How do levels of EGCG and caffeine in green tea supplements and bottled teas compare with levels provided in a typical brewed green tea? It very much depends on the brand, according to new tests by ConsumerLab.com.
Most teas brewed from green tea sold in stores in the U.S. provide about 10 to 40 mg per cup of the key green tea compound EGCG and 5 to 20 mg of caffeine. ConsumerLab.com's tests found that green tea supplements provided 22 mg to over 300 mg of EGCG in a suggested daily serving and zero to 136 mg of caffeine per serving, depending on the product. Its tests of bottled green teas found EGCG levels ranged from 4 mg to 47 mg per cup, and caffeine ranged from 8 to 37 mg. Preliminary studies suggest that EGCG and related catechin compounds in green tea may aid in weight management and reduce the risk of certain types of cancer.
"Although a label says 'green tea,' the actual amounts of EGCG and caffeine you get from a supplement or drink vary widely by brand," said Tod Cooperman, M.D., President of ConsumerLab.com. "Labels often don't tell you what you're getting and some are plain wrong," he added.
One "GMP certified" green tea supplement tested by ConsumerLab.com contained only 38 percent of the claimed EGCG. It also contained an unusually high amount of caffeine—136 mg per capsule, which is 40 mg more than a cup of brewed coffee and several times as much as most other products—although there is no mention of caffeine on the label. One bottled green tea contained only 63 percent of the listed amount of green tea catechins listed on its label.
Across the products, ConsumerLab.com found the cost to obtain 200 mg of EGCG to range from 10 cents to over $70.
ConsumerLab.com's Product Review of Green Tea Supplements and Bottled Drinks can be found at consumerlab.com. The report provides information on how to choose and use these supplements and drinks as well as test results, quality ratings, and comparisons of ingredients and cost. The following products are included in the report, including twelve products selected for testing by ConsumerLab.com, five recently approved in its Voluntary Certification Program, and two products similar to an approved product:
• Andrew Lessman's Green Tea EGCG-200
• Arizona Green Tea -- Ginseng & Honey
• Diet Snapple Green Tea
• Enzymatic Therapy Green Tea Elite with EGCG
• Gaia Herbs Green Tea
• Harney & Sons Organic Green
• Healthy Origins Teavigo
• Honest Tea Green Tea with Honey
• Life Extension Mega Green Tea Extract
• Nature's Bounty Standardized Green Tea Extract
• New Chapter Green & White Tea Force
• NOW EGCg Green Tea Extract
• Omega Sports Green Tea
• Solgar Green Tea Leaf Extract
• Swanson Superior Herbs Green Tea Extract
• Trunature (Costco) Green Tea
• Puritan's Pride Standardized Green Tea Extract
• Vitamin Shoppe Green Tea Extract
• Vitamin World Standardized Green Tea Extract