Researchers believe this may be because smoking reduces the number of Y chromosomes in blood cells. (Video Via CNN)

Y chromosomes are only present in men and previous research has indicated cancer is more likely to occur when men lose those chromosomes.

To come to these conclusions, Uppsala University researchers in Sweden evaluated more than 6,000 men and looked at at how a variety of factors impacted Y chromosomes — including age, exercise, cholesterol and smoking.

In the end, researchers found both age and smoking appeared to be associated with loss of Y chromosomes.

But it's not all bad news for men. The study also noted Y chromosomes returned to the blood cells of those who kicked the habit, indicating the process may be reversible.

Earlier this year, the same researchers found a relationship between the loss of Y chromosomes and shorter lifespans in men.

They found the age-related loss of the Y chromosome may explain why men generally do not live as long as women.

That study is published in Nature Genetics.

This video includes images from Getty Images