Tea Polyphenols More Bioavailable in Capsules

LOS ANGELES--Tea polyphenols are more bioavailable when delivered as encapsulated green tea extract than when taken as a traditional beverage, according to a study published in the December issue of the American Journal of Clinical Nutrition (80, 6:1558-1564, 2004) (www.ajcn.org).

Thirty healthy subjects were randomized to three different sequences of green tea, black tea, or capsular green tea extract providing similar amounts of (-)-epigallocatechin-3-gallate in a 3 x 3 crossover design including a one-week washout period between phases. Absorption of tea polyphenols was highest in capsule form and led to a small but notable increase in plasma antioxidant activity, compared with tea polyphenols consumed as green or black tea beverages.

The scientists concluded encapsulated green tea extract retains the beneficial effects of green and black tea beverages and may be used in future studies to provide a large dose of tea polyphenols without the side effects of caffeine associated with drinking green and black tea.