Green tea extract vendors advertise significant quantities of Green tea flavanols contained in their products. The myriad of cognitive benefits conferred by green tea flavanols was discussed in a previous article, “L-theanine in Green tea enhances memory”. Bioavailability issues have been known to occur during some extraction techniques which could result in low quantities of green tea flavanols. This could mean that taking green tea extract might offer little to no benefits without the proper amount of flavanols. Fortunately a definitive study was published in the American Journal of Nutrition, which tests the green tea flavanol content of over the counter green tea extract.
Green tea, green tea extract, and black tea are all derived from the same plant, Camellia sinensis, therefore the research group decided to test all three preparations of the plant to see which resulted in the highest antioxidant levels in the blood following ingestion. They measured three different green tea flavanols in the patient’s blood following ingestion of either Black tea (BT), Green tea (GT), or green tea extract (GTS).
The results proved very interesting. After measuring antioxidant levels in each group of volunteers they found that the average blood concentration of green tea flavanols was elevated in the group of volunteers who consumed green tea extract.
“We conclude that polyphenols administered in the form of GTS showed enhanced bioavailability compared with that of GT or BT, which led to a small but significant increase in antioxidant capacity.”
Given the author’s conclusion, it’s clear that taking a green tea extract supplement is an enhanced way to deliver vital green tea flavanols to your body. Green tea extract promotes flavanol bioavailability so you can take full advantage of the antioxidant benefits.
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