Many think that every human year is the equivalent of seven years of the dog. It is a wrong thinking and, above all, without any scientific certainty. To eradicate this myth, a team of scientists has created a formula that more accurately compares the age of men and their best four-legged friends.
The formula is based on the changing patterns of methyl groups in dog and human genomes which, in a nutshell, change with age. Since the two species don’t age at the same rate during their life, it turns out that it is not possible to conduct a perfectly linear comparison, as the rule suggests: 1 human year equals 7 canine years.
This technique will be very useful for veterinarians and to evaluate anti-aging interventions. The formula provides a new “epigenetic clock”, a method of determining the age of a cell, tissue or organism. Epigenetic changes provide scientists with clues to the age of a genome, just like the wrinkles on a person’s face provide clues to their age.
The team of researchers analyzed the blood of 105 labrador retrievers. Since dogs live near us, perhaps more than any other animal, the environmental and chemical exposures of these creatures are very similar to humans and receive almost the same levels of health care. What emerged from the study is a graph (visible at the bottom of the news) that can be used for match the age of our four-legged friend to that of a human being.
The comparison is not a 1: 7 ratio. When dogs are young, they age rapidly compared to humans. A one year old dog is similar to a 30 year old human being; while a four year old dog is similar to a 52 year old person. At seven years of age, the creature’s aging slows down. “This makes sense: after all, a nine-month-old dog can have puppies, so we already knew that the 1: 7 ratio was not an accurate measure of age“says senior study author Trey Ideker.
This model has a limit: it was developed using a single breed of dog, and some breeds of dogs are known to live longer than others. Therefore, other studies are needed. Did you know? Dogs also go through a “puberty phase”.