READ THIS NEXT: Doing This at Night Could Lead to Heart Failure, Study Warns. Composed of proteins and DNA, chromosomes are structures found within the nuclei of cells that contain your genes. Within each human cell, there are two pairs of 23 chromosomes (a total of 46), two of which can differ depending on biological sex. Women have two X chromosomes, while men have one X and one Y chromosome. However, experts say many men begin losing their Y chromosomes as they age, a phenomenon known among scientists as hematopoietic mosaic loss of Y chromosome (mLOY). “At least 40 percent of males lose the Y chromosome from some of their blood cells by age 70. And by age 93, at least 57 percent have lost some of it,” The New York Times recently reported. READ THIS NEXT: If This Happens to You in the Bathroom, Get Checked for Heart Failure. Though researchers have been aware of mLOY for decades, much was still unknown about its impact on the body. Now, they’re exploring its link to age-related disease and higher risk of mortality in men.ae0fcc31ae342fd3a1346ebb1f342fcb To do so, one group of researchers studied genetically engineered male mice, who were “reconstituted with bone marrow cells lacking the Y chromosome.” They found that as the mice lost their Y chromosomes, they developed scar tissue on the heart, resulting in “reduced cardiac function,” heart failure, and increased mortality from heart disease. Though the study, published in the Jul. 2022 issue of the journal Science, used mice as subjects, the researchers behind the study believe their findings are applicable to human males. Other studies have supported this notion, having found a causal link between loss of Y chromosomes and chronic illnesses such as cancer and heart disease. Some scientists say this could help explain the difference in life expectancy between men and women. According to the CDC, women live an average of five years longer than men. According to a 2020 report by the health authority, women live an average of 80 years, while men live an average of 75 years. A 2014 study on the subject published in the journal Nature Genetics reviewed data from 1,153 men in Sweden. The team discovered that men who were missing the Y chromosome in a large percentage of their blood cells were at notably heightened risk of mortality in the years that followed. “I saw that men with loss of Y in a large proportion of their blood cells survived only half as long, 5.5 years versus 11.1 years,” Lars Forsberg, a researcher at Uppsala University and one of the study’s lead authors, told the Times. For more health news sent directly to your inbox, sign up for our daily newsletter. The New York Times reports that having low testosterone levels is unrelated to loss of Y chromosome, and testosterone supplements do not benefit men with mLOY. However, experts say there is one known way to reduce your risk of Y chromosome loss: quitting smoking. In fact, according to a separate study published in Science, smokers are up to four times more likely to lose all Y chromosomes in the blood cells, compared with non-smokers. Addicted to nicotine? Speak with your doctor for tips on how to quit—and to learn more about the benefits of doing so.
