Dogs can perform many tricks for their owners, but the best one might be extending their life.
"Our analysis found having a dog is actually protective against dying of any cause," said Dr. Caroline Kramer, lead author of a study published Tuesday in Circulation, a journal of the American Heart Association.
Kramer's team studied data on 3.8 million patients taken from 10 other studies conducted worldwide over more than 70 years. They found a 24% reduction in the risk of death from all causes, and a 31% reduction of death due to cardiovascular problems.
"Having a dog was associated with increased physical exercise, lower blood pressure levels and better a cholesterol profile in previous reports,"she said.
Another study also published Tuesday in the same journal found that dog owners living alone had a 33% better chance of surviving a heart attack than patients living alone without a dog. In stroke patients living alone, the chance of survival increased 27%.
That study was conducted in Sweden between 2001 and 2012 using the country's National Patient Register.
"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 the study's author Tove Fall, an associate professor of epidemiology at Uppsala University in Sweden.