Nogueira Lívia de P, Nogueira Neto José Firmino, Klein Márcia R S T, Sanjuliani Antonio F
a Clinical and Experimental Pathophysiology , Rio de Janeiro State University , Rio de Janeiro , BRAZIL.
b Lipids Laboratory , Rio de Janeiro State University , Rio de Janeiro , BRAZIL.
J Am Coll Nutr. 2017 Feb;36(2):108-115. doi: 10.1080/07315724.2016.1194236. Epub 2016 Oct 31.
Green tea consumption has been inversely associated with cardiovascular disease (CVD) in epidemiological studies. Although some interventional trials suggest that green tea has beneficial effects on CVD risk factors, such as hypertension and obesity, others have failed to show such benefits.
To evaluate the short-term effects of green tea on blood pressure, endothelial function, metabolic profile, and inflammatory activity in obese prehypertensive women.
This study was a crossover, randomized, double-blind, placebo-controlled clinical trial. Participants were randomly allocated to receive daily 3 capsules containing either 500 mg of green tea extract (GTE) or a matching placebo for 4 weeks, with a washout period of 2 weeks between treatments. Each GTE capsule contained 260 mg of polyphenols. At the beginning and at the end of each treatment, participants were submitted to evaluation of blood pressure (ambulatory blood pressure monitoring, ABPM), endothelial function (Endo-PAT 2000 and cellular adhesion molecules), nutritional parameters, metabolic profile, and biomarkers of inflammation.
Twenty women age 41.1 ± 8.4 years completed the study. After 4 weeks of GTE supplementation in comparison with placebo, there was a significant decrease (p < 0.05) in systolic blood pressure at 24 hours (-3.61 ± 1.23 vs 1.05 ± 1.34 mmHg), daytime (-3.61 ± 1.26 vs 0.80 ± 1.57 mmHg), and nighttime (-3.94 ± 1.70 vs 1.90 ± 1.66 mmHg). Changes in diastolic blood pressure and in all other parameters did not present a significant difference between GTE and placebo.
The findings of this study suggest that in obese prehypertensive women, short-term daily intake of GTE may decrease blood pressure.
在流行病学研究中，饮用绿茶与心血管疾病（CVD）呈负相关。尽管一些干预试验表明绿茶对心血管疾病风险因素（如高血压和肥胖）有有益影响，但其他试验未能显示出此类益处。
评估绿茶对肥胖的高血压前期女性的血压、内皮功能、代谢状况和炎症活性的短期影响。
本研究为交叉、随机、双盲、安慰剂对照临床试验。参与者被随机分配，每天服用3粒含有500毫克绿茶提取物（GTE）的胶囊或匹配的安慰剂，为期4周，治疗之间有2周的洗脱期。每粒GTE胶囊含有260毫克多酚。在每次治疗开始和结束时，对参与者进行血压评估（动态血压监测，ABPM）、内皮功能（Endo-PAT 2000和细胞粘附分子）、营养参数、代谢状况和炎症生物标志物的评估。
20名年龄为41.1±8.4岁的女性完成了研究。与安慰剂相比，补充GTE 4周后，24小时收缩压显著降低（p<0.05）（-3.61±1.23对1.05±1.34毫米汞柱），白天（-3.61±1.26对0.80±1.57毫米汞柱）和夜间（-3.94±1.70对1.90±1.66毫米汞柱）。舒张压和所有其他参数的变化在GTE和安慰剂之间没有显著差异。
本研究结果表明，在肥胖的高血压前期女性中，短期每日摄入GTE可能会降低血压。
