别在运动后用漱口水，会有反作用

In ads on TV, it all looks so simple. People use mouthwash, it instantly neutralises all the nasty bacteria hiding in their mouths, and – just like that – their dental hygiene is assured.

在电视广告里，什么东西看起来都很简单。人们使用漱口水以后，隐藏在口腔中的有害细菌立刻就被清除了。就这样，他们的口腔卫生得到了保证。

But what's really going on when you rinse a cap-load of antibacterial chemicals around your mouth? What does that to your body, and to other kinds of microorganisms that may actually be beneficial to health?

但你用一瓶盖的抗菌化学品冲洗口腔时究竟会发生什么呢？对你的身体会有什么影响？对其他有益健康的微生物又会有什么影响呢？

As a study showed last year, the downstream effects can be surprising, and far-reaching too, affecting much more than just your dental wellbeing.

去年一项研究表明，下游效应令人意外、影响深远，而且影响的不仅仅是口腔健康。

In an experiment led by scientists from the UK and Spain, researchers found that the simple act of using mouthwash after exercising can reduce one of the benefits of exercise: lowering blood pressure.

英国和西班牙的科学家进行了一项实验，研究人员发现锻炼后使用漱口水这一简单的行为会降低运动带来的一种好处：降血压。

When you exercise, your blood vessels open in response to the production of nitric oxide, which increases the diameter of blood vessels. This process is called vasodilation, and it increases blood flow circulation to active muscles.

锻炼时，血管会因一氧化氮的产生而打开，血管直径扩大。这一过程被称为血管舒张，能促进活跃肌肉的血液循环。

For a long time, researchers thought this only happened during exercise, but in more recent years, evidence has shown that circulation stays high (meaning blood pressure is lowered) even after exercise – thanks to how bacteria interact with a compound called nitrate, which forms when nitric oxide degrades.

很长时间以来，研究人员以为这只发生在运动期间。但近些年，有证据表明甚至在锻炼之后血液循环依然很快（这意味着血压下降了），这都是因为细菌在和一种叫作硝酸盐的化合物发生相互作用。硝酸盐是在一氧化氮降解时形成的。

"Research over the last decade has shown that nitrate can be absorbed in the salivary glands and excreted with saliva in the mouth," explains physiology specialist Raul Bescos from Plymouth University.

普利茅斯大学生理学专家Raul Bescos解释说：“过去十年的一项研究表明，硝酸盐能被唾液腺吸收，并在口中随唾液分泌。”

"Some species of bacteria in the mouth can use nitrate and convert into nitrite – a very important molecule that can enhance the production of nitric oxide in the body."

“口腔中一些细菌可以利用硝酸盐，转换成亚硝酸盐，这种重要的微粒可以提高人体内一氧化氮的产生。”

Once nitrite is produced and swallowed with saliva, it becomes absorbed into blood circulation and reduces back to nitric oxide, which keeps blood vessels wide and lowers blood pressure.

一旦产生亚硝酸盐，并随唾液一起吞咽，就会进入血液循环中，还原为一氧化氮，这样可以保持血管宽阔，降低血压。

But according to this small study, it looks like this biological mechanism can be significantly interrupted if anti-bacterial mouthwash gets added into the post-exercise mix.

但这项小型研究显示，如果运动后喝抗菌漱口水，这种生物学机制会大大减少。