洋蔥汁調降血脂之研究

洋蔥含有類黃酮、硫化物及多種維生素和礦物質。許多研究已指出洋蔥具有抗氧化、抗癌等功效，本研究以人體試驗探討洋蔥汁抗氧化及調降血脂之能力。 共計24位膽固醇偏高之健康受試者全程參與，採隨機、平行、雙盲、安慰劑組對照進行。本試驗將受試者分為兩組，受試者每日服用100㏄洋蔥汁或安慰劑飲料。試驗進行11週，試驗前1週為飲食調整期，試驗期為8週，試驗結束後的2週為觀察期，分別在0、2、6、8、10週採集血液檢體，並進行體位測量。結果顯示，飲用洋蔥汁10週後，體重與身體質量指數皆顯著降低；在抗氧化性方面，降低脂質過氧化，而體內總抗氧化力、血漿含硫官能基化合物含量顯著增加。此外，血漿總膽固醇及LDL-膽固醇的含量亦顯著降低，並顯著延長LDL之氧化時間。由本研究可知，每天飲用洋蔥汁可有效降低血脂、增加體內之抗氧化能力，對於心血管疾病可能具有預防之功效。

Onion contains flavonoids, sulfur-containing compounds and a lot of vitamins and minerals. Many studies indicated that onion showed antioxidation and anticarcinogen.This study was focused on the antioxidant capacity and hypolipidemic effects of onion juice. Twenty-four healthy subjects with board line high serum cholesterol (≧200mg/dL) was involved in the study. This was a randomized, parallel, placebo controlled and double blind design. We randomized subjects into two groups. Each subject drank 100ml of onion juice or placebo every day for continuous eight weeks. The total experimental period was eleven weeks, including one week of run in period, eight weeks of administration and two weeks of follow-up period. Anthropometric measurements, blood collecting were performed at the initial, 2nd, 6th ,8th,10th week of the testing period. After eight weeks of intervention, onion juice greatly decreased serum total cholesterol and low-density lipoprotein cholesterol (LDL-C). In addition, increasing total antioxidant capacity of plasma and longer lag-time of LDL oxidation were found. In conclusion, drinking onion juice could decrease plasma lipid and increase its antioxidant capacity. So onion juice probably showed benefit to the prevention of cardiovascular disease.