In this heart-filled month, loving relationships are highlighted with red and retailers work hard to convince us that what they are offering is guaranteed to bring desired results (or at least results for our desires.) Of all the enticements, there are two that research shows really do work in terms of producing those loving feelings: chocolate and dogs.

Chocolate, first. Whether it's the $5-a-piece handmade chocolate truffle or a good-old Hershey's Kiss, the biological mechanism leading to pleasure is the same. Chocolate contains chemicals that turn on the pleasure centers of the brain.

First there's tryptophan, which the brain uses to make the neurotransmitter serotonin, which in high levels produces feelings of elation, even ecstasy.

Then, there's phenylethylamine, the “chocolate amphetamine,” which helps promote feelings of attraction, excitement, giddiness, and apprehension. Finally, there's anandamide, the neurotransmitter that targets the same brain structure as THC, the active ingredient in cannabis. Powerful stuff, chocolate is.

The hottest news though is that certain chocolates are good for your heart. Flavonoids in chocolate are most likely the reason. (And you thought the film “Chocolat” was all fiction, didn't you.) Flavonoids are antioxidants, which are known to protect against the free radicals in the body that are suspected culprits in damaging arteries and triggering buildup of plaque in blood vessel walls, leading to atherosclerosis. Dark chocolate, eaten with regularity, has been shown to lower blood pressure. So, the more chocolate, and the darker the chocolate, the fewer by-pass surgeries? (If only it were that simple.)

Serious About Puppy Love

Now, on to the dogs. When Tashi and Bodhi, our Tibetan Terriers, visited Blair after his quadruple by-pass surgery last fall, we knew Blair's spirits were lifted, as were those of doctors, nurses, and patients who saw the tail wagging, face-kissing pups. It turns out our furry valentines were helping Blair's heart as much as his spirits.

The benefit of puppy petting can be attested to even in the White House. As Laura Bush was giving a press conference just prior to the inauguration, she sat stroking her new puppy, Miss Beazley, while she responded to challenging questions. The New York Times described Mrs. Bush as “calm.” Little did those flinty reporters know how much tiny Miss Beazley was aiding her mistress in remaining composed.

For some time, researchers have known that the presence of dogs can lower blood pressure, but now new research, conducted at the Center for Animal Wellness at the University of Missouri College of Veterinary Medicine, shows that just a few minutes of stroking our own dogs releases a number of hormones (here we go with the neurotransmitters again) that help people feel better: serotonin, prolactin and oxytocin. Petting our pooches also results in decreased levels of the primary stress hormone cortisol, the adrenal chemical responsible for regulating appetite and cravings for carbohydrates.

In this study, conducted by Dr. Rebecca Johnson, 50 dog owners and 50 non-dog owners over the age of 18 sat in a quiet room for 15 to 39 minutes with their own dog, a friendly but strange dog, and a robotic dog. Each session involved calm stroking or petting.

Researchers checked blood samples of both the humans and dogs at the beginning of each session and monitored their blood pressure every five minutes. The dogs' blood pressures dropped as soon as they were petted. The humans' blood pressures dropped by approximately 10 percent about 15 to 30 minutes after they began petting the animal, at which point blood was drawn again.

What Dr. Johnson's study found was that serotonin levels increased when the people were interacting with their own dogs, but not with the unfamiliar animal. Serotonin actually decreased when they interacted with the robotic dog. The importance of the findings is that the serotonin changes reveal the mechanism of how pets influence our health. Says Dr. Alan Beck, director for the Center for the Human-Animal Bond at Purdue University, “It shows that there is a physiological mechanism [to relaxing with a pet], that it really is comparable to other things we know cause relaxation, like eating chocolate.”

The “Crush” VS the “Commitment”

It's worth noting that the physiological changes in serotonin occurred when the subjects in the study were petting their own dogs, which brings us to the subject of love and commitment. While romantic love can sustain you temporarily (people who are romantically in love suffer fewer colds and have white blood cells that more actively fight infections), committed love will keep you alive and well longer.

The evidence is clear (Blair Justice's Who Gets Sick and A Different Kind of Health) that the more attached we are to others, the longer we will live. Whether we have heart disease or cancer, our survival will be significantly increased if we have friends, good family relations, and a loving marriage. When we are ill, long- lasting, intimate bonding with at least one other being, two legged or four, give us the strength to persevere.

So, for love and for longevity, grab hold of a Valentine, smooth or furry, and pet with love, not just in this month of hearts, but each day of your life.

Pet Lover's Disclaimer
Though chocolate and dogs are good for the heart and soul of humans, chocolate, especially dark chocolate, does not mix with your dog. Theobromine, a natural ingredient, unleashes a toxic level of epinephrine in dogs that can cause convulsions, even death.

Last Updated: 2-22-2005

 

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