By Malika Ramani ‘21
Edited by Tiffany Lin ‘21
From serving as seeing-eye animals to licensed emotional support pets, dogs have long been declared man’s best friend. A recent study, however, further elevates this discourse: not only might dogs be our best friends, but could they perhaps help us live longer lives, too?
Numerous past studies have postulated that dog ownership can be correlated with an improved lipid profile, lower levels of blood pressure, and diminished responses of the sympathetic nervous system to stress (1). According to Dr. Caroline Kramer, an endocrinologist at the University of Toronto, these previous studies did not adequately examine the impact that dog ownership may have upon cardiovascular health and, more specifically, upon cardiovascular and all-cause death rates. Thus, she led a team in performing a recently published meta-analysis, comprising of 10 studies since 1950, that was designed to explicitly evaluate the potential relationship between dog ownership and subsequent mortality (2).
Based on the pooled data, the researchers found that dog ownership was associated with a risk reduction of 24% for all-cause mortality (as compared to individuals who were not dog owners); six of these studies yielded a statistically significant reduction in mortality risk (1). Remarkably, the most prominent reduction in risk of all-cause mortality was demonstrated in the population of dog-owners who had a history of prior coronary events; they were found to have a mortality rate that was 65% lower than their non-dog-owning counterparts (1). Upon restricting the studies to only those that specifically evaluated cardiovascular mortality, Kramer’s team found that dog ownership was associated with a 31% reduction in the risk of cardiovascular death (1).
Although this observational study cannot prove a direct causal relationship, the investigators claim that there are several possible reasons behind this correlation between dog ownership and mortality risk reduction. They suggest that some life-extending benefits – such as better cardiovascular health and lower blood pressure – were conferred in part due to the exercise that is often involved in caring for dogs (2). They also posit that the psychological benefits of this companionship – such as reduced symptoms of depression – could have contributed to the reductions in mortality rates (2).
The fact that cardiovascular disease remains the leading cause of death for both men and women in America – accounting for a striking 23.5% of all deaths – suggests that this merits further exploration. Perhaps interaction with dogs can be feasibly implemented among populations that this study has already proven can greatly benefit from it, particularly those who have already suffered a cardiac event (3). Certainly, physicians must continue to advocate for a “heart-healthy” diet and regular exercise when it comes to ameliorating patients’ cardiovascular health, but perhaps canine companionship deserves to be added onto this list of recommendations, as well.
1. Kramer CK, Caroline K. Kramer Caroline K. Kramer, Suen RS, Suen RS, Kramer, Kazi DS, et al. Dog Ownership and Survival [Internet]. Circulation: Cardiovascular Quality and Outcomes. 2019 [cited 2019 Oct 24]. Available from: https://ahajournals.org/doi/full/10.1161/CIRCOUTCOMES.119.005554
2. Bakalar N. Get a Dog, Live Longer? [Internet]. The New York Times. The New York Times; 2019 [cited 2019 Oct 24]. Available from: https://www.nytimes.com/2019/10/10/well/family/dog-heart-health-death-pets.html
3. The top 10 leading causes of death in the United States [Internet]. Medical News Today. MediLexicon International; 2019 [cited 2019 Oct 24]. Available from: https://www.medicalnewstoday.com/articles/282929.php