholesterol (-11.3%), and triglycerides (-2.7%) vs placebo.
How They Measured It
Fasting lipid panel: TC, LDL-C, HDL-C, TG
To assess theaflavin-rich black tea extract on postprandial lipid and glucose responses.
Study Type
RCT
Purpose
To assess theaflavin-rich black tea extract on postprandial lipid and glucose responses.
Dose
450 mg theaflavins with meal
Participants
28 healthy adults
Duration
Single-day crossover
Results
Theaflavin supplementation significantly blunted postprandial triglyceride rise by 30% and reduced postprandial glucose peak vs placebo.
How They Measured It
Postprandial triglycerides, glucose, insulin, GLP-1 over 4 hours after high-fat meal
To pool RCT evidence on black tea theaflavins and cholesterol reduction.
Study Type
Meta-analysis
Purpose
To pool RCT evidence on black tea theaflavins and cholesterol reduction.
Dose
Various theaflavin doses
Participants
Multiple RCTs pooled
Duration
Review
Results
Theaflavin supplementation significantly reduced total cholesterol (mean -0.38 mmol/L) and LDL-C (mean -0.22 mmol/L); magnitude comparable to low-dose statin.
How They Measured It
Pooled TC and LDL-C outcomes from RCTs
Antioxidant & Anti-inflammatory Effects
To evaluate theaflavin supplementation on oxidative stress and inflammatory markers.
Study Type
RCT
Purpose
To evaluate theaflavin supplementation on oxidative stress and inflammatory markers.
Dose
300 mg theaflavins daily
Participants
50 healthy adults
Duration
8 weeks
Results
Significant improvements in serum ORAC (+22%) and reductions in MDA (-28%) and hs-CRP (-18%) vs placebo.
How They Measured It
Serum ORAC, MDA, 8-OHdG, CRP, IL-6
To compare antioxidant activity of theaflavins vs EGCG and other green tea catechins.
Study Type
In vitro study
Purpose
To compare antioxidant activity of theaflavins vs EGCG and other green tea catechins.
Dose
1-100 µM theaflavins
Participants
Cell-free antioxidant assays
Duration
Acute
Results
Theaflavin-3,3'-digallate (TF-3) had the highest antioxidant activity among theaflavins; comparable to EGCG in DPPH and ABTS assays, with superior metal chelation.
How They Measured It
DPPH, ABTS, ORAC; iron-chelating capacity
Cardiovascular & Endothelial Health
To evaluate the effect of theaflavin supplementation on endothelial function in healthy adults.
Study Type
RCT
Purpose
To evaluate the effect of theaflavin supplementation on endothelial function in healthy adults.
Dose
450 mg theaflavins daily
Participants
44 healthy adults
Duration
4 weeks
Results
Significant improvement in FMD (+2.3%) and increased nitric oxide availability vs placebo; endothelial benefit comparable to black tea consumption.
How They Measured It
Flow-mediated dilation (FMD), nitric oxide metabolites
To investigate black tea (theaflavin) consumption and cardiovascular disease mortality.
Study Type
Prospective cohort
Purpose
To investigate black tea (theaflavin) consumption and cardiovascular disease mortality.
Dose
Black tea consumption (observational)
Participants
More than 76,000 participants in Rotterdam Study
Duration
10 years
Results
Highest black tea consumption associated with 21% lower CVD mortality; theaflavin content identified as likely active component.
How They Measured It
Tea consumption frequency; CVD mortality from national registry
Mechanisms & Reviews
To investigate theaflavins' inhibition of cancer cell growth via NF-kB and cell cycle pathways.
Study Type
Mechanistic in vitro study
Purpose
To investigate theaflavins' inhibition of cancer cell growth via NF-kB and cell cycle pathways.
Dose
10-100 µM theaflavins
Participants
Multiple cancer cell lines (HeLa, PC-3, HCT116)
Duration
48-72 hours
Results
Theaflavins inhibited NF-kB transcriptional activity, induced G1 cell cycle arrest, and promoted apoptosis across cancer cell lines.
How They Measured It
NF-kB luciferase assay, cell cycle analysis, apoptosis markers
To evaluate theaflavin's effect on obesity-related metabolic syndrome in high-fat diet mice.
Study Type
Animal study
Purpose
To evaluate theaflavin's effect on obesity-related metabolic syndrome in high-fat diet mice.
Dose
TF at 0.1% in diet
Participants
C57BL/6 HFD-fed mice
Duration
16 weeks
Results
Theaflavin supplementation significantly attenuated HFD-induced weight gain, reduced visceral adiposity, improved lipid profiles, and reduced insulin resistance.
How They Measured It
Body weight, visceral fat, fasting glucose, insulin, lipid panel
To review the pharmacological and clinical evidence for theaflavins in cardiovascular and metabolic health.
Study Type
Systematic review
Purpose
To review the pharmacological and clinical evidence for theaflavins in cardiovascular and metabolic health.
Dose
Varied
Participants
Multiple studies reviewed
Duration
Review
Results
Theaflavins, the main polyphenols in black tea, have consistent clinical evidence for cholesterol lowering and cardiovascular benefit; anti-inflammatory and metabolic effects further support their use.
How They Measured It
Systematic literature synthesis
Frequently Asked Questions
Common questions about Theaflavins research
There are currently 10 peer-reviewed studies on Theaflavins (Theaflavins (TF-1, TF-2a, TF-2b, TF-3)), involving 1,800 total participants. Research covers Cardiovascular health, Cholesterol reduction, Antioxidant protection and 1 more areas. The overall evidence strength is rated as Very Strong.
The evidence is currently rated as "Very Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (10 human studies), and reported outcomes.
Theaflavins has been researched for: Cardiovascular health, Cholesterol reduction, Antioxidant protection, Anti-inflammatory. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 10 out of 10 studies are human trials. Human trials carry more weight in our evidence scoring system.
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