By Matt Kaeberlein
Original Publication: Época Negócios
A better understanding of the mechanisms of ageing through research on dogs could lead to more effective and economical interventions that prolong good health in old age.
Longevity has long been a desire of mankind. Peter Pan's dream of eternal youth encourages us to want to live longer and better. But the longed-for "young forever" is far from a reality. And it's in this context that science is advancing to provide greater health, mobility, cognition and, consequently, a delay in the symptoms of old age. This "passing of the years" affects not only us humans. Like any good best friend, dogs are also by our side at this time, suffering from the same consequences of cellular degeneration. It is precisely because they live in the same environment as us and respond in much the same way to the arrival of old age that the science supporting canine longevity is valuable, and can also revolutionize our understanding of living longer and better.
The study of canine longevity involves an in-depth analysis of the biological processes that impact ageing, such as genetics and environmental variables, for example. As with humans, each dog is unique and will exhibit different signs of old age when they reach senior status. Some will show physical changes, such as slowness, cloudy eyes and lethargic senses. Others may show behavioral changes, such as increased anxiety or disorientation.
The uniqueness appears even in breeds. Larger dogs, such as German dogs, seem to age faster and become elderly as early as six or seven years old, while smaller dogs can take nine or ten years to start showing signs. So, if we can better understand how the body ages, we can investigate interventions that help slow down the aging process, which can range from an anti-aging pill to lifestyle changes.
That's why pet dogs become a valuable comparative model for three reasons, which I'll cover separately over the ten years I've been studying canine longevity: our shared biology, common environment and significantly shorter lifespan.
Dogs and humans share more than 17,000 special genes called orthologs. Each pair of orthologs is derived from the same common ancestor by vertical descent (species) and tends to have similar functions. We have countless similarities even in our genes. Sometimes the effects are identical, as is the case with EPAS1, a gene triggered by low oxygen conditions. People who live on the Tibetan Plateau and the strains of dogs that developed there have the same genetic change in this gene, which occurred to help the body's responses to low oxygen levels at high altitudes.
We also have similar genes, which are not identical, but which influence health and longevity. As an example, we can look at the variation in genes that regulate insulin-like growth factor 1 (IGF1), which plays a role in body size and cancer risk in dogs and humans. This pathway is also a critical regulator of longevity throughout the animal kingdom. Understanding these genetic connections helps to study and potentially treat health conditions shared between species.
