Everyone knows that a woman who smokes and plans to become pregnant should stop smoking. A new study suggests that the future father should quit, too.

人人都知道，吸烟的女性如果计划怀孕，就应该戒烟。一项新研究表明，计划要孩子的男性也应该戒烟。

Brazilian researchers analyzed¹ the sperm² of 20 smokers³ and 20 nonsmokers and found that the smokers’ sperm was damaged in ways that could reduce the chance of fertilization and might also lead to health problems in the baby.

巴西的一些研究人员分析了20位吸烟者和20位不吸烟者的精子，发现吸烟者的精子受到了损伤，而这可能降低卵子成功受精的几率，还可能为婴儿带来健康问题。

The DNA⁴ in smokers’ sperm was fragmented, probably because of oxidative stress from the cadmium and nicotine⁵ in cigarette smoke. Sperm DNA fragmentation has been shown in other studies to be associated with an increased risk of genetic⁶ problems in the offspring as well as with an increased risk of childhood cancer. Mitochondria, the energy centers of cells, were also less active in the sperm of smokers.

吸烟者精子中的DNA出现了断裂，究其原因或许是香烟烟雾中的镉和尼古丁诱导了氧化应激。其他一些研究显示，精子DNA断裂会增加后代遗传病的发病率，以及在儿童时期患上癌症的风险。吸烟者精子中的线粒体活性也较低。线粒体是细胞的能量中心。

The study, in BJU International, also found that smokers had a larger percentage of nonintact acrosomes, the part of the head of the sperm that releases enzymes⁷ that allow the sperm to penetrate⁸ the ovum’s shell. And the researchers discovered alterations⁹ in the proteins in smokers’ seminal¹⁰ plasma¹¹ that might impair¹² fertilization.

这份发表在《英国国际泌尿学期刊》(BJU international)上的研究报告还显示，吸烟者精子顶体——位于精子头部，会释放让精子穿透卵子外壳的酶——的完整率也更低一些。此外，研究人员发现，吸烟者精浆中的蛋白质出现了可能会影响受精的变化。

“All these effects were found in smokers,” said the senior author, Ricardo Pimenta Bertolla of the São Paulo Federal University. The message, he said, is straightforward¹³: Smoking alters a man’s capacity to produce sperm that can successfully fertilize¹⁴ an egg.

“我们在吸烟者身上发现了所有这些后果，” 研究报告的资深作者、圣保罗联邦大学(São Paulo Federal University)的里卡多·皮门塔·贝尔托拉(Ricardo Pimenta Bertolla) 表示。他说，很明显：吸烟会损害男性排出那些能让卵子成功受精的精子的能力。