Need an excellent reason to add a dog to your life? How about living longer?
“Our analysis found having a dog is actually protective against dying of any cause,” said Mount Sinai endocrinologist Dr. Caroline Kramer, lead author of a new systematic review of nearly 70 years of global research published Tuesday in “Circulation,” a journal of the American Heart Association.
The review of the health benefits of man’s best friend analyzed research involving nearly 4 million people in the United States, Canada, Scandinavia, New Zealand, Australia and the United Kingdom.
“Dog ownership was associated with a 24% reduction in all cause mortality,” said Kramer, an assistant professor in the division of endocrinology and metabolism at the University of Toronto.
The meta-analysis found an even bigger benefit for people who had already had a heart attack or stroke.
“For those people, having a dog was even more beneficial. They had a 31% reduced risk of dying from cardiovascular disease,” Kramer said.
Dogs and surviving illness
A separate study of more than 336,000 Swedish men and women, also published Tuesday in “Circulation,” likewise found people who owned dogs had better health outcomes after suffering a major cardiovascular event such as heart attack or stroke.
Heart attacks and stroke are the leading causes of death globally, according to the World Health Organization.
The benefit was highest for dog owners who lived alone.
“The most interesting part of this study was that people who lived alone actually seem to get the greatest benefit in both the heart attack group and the stroke group,” said dog owner Dr. Martha Gulati, who is the editor-in-chief of CardioSmart.org, the American College of Cardiology’s patient education platform.
“People who lived with a dog actually had less mortality than people living alone who didn’t have a dog,” said Gulati, who was not involved in either study.
Heart attack survivors living alone who owned dogs had a 33% lower risk of death compared to people who did not own a dog. Stroke survivors living alone had a 27% reduced risk of death.
“We know that loneliness and social isolation are strong risk factors for premature death and our hypothesis was that the company of a pet can alleviate that,” said study author Tove Fall, an associate professor of epidemiology at Uppsala University in Sweden.
“Single owners have to do all the dog walks and we know that physical activity is important in rehabilitation after a myocardial infarction or stroke,” Fall added.
Observational but significant
Both published studies were observational, meaning that researchers cannot prove that dog ownership was the direct cause of the increased life expectancy or the better health outcomes after heart attack and stroke; only a randomized clinical trial could answer those questions.
“Is it the dog or is it the behaviors?” Gulati asked. “Is it because you’re exercising or is it because there is a difference in the type of person who would choose to have a dog versus somebody who would not? Are they healthier or wealthier? We don’t know those things.”