Male smokers are 3 times more likely than non-smoking males to lose their Y chromosomes in blood cells as they age, a new study published in Science suggests.


Although it is a known fact, according to scientists, that as men grow older, the Y chromosome can begin to disappear from some of their somatic (normal, non-sex) cells: a team of Finnish researchers had already revealed that males who are losing the Y chromosome from their red blood cells have a higher risk of cancer.

Because it was initially thought to be a normal part of aging, the scientists still not sure if we can consider the results of this research as an answer to the wonders of why men develop and die from many cancers at disproportionate rates compared to women.

According to the research, there is a connection between Y chromosome loss and a shorter life span. A higher risk of multiple cancers could be considered when the immune cells in the blood, which would otherwise fight cancer, may be hampered without their Y chromosome.

The research published in the journal Science, from a team led by Lars Fosberg and Jan P. Dumanski of Sweden’s Uppsala University, looked at blood samples from about 6,000 men taking part in other health studies. They looked at the men’s blood samples and lifestyle factors including age, blood pressure, diabetes and drinking. The research discovered:

“These … could explain why males are more frequently affected by cancer and suggest that chromosome Y is important in processes beyond sex determination.”

According to IFL Science, the scientists found: the more the men smoked, the more likely they were to be missing the Y chromosome in their blood cells, adding that the loss of Y chromosomes from blood cells was found in 8.2% of elderly men in a sample of 1,153, and that those affected had life expectancies 5.5% shorter and three and half times the rate of cancer, after excluding haematological cancers.

The loss of Y chromosomes leads to an important question: how could this happen?

Lars Forsberg, a researcher at Finland’s Uppsala University who led the study, explained that the copies of all of the chromosomes are made and sorted into the two new daughter cells during cell division, adding that chromosomes are sometimes lost during the complex process. RT reported:

“Usually, a missing chromosome would result in the death of the new cell, but cells can survive without a Y chromosome.”

Lars Forsberg also said:

“The cells that lose the Y chromosome… they don’t die. But we think that they would have a disrupted biological function.”

It’s known that Men have an X and a Y chromosome, while women have two X chromosomes. But the Y chromosome supervises more than the production of male hormones. It may have an effect on how the body fights cancer, the Finnish team claimed. It is an interesting question as to why female immune cells work fine without a Y chromosome, and yet somehow male immune cells would be inhibited by its loss.


The researchers reportedly said:

“There is a correlation between a common and avoidable risk factor, that is smoking, and the most common human mutation — loss of the Y chromosome.”

Dr. Martin Bialer, a medical geneticist at North Shore-LIJ Health System in Great Neck, N.Y. who was also involved in the study said:

“The bottom two-thirds of the Y chromosome was seen as just repetitive DNA that doesn’t code for anything. But now we’re starting to think it may have more roles than just determining sex — though that’s a pretty important one.”

Forsberg’s team also revealed that the Y chromosome actually contains a large number of genes; their jobs are not fully understood yet. At least a couple of those genes may help suppress tumors, though. Forsberg and his team still have no answer for the question of which blood cells lose their Y chromosomes and which ones don’t. That’s what they hope to know with further research.

Previous studies have shown that men are more likely to get non-lung cancers from smoking than women are — from bladder cancer to colon cancer, according to The Daily Mail, it added:

“It might be that smoking damages DNA in general and that the Y chromosome, which is one of the smallest chromosomes in the human genome and already mutation-prone, is just more vulnerable, the researchers say. More research is needed to get the answer.”

Because of the fact that many people may not know everything smoking can potentially lead to, a lot of them are looking for ways to quit. It’s wise to find out and be motivated from what happens when you quit smoking.


(1) Science

(2) The Daily Mail

(3) IFL Science