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Proprietary Green Tea Blend

Also known as: Green tea, Green tea extract (GTE), Green tea catechins (GTCs), Proprietary green tea blend, Camellia sinensis

Overview

Green tea, derived from the *Camellia sinensis* plant, is a minimally oxidized tea known for its rich polyphenol content, particularly catechins like epigallocatechin gallate (EGCG). Proprietary blends often standardize extracts or combine specific ratios of catechins and caffeine. It is commonly used for cardiovascular health, metabolic support, weight management, and antioxidant effects. Research on green tea is extensive, with numerous randomized controlled trials and meta-analyses, although inconsistencies exist. The quality of evidence is generally moderate to low due to heterogeneity, imprecision, and potential bias in some studies. Green tea's benefits are attributed to its antioxidant and anti-inflammatory properties, primarily through its catechin compounds. It is available in various forms, including tea leaves, powders, capsules, and extracts.

Benefits

Green tea and its extracts have shown several potential health benefits. Studies indicate small but significant reductions in both systolic (SBP) and diastolic blood pressure (DBP) in overweight or obese adults. Meta-analyses also suggest improvements in lipid profiles, including total cholesterol (TC), LDL, and HDL levels, as well as favorable effects on triglycerides (TG) with long-term use. Additionally, green tea may contribute to glycemic control, with modest reductions in fasting blood sugar (FBS) and HbA1c levels. Some research suggests that green tea extract (GTE) supplementation can lead to decreases in body mass (BM), BMI, and body fat percentage (BFP), along with an increase in total antioxidant capacity (TAC). These benefits are most consistently observed in overweight or obese individuals and those with mild metabolic disturbances. However, the clinical relevance of these effects may be modest for most individuals.

How it works

Green tea's mechanism of action primarily involves its antioxidant activity, largely attributed to polyphenols, especially EGCG. These compounds inhibit lipid absorption and modulate lipid metabolism, contributing to improved cardiovascular and metabolic health. Green tea also enhances endothelial function, promoting healthy blood vessel function. At the molecular level, it interacts with key targets such as AMP-activated protein kinase (AMPK) and nuclear factor erythroid 2-related factor 2 (Nrf2), as well as enzymes involved in lipid and glucose metabolism. Catechins, including EGCG, have variable bioavailability, with absorption enhanced when taken on an empty stomach and inhibited by food, particularly dairy products.

Side effects

Green tea is generally considered safe for most adults when consumed in recommended amounts. Common side effects, affecting more than 5% of users, include mild gastrointestinal upset, nausea, headache, and insomnia, primarily due to its caffeine content. Less common side effects (1-5%) may include palpitations, dizziness, and increased heart rate. Rare side effects, occurring in less than 1% of users, involve liver enzyme elevations, mainly with high-dose extracts. Green tea may interact with anticoagulants, stimulants, and certain medications metabolized by CYP enzymes. It is contraindicated in individuals with severe liver disease, caffeine sensitivity, and during pregnancy at high doses. Caution is advised for individuals with hypertension, arrhythmias, or anxiety disorders.

Dosage

The minimum effective dose of green tea catechins for metabolic effects is approximately 200 mg per day. Optimal dosage ranges typically fall between 200 and 800 mg of catechins daily, equivalent to 2-4 cups of green tea (approximately 100-200 mg catechins per cup). The maximum safe dose is generally considered to be up to 800 mg of catechins per day; higher doses may increase the risk of liver toxicity. For optimal absorption, it is best taken between meals. Standardized extracts are preferred for consistent dosing, and individuals sensitive to caffeine should avoid high-caffeine products. Absorption is enhanced by fasting and inhibited by food, especially dairy products.

FAQs

Is green tea safe?

Green tea is generally safe and well-tolerated, but high doses or extracts may cause side effects. Liver toxicity is rare but possible with high-dose extracts; monitor if using >800 mg catechins/day.

When should I take green tea?

Take green tea between meals for best absorption; avoid consuming it with dairy products, as they can inhibit the absorption of beneficial compounds.

What results can I expect from taking green tea?

Expect small improvements in blood pressure, lipids, and glycemic control over weeks to months. Green tea is not a "miracle" weight loss supplement; effects are modest and require consistent use.

Can green tea help with weight loss?

Green tea may assist with weight management by slightly increasing metabolism and fat oxidation, but it's not a standalone solution. Combine it with a healthy diet and exercise for best results.

Are there any drug interactions with green tea?

Yes, green tea may interact with anticoagulants, stimulants, and certain medications metabolized by CYP enzymes. Consult with a healthcare provider if you are taking any medications.

Research Sources

https://pubmed.ncbi.nlm.nih.gov/25479028/ – This systematic review and meta-analysis of 14 RCTs involving 971 overweight/obese adults found that green tea consumption led to a significant reduction in both systolic and diastolic blood pressure compared to placebo. However, the authors noted that the quality of evidence was low due to heterogeneity and potential risk of bias across the included studies.
https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.1084455/full – This systematic review and meta-analysis examined the effects of green tea on cardiovascular risk factors. The study found improvements in lipid profiles, including decreased total cholesterol and LDL, increased HDL, and a small reduction in diastolic blood pressure. The evidence quality was moderate for lipids and DBP, but low for SBP and glycemic indices due to inconsistency and imprecision.
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 meta-analysis investigated the effects of green tea extract supplementation on body composition, obesity-related hormones, and oxidative stress markers. The study revealed a significant decrease in body mass, BMI, body fat percentage, and the oxidative stress marker MDA, along with an increase in total antioxidant capacity. The quality of evidence was considered moderate, with some risk of bias and imprecision noted.