A study of 3.4 million people suggests dog owners are less likely to develop heart disease

A study of 3.4 million people suggests dog owners are less likely to develop heart disease

dog in car


More than just a cute face?

  • A 12-year study of 3.4 million Swedes found that dog owners are less likely than their peers to develop heart disease.
  • The study authors said that single dog-owners were especially protected.
  • Scientists aren't sure whether owning a pet causes better health or whether it's just an indicator of a better life.

Pet ownership may be a prescription for good health.

A massive, 12-year study of 3.4 million Swedish people released Friday in the journal Scientific Reports reveals that adult dog owners are less likely to die than their dog-free peers.

For the study, researchers from Uppsala University compared data from Sweden's national dog ownership registry with hospital visits for adults aged 40 to 80. (That analysis would be nearly impossible to replicate in the US, since American pet owners are not required to register their pooches the way Swedes are.)


Researchers started following the 3.4 million people in 2001, and selected the group so that no participants had pre-existing heart conditions. After 12 years, they found that people with dogs had a 23% reduced risk of death from cardiac diseases like heart failure, stroke, or heart attack than their dog-less peers. Dog owners were also 20% less likely to die, period.

If you're a single dog-owner, the news is even better: The study found that people who live on their own with a dog had a 33% reduced risk of death compared to their non-dog-owning single counterparts.

"Dog ownership was especially prominent as a protective factor in persons living alone," Mwenya Mubanga, lead junior author of the study, said in a release. "Perhaps a dog may stand in as an important family member in the single households."

But not all dog breeds "protected" their owners equally, according to the study. Owners of hunting-breed dogs had some of the lowest risk of developing cardiovascular diseases and death. People with pointer dogs, for example, were 40% less likely to die, and people with retrievers were 26% less likely.

Overall, the study in Sweden backs up a similar finding that the American Heart Association reported in 2013. The AHA said dog owners get more exercise, have better blood pressure and cholesterol levels, and even have "diminished sympathetic responses" to stress.


But it's difficult to determine why people with dogs see these health benefits. The Swedish study didn't try to answer that question empirically, but the researchers have a few ideas.

Senior study author Tove Fall said the link might be due to the fact that dog ownership gets people moving around more and going for walks. She also suggested that having a dog might lead to "increased well being" or more social interaction. Having a dog around could even help keep a person's microbiome healthy too, Tove said, since the bacteria and viruses on dogs could expose people to a higher diversity of microbes.

But the study authors are aware that dog owners may not actually owe their good health to their pets. It could be that healthy people are just more likely to bring a furry friend into their home in the first place.

A study released earlier this year found that kids in the US who grow up with cats have fewer behavioral issues. But as James Hamblin at The Atlantic pointed out, the health benefits for cat owners disappeared when the researchers factored in socioeconomic status.


As Hamblin put it, "pet ownership is more of a signifier of the sort of life that leads to better health, not the driver of that better health."

That may be the case in Sweden too, but more research into the potential health benefits of dog ownership is needed to know for sure.