The saying that dogs are man’s best friend is now supported by even more evidence. Findings from two new studies published in Circulation: Cardiovascular Quality and Outcomes, a journal of the American Heart Association (AHA), show that canines can extend the life expectancy of heart attack and stroke survivors who live alone, reports AHA.

Researchers conducted a study of Swedish residents, ages 40 to 85, who suffered a heart attack or ischemic stroke between 2001 and 2012. Scientists compared health outcomes for these individuals whether they owned a pooch or not.

Results showed that heart attack survivors who lived alone and owned a dog had a 33% lower risk of death compared with those who didn’t have a dog. In addition, stroke survivors with pooches had a 27% reduced risk of death. (Risk of mortality was also lower for dog owners who lived with a partner or child and survived a heart attack (15%) and those in that same situation who suffered a stroke (12%)).

“We know that social isolation is a strong risk factor for worse health outcomes and premature death,” said Tove Fall, DVM, a professor at Uppsala University in Sweden and a coauthor of the inquiry. “Previous studies have indicated that dog owners experience less social isolation and have more interaction with other people. Furthermore, keeping a dog is a good motivation for physical activity, which is an important factor in rehabilitation and mental health.”

For the second study, investigators reviewed the patient data of more than 3.8 million people from 10 separate inquiries for a meta-analysis. (Nine studies compared mortality outcomes for dog owners and nonowners from all causes, and four compared cardiovascular outcomes for the same demographic.)

Compared with nonowners, dog owners experienced a 24% reduced risk of all-cause mortality (death from any cause), a 65% reduced risk of death after a heart attack and a 31% reduced risk of mortality due to cardiovascular-related issues.

“These two studies provide good, quality data indicating dog ownership is associated with reduced cardiac and all-cause mortality,” said Glenn N. Levine, MD, chair of the writing group of the AHA’s scientific statement on pet ownership. “While these nonrandomized studies cannot ‘prove’ that adopting or owning a dog directly leads to reduced mortality, these robust findings are certainly at least suggestive of this.” 

For related coverage, read “Pets Can Help Older Adults With Chronic Pain,” “Can Dogs Protect Kids’ Against Common Childhood Illnesses” and “Why Schools Should Offer College Students Downtime With Therapy Dogs.”