A team of scientists found that dog owners have lower risks of cardiovascular disease and death. How do dogs protect their humans from untimely disease and death?

Canine Protectors From Cardiovascular Disease And Death

Utilizing data from seven different national registries of 3.4 million individuals in Sweden, a team of Swedish scientists wanted to find out whether dog owners have different disease and death risks compared to non-dog owners. The data they studied included dog ownership registration, which has been mandatory in Sweden since 2001, and hospital records in the national database.

What they found was that having a dog evidently lowers the risk of death due to cardiovascular disease and other causes. Generally, they found that having a dog lowers the risk of cardiovascular disease among single-person households, and lowers death risks among the general public.

Their results also showed that people with hunting dogs actually have the lowest risk of cardiovascular diseases compared to other groups. What's more, they found a 33 percent reduction in death risk and 11 percent reduction in myocardial infarction risk among single dog owners compared to single non-owners, something that the authors find quite interesting.

"A very interesting finding in our study was that dog ownership was especially prominent as a protective factor in persons living alone," said Mwenya Mubanga of the Uppsala University, lead junior author of the study who also points out that perhaps dogs serve as a stand-in family member in single households.

How Do Dogs Protect Their Humans?

While researchers could not point out a single cause or way as to how dogs protect humans, they state that it's possible that dogs motivate their humans into being more physically active, especially since dog owners generally have higher levels of physical activity. However, this could also be a predisposing factor as to why the individual got a dog in the first place.

Another possible way that dogs protect their owners' health is by alleviating their feelings of social isolation, as perhaps shown by the positive results among single dog owners, and improving their humans' general well-being especially among the elderly and single persons. The results of the study are relevant especially since cardiovascular disease is the leading cause of death worldwide, accounting for 45 percent of all deaths in Europe in 2016.

Their population-based study and 12-year follow-up is, to the researchers' knowledge, the largest study associating dog ownership and human health to date. According to the paper, their sample size is a hundredfold larger than the sample size of the largest previous study, which allows them to make more precise estimates and analyses.

The study is published in Scientific Reports.