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Theaflavins are a group of molecules that are found in black tea (due to an additional fermentation process from green tea) that are said to be the bioactives of black tea.

Our evidence-based analysis on theaflavins features 177 unique references to scientific papers.

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Summary of Theaflavins

Primary information, health benefits, side effects, usage, and other important details

Theaflavins are a group of molecules that are created from green tea catechins when heat treatment damages the catechin molecule and they begin to resynthesize in various configurations; Theaflavins are the product of two catechin molecules binding together on the C ring, and similar to catechins can come in various gallated forms (whether there is gallic acid molecules bound to them or not).

Currently, Theaflavins appear to have really poor oral bioavailability and absorption. For systemic effects after absorption, it is likely that the bioactivity of Theaflavins (which is present) is due to a metabolite that is not Theaflavins. For most evidence outside of the gastrointestinal tract (mouth to anus), the molecule of Theaflavins per se may not be relevant unless below the 1 nanomolar range.

For effects within the gastrointestinal tract, Theaflavins appear to have promising anti-ulceration and oral cavity health properties that should be active at the concentrations found in black tea. Either black tea or supplementation also appears to reduce the absorption of fatty acids, cholesterol, and starches from the intestinal tract which can reduce nutrient absorption quantities (and secondary to inhibiting starch absorption, there may be some probiotic effects similar to dietary fiber).

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How to Take

Recommended dosage, active amounts, other details

Theaflavins for purposes that do not require absorption (oral health, stomach ulceration, intestinal or colonic interactions) can have bioactivity in the doses found in Black Tea (this may also be advisable as the capsule of a supplement would need to break for it to influence the stomach or oral cavity)

There is currently no evidence to support the best oral dose of supplementation, although studies tend to use 700mg of Theaflavins once a day (this is said to be 30 cups of Black Tea, but that is a variable claim due to varying levels of Theaflavins in Black Tea to start)

Currently no evidence to support the best time of day or manner to take Theaflavin supplementation, although if using it for the purposes of hindering fat or carbohydrate absorption it would need to be taken alongside a meal containing those nutrients.

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Human Effect Matrix

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The Human Effect Matrix summarizes human studies to tell you what effects Theaflavins has on your body, how much evidence there is, and how strong these effects are.

Full details are available to Examine members.
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
grade-c Minor - See study
A decrease in exercise-induced cortisol secretions has been noted with theaflavin consumption in high doses (above 1,800mg daily)
grade-c Minor - See study
May decrease muscle soreness at high doses, with the efficacy of lower doses uncertain.
grade-c Minor - See study
An increase in power output on a Wingate test has been noted with theaflavins supplementation above 1,800mg daily; efficacy of lower doses is uncertain
grade-c - - See study
No significant influence of theaflavins on HDL-C
grade-c - - See study
No significant influence on inflammatory cytokines noted with theaflavins supplementation
grade-c - - See study
No detectable influence on LDL-C levels following theaflavin consumption
grade-c - - See study
No significant influence on total cholesterol levels with theaflavins supplementation
grade-c - - See study
No significant influence of theaflavins on triglycerides (hypercholesterolemic persons)

Studies Excluded from Consideration

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Things to Note

Do Not Confuse With

L-Theanine (a similar sounding compound also found in tea)

Goes Well With

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Click here to see all 177 references.