Green Tea Extract

    Researchedby:
    Katherine Nguyen

    Fact-checked

    by:

    Gregory Lopez
    Last Updated: October 13, 2024

    Green Tea extract contains phytochemicals, especially catechins like epigallocatechin gallate(EGCG) and caffeine. EGCG and caffeine have been shown to synergistically influence health indices, including body composition, but the contents within green tea extracts vary among brands. Notably, adverse effects have also been reported upon consuming green tea extract.

    Summary

    Green tea extract (GTE) is derived from the Camellia sinensis plant and is added to dietary supplements such as fat burners. Phytochemicals from this plant, especially epigallocatechin gallate (EGCG) and caffeine, can be found in GTE but in higher concentrations. How, when, and where the Camellia sinensis plant is grown, as well as processing practices, influence the constituents of GTE. Therefore, GTE and its contents vary among products. GTE and its benefits have been investigated in diseases such as obesity, cardiovascular disease, cancer, and type 2 diabetes. A meta-analysis of 11 randomized controlled trials (10 that used GTE and one that used whole green tea) found a statistically significant reduction in body weight, BMI, and body fat in participants with type 2 diabetes.[1] Because the participants all had type 2 diabetes, it’s unclear whether this benefit is also found in people with overweight or obesity but without type 2 diabetes. Other studies also suggest that GTE may benefit cardiovascular health[2] and may have anticancer properties.[3] On the other hand, studies of the effects of GTE on glucose metabolism have reported inconsistent results.[4] Caution should be exercised when taking GTE, as adverse effects have been reported.[5] Such adverse effects include gastrointestinal and liver distress but are considered extremely rare.

    What are other names for Green Tea Extract

    Note that Green Tea Extract is also known as:
    • Camellia Sinensis
    • Green Tea Extract
    • GTE
    • Green Tea Catechins
    Green Tea Extract should not be confused with:

    Dosage information

    Most doses are standardized against EGCG. Although the amount of EGCG-equivalent varies from one cup of tea to another, depending on many factors (species of tea, length of steeping, time spent oxidizing), one cup of camellia sinensis green tea contains approximately 50mg of EGCG-equivalent.

    The benefits of green tea catechins on lipid oxidation and related fat-burning pathways are achieved in a dose dependent manner. Significant effects in humans are noted only at high doses, such as 400-500mg EGCG equivalent per day (most Green Tea Extract supplements are roughly 50% EGCG). Fat burning effects are highly synergistic, almost dependent, on not consuming caffeine habitually.

    Research Breakdown

    References

    1. ^Asbaghi O, Fouladvand F, Gonzalez MJ, Aghamohammadi V, Choghakhori R, Abbasnezhad AEffect of Green Tea on Anthropometric Indices and Body Composition in Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis.Complement Med Res.(2021)
    2. ^Raman G, Avendano EE, Chen S, Wang J, Matson J, Gayer B, Novotny JA, Cassidy ADietary intakes of flavan-3-ols and cardiometabolic health: systematic review and meta-analysis of randomized trials and prospective cohort studies.Am J Clin Nutr.(2019-11-01)
    3. ^Tommaso Filippini, Marcella Malavolti, Francesca Borrelli, Angelo A Izzo, Susan J Fairweather-Tait, Markus Horneber, Marco VincetiGreen Tea (Camellia Sinensis) for the Prevention of CancerCochrane Database Syst Rev.(2020 Mar 2)
    4. ^Wang X, Tian J, Jiang J, Li L, Ying X, Tian H, Nie MEffects of green tea or green tea extract on insulin sensitivity and glycaemic control in populations at risk of type 2 diabetes mellitus: a systematic review and meta-analysis of randomised controlled trials.J Hum Nutr Diet.(2014-Oct)
    5. ^Oketch-Rabah HA, Roe AL, Rider CV, Bonkovsky HL, Giancaspro GI, Navarro V, Paine MF, Betz JM, Marles RJ, Casper S, Gurley B, Jordan SA, He K, Kapoor MP, Rao TP, Sherker AH, Fontana RJ, Rossi S, Vuppalanchi R, Seeff LB, Stolz A, Ahmad J, Koh C, Serrano J, Low Dog T, Ko RUnited States Pharmacopeia (USP) comprehensive review of the hepatotoxicity of green tea extracts.Toxicol Rep.(2020)