As if puppy kisses weren’t enough reason to adopt a dog, Swedish research links dog ownership to living longer.

A meta-analysis of more than 3.4 million heart-healthy Swedes aged 40 to 80 found an association between owning a dog and cardiovascular health.

Researchers at Uppsala University reviewed data collected from 2001 to 2012 from seven different national registries, including the Swedish Agricultural Agency's dog owner's register and the Swedish Kennel Club's register, in addition to the Register of the Total Population, which contains information on birth, migration, changes of citizenship, civil status and death on all Swedish citizens and residents.

The research, published in Scientific Reports, found that dog owners were 20 percent less likely to die of heart disease or other causes during the 12-year follow-up period.

People who live alone seemed to benefit the most from man’s best friend. The results showed that single dog owners had a 33 percent reduction in risk of death and 11 percent reduction in risk of heart attack, compared to single non-owners. That’s good news since people who live alone have been shown to have a higher risk of cardiovascular death.

The researchers believe that the single dog owners benefit from both walking and interacting with their pet.  

"A very interesting finding in our study was that the results were clearest in single-family homes. Being a single has previously been reported as a risk factor for cardiovascular disease and it seems that a dog may be able to neutralize this over-risk,” said Tove Fall, veterinarian and lecturer in epidemiology at the Department of Medical science at Uppsala University, in a statement.

“Another interesting finding was that owners of different breeds differed clearly as regards to cardiovascular health,” she added. “We observed, for example, that owners of dogs of different hunting breeds stood out as healthier.”

While it makes sense that owning a dog may encourage physical activity, and previous studies has shown that to be true, researchers say it’s also possible that more active people choose to own dogs.

The researchers stressed that while these types of studies show a relationship between the environmental factor and diseases in a large population, they do not provide answers to if and how dogs actually protect from heart disease and premature death. “The associations we see may be that dogs affect the owner's lifestyle and well-being positively,” said Fall. “It may also be that those who choose to get a dog from the beginning have lower risk of cardiovascular disease, for example, through an active lifestyle.”