Dogs’ DNA Ages 30 ‘Human Years’ in the First Year of Life

According to a study, dogs do not simply age seven times faster than humans. Rather, young dogs appear to be biologically much older than the equivalent young human.

Researchers at the University of California studied DNA methylation – the addition of methyl groups to the DNA molecule that can change gene expression without changing the DNA sequence itself. DNA methylation patterns change with age and can be used to accurately predict biological age in humans.

The researchers studied DNA methylation changes in around 100 Labrador retrievers and compared these to the equivalent methylation changes that are known to occur in humans. They found that a one year old dog has methylation changes equivalent to those of a 30 year-old human, suggesting a dog’s biological age may increase significantly faster at the start of its life before slowing down relative to human ageing.

This finding is interesting, as it demonstrates that while methylation changes may occur with age in many species, they don’t necessarily follow the same trajectory as each other.

Studying ageing in different species can provide important insights into human longevity, as it presents an opportunity to investigate the biological mechanisms that might distinguish a short-lived species from a long-lived one. Even species that are genetically very similar can have radically different lifespans, and understanding what causes this could help us extend longevity in humans.