Two recently published studies have associated dog ownership with reduced all-cause mortality. The protective effect of canine ownership is especially pronounced in the case of cardiovascular disease. The researchers found that, compared to non-owners, dog owners experienced a 24% reduced risk of all-cause mortality and a 65% reduced risk of mortality after suffering a heart attack.
In the past, studies have shown that having a dog alleviates the symptoms of social isolation. Solitary people typically don’t exercise, but having a dog forces people to go outside and have a walk at least once per day. Having a canine around also seems to lower blood pressure, which might explain the better cardiovascular outcomes.
In the first study, researchers compared the health outcomes of dog owners and non-owners after a heart attack or stroke using data from the Swedish National Patient Register. The participants involved in the study were aged 40 to 85 and experienced a heart attack or ischemic stroke between 2001 and 2012.
The studies found that the participants who owned a dog had a 33% lower risk of death from a heart attack if they lived alone and 15% lower if they lived with a partner or child. The risk of death for stroke patients living alone was 27% and 12% for those living with other people in the household, as reported in the journal Circulation: Cardiovascular Quality and Outcomes.
The Swedish researchers claim that the lower risk of death can be explained by increased physical activity and lower levels of depression and loneliness.
“We know that social isolation is a strong risk factor for worse health outcomes and premature death. Previous studies have indicated that dog owners experience less social isolation and have more interaction with other people,” said Tove Fall, D. V. M., professor at Uppsala University in Sweden. “Furthermore, keeping a dog is a good motivation for physical activity, which is an important factor in rehabilitation and mental health.”
In the future, the researchers would like to explore this link even further in order to tease out the causal relationships. It might be possible, for instance, that doctors might someday prescribe ownership of a dog to certain vulnerable patients, based on a new evidence-based policy.
A second study, this time a meta-analysis (a study of studies), involved 3.8 million people pooled from 10 separate studies. Compared to non-owners, people with dogs had a 24% reduced risk of all-cause mortality, a 65% reduced risk of dying from a heart attack, a 31% reduced risk of mortality due to cardiovascular-related medical conditions.
“Having a dog was associated with increased physical exercise, lower blood pressure levels and better cholesterol profile in previous reports,” said Caroline Kramer, M.D. Ph.D., Assistant Professor of Medicine at the University of Toronto. “As such, the findings that people who owned dogs lived longer and their risk for cardiovascular death was also lower are somewhat expected.”
“Our findings suggest that having a dog is associated with longer life. Our analyses did not account for confounders such as better fitness or an overall healthier lifestyle that could be associated with dog ownership. The results, however, were very positive,” Dr. Kramer added.
“The next step on this topic would be an interventional study to evaluate cardiovascular outcomes after adopting a dog and the social and psychological benefits of dog ownership. As a dog owner myself, I can say that adopting Romeo (the author’s miniature Schnauzer) has increased my steps and physical activity each day, and he has filled my daily routine with joy and unconditional love.”
