Can owning a dog increase your lifespan?

We all are familiar with the fact that certain physical activities, for instance, walking, can help in recovering from a stroke and heart attack. Taking care of a dog also makes individuals physically active by taking their dogs for a walk.

Here is a Harvard University report on how dogs can help:

The Times reports that dogs can prove to be your heart’s best friend. This report was based upon two studies that stated the individuals who own a dog have a more extensive life span than others who do not have one.

The favorable effects – considered to be a blend of increased social support and physical activity – were more visible in those individuals that lived a solitary life with their pets.

Some studies have an overall look at the lifespan, whereas others start looking at the life span after a stroke or heart attack.

Social support also plays an important role in health, especially for the recovery of individuals from an illness. A dog not only acts as a source of companionship but also acts as a means of knowing other dog owners of the neighborhood.

Although no studies prove the direct influence of dog ownership on health, it is surely linked with longer life. Moreover, those people that own dogs can take advantage of companionship and exercise, note the studies do not state that those people should get dogs who are already happy and active without dogs.

Where did the story originate from?

The origin of the story is from two studies.

The first one is the review of former researches, which was carried by the scientists of the University of Toronto and Mount Sinai Hospital of Canada, without any funding.

The other one is a recent study from Sweden that was carried by the scientists of the Swedish University of Agricultural Sciences and Uppsala University. Swedish research Council and Agria Research Foundation funded these researches for Spatial Planning and Environmental Agricultural Sciences.

Both of these studies were printed in a keenly reviewed journal Circulation, named as Cardiovascular Quality and Outcomes. One can read these Canadian and Swedish studies online for free.

UK media reported these studies enthusiastically, especially in The Times where a pun was added about patients where they were prescribed with “woof-arain” instead of the drug warfarin. But in most instances, both The Telegraph and the Times showed the researches with balance and accuracy.

What Type of Research was conducted?

The first research was a blend of the meta-analysis and systemic analysis of cohort studies. The second research was a cohort study.

The systemic analysis is an efficient way to state shreds of evidence about a particular subject. Whereas cohort study is an efficient way to study the linkage between factors (for instance owning a dog) and results (such as lifespan), but they do not prove that one is the cause of the other.

What did the study involve?

The Canadian research

The systemic analysis studied prospective cohort studies that included all the information about owning a dog at the starting of the study, and data about the age of participants.

The researchers gathered all the information for meta-analysis to notice the results that whether those people who had dogs lived longer or not than those who didn’t have dogs. They not only looked at mortalities from the cardiovascular causes but also from all other causes. The studies were graded according to their qualities.

The Swedish Study

In Sweden, the cohort study focused on the information from national databases to perform the investigation of the people belonging to the age group 45-80 who experienced a stroke or heart attack between the time of December 2012 and January 2001.

They noticed whether these people were alive at the end of the study, or they registered themselves as a dog owner. Since 2001, it is necessary for the owners of dogs to register their pets with the help of a dog registration scheme.

They studied whether those people who owned dogs had more or less survival rate by the end of the study. The researchers put the following factors into consideration while adjusting their figures:

• Age
• Gender
• Marital status ( which also includes living with your partner irrespective of the sex)
• Children living in the home
• Place of birth and residential area
• Income
• Illness (If any)
• History of cardiovascular disease in the last 5 years

What are the main results?

The Canadian Study

10 studies suited the criteria of meta-analysis which included 3.8 million individuals that have an average of 10 years of follow-up time. During the follow-up, the owners of the dogs were less likely to die than those who did not have dogs:

• The owners of the dogs were 24% less likely to die due to any cause (RR Risk reduction 0.76, and 95% Confidence Interval was 0.67 – 0.86)
• The death of the dog owners due to cardiovascular disease was 31 % less likely (Risk reduction is 0.69, 95% confidence interval is 0.67-0.71)

The Swedish Study

Similar results were also shown by the Swedish study. After a follow-up of an average of 4 years, it was founded,

• The deaths of dog owners due to heart attacks were 25% less likely (aHR adjusted hazard ratio is 0.79, 95% Confidence Interval is 0.75 – 0.83)
• The death of dog owners due to stroke was 18% less likely (95% CI is 0.78 – 0.86, aHR is 0.82)

For reference, on average 38.1% of individuals died of a heart attack and 43.5% of a stroke.

The results were noticeable for those people who were living a life of solitary with a dog. In this group of study, there was a drop of 33% in chances of death following a heart attack (aHR is 0.67 and 95% CI is 0.61 – 0,75) and a drop of 27% in chances of death following a stroke (aHR is 0.73 and CI is 0.66 – 0.80)

How did Research succeed in the interpretation of results?

Both groups of researchers stated that their results showed that there was an improvement in the survival period of those people who owned dogs.

The Canadian Researchers stated that their meta-analysis suggested that ownership of a dog warrants more investigation as an intervention of lifestyle given the favorable association with extended survival.

The researchers of Sweden were more careful, as they stated that the associations that were founded for the present study might depict a causal linkage between dog ownership and survival after the attacks of acute myocardial infarction and ischemic stroke.

Conclusion

One does not need to tell dog owners that having a dog is good both for their mental and physical health, no matter whether it is by motivating them to go for a walk or by supplying social and emotional support.

However, there is no need to be thrilled by the results. Maybe there is a difference between the people who own dogs and who do not, that might be the reason behind some of the differences in the duration of life. The difference between the results of the two types of research is a clear representation of this.

The researchers of Sweden adjusted various factors in order to take account of other factors i.e. age, health and the income of god owners. They established that most dog owners were young, had greater chances of having children at home and were mostly financially stable.

The Canadian researchers succeeded in establishing stronger facts about dog ownership, ignored potentially confounding factors. This is why the Canadian researchers showed a stronger linkage between dog ownership and the duration of life.

Moreover, Swedish research might ignore some other factors that represent differences. For instance, those people who own dogs are less likely to smoke, and more likely to take a healthy diet.

One can’t say surely that dog owners have an effect on the length of the life of people. There is another point to notice that dog owners who had a heart attack (64 versus 71 on average) and stroke (67 versus 73 on average) were younger, which opposes the theory that states, dog ownership makes you healthier.

Well, we do know that doing regular exercise and keeping social support and companionship is going to help you in living an extended and healthy life. Whether you do this by keeping a dog or with the help of other means is of less importance.