To assess possibility of polyphenol-enriched oolong tea to reduce dietary lipid absorption in humans.
Twelve healthy adult subjects, three males and nine females, aged (mean±s.d.) 22.0±1.8 years, respectively, were randomly divided into two groups. The participants were followed a double-blind placebo-controlled crossover design, including 7-day washout periods and 10-day treatment periods. During the treatment periods, subjects were given about 38 g of lipids from potato chips (19 g each within 30 min after lunch and dinner) and total 750 ml beverages (placebo- or polyphenol-enriched oolong tea) at three meals. Blood samples were collected for biochemical examination at days 8, 18, 25 and 35 of the study period. On the last 3 days of each treatment period, feces were collected to measure the excretion of lipids.
Lipid excretion into feces was significantly higher in the polyphenol-enriched oolong tea period (19.3±12.9 g/3day) than in the placebo period (9.4±7.3 g/3day) (P<0.01). Cholesterol excretion tended to increase in polyphenol-enriched oolong tea period (1.8±1.2 g/3day) compared with that of placebo (1.2±0.6 g/3day) (P=0.056).
The results of this study indicated that polyphenol-enriched oolong tea could increase lipid excretion into feces when subjects took high-lipid diet.