Having a pet — particularly a dog — may help reduce your risk of heart disease, according to the American Heart Association.
In a scientific statement published online Thursday in the AHA journal Circulation, a panel of cardiovascular experts concluded, after reviewing all the best studies on the topic, that pet ownership is associated with a lower risk of heart disease.
Pet owners tend to have lower blood pressure and cholesterol levels, and are less likely to be obese than their pet-less peers, the experts noted. Research has also shown that pets help the body react in a less harmful way to stress, by decreasing the heart rate, for example, and by reducing the release of stress hormones. In addition, some evidence suggests that heart-attack patients who are pet owners live longer after their heart attack than non-pet-owners.
All those benefits are especially true, the experts added, when the pet is a dog. (Most studies that looked at the effects of pets on health have involved either cats or dogs.)
A possible link, not a cause-and-effect
Note, however, that the experts say there is only an association between having a pet and a lower risk of heart disease. Almost all the studies that have investigated pet ownership and heart health are observational ones, which are not designed to prove cause-and-effect. Observational studies can show only a correlation between two things.
It’s very possible that people who choose to bring pets into their homes are in better overall health to start with than their non-pet-owning peers. Dog owners, for example, need to be physically active enough to walk their dogs.
Indeed, studies cited in the AHA statement found that dog owners were, on average, much more physically active than non-owners. Two studies, conducted in Japan and Australia, found that even after controlling for such factors as age, gender, and socioeconomic status, dog owners were well above 50 percent more likely to meet the recommended level of physical activity than people without dogs. A Canadian study found that dog owners walked an average of 300 minutes each week, compared with an average of 168 minutes for non-dog-owners.
The only randomized clinical trial on pet ownership and heart disease risk factors, the AHA experts point out, comes from a small (30 participants) unpublished (and, thus, un-peer-reviewed) study. People in that study were randomized to either adopt a dog from a shelter or to put off the adoption for a few weeks. Five months later, those in the dog-adoption group had significantly lower blood pressure than the people who had been asked to wait.
Not everyone should have a pet
The AHA experts are also careful to point out that despite the positive association between pet ownership and a healthier heart, people shouldn’t go out and purchase a pet simply to reduce their risk of heart disease.
As one of the panel’s experts told the New York Times: “If someone adopts a pet, but still sits on the couch and smokes and eats whatever they want and doesn’t control their blood pressure, that’s not a prudent strategy to decrease their cardiovascular risk.”
It’s also not a prudent strategy for the pet’s health. But it may explain why more than half of all the pet dogs and cats in the United States are now, like their human owners, either overweight or obese.
You can read the AHA's "Pet Ownership and Cardiovascular Risk" statement (behind a watermark) on the Circulation website.