Standardized capsule of Camellia sinensis lowers cardiovascular risk factors in a randomized, double-blind, placebo-controlled study
Received 5 March 2008; accepted 18 July 2008. published online 10 October 2008.
Abstract
Objective
Previous studies examining the effect of tea drinking on cardiovascular health have produced mixed results due to their observational nature and qualitatively and quantitatively imprecise definitions of active tea components. The objective of this study was to determine if a standardized and defined decaffeinated green tea (Camellia sinensis) product lowers blood pressure, serum lipids, oxidative stress, and markers of chronic inflammation.
Methods
A randomized, double-blind, placebo-controlled, parallel study on 111 healthy adult volunteers 21–70 y old was performed. We administered a standardized capsule of Camellia sinensis compounds (CSC) twice a day. Before and after 3 wk, blood pressure, serum lipids, serum amyloid-α (a marker of chronic inflammation), and serum malondialdehyde (a marker of oxidative stress) were measured.
Results
After 3 wk, CSC lowered systolic and diastolic blood pressures by 5 and 4 mmHg, respectively. After 3 mo, systolic blood pressure remained significantly lower. CSC lowered serum amyloid-α by 42% and lowered malondialdehyde by 11.9%. In men, there were 10- and 9-mg/dL reductions in total and low-density lipoprotein (LDL) cholesterol, respectively. In all subjects with a baseline LDL cholesterol level >99 mg/dL, there was 9 mg/dL lowering of total and LDL cholesterol. Adverse effects were mild and few and not different from placebo.
Conclusion
CSC was effective for decreasing, in as quickly as 3 wk, blood pressure, LDL cholesterol, oxidative stress, and a marker of chronic inflammation, all independent cardiovascular risk factors.
aFood Science and Human Nutrition Department, University of Florida, Gainesville, Florida, USA
bDivision of Rheumatology, Allergy & Immunology, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
cNutritional Science Research Institute, Boston, Massachusetts, USA
This study was funded in part by Taiyo, International (Minneapolis, MN, USA). The contribution by Jack F. Bukowski, M.D., was in his capacity as Nutritional Science Research Institute Director; he is also a consultant for Taiyo International.
ABSTRACT