Greenselect Green Tea Extract
Also known as: Green tea extract, GTE, Greenselect Green Tea Extract, Greenselect Phytosome, Camellia sinensis extract
Overview
Green tea extract (GTE) is a dietary supplement derived from the leaves of *Camellia sinensis*, a plant native to Asia. It is highly concentrated in catechins, particularly epigallocatechin gallate (EGCG), which is considered the primary active compound responsible for its health benefits. GTE is widely used for its potential role in weight management, its potent antioxidant properties, and its positive impact on cardiovascular health. While research on GTE is extensive, including numerous systematic reviews and meta-analyses, the quality and consistency of evidence can vary depending on the specific formulation and study design. It is available in various forms, with proprietary formulations like Greenselect Phytosome designed to enhance bioavailability.
Benefits
Green tea extract (GTE) offers several evidence-based benefits, primarily due to its rich catechin content. It has been shown to significantly reduce body mass (BM), body mass index (BMI), and body fat percentage (BFP), making it beneficial for individuals with obesity or metabolic syndrome. Studies also indicate its effectiveness in reducing oxidative stress markers like malondialdehyde (MDA) and increasing total antioxidant capacity (TAC) and adiponectin levels, highlighting its antioxidant and metabolic regulatory roles. Furthermore, GTE may improve blood lipid profiles and contribute to lower blood pressure, supporting cardiovascular health. The effects are often observed within 12 weeks of consistent supplementation, with effect sizes varying but showing clinically significant reductions in BMI and BFP in some populations.
How it works
Green tea extract (GTE) exerts its effects primarily through its potent antioxidant properties, largely attributed to epigallocatechin gallate (EGCG). EGCG interacts with various molecular targets, including enzymes and receptors involved in metabolic regulation and inflammation. GTE influences metabolic pathways, potentially enhancing fat oxidation and thermogenesis, which contributes to its weight management benefits. It also impacts hormone regulation, such as increasing adiponectin levels, a hormone involved in glucose and lipid metabolism. Furthermore, GTE interacts with the cardiovascular system by potentially improving endothelial function, leading to reduced blood pressure and improved lipid profiles. The catechins are generally absorbed in the small intestine, with bioavailability varying based on the specific formulation.
Side effects
Green tea extract (GTE) is generally considered safe when consumed within recommended dosages. The most common side effects, affecting more than 5% of users, are gastrointestinal issues such as nausea, stomach discomfort, and constipation. Less common side effects (1-5%) include headaches and dizziness. Rare but serious side effects, occurring in less than 1% of users, can include allergic reactions and, in very rare cases, liver damage, particularly with high doses or in susceptible individuals. GTE may interact with certain medications, notably blood thinners, increasing the risk of bleeding. It is contraindicated in individuals with pre-existing liver disease and should be used with caution during pregnancy due to potential risks associated with high catechin intake. Individuals with specific health conditions or those on multiple medications should consult a healthcare professional before use.
Dosage
The typical minimum effective dose for green tea extract (GTE) is around 250-500 mg per day, though this can vary based on the specific formulation and desired health outcome. Optimal dosage ranges are generally between 500-1000 mg per day. The maximum safe dose is considered to be up to 1200 mg per day; however, higher doses may increase the risk of adverse effects, particularly liver toxicity. It is generally recommended to take GTE with meals to minimize potential gastrointestinal side effects. Proprietary formulations like Greenselect Phytosome, which incorporate lecithin, are designed to enhance the absorption and bioavailability of catechins. No specific cofactors are required for GTE absorption, but a balanced diet is always recommended for overall health.
FAQs
Is Greenselect Green Tea Extract safe?
Yes, it's generally safe when taken as directed. However, high doses should be avoided, especially if pregnant or with liver conditions, due to potential side effects like liver damage.
When is the best time to take green tea extract?
It's best taken with meals to help reduce the likelihood of gastrointestinal upset, such as nausea or stomach discomfort.
What results can I expect from taking GTE?
Potential benefits include reductions in body weight, BMI, and body fat percentage, along with improved antioxidant status and cardiovascular markers like blood pressure.
Is green tea extract a magic bullet for weight loss?
No, it's not a magic bullet. While it can support weight management, it's most effective when combined with a healthy diet and regular exercise.
Research Sources
- 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, including 59 trials and 3802 participants, concluded that green tea extract supplementation significantly reduces body mass, BMI, body fat percentage, and malondialdehyde. It also found increases in total antioxidant capacity and adiponectin levels, supporting GTE's role in improving body composition and oxidative stress markers.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC3848081/ – This controlled registry study investigated Greenselect Phytosome in 50 subjects with borderline metabolic syndrome over 24 weeks. The findings indicated improvements in body weight, blood lipid profiles, and blood pressure, suggesting that this specific green tea extract formulation may be beneficial for managing metabolic syndrome components.
- https://www.nature.com/articles/srep06251 – This meta-analysis, encompassing 13 articles, examined the effect of green tea consumption on blood pressure. The study found a significant decrease in systolic blood pressure, highlighting the potential cardiovascular benefits of regular green tea intake and its components.
