Dogs may truly be a man’s best friend, especially if that man wants to live a long and healthy life. Public health experts have recognized the importance of the human/animal interaction (including pet ownership) in providing social support, alleviating social isolation, and increasing physical activity. But are dog owners healthier than non-dog owners? What are some of the factors associated with lower mortality in dog owners? Mwenya Mubanga is a PhD student in the Department of Medical Sciences - Molecular Epidemiology at Uppsala University in Sweden who researches the effects of pet ownership on cardiometabolic risk. She and her colleagues found that dog ownership was associated with a lower risk of cardiovascular disease and death.
For this study, Mwenya was excited to make use of Sweden’s extensive population registers and databases which are a goldmine for this sort of research. Sweden has a long-standing tradition of using population-based registers to track vital statistics, socio-demographic information, health outcomes, and—since 2001—dog ownership. These various databases and registers are all linked by the unique personal identity number that every Swedish resident has. To compare cardiovascular disease outcomes and mortality in dog owners and non-owners, Mwenya and her colleagues linked together information on adults aged 40 to 80 with no prior history of cardiovascular disease across the population registers, health registers and dog ownership registers with 12 years of follow-up. Their sample size of 3.4 million was hundredfold larger than previous reported studies.
They found that dog ownership in Sweden was overall associated with a lower risk of cardiovascular disease and death. For people who live alone, a group that generally experiences a higher risk of cardiovascular disease and death, owning a dog significantly reduced their risk. In fact, this group had the lowest risk of all dog owners. Single dog owners had a 33% lower risk of death, 36% lower chance of cardiovascular death, and 11% lower risk of heart attack compared to those who lived alone and were pet-less. There were also benefits for multi-person households, including a 11% lower risk of death and 15% lower chance of cardiovascular death. Owning a hunting breed (like a terrier, retriever, or hound) was associated with the lowest risk of cardiovascular disease, but any breed of dog was shown to lower the risk. Although their results are based on the Swedish population, they can likely be generalized to other European countries with similar demographics and dog-ownership practices.
The study doesn’t indicate why dog ownership protects your heart, though Mwenya offers a few ideas. “We believe that increased physical activity of dog owners may be an important factor, but we cannot discount that character traits and lifestyle choices may influence dog ownership, making the two populations different even prior to dog acquisition,” she says. For example, hunting breeds require more exercise than other dogs, and it is possible that people who enjoy long walks and outdoor activities are more likely to choose these active breeds.
Mwenya has always been passionate about public health and worked as a mission epidemiologist for Médecins sans Frontiers in South Africa before starting her doctoral studies. “Having worked in an HIV- and TB-based environment, the part of me that is passionate about making an immediate impact on the lives of people struggles with assuming my current work will impact the world. However, it is well known that urbanization and development have increased social isolation and loneliness globally. As we conduct more research on the interaction between pet ownership and human health, I am gaining confidence about providing some beneficial insights for those who choose to derive the greater part of their companionship from pet ownership.”