Large dog breeds age faster due to DNA methylation loss

Researchers have identified a molecular explanation for why large dog breeds tend to age faster and have shorter lifespans than smaller breeds. A study published in the journal Science, involving data from the Dog Aging Project, reveals that the accelerated aging is driven by epigenetic changes at the DNA level.

The study found that large dogs experience a faster loss of DNA methylation, a process that regulates gene activity. Specifically, there is a significant loss of control over “jumping genes” known as LINE1 transposable elements. These elements can replicate and insert themselves into different parts of the genome, causing instability. Large breeds lose approximately 35 percent more methylation in these LINE1 regions per year compared to smaller breeds.

Led by scientists from Arizona State University, the research analyzed DNA from hundreds of dogs. The findings suggest that this biological aging process begins early in life and is more pronounced in larger animals and males, though some data indicated females might also experience significant LINE1 activity. Because dogs share similar environments and lifestyles with humans, researchers believe these findings could provide valuable insights into the mechanisms of human aging.