| Author: | Wong, Kit-chu Angela |
| Title: | To study and compare the effects of two types of Chinese green tea (Loongjin and Screw-shaped green tea) for health promotion, with particular focus on selected biomarkers of cardiovascular disease risk in a controlled human intervention trial |
| Degree: | M.Sc. |
| Year: | 2009 |
| Subject: | Hong Kong Polytechnic University -- Dissertations. Green tea -- Therapeutic use. Cardiovascular system -- Diseases -- Alternative treatment. |
| Department: | Department of Health Technology and Informatics |
| Pages: | xii, 104 leaves : ill. (some col.) ; 30 cm. |
| Language: | English |
| Abstract: | Cardiovascular diseases place a heavy burden on the economies of countries. In vitro and animal studies indicate that green tea consumption reduces cardiovascular disease (CVD) risk. The cardioprotective effect of green tea may contribute in lowering the progression of CVDs, thus reducing healthcare costs. However, epidemiological and human intervention studies on green tea effect show controversial results. Loongjin and Screw-shaped green tea are the most commonly consumed green tea among the Chinese population. As the amount of catechins varies in the original tea leaves with different varieties, origins and growing conditions, Loongjin and Screw-shaped green tea may have different beneficial health effects on human subjects. The aim of the present study was to investigate and compare the effects of Loongjin and Screw-shaped green tea for health promotion, with particular focus on selected biomarkers of cardiovascular disease risk. The study design was a randomized, placebo-controlled, single-blinded human intervention trial of multiple crossover design. Eighteen apparently healthy non-smokers of age 35 to 50 were recruited with their informed content. Subjects were randomly divided into three groups for supplementation treatment of receiving water (as placebo), Loongjin or Screw-shaped green tea (300 ml of 1.0% w/v tea) (n = 6 in each group). Each intervention period lasted for 4 weeks with a 6-week washout period between them. Each subject took all three different treatments, in a random order. Before and after each 'treatment' session, blood pressure, weight, height, waist and hip measurement was recorded. In addition, 6ml fasting venous blood samples was collected for biochemical testing. During the treatment periods, the subjects were asked not to change their regular diet and lifestyle habits apart from taking the supplement. The selected markers for assessment of cardiovascular risk to be measured included systolic and diastolic blood pressure, body mass index, waist/ hip ratio, fasting plasma lipid profiles (total cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol), glucose, uric acid, hsCRP and sVCAM-1. Result showed statistically significant decrease (p = 0.004) in post-treatment levels of triglyceride after 4-week Screw-shaped green tea supplementation. For plasma triglyceride, statistically significant decrease of response was observed in treatment of Screw-shaped green tea when comparing that with treatment of Loongjin green tea (p <0.05). However, no statistically significant effects of either tea on any of the biomarkers or measurement made were seen in comparison to the placebo (water) treatment. There was evidence of period effect in response of plasma uric acid and sVCAM-1 concentration after Screw-shaped green tea supplementation but not that in other biomarkers. On the other hand, no evidence of an order effect was seen in the study. In conclusion, the current study results reflected that 4 weeks' supplementation with Loongjin and Screw-shaped green tea did not have marked effect on selected CVD biomarkers in healthy middle aged Chinese adults. Further study with modified design is suggested to be carried out for inducing the possible effect of green tea. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b23056125.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 5.36 MB | Adobe PDF | View/Open |
Copyright Undertaking
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
- I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.
Please use this identifier to cite or link to this item:
https://theses.lib.polyu.edu.hk/handle/200/5247