Why Your Dog Lengthens Your Lifespan

New insights about our oldest friend

Posted Mar 25, 2016

My father did virtually everything wrong his entire life:

  • He smoked heavily from his early twenties to the day he died.
  • He got no exercise.
  • He ate a high-fat, high-salt, high-sugar diet.
  • He lived alone and had no friends for the last 24 years of his life.
  • He never went to church or prayed.
  • He drank alcohol to excess the last 24 years of his life.
  • He had a short fuse and was quick to anger.
  • He did not floss.

And...he lived in robust good health until he died suddenly at 94.

Most of us who knew him believed that he lived such a long, healthy life because he inherited good genes. His brother died last year at 101 and his sister will turn 100 soon. So genes certainly were a factor. But I’m convinced there was another, far more important reason for his longevity: He owned at least one dog from his forties until the day he died.

Source: Eric Haseltine

Trisha McNair, MD, who has extensively studied the relationship between lifestyle and longevity estimates that dog ownership adds about two years to your life.

And science backs her up. The American Heart Association has found that dog ownership lowers the incidence of cardiovascular disease and speeds recovery from heart attacks. Other research has shown that petting a dog lowers people’s heart rate and blood pressure.

These findings could partly account for my father’s lack of heart disease despite his horrendous diet and allergy to exercise.

But my father also rarely got colds, flu or any other type of infection, and he avoided cancer despite his smoking and heavy consumption of highly processed meat, sugar and fat.

In other words, his immune system was strong.

Could his dogs be the reason?

Probably, at least in part.

Students at Wilkes University who petted a dog for 18 minutes had elevated Immunoglobulins (antibodies) and a recent study of the health of infants showed that newborns who lived in a “dog” household were less likely to develop respiratory tract infections. Finally, a comprehensive study of the effects of pet ownership on the immune system at Rutgers university showed that pet owners have significantly less sick days per year than non-pet owners.

The emerging field of Psychoneuroimmunology (PNI) is beginning to shed light on precisely how dog ownership boosts immune function. Dr. Andrea Beetz and colleagues at Rostock University, in a comprehensive survey of research on the relationship between exposure to animals and immune function, found strong evidence that owning dogs or other pets:

  • Reduces levels of stress hormones such as cortisol that depress immune function
  • Increases circulating levels of oxytocin, which promotes a sense of well being and had been linked to improved immune response
  • Increases parasympathetic function (relaxation response), which has also been linked to elevated immune function (parasympathetic neurons directly innervate, and stimulate components of the immune system such as spleen and bone marrow)

In addition to boosting “good” immune responses, there is also mounting evidence that dog ownership damps down “bad” immune functions such as allergies and asthma. Children raised in a dog household are less likely to develop allergies and asthma later in life, probably because their immune systems are “trained” to cope with allergens such as dog-borne microbes early in life.

If you’re a dog lover, you may have already read about such immune benefits in the media. But here are a couple more that you may not have heard about:

  • Some dogs are really good at sniffing out cancer. One study showed that dogs’ noses can reliably detect lung cancer and breast cancer in the breath of patients. Other studies have demonstrated similar results for melanoma and thyroid cancer. Although your dog may not be trained to do this, training and breeding programs are underway to develop a cadre of canines to sniff out malignancies. The same programs are also training pooches to detect infections, such as urinary tract infections (UTI’s)
  • The phrase “licking your wounds” has a strong foundation in science. Canine saliva has been demonstrated to have strong bactericidal properties, which probably explains why dogs instinctively lick their wounds (and your wounds if you give them a chance).

It’s intriguing to consider that when humans originally domesticated dogs to help protect us from external dangers, we got a lot more than we bargained for, in that canines also protect us from internal dangers such as microbes and cancer.

So, if you feel yourself coming down with something…hug your dog.

If you’re worried about developing cancer…hug your dog some more.

If you want to keep your immune system from attacking you…hug your dog yet again.

In other words, don’t forget to take massive doses the most important vitamin of all…Vitamin Dog