Dogs really are our best friends, according to a Swedish study that says canine ownership could reduce heart disease. A study of 3.4 million people between the ages of 40 and 80 found that having a dog was associated with a 23% reduction in death from heart disease and a 20% lower risk of dying from any cause over the 12 years of the study. Previous studies have suggested dogs relieve social isolation and depression – both linked to an increased risk of heart disease and early death.
Dog owners show better responses to stress (their blood pressure and pulse rates don’t soar), have higher levels of physical activity and slightly lower cholesterol levels. The American Heart Association was sufficiently swayed by a review of dozens of studies to release a statement in 2013 saying that owning a dog “was probably” associated with a reduced risk of heart disease. Their reluctance to more strongly endorse dog ownership is because most studies are what is called observational – researchers note an association, but can’t prove causation. This means that other factors might explain why dog owners are healthier than, say, goldfish owners – for example, perhaps only people who are fit in the first place buy pets that need daily walkies.