Compared to their non-smoking male counterparts, male smokers face a threefold increased risk of losing their Y chromosomes, according to a new study.
In a recent study published in the journal Science, experts from Uppsala University (Sweden) discovered that the Y chromosome, which plays a critical role in determining male sex and sperm production, is lost more frequently in the blood cells of heavy smokers than in those of their non-smoking peers or those who have just started smoking.
As only men possess the Y chromosome, this finding may explain why the rates of men diagnosed with and dying from various cancers are higher than those of women. Another recent study found a correlation between the loss of the Y chromosome and shorter lifespan as well as a higher risk of developing multiple types of cancer.
Compared to their non-smoking peers, male smokers face a threefold increased risk of losing their Y chromosomes in their blood cells. (Image source: Getty Images)
“There is a correlation between a common but preventable risk factor – smoking – and the most prevalent mutation in humans – the loss of the Y chromosome. This may partly explain why men generally have shorter lifespans than women and why smoking poses greater risks for men,” emphasized Professor Jan Dumanski, a member of the research team.
In addition to the deadly risk of lung cancer, smoking is also a leading risk factor for a range of other serious diseases. It is a major cause of early death from chronic conditions (such as heart disease, stroke, and high blood pressure), which are preventable worldwide.
Epidemiological data reveal that male smokers face a higher risk of developing non-lung-related cancers, such as colorectal cancer, compared to female smokers.
The research team analyzed data from over 6,000 men, accounting for age, exercise habits, cholesterol levels, education, alcohol consumption, and various other health and behavioral factors. They found that for smokers, the loss of the Y chromosome appears to be dose-dependent. In other words, the more a man smokes, the more Y chromosomes he loses. However, if a smoker can quit, this loss of the Y chromosome will not continue.
The probability of losing Y chromosomes in the blood cells of male smokers is three times higher than that of non-smokers.
However, the research team also noted that some men who quit smoking seem to recover their Y chromosomes. Researcher Lars Forsberg stated that this could serve as motivation for smokers to give up this unhealthy habit.
What is the impact of Y chromosome loss? Some preliminary studies have indicated that the loss of the Y chromosome in blood cells does not cause certain blood-related cancers, but men are at risk of various other diseases, including 12 types of cancer and Alzheimer’s disease. Additionally, in a study published in Science last July, researchers found that when hematopoietic stem cells in the blood lost their Y chromosome, the hearts of the mice weakened and developed scarring, while they faced a higher risk of heart failure leading to death and cardiovascular dysfunction. Some investigations have suggested that a similar situation occurs in male smokers. “Especially after the age of 60, men have a significantly higher mortality rate than women. It seems they age biologically faster,” the research team at the University of Virginia indicated. Not only blood cells losing the Y chromosome can be harmful. Recently, scientists from Cedars-Sinai Medical Center in the United States published a study in the journal Nature, discovering that among bladder cancer patients, 10% to 40% of tumors in these individuals would lose their Y chromosome. This is not surprising, as factors such as smoking and chemical exposure can lead to increased or decreased levels of methylation on the Y chromosome. However, these tumors that have lost the Y chromosome are more likely to become malignant, meaning they are harder to treat and more lethal. Researchers compared over 200 patients with the same type of bladder cancer and found that those with tumors that lost the Y chromosome not only grew faster than those without loss but also had worse prognoses after surgery. Researchers speculate that the loss of the Y chromosome may be a better survival strategy for tumors. They grow faster and evade immune responses more effectively. |
Scientists still do not know exactly how much Y chromosome loss in blood cells is related to cancer development, although there remains the possibility that immune cells in the blood that have lost the Y chromosome may be less capable of fighting cancer cells. They claim that further research is needed to solve this mystery.
