Tree Tea Extract
Also known as: Green Tea Extract (GTE), Tree Tea Extract, Camellia sinensis, Epigallocatechin gallate (EGCG), Catechins, Polyphenols, Camellia sinensis Extract
Overview
Green Tea Extract, also sometimes referred to as Tree Tea Extract, is derived from the leaves of the *Camellia sinensis* plant. It is a rich source of polyphenols, particularly catechins like epigallocatechin gallate (EGCG), known for their antioxidant properties. Primarily used as a dietary supplement, it's often incorporated into regimens for weight management, cardiovascular health, and antioxidant support. Research indicates potential adjunctive benefits in cancer therapy, though this is still under investigation. Available in various forms, including capsules, powders, and liquids, the extract's efficacy is largely attributed to its high concentration of bioactive catechins. The quality of evidence supporting its benefits is generally high, with numerous studies and meta-analyses available, though heterogeneity in study designs should be considered.
Benefits
Green Tea Extract (GTE) has several evidence-based benefits. Meta-analyses suggest GTE supplementation can significantly reduce body mass (BM), body mass index (BMI), and body fat percentage (BFP). Studies show a weighted mean difference in body weight reduction of approximately -1.78 kg and BMI reduction of -0.65 kg/m². GTE also decreases oxidative stress markers like malondialdehyde (MDA) and increases total antioxidant capacity (TAC). Research on cardiovascular risk factors shows mixed results, with some studies indicating potential benefits on lipid profiles, particularly triglycerides, with longer intervention durations. These benefits are more pronounced in overweight or obese adults, suggesting population-specific effects.
How it works
The primary mechanism of action for Green Tea Extract revolves around its high catechin content, especially EGCG. These catechins act as antioxidants by scavenging free radicals and upregulating endogenous antioxidant enzymes, reducing oxidative stress. Additionally, GTE may enhance thermogenesis and fat oxidation, contributing to weight loss. It interacts with various body systems, influencing metabolic rate, lipid metabolism, glucose regulation, and inflammatory pathways. Molecularly, EGCG modulates signaling pathways such as AMP-activated protein kinase (AMPK) and nuclear factor kappa B (NF-κB), which are involved in oxidative stress and metabolism.
Side effects
Green Tea Extract is generally considered safe when taken at recommended supplemental doses. Common side effects, occurring in more than 5% of users, include mild gastrointestinal discomfort. Uncommon side effects (1-5%) may include headache, dizziness, or insomnia, primarily due to the caffeine content. Rare side effects, affecting less than 1% of users, involve reports of liver toxicity with very high doses or prolonged use, necessitating caution. Drug interactions are possible with anticoagulants, stimulants, and certain medications metabolized by the liver. It is contraindicated or requires caution in individuals with liver disease or caffeine sensitivity. Pregnant and breastfeeding women should consult healthcare providers before use.
Dosage
The minimum effective dose of Green Tea Extract is often cited between 250 mg to 1000 mg of green tea catechins per day. Optimal dosage ranges appear to be around 400–600 mg of catechins daily for weight and oxidative stress benefits. The maximum safe dose is generally considered to be up to 800–1000 mg of catechins per day; exceeding this increases the risk of adverse effects. Dividing doses with meals may improve tolerance and absorption. Standardized extracts with defined EGCG content are preferred for consistency. Bioavailability can be enhanced by the food matrix and formulation, and the presence of caffeine may influence effects. Adequate hydration and a balanced diet are recommended.
FAQs
Is Tree Tea Extract the same as Green Tea Extract?
Yes, Tree Tea Extract typically refers to Green Tea Extract, both derived from *Camellia sinensis* and sharing similar properties and benefits.
How long does it take to see effects from Green Tea Extract?
Noticeable effects on weight and oxidative stress markers usually appear after 8–12 weeks of consistent supplementation at recommended dosages.
Is Green Tea Extract safe for long-term use?
Generally safe at recommended doses, but long-term safety beyond 6 months requires monitoring, especially liver function, to mitigate potential risks.
Can Green Tea Extract replace other weight loss methods?
No, Green Tea Extract is an adjunct to, not a substitute for, a balanced diet and regular exercise in a comprehensive weight management plan.
Does the caffeine content in Green Tea Extract affect safety?
Yes, individuals sensitive to caffeine should opt for decaffeinated extracts or lower doses to avoid potential adverse effects like insomnia or anxiety.
Research Sources
- https://pubmed.ncbi.nlm.nih.gov/38031409/ – This systematic review and meta-analysis of multiple RCTs found that green tea extract (GTE) reduces body mass, BMI, body fat, and oxidative stress markers while increasing antioxidant capacity in adults. The study assessed the quality using GRADE, indicating high confidence in the findings despite heterogeneity in doses and populations.
- https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.1084455/full – A systematic review and meta-analysis of 40 clinical trial arms showed a non-significant overall effect of green tea extract on triglycerides, but a significant reduction in subgroups with longer duration and mixed-sex populations. The study found variable effects on other cardiovascular markers and noted high heterogeneity, indicating the need for cautious interpretation.
- https://onlinelibrary.wiley.com/doi/abs/10.1002/ptr.6697 – This meta-analysis of multiple RCTs focusing on overweight/obese adults found significant reductions in body weight (WMD −1.78 kg) and BMI (WMD −0.65 kg/m²) with green tea extract supplementation. The study acknowledges heterogeneity due to variations in dose, type, and duration of the interventions, affecting the overall strength of the conclusions.
- https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/effects-of-green-tea-extract-supplementation-on-body-composition-obesityrelated-hormones-and-oxidative-stress-markers-a-gradeassessed-systematic-review-and-doseresponse-metaanalysis-of-randomised-controlled-trials/5F7DCFF04BE51796D39A6CC5B0A3089A – This systematic review and dose-response meta-analysis assessed the effects of green tea extract supplementation on body composition, obesity-related hormones, and oxidative stress markers. The study used GRADE assessment and provided a comprehensive analysis of randomized controlled trials, contributing to a better understanding of the supplement's impact.
- https://pubmed.ncbi.nlm.nih.gov/30985669/ – This study investigates the effects of green tea extract, providing insights into its potential benefits and mechanisms of action. Further details about the specific findings would require a deeper review of the study itself.
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