多吃蓝莓真的可以降血压吗

Can a cup of blueberries keep the doctor away? Maybe.

一杯蓝莓能保持身体健康？也许能。

Researchers conducted a randomized, double-blind, placebo-controlled study of 40 postmenopausal women ages 45 to 65 with high blood pressure. Half ate 22 grams of freeze-dried blueberry powder (equivalent to a cup of blueberries) daily for eight weeks. The others consumed an identical-looking and tasting placebo.

研究者对40位45岁至65岁的绝经后高血压妇女进行了一项随机、双盲、安慰剂对照的研究。其中一半每天吃22克冷冻干燥的蓝莓粉（相当于一杯蓝莓），共吃八周。另一半服用一种外观和味道与蓝莓粉完全相同的安慰剂。

The study, in The Journal of the Academy of Nutrition and Dietetics, found that those who ate the blueberry preparation saw an average 5.1 percent decrease in systolic blood pressure (the top number) and a 6.3 percent decrease in diastolic pressure. Levels of nitric oxide, known to be involved in relaxing and widening blood vessels, increased significantly in the blueberry eaters. There were no significant changes in the placebo group.

这项发表在《美国营养与饮食学会会刊》上的研究发现，蓝莓粉服用者的收缩压（高压）平均降低了5.1%，舒张压平均降低了6.3%，一氧化氮水平提高了很多——一氧化氮有助于放松和扩张血管。安慰组的相关指数没有显著变化。

The improvement, the scientists write, was moderate compared with that of blood pressure medicines. But, they say, eating blueberries in larger amounts or for longer periods could increase the effect.

研究者们写道，这些改善与降压药的作用相比较为温和。但是他们说，长期大量食用蓝莓能提升效果。

The lead author, Sarah A. Johnson, a postdoctoral researcher at Florida State University, said she saw no reason for people to radically change their diet, but that if they are not eating blueberries, they might want to try them. “There is something very special about the composition of blueberries that is responsible for their effect on blood pressure,” she said. “Other fruits and plant extracts have not produced the same result.”

这项研究的主要作者莎拉·A·约翰逊(Sarah A. Johnson)是佛罗里达大学的博士后研究员。她认为人们没必要彻底改变饮食习惯，但是如果他们没有在吃蓝莓，可以尝试一下。“蓝莓的成分中有一种很特别的东西，对降压有效，”她说，“其他水果和植物萃取物没有这样的效果。”