Smoking May Permanently Damage Genetic Material

Here is another reason to not light up a cigarette.

这是另一个不吸烟的原因。

Smoking can permanently damage your genetic material, according to a new study.

根据一项新的研究，吸烟会永久性地损害你的遗传物质。

Researchers at the Hebrew SeniorLife Institute for Aging Research say smoking leaves a long-term "footprint" on a person's DNA or deoxyribonucleic acid. The researchers have ties to Harvard Medical School in the American state of Massachusetts.

希伯来人老年研究所的研究人员说，吸烟会在人的DNA或脱氧核糖核酸上留下长期的“脚印”。研究人员与美国马萨诸塞州的哈佛医学院有联系。

DNA is the genetic material of which all living things are formed. Health problems, like heart disease and cancer, are believed to be at least partly a result of damage to a person's DNA.

dna是所有生物形成的遗传物质。健康问题，如心脏病和癌症，被认为至少部分是由于一个人的DNA受损。

The changes in the genes are a result of a natural process called "DNA methylation." It changes how the DNA works or operates, and possibly affects the body's natural defenses against disease.

基因的变化是一种叫做“DNA甲基化”的自然过程的结果，它改变了DNA的工作或运作方式，并可能影响身体对疾病的自然防御。

Roby Joehanes is the first author of a report on the study. He said the researchers found ‘compelling evidence' that smoking has a long-lasting influence on our ‘molecular machinery.'

Roby Joehanes是这项研究报告的第一作者。他说，研究人员发现了“令人信服的证据”，证明吸烟对我们的“分子机制”有着长期的影响。

"The encouraging news is that once you stop smoking, the majority of DNA methylation signals return to never smoker levels after five years, which means your body is trying to heal itself of the harmful impacts of tobacco smoking," he said.

他说：“令人鼓舞的消息是，一旦你戒烟，5年后，大部分DNA甲基化信号会恢复到从不吸烟的水平，这意味着你的身体正在努力治愈吸烟的有害影响。”

However, cigarette smoking can still have an influence on people's health more than 30 years after they stopped smoking, he said.

不过，他说，戒烟30多年后，吸烟仍然会对人们的健康产生影响。

The researchers studied blood samples from 16,000 people, smokers and non-smokers alike. They found that for most, DNA damage resulting from smoking slowly disappeared five years after people quit smoking.

研究人员研究了16000名吸烟者和不吸烟者的血液样本。他们发现，大多数情况下，人们戒烟五年后，吸烟导致的DNA损伤慢慢消失。

But some of the damage appeared to be permanent.

但有些损害似乎是永久性的。

Researchers said in the study, the smokers experienced changes to more than 7,000 genes. That is about one-third of known human genes.

研究人员说，在这项研究中，吸烟者经历了7000多个基因的变化。这大约是已知人类基因的三分之一。

DNA methylation is one of the ways genes are expressed, or show up, in the body. It affects which genes ‘turn on' and that can lead to the development of smoking-related diseases, said Dr. Stephanie J. London. She works at the U. S. National Institutes of Health and was another author of the study.

dna甲基化是基因在体内表达或显现的方式之一。斯蒂芬妮·J·伦敦博士说，它会影响哪些基因“启动”，从而导致与吸烟有关的疾病的发展。她在美国国立卫生研究院工作，也是这项研究的另一位作者。

"Equally important is our finding that even after someone stops smoking, we still see the effects of smoking on their DNA," she said.

她说：“同样重要的是，我们发现，即使有人戒烟，我们仍然能看到吸烟对他们DNA的影响。”

Smoking is the leading cause of preventable health disorders. It kills an estimated 480,000 Americans every year, according to the Centers for Disease Control and Prevention.

吸烟是可预防的健康障碍的主要原因。据美国疾病预防控制中心（centers for disease control and prevention）估计，每年约有48万美国人死于艾滋病。

Smoking is believed to cause more than 6 million deaths worldwide each year, mostly through cancer, heart disease and lung disease.

据信，吸烟每年在世界范围内造成600多万人死亡，主要是癌症、心脏病和肺病。

Campaigns to get people to give up smoking have seen some success in the United States. Smoking levels have dropped. Now only an estimated 15 percent of the adult population smokes.

促使人们戒烟的运动在美国取得了一些成功。吸烟水平下降了。现在估计只有15%的成年人吸烟。

The study was published in the American Heart Association journal,Circulation: Cardiovascular Genetics.

这项研究发表在美国心脏协会期刊《循环：心血管遗传学》上。

I'm Anne Ball.