高濃度兒茶素綠茶飲料血脂調節及延緩老化之研究

Study on the blood lipid regulation and anti-aging by high concentration catechin green tea drink

鄭如君(Ju-Chun Cheng)

指導教授 ： 王進崑 ； 陳肅霖

中山醫學大學/健康管理學院/營養學研究所/碩士(2006年)

摘要

攝取茶類飲料的習慣已遍及全世界。許多細胞與動物試驗結果指出，攝取茶與預防心血管疾病、癌症、抗氧化及降低體脂肪有關。這些生理功能主要來自茶中所含的多酚化合物，特別與兒茶素有關。本研究利用隨機、對照控制、雙盲交叉設計之人體試驗，評估飲用綠茶飲料對血脂調節及延緩衰老之功能性。
本研究分別公開徵求20位受試者參與為期3個月的血脂調節及50位受試者參與為期13個月 (含一個月wash-out)之延緩衰老試驗。在調節血脂的研究中，將20位受試者分為兩組，試驗組之受試者每天飲用600毫升之綠茶飲料(兒茶素含量為780 mg)，對照組則飲用安慰劑飲料(600毫升/天)，為期3個月。試驗初期及3個月後，採取血液檢體，分析血脂的變化並測定血液中低密度脂蛋白質(low-density lipoprotein; LDL)氧化之情形。結果顯示，連續飲用綠茶飲料3個月後，受試者血液中高密度脂蛋白質膽固醇(high-density lipoprotein cholesterol; HDL-C)含量顯著地提升。此外， LDL氧化的時間亦顯著地由48分鐘延長至57分鐘。在延緩衰老評估試驗中，將50位受試者分為兩組，一組每天飲用600毫升之綠茶飲料(兒茶素含量為780 mg)，連續飲用6個月後，停止1個月(wash-out)後，再連續6個月飲用對照之安慰劑飲料(600毫升/天)。相對地，另一組則先連續飲用6個月對照之安慰劑飲料(600毫升/天)，停止供應1個月(wash-out)後，再連續飲用6個月600毫升之綠茶飲料。試驗初期，採取血液檢體並作體位測量及腹部超音波檢查。試驗進行後，每3個月進行體位測定及血液追蹤分析，試驗進行後半年，執行腹部超音波檢查。試驗期間，排除腸胃道不適及飲用率低的受試者後，完成13個月延緩衰老試驗的人數有46人。結果顯示，每天攝取600毫升綠茶飲料並連續六個月後，對體重、體脂肪及身體質量指數無顯著影響。血漿中總抗氧化力(trolox equivalent antioxidant capacity; TEAC)顯著地提高，且血漿中脂質過氧化物(thiobarbituric acid-reactive substances; TBARS)值顯著地調降。血漿中抗氧化物質如總酚類化合物、麩胱甘肽(reduced glutathione; GSH)之含量有明顯的增加。血球內抗氧化酵素葡萄糖六磷酸去氫酶(glucose-6-phosphate dehydrogenase; G-6-PDH)、觸酶(catalase)、麩胱甘肽過氧化酶(glutathione peroxidase; GSH Px)、麩胱甘肽還原酶(glutathione reductase; GSH Rd)的活性也顯著地提高。腹部超音波的臨床檢查結果可知，46位受測者飲用綠茶飲料後，肝、腎器官並無顯著改變。其中四位受試者在連續飲用綠茶飲料六個月後，脂肪肝的現象可獲得改善，可知攝取綠茶飲料可能具有改善脂肪肝的功效。

關鍵字

綠茶 ； 兒茶素 ； 低密度脂蛋白 ； 抗氧化性 ； 肝功能

並列摘要

Tea consumption becomes worldwide. Many cell and animals studies show that tea consumption has benefit on the prevention of cardiovascular disease, cancer, antioxidant and body fat reduction. Most functions are from tea polyphenols, especially catechins. The study employed randomized, placebo controlled, double blind and cross-over design to evaluate blood lipid regulation and anti-aging function of green tea. Twenty and fifty subjects were enrolled respectively in three-month and thirteen-month (including one month wash-out period time) trials. For blood lipid regulation, twenty subjects were divided into two groups. Each subject of experimental group drank 600ml of green tea (including 780 mg catechin) every day for continuous three months; each subject of placebo group drank placebo drink (600ml) every day for continuous three months. Blood collection for lipid and oxidative lag time of LDL were performed at the beginning and end of three months. Results revealed that HDL-c contents were significantly increased after three months of tea consumption. In addition, the oxidative lag time of LDL was greatly delayed from 48 mins to 57 mins. For anti-aging function, fifty subjects were divided into two groups. One group drank green tea (600ml including 780 mg catechin) in the first six months and placebo in the next six months, one month between these two periods was wash-out period; the other group drank placebo in the first six months and green tea drink in the next six months. Blood collection and anthropometric measurements were performed in the beginning、3rd month、6th month and after wash-out period. To futher understand the effect on liver, abdominal ultrasound examination were performed at the beginning and 6th month. Subjects with gastrointestinal uncomfort and low frequency were excluded. Forty-six subjects completely finished this thirteen-month trial. Results showed that no significant difference in body weight, body fat and after tea consumption. However, total antioxidant capability of plasma was significantly increased and TBARS values were greatly reduced. In addition, the levels of total phenols and GSH in plasma were significantly increased. Antioxidant enzymes such as glucose-6-phosphate dehydrogenase, catalase, glutathione peroxide and glutathione reductase in erythrocytes were significantly increased. Abdominal ultrasound examination showed that fatty liver syndrom of four subjects were improved after six months of green tea consumption.

並列關鍵字

green tea ； catechin ； LDL ； total antioxidant capability ； liver function ； antioxidant enzyme

參考文獻

陳明豐 (1992). 冠狀動脈與心臟病. 健康世界雜誌社，台北。

Allain, C. C., Poon, L. S., Chan, C. S., Richmond, W., and Fu, P. C. (1974). Enzymatic determination of total serum cholesterol. Clin Chem 20, 470-475.

Aebi, H. (1984). Catalase in vitro. Methods Enzymol 105, 121-126.

Agarwal, R., Katiyar, S. K., Khan, S. G., and Mukhtar, H. (1993). Protection against ultraviolet B radiation-induced effects in the skin of SKH-1 hairless mice by a polyphenolic fraction isolated from green tea. Photochem Photobiol 58, 695-700.

Ahmad, N., and Mukhtar, H. (1999). Green tea polyphenols and cancer: biologic mechanisms and practical implications. Nutr Rev 57, 78-83.