Green Tea Dietary Supplement Pilot Study
A botanical initiative for the DSID is now underway to evaluate levels of ingredients and ingredient constituents in botanical DS, reported to be taken by 7.5% of the US population.
Supplement labels may provide only partial information about the actual content of bioactive components in botanicals. Current label regulations require information on the amount of each botanical,
botanical extract or blend present in a DS while information on their concentration or standardization is not obligatory.
Although some companies voluntarily list information about the concentration of phytochemical constituents, many do not.
Complete composition information for botanicals must be determined analytically so researchers can more accurately obtain estimates for the phytochemical intakes from botanicals.
A single serving of a botanical extract may provide amounts of bioactive components (for example, flavonoids) equal to or significantly exceeding their daily intake from foods.
Green tea (GT) dietary supplements (DS) were chosen as the first botanical to be studied for the DSID Botanical Initiative, because they are commonly consumed and frequently studied for their health benefits. The goal of this pilot study is to test GT DS for botanical constituent content to provide analytical information about the content and variability of individual catechins and caffeine. This study was limited to products containing GT as the only botanical and the primary ingredient in order to minimize interferences for comparing results to label claims for GT components.
The content of seven catechins, including epigallocatechin gallate (EGCG), and caffeine was measured in 32 green tea DSs. Quality control materials were sent with product samples in order to evaluate the accuracy and precision of the laboratory methods. Summary information about the methods for sampling and testing GT products and 3 tables of results are reported in the GT Research Summaries and Results.