即使没有尼古丁，只吸一次也能立即改变你的血管

即使没有尼古丁，只吸一次也能立即改变你的血管

For more than a decade, vaping has been sold as a safer alternative to smoking cigarettes. But puffing on an e-cigarette is not without its harms.

十多年来，电子烟一直被视为比吸烟更安全的选择。但是吸电子烟也有它的危害。

In recent years, a growing number of concerns have surfaced over vaping and its potential to disrupt our health. Normal cigarettes are a leading cause of cardiovascular disease in the United States, and a new study suggests the effects of e-cigarettes may also travel beyond the lung.

近年来，越来越多的人开始关注电子烟及其对健康的潜在危害。在美国，普通香烟是导致心血管疾病的主要原因，而一项新的研究表明，电子烟的影响也可能不只是肺部。

After just one puff, researchers at the University of Pennsylvania found an immediate change in the body's blood vessels and circulation, even when there was absolutely no nicotine present.

宾夕法尼亚大学的研究人员发现，只要吸一口，即使完全不含尼古丁，人体内的血管和血液循环也会立即发生变化。

"E-cigarettes are advertised as not harmful, and many e-cigarette users are convinced that they are just inhaling water vapour," says radiologist Alessandra Caporale.

放射科医生亚历山德拉·卡波拉说：“电子烟的宣传是无害的，许多电子烟使用者相信他们只是在吸入水蒸气。”

"But the solvents, flavourings and additives in the liquid base, after vaporisation, expose users to multiple insults to the respiratory tract and blood vessels."

但液体碱中的溶剂、调味剂和添加剂在蒸发后，会使使用者受到呼吸道和血管的多重损伤。

E-cigarettes essentially work by converting a liquid base into an aerosol that is easily puffed into your lungs. This liquid usually contains some combination of propylene glycol, glycerol, nicotine, water, flavorings, or preservatives.

电子烟的工作原理是将液态碱转化成一种容易被吹进肺部的气溶胶。这种液体通常含有丙二醇、甘油、尼古丁、水、调味品或防腐剂的某种组合。

To research the health effects of just the vape juice, Caporale and her colleagues examined 31 adults, aged between 19 and 33, who had no history of smoking or overt cardiovascular, respiratory, or neurovascular issues.

为了研究电子烟对健康的影响，Caporale和她的同事对31名年龄在19岁到33岁之间的成年人进行了检查，这些人没有吸烟史或明显的心血管、呼吸或神经血管问题。

Each of these participants was given a vape with a cartridge that contained no nicotine, only a mix of water and propylene glycol or glycerol. Participants were then instructed to take 16 three-second puffs; an MRI was used to examine their blood vessels before and after.

每一个参与者都得到了一个装有尼古丁的真空聚乙烯，里面没有尼古丁，只有水和丙二醇或甘油的混合物。然后要求受试者吸16口三秒钟的烟，并用核磁共振检查前后的血管。

Focusing on three arteries in the leg, heart, and brain, the researchers noticed a lack of constriction in each one by more than 30 percent. On average, their blood vessels dilated 34 percent less than they did before vaping.

研究人员将注意力集中在腿部、心脏和大脑的三条动脉上，发现每一条动脉的收缩率都超过30%。平均来说，他们的血管比打气前扩张了34%。

By cuffing the leg and then releasing it, researchers also noticed a 25 percent reduction in blood acceleration after vaping, and peak blood flow was reduced by 17.5 percent. At the same time, oxygen levels within these vessels also dropped by 20 percent.

研究人员还注意到，在抽完烟后，将腿铐起来然后松开，血液加速速度降低了25%，峰值血流量减少了17.5%。与此同时，这些血管内的氧气含量也下降了20%。

"We did expect an effect, but we never thought the effect was as big as what we found," radiologist Felix Wehrli told Wired. "It's not just a little change we detect - it's a major effect."

放射学家费利克斯·韦利告诉《连线》杂志:“我们确实预期会有效果，但我们从未想过效果会像我们发现的那么大。”“这不仅仅是我们发现的一个小变化——这是一个重要的影响。”

It's important to note that the sample size here is small. But the findings do suggest that vaping might be damaging to the inner lining of our blood vessels, known as the endothelium.

需要注意的是，这里的样本量很小。但研究结果确实表明，蒸汽可能会损害我们血管内的内皮细胞。

Endothelial injury is thought to be a key initiating event in the build-up of plaque in our arteries, and even though the vascular inflammation was short-lived and reversible, it suggests there's something more insidious at play. And it has nothing to do with nicotine.

内皮细胞损伤被认为是动脉斑块形成的一个关键起始事件，尽管血管炎症是短暂的和可逆的，但它表明有一些更隐蔽的因素在起作用。它与尼古丁无关。

"The common belief is that the nicotine is what is toxic, but we have found that dangers exist, independent of nicotine," says Wehrli.

韦赫利说：“人们普遍认为尼古丁是有毒的，但我们发现，独立于尼古丁，存在危险。”

"Clearly if there is an effect after a single use of an e-cigarette, then you can imagine what kind of permanent damage could be caused after vaping regularly over years."

“很明显，如果一次性使用电子烟有效果，那么你可以想象多年来定期吸电子烟会造成什么样的永久性损害。”

While the ingredients in vape liquid might be harmless to eat, when they are heated, they have the potential to turn toxic. Once inhaled, these toxins could then seep into the bloodstream, potentially leading to vascular inflammation or oxidative stress.

虽然电子烟液体中的成分可能是无害的，但当它们被加热时，它们有可能变成有毒物质。一旦吸入，这些毒素就会渗入血液，可能导致血管炎症或氧化应激。

Given that vapes have only been around for some 15 years, it's currently impossible to say what the long-term effects are but even the short term effects have only recently been explored.

考虑到电子烟只存在了大约15年，目前还不可能说出长期效应是什么，但即使是短期效应也只是最近才被研究过。

In 2017, a study on mice found just five minutes of vaping can damage blood vessels, causing stiffness and narrowing. A year later, researchers noticed a loss of endothelial cell function in the blood vessels of those people who vaped. In fact, the harmful effects they found were similar to smoking tobacco cigarettes.

2017年，一项针对老鼠的研究发现，仅仅五分钟的蒸汽就会损害血管，导致血管僵硬和变窄。一年后，研究人员注意到那些吸电子烟的人的血管内皮细胞功能受损。事实上，他们发现的有害影响类似于吸烟。

As of this week, over 150 people in the United States have fallen ill with a severe and potentially dangerous lung injury linked to e-cigarette use. Some of these patients had such bad respiratory failure, they were sent to intensive care and put on ventilators.

截至本周，美国已有150多人因使用电子烟而导致严重且潜在危险的肺损伤而生病。其中一些病人严重呼吸衰竭，他们被送往重症监护室，并使用呼吸机。

The Centres for Disease Control and Infection have now launched an investigation into the cause.

疾病控制和感染中心现在已经对病因展开调查。

Michael Siegel, a health scientist at Boston University who didn't take part in the research, told Live Science that the new study confirms e-cigarettes seem to cause some dysfunction of the blood vessels, although the effect appears to be short-lived.

波士顿大学的健康科学家迈克尔·西格尔(Michael Siegel)没有参与这项研究，他告诉《生活科学》(Live Science)，这项新的研究证实了电子烟似乎会导致一些血管功能障碍，尽管这种效应似乎是短暂的。

"Further research will be needed to determine whether vaping poses a risk of irreversible blood vessel injury," he said.

他说:“要确定电子烟是否会造成不可逆转的血管损伤，还需要进一步的研究。”

The findings have been published in Radiology.

研究结果发表在《放射学》杂志上。