含γ-胺基丁酸之飲品調節血壓效果之研究

γ- 胺基丁酸 (γ- aminobutyric acid, GABA)為神經傳導抑制物質，可以抑制過度興奮的神經傳導訊息，對於交感神經也有調節之作用，當血管過度收縮而導致高血壓時，GABA可以抑制交感神經傳導物質正腎上腺素之釋放，進而調節血壓。本試驗以含GABA的飲品輔助血壓調節，進行隨機平行雙盲人體試驗，受試者為20歲以上之成年人，連續兩週穩定收縮壓介於120～159 mmHg或舒張壓介於80～99 mmHg，於確認後開始每天飲用2瓶含GABA之飲品 (20mg/ 瓶)或安慰劑連續8週，每兩週檢測血壓變化，觀察飲用含GABA之飲品是否具血壓調節功效，另外每四週採取血液檢體分析血球、血脂、肝、腎功能、血糖、尿酸、電解質、正腎上腺素、血管收縮素轉化酶等生化指標，作為觀察受試物是否會對人體造成其他影響。完成試驗者為40位結果發現連續飲用GABA飲品8週後，收縮壓從136.75±11.10 mmHg非常顯著下降至121.65±12.24 mmHg (p< 0.001)，舒張壓從84.95±7.23 mmHg則是下降至81.05±9.30 mmHg，分別下降了15.10±7.06 mmHg (11.04 %)及3.90±6.43 mmHg (4.06 %)。試驗期間兩組之收縮壓從第2週開始即有顯著差異 (p< 0.01)，效果持續到第8週。進一步將受試者分為高血壓第一期組7位及高血壓前期組13位，探討GABA飲品對於血壓高族群之影響，結果發現高血壓第一期組收縮壓於試驗期間其變化幅度均高於高血壓前期組，且於第四週有顯著差異。另外也將血脂與飯前血糖分為正常組與偏高組。結果發現，總膽固醇與飯前血糖，兩組變化幅度雖無顯著差異，但偏高組之降低幅度皆高於正常組。不論是飲用含GABA飲品或是安慰劑之受試者之生化指標及體位測量值於試驗前後並無顯著差異。試驗結果顯示，飲用含GABA之飲品可能因透過抑制正腎上腺素之釋放以及抑制血管收縮素轉化酶的之活性，進而輔助血壓偏高之患者調節血壓，且對人體無不良影響。

γ- aminobutyric acid (GABA) is a nerve conduction inhibitory substance that can suppress excessively excited nerve conduction signals and have a regulatory effect on sympathetic nerves. When blood vessels contract excessively, resulting in high blood pressure, GABA can inhibit the release of sympathetic nerve conduction substance norepinephrine, thereby regulating blood pressure. In this study, GABA drink was used to assist blood pressure regulation. This is a random parallel double-blind human trial. The subjects were adults and age over 20 years. Subjects inclusion criteria were systolic blood pressure (SBP) is 120-159 mmHg, or diastolic blood pressure (DBP) is 80-99 mmHg. After confirmation, start drinking two bottles of GABA drink (20 mg/ bottle) or placebo for eight weeks and check blood pressure changes every two weeks Thus study aims to observe whether drinking GABA drink has a blood pressure-lowering effect. Collected blood samples at 0, 4, 8 weeks to analyze blood cells, blood lipids, liver and kidney function, blood glucose, uric acid, electrolytes, norepinephrine (NE) and angiotensin-converting enzyme (ACE). Total of 40 people completed and found that after drinking GABA drink continuously for eight weeks, the SBP decreased very significantly from 136.75±11.10 mmHg to 121.65±12.24 mmHg (p< 0.001), and the DBP decreased from 84.95±7.23 mmHg to 81.05±9.30 mmHg, there was a decrease of 15.10±7.06 mmHg (11.04 %) and 3.90±6.43 mmHg (4.06 %), respectively. During the trial period, the SBP of the two groups was significantly different from the second week (p< 0.01), and the effect continued until the eighth week. The subjects were further divided into seven patients in the hypertension group and 13 patients in the pre-hypertension group to discuss the effects of GABA on the high blood pressure group. The results showed that the SBP of the hypertension group had a higher-lowering change than the pre-hypertension group, and there was a significant difference in the fourth week. In addition, blood lipids and blood glucose were divided into normal group and higher group. Although there was no significant difference in total cholesterol and blood glucose between the two groups, the higher group was higher-lowering than the normal group. There was no significant difference in the liver and kidney function, and anthropometric measurements of subjects who consumed the GABA drink or placebo before and after the trial. The results show that drinking GABA drink may help subjects with high blood pressure to regulate blood pressure by inhibiting the release of NE and inhibiting the activity of the ACE, and without side effect.