Researchers at the University of Tokushima, Japan have found that simply drinking a glass of tea with a meal increases the amount of fat excreted into feces by 50% and reduces the absorption of fat and cholesterol through the digestive tract. This study was published in November 2006 edition of the European Journal of Clinical Nutrition.
Researchers recruited 12 subjects - three men and 9 women - for this small study, and divided them into 2 groups. The first group received about 24 ounces of ooling tea with each of three meals per day, then 19 grams of fat twice a day in the form of potato chips - about half an hour after lunch and dinner. The second group received a placebo drink instead of the tea, but still ate the potato chips. Each group continued on this regimen for ten days, then after a seven-day washout period, the two groups were reversed.
Oolong tea is created using the same oxidation process that turns green tea into black tea, but the process does not take as long. So Oolong tea is a cross between green and black tea, having some of the characteristics of both, with moderately high levels of polyphenol antioxidants, such as epigallocatechin gallate (EGCG), but a more robust taste.
Blood samples were taken from each participant four times during the trial, and stool samples were taken on the last three days of each trial period. Those drinking the tea excreted just over twice as much fat as those on the placebo drink, and about 50 percent more cholesterol was excreted.
Much of the fat you eat passes through the stomach unchanged. Fat absorption occurs mainly in the intestines, where it is absorbed slowly as the food you eat passes through your small intestine. Note that if food passes quickly through your intestines, less nutrients may be absorbed. In the case of constipation, and slow passage of food through the intestines, more nutrients and fats are absorbed.
Source: T-F Hsu, A Kusumoto, K Abe, K Hosoda, Y Kiso, M-F Wang and S Yamamoto; Polyphenol-enriched oolong tea increases fecal lipid excretion. Eur J Clin Nutr 60: 1330-1336;
By: Howard Simon