If you live alone and want for healthy life, you should own a dog, according to Tove Fall, a professor of epidemiology at Uppsala University.
Her recent study subjected a total of 3.4 million people lived in Sweden. After a follow-up up to 12 years, single dog owners had reduced risk of cardiovascular diseases by 36%.
The Guardian: Owning a dog cuts risk of heart attacks and other fatal diseases, study shows
There are some potential explanations for this outcome. It has been widely said that living alone increases the risk of premature death. Dogs may substitute a human partner. Also, they let the owner take regular exercise. Dog owners are likely to be free from indulgement to unhealthy habits such as drugs and sleepless.
However, there is still a possibility of selection bias in this study. People potentially ill may tend to avoid owning pets, even unconsciously. People disliking physical activities seem not to be fond of the life with dogs.
After all, if you are alone and want to be together with a dog, I recommend you to do so. If you dare not, I am not sure.