Scientific StudiesThere have been numerous studies on Wu-Yi (oolong) tea. Here are some of them and the results they produced. Wulong Tea/Oolong tea increases energy metabolism in Japanese females. Department of Applied Nutrition, The University of Tokushima School of Medicine, Tokushima, Japan. Oolong tea is a traditional Chinese tea that has long been believed to be beneficial to health such as decreasing body fat. We were interested in this assertion and tried to evaluate the effect of oolong tea on energy expenditure (EE) in comparison with green tea. The subjects were eleven healthy Japanese females (age 20+/-1 y; body mass index (BMI) 21.2+/-2.5 kg/m2) who each consumed of three treatments in a crossover design: 1) water, 2) oolong tea, 3) green tea. Resting energy expenditure (REE) and EE after the consumption of the test beverage for 120 min were measured using an indirect calorimeter. The cumulative increases of EE for 120 min were significantly increased 10% and 4% after the consumption of oolong tea and green tea, respectively. EE at 60 and 90 min were significantly higher after the consumption of oolong tea than that of water (P<0.05). In comparison with green tea, oolong tea contained approximately half the caffeine and epigallocatechin galate, while polymerized polyphenols were double. These results suggest that oolong tea increases EE by its polymerized polyphenols. PMID: 13678386 [PubMed - indexed for MEDLINE] Oolong tea increases metabolic rate and fat oxidation in men. Beltsville Human Nutrition Research Center, Beltsville, MD 20705, USA. rumpler@bhnrc.ars.usda.gov According to traditional Chinese belief, oolong tea is effective in the control of body weight. Few controlled studies, however, have been conducted to measure the impact of tea on energy expenditure (EE) of humans. A randomized cross-over design was used to compare 24-h EE of 12 men consuming each of four treatments: 1) water, 2) full-strength tea (daily allotment brewed from 15 g of tea), 3) half-strength tea (brewed from 7.5 g tea) and 4) water containing 270 mg caffeine, equivalent to the concentration in the full-strength tea treatment. Subjects refrained from consuming caffeine or flavonoids for 4 d prior to the study. Tea was brewed each morning; beverages were consumed at room temperature as five 300 mL servings. Subjects received each treatment for 3 d; on the third day, EE was measured by indirect calorimetry in a room calorimeter. For the 3 d, subjects consumed a typical American diet. Energy content of the diet was tailored to each subject's needs as determined from a preliminary measure of 24-h EE by calorimetry. Relative to the water treatment, EE was significantly increased 2.9 and 3.4% for the full-strength tea and caffeinated water treatments, respectively. This increase over water alone represented an additional expenditure of 281 and 331 kJ/d for subjects treated with full-strength tea and caffeinated water, respectively. In addition, fat oxidation was significantly higher (12%) when subjects consumed the full-strength tea rather than water. PMID: 11694607 [PubMed - indexed for MEDLINE] Polyphenol-enriched oolong tea increases fecal lipid excretion. International Public Health Nutrition, Graduate School of Health Biosciences, The University of Tokushima, Tokushima, Japan. OBJECTIVE: To assess possibility of polyphenol-enriched oolong tea to reduce dietary lipid absorption in humans. DESIGN: 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. RESULTS: Lipid excretion into feces was significantly higher in the polyphenol-enriched oolong tea period (19.3+/-12.9 g/3 day) than in the placebo period (9.4+/-7.3 g/3 day) (P < 0.01). Cholesterol excretion tended to increase in polyphenol-enriched oolong tea period (1.8+/-1.2 g/3 day) compared with that of placebo (1.2+/-0.6 g/3 day) (P = 0.056). CONCLUSIONS: The results of this study indicated that polyphenol-enriched oolong tea could increase lipid excretion into feces when subjects took high-lipid diet. PMID: 16804556 [PubMed - indexed for MEDLINE] For an authentic Wu-Yi tea experience we recommend a free trial from Wu-Yi Source. |