When people smoke, not only do they inhale burnt pieces of paper which damage their lungs, or have tar accumulate inside of them, which is likely to cause lung cancer, or inject nicotine into their bloodstream, which increases heart rate and blood pressure; it also causes the Y chromosome to eventually disappear. Of course, this only affects males, since the presence of a Y chromosome determines you’re male in gender, but for women smoking is still unhealthy and should be stopped.
Chemicals in tobacco affect this chromosome during cell division or mitosis when the chromosomes are being separated to either sides of the cell. Damage to the chromosome can build up until it eventually disappears. The study, carried out in Sweden, showed that people (men, specifically) who smoked had 33% more chances of loosing their Y chromosome compared to men who didn’t smoke.
However, it has been widely thought for many years that the Y chromosome is so small (in fact, it’s the smallest out of our 46 chromosomes), that its loss wouldn’t have too dire consequences. Past experiments on cells show that they can survive just as well without said chromosome. But new studies show that the lack of this chromosome, although not directly fatal, can shorten life duration and causes an increase in the likelihood of developing cancer. Lung cancer or any other cancer having to do with the respiratory system aside, male smokers are twice as likely to develop cancer as female smokers.
A possible explanation for this is that the Y chromosome contains tumour suppressing genes, so if it disappears, tumours are not going to be controlled and inhibited and therefore will be able to reproduce uncontrollably, causing cancer.
The newest research shows that this effect changes intensity depending on the dose of tobacco smoked. Obviously, the more tobacco you smoke, the more likely you are to suffer from its negative effects. But there’s a silver lining: this process is reversible. If you were to stop smoking, your cells would stop taking damage and after some time they’d be repaired, so you would have the same percentage of healthy cells with a Y chromosome as a non-smoker.