People who own dogs may live longer

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If you needed one more reason to love your puppy, here's a pretty good one: your furry best friend might help you live longer.

Researchers in Sweden tracked more than 3.4 million Swedish people with no heart disease over a period of 12 years. Some owned dogs and some didn't. By looking at how many died in the 12-year follow-up, and adjusting for relevant factors like age and sex, the scientists calculated the risk of death. It turns out that dog owners had a 20 percent lower risk of dying compared to people who didn't have a dog. The benefits were particularly strong for dog owners who lived alone: they had a 33 percent lower risk of death, and an 8 percent lower risk of cardiovascular disease, like stroke and heart failure.

Research has shown that living with pets has certain health benefits: people who own dogs tend to be more physically active, for instance, and have lower blood pressure. Today's study, published in the journal Scientific Reports, adds to the body of research, especially in regards to cardiovascular disease — the number one killer in the world, including in the U.S. "It could be a very efficient lifestyle intervention to get a dog," says senior study author Tove Fall, an associate professor in epidemiology at Uppsala University. "For some people that feel lonely or have problems of keeping a good lifestyle, this could be a good help."

For the study, researchers analyzed 12 years of government-collected data on 3.4 million Swedish residents, which includes information on birth, sex, age, health, marital status, as well as death. Since 2001, dog owners in Sweden have had to register their dogs by using an ear tattoo or under-skin chip, so the researchers could also check which of those 3.4 million people owned a puppy. Dog owners were then compared with pet-less people: those who had a dog were found to have a lower risk of death due to cardiovascular disease or other causes during the 12-year follow-up. Dog owners who lived alone had a lower risk of cardiovascular disease, as did people who had hunting dogs compared to other breeds.

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The exact reasons behind the results aren't clear: it could be that people who own dogs live longer because they're more physically active, or are less stressed, Fall tells The Verge. People who live alone may benefit even more because they're the only ones taking care of the dog, so they're forced to go take the pooch out for a walk. Single people might also get a stronger emotional support from their furry friends since they don't live with a husband or have kids, Fall says. "I got my first dog when I was single and she was my best friend," she says. "She was super important."

The study has some obvious limitations: even though the researchers adjusted their estimates for confounding factors such as income and education, there's a lot they still don't know about their study subjects. For example, it could be that people who live alone and have dogs have a lower risk of cardiovascular disease because they're generally healthier to begin with. Getting a dog is time-consuming and expensive, so if you're dealing with an important health issue and live by yourself, maybe you'd think twice about it. The study subjects were also all from Sweden, so results could be different in different countries.

Still, the researchers looked at a lot of people, and that makes their results stronger. The study is also in line with what other research has found — and what dog owners have probably long known. Fall says her family has an "active little dog," a Kooikerhondje retriever, whom her kids love playing with in the forest. "We really think that it adds to the well being in the family," Fall says. "It's really nice when you come home and you had a crappy day but the dog won't care. It just jumps up, wags the tail, and is happy anyway."