Cigarettes, smoking
Research shows why smoking increases risk of cancer, early death in men and chances of having a baby girl.Reuters

Smoking has been known to increase the risk of cancer in men than women. However, till date, it was not clear what factors exactly contributed to this occurrence.

A new study published in Science has found that smoking kills the Y chromosome in blood cells, which further increases the risk of cancer and early death.

Researchers from the Uppsala University in Sweden based their findings on a previous study they published early this year. At that time, they had reported that loss of the Y chromosome from the blood cells played a huge role in cancer.

In the new study, Lars Forsberg and colleagues analysed the roles of different factors including age, blood pressure, diabetes, alcohol intake and smoking in disappearance of the Y chromosome.

Loss of the Y chromosome was more common in smokers than non-smokers. However, the loss was temporary and the men who stopped smoking had the same number of Y chromosomes as non-smokers.

"These results indicate that smoking can cause loss of the Y chromosome and that this process might be reversible. We found that the frequency of cells with loss of the Y chromosome was not different among ex-smokers compared to men who had never smoked. This discovery could be very persuasive for motivating smokers to quit," Forsberg, said in a news release.

While explaining the link between loss of Y chromosome and cancer, researchers said that it may be because the immune cells with reduced Y chromosomes become less capable of fighting infections.

"This finding may in part explain why men in general have a shorter life span than women, and why smoking is more dangerous for men," researcher Jan Dumanski, explained.

How Smoking Increases Chances of Having Baby Girls

Meanwhile, another study in The Lancet released in 2002 had shown that smoking couples were more likely to get girl babies than boys as the tobacco damaged the Y chromosome in sperms, The Daily Mail reported. More than 11,800 new-borns in Japan and Denmark were included in the study.