Yes, this might be a little hard to believe – and cat people might choose to argue – but scientists have concluded a dog could add years to your life.
“Dog ownership was associated with a 24 percent risk reduction for all-cause mortality as compared to nonownership,” Canadian scientists reported in the October issue of Circulation: Cardiovascular Quality and Outcomes.
“Notably, in individuals with prior coronary events (a heart attack or chest-pain signalling a heart attack), living in a home with a dog was associated with an even more pronounced risk reduction for all-cause mortality. Moreover, when we restricted the analyses to studies evaluating cardiovascular mortality, dog ownership conferred a 31 percent risk reduction for cardiovascular death.”
The team led by Dr. Caroline K. Kramer from the University of Toronto Leadership Sinai Centre for Diabetes noted, however, that it did not correct its statistical meta-analysis for “confounders,” variables that could influence the conclusions.
Dogs, for instance, might simply be encouraging people to get up off the couch to take them for a walk, and exercise is a well-documented way to lower “all-cause mortality.”
A 2018 study of 122,007 people involved with the Cleveland Clinic Foundation found that the more people exercised the longer they lived. The doctors involved with that study set out to investigate whether there was an upper limit to how much exercise was too much and instead found that “extremely high aerobic fitness was associated with the greatest survival and was associated with benefit in older patients and those with hypertension.”
The study reported in The Journal of the American Medical Association (JAMA) also concluded the overall risks of dying associated with lack of fitness were “comparable to or greater than traditional clinical risk factors,” such as coronary heart disease, smoking and diabetes.
So if Fido got you up and moving today, give him or her a pat on the head and a “thank you” because that act alone could be a beneficial confounder in the Canadian study. But not all dog owners are exercised by their dogs, which leaves open questions of what else could be going on to provide dog owners a longer life.
The authors of the Canadian study suggested that the one of the benefits of dog ownership to humans could be linked to the general calming influence of a canine companion.
“Recent reports have suggested an association of dog companionship with lower blood pressure levels, improved lipid profile, and diminished sympathetic responses to stress,” they wrote.
Kramer, the lead author, confessed a possible conflict in the study; she is “a proud dog owner.” But that is unlikely to influence a statistical analysis given the generally poor math schools of canines.
What is more likely to be going on here is some way big or small is the all-powerful placebo effect which links human psychology to human physiology.
“Contrary to popular belief, patients don’t just imagine placebo responses,” writes Benika Pinch at Harvard University’s Science in the News. “Rather, numerous brain-imaging studies have confirmed that placebos cause measurable changes in neurobiological signaling pathways.”
The placebo effect pops up all over the place, but has been most noted in pain studies. In one famous 1980s exercise, postoperative patients were given secret doses of pain-deadening morphine or saline solution described to them as a powerful painkiller.
The patients getting the saline reported no more pain than the people getting the morphine, a proven and potent painkiller.
The likely placebo connection between humans and canines would come in dogs making people happier, for reasons hard to fully explain, and a happy view of life working to extend it, again for reasons hard to fully explain.
There is a lot that remains unknown about the subtle ways in which the mind influences the operations of the body, but we now know the mind does influence physiology. The medical community has for years been wrestling with how to take advantage of this fact.
“… The benevolent use of deception to invoke a placebo response is contrary to the principle of respect for patient autonomy,” a 2011 study noted. “Very little research has been conducted to understand whether placebo interventions can be prescribed overtly without deception, (but one) found that patients with irritable bowel syndrome showed significant improvement of symptom severity after receiving open-label placebo when compared with a no-treatment control group….”
The human-dog relationship would seem little influenced by such attitudes. Most people don’t keep dogs around if they don’t like them. They keep them around when they provide solid emotional support.
The science now indicates that has real value, and the best news is you don’t need to go to a doctor for a diagnosis or a prescription before undertaking this life-extending treatment.