For 12 years, researchers studied demographic data from 3.5 million Swedish people aged 40 to 80, excluding people who had cardiovascular disease before the study began. Now adjusting for factors like income, age, sex, and marital status, the study found that people had a 20% lower all-cause mortality and 23% lower risk of cardiovascular disease if they owned a dog. For people living alone, those numbers jump to a reduction of 33% and 36% respectively and chances for having a heart attack those were 11% lower. Dogs were also shown to boost the immune system of their owners, possibly due to bringing in bacteria from outside.
The effects even were stronger among certain breeds like retrievers and pointers. Who’s a better boy than a shih tzu? You are! You are! The results may be reflective of the fact that big dogs require more exercise, so the owners tend to get more exercise as well. Big or small dog choice also may be reflective of the kind of person who would own one type of dog over another. Who’s a potential symbol of better healthier decision? You are! Yes you are! One of the authors of the study noted that these results were especially promising for people living alone because they’re generally at a higher risk for cardiovascular disease and increased mortality.
But there are some problems with saying that pets lead to a longer life. For instance, cause and effect are unclear. Example: giving your 95-year-old grandma a chihuahua is probably less likely to make her live to 105 and more likely to make her wonder where this chihuahua came from. Hey buddy, hey. In fact, a recent study on pet owners by the RAND Corporation showed no health benefits from owning a pet, which I can understand about cats, but DOGS?? Not dogs!
Now, initially the data looked like cat and dog ownership did increase overall health like we all thought it would, but when variables like home size and income were controlled for, those benefits disappeared, which indicates that the kind of person who owns a pet is also the kind of person who’s just healthier anyway. Who’s a good boy? I am. I’m the good boy. You might be thinking, but didn’t that other study in Sweden find that dogs increase longevity while adjusting for variable factors like income? Yes, and I can think of 3 possible explanations for this discrepancy in findings:
- Only Swedish people get health benefits from pets.
- One of the studies’ must be wrong.
- In the RAND study, cats may have decreased longevity so much that it cancelled out the positive health effects from dogs.
- There are too many variables and not enough research to show causation. Like the RAND study pointed out, people who own pets might be the types of people who are already leading healthier lives and in the Swedish study, the people who had the greater health benefit were exercising with the dogs, so we can’t just say it’s the presence of the dog without considering effect of the physical activity.