Beneficial effects of oolong tea consumption on diet-induced overweight and obese subjects
- 583 Downloads
To determine the anti-obesity effects of oolong tea on diet-induced overweight or obesity.
A total of 8 g of oolong tea a day for 6 weeks was ingested by 102 diet-induced overweight or obese subjects. The body fat level of the subjects was determined at the same time by taking body weight, height and waist measurements. The thickness of the subcutaneous fat layer was also determined on the abdomen 3 cm to the right of the navel by the ultrasonic echo method. On the other hand, effects of oolong tea ingestion on plasma triglyceride (TG) and total cholesterol (TC) were determined. Inhibitions of pancreatic lipase by oolong tea extract and catechins in vitro were also determined.
A total of 70% of the severely obese subjects did show a decrease of more than 1 kg in body weight, including 22% who lost more than 3 kg. Similarly, 64% of the obese subjects and 66% of the overweight subjects lost more than 1 kg during the experiment, and the subcutaneous fat content decreased in 12% of the subjects. The correlation between weight loss and subcutaneous fat decrease in men (r=0.055) was obviously lower than that in women (r=0.440, P<0.01). Body weight loss was signifificantly related to the decrease of the waist size in men (r=0.730, P<0.01) and women (r=0.480, P<0.01). Also, the correlation between subcutaneous fat reduction and decreased waist size was signifificant in women (r=0.554, P<0.01), but not in men (r=0.050, P>0.05). Moreover, the plasma levels of TG and TC of the subjects with hyperlipidemia were remarkably decreased after ingesting oolong tea for 6 weeks. In vitro assays for the inhibition of pancreatic lipase by oolong tea extract and catechins suggest that the mechanism for oolong tea to prevent hyperlipidemia may be related to the regulative action of oolong tea catechins in lipoprotein activity.
Oolong tea could decrease body fat content and reduce body weight through improving lipid metabolism. Chronic consumption of oolong tea may prevent against obesity.
Key Wordsoolong tea overweight obesity cholesterol triglyceride pancreatic lipase
Unable to display preview. Download preview PDF.
- 4.Astrup A, Buemann B, Western P, Toubro S, Raben A, Christensen NJ. Obesity as an adaptation to a high-fat diet: evidence from a cross-sectional study. Am J Clin Nutri 1994;59:350–355.Google Scholar
- 8.Kuo KL, Weng MS, Chiang CT, Tsai YJ, Lin-Shiau SY, Lin JK. Comparative studies on the hypolipidemic and growth suppressive effects of oolong, black, pu-erh, and green tea leaves in rats. J Agric Food Chem 2005; 53:489–489.Google Scholar
- 11.Davies MJ, Judd JT, Baer DJ, Clevidence BA, Paul DR, Edwards AJ, et al. Black tea consumption reduces total and LDL cholesterol in mildly hypercholesterolemic adults. J Nutr 2003;133:3298–3302.Google Scholar
- 13.WHO Physical Status: The use and interpretation of anthropometry. Report of a WHO expert committee Geneva: World Health Organization Technical Report Seriels; 1995:854.Google Scholar
- 14.WHO. Obesity: preventing and managing the global epidemic. Report of a WHO Consultation on obesity, Geneva 3–5, June 1997. World Health Organization Techinical Report Series. Vol. 210. Geneva: World Health Organization;1997:1–276.Google Scholar
- 15.Xie B, Shi H, Chen Q, Ho CT. Antioxidant properties of fractions and polyphenol constituents from green, oolong and black teas. Proc Natl Sci Counc Repub China (B) 1993;17:77–84.Google Scholar
- 18.Saris W. Sugars, energy metabolism, and body weight control. Am J Clini Nutri 2003;78:850–857.Google Scholar
- 19.Iwata K, Inayama T, Miw S, Kawaguchi K, Koike G. Effect of oolong tea on plasma lipids and lipoprotein lipase activity in young women. J Jpn Soc Nutr Food Sci 1991;44:251–259.Google Scholar
- 21.Dulloo AG, Dure C, Rohrer D, Girardier L, Mensi N, Fathi M. Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans. Am J Clin Nutri 1999;70:1040–1045.Google Scholar
- 22.Bianchi CP. Cellular pharmacology of contraction of skeletal muscle. In: Narahashi T, ed. Cellular pharmacology of excitable tissues. Charles C: Thomas Publisher;1975:485–519.Google Scholar
- 31.Wang SR, Infante J, Catala D, Petit D, Bonnefis MT, Infante R. Lipid and lipoprotein synthesis in isolated and cultured hepatocytes from lean and obese Zucker rats. Biochim Acta 1989;1002:302–311.Google Scholar