Researchers just discovered a simple way to fight obesity, heart disease, and mental illness – by giving people puppies.

That may sound barking mad. But a new round of medical research shows that dogs, cats, and other four-legged friends can significantly boost people's physical and mental health – to the point where interacting with pets can actually be an effective form of therapy.

Consider how pets could help the 75 million Americans who suffer from high blood pressure, which increases the likelihood of experiencing a heart attack or stroke. In one study of more than 1,500 people aged 60 and over, dog owners had systolic blood pressure that was 3.34 milligrams of mercury lower than that for non-owners. Systolic blood pressure is the pressure in a person's blood vessels when his heart beats – the first number in a blood pressure reading.

A difference of just over 3.34 milligrams of mercury may not sound like much. But for each milligram of mercury decline in blood pressure, a person's risk of stroke goes down by 5 percent.

After five months, those who adopted dogs had significantly lower blood pressure than those who did not. When the remaining patients eventually adopted companions, their blood pressure also dropped.

Another analysis examined 30 patients at risk of high blood pressure. Some of the patients adopted dogs right away; others waited. After five months, those who adopted dogs had significantly lower blood pressure than those who did not. When the remaining patients eventually adopted companions, their blood pressure also dropped.

Pet owners are also more likely to exercise regularly. A study conducted by Australian researchers found that dog owners were physically active for an hour more each week than those who didn't have dogs.

My own research aligns with these findings. In a survey of people in Grenada – home to St. George's University, where I teach – my team found that less than 13 percent of pet-owners were obese. By contrast, 50 percent of the people in our sample who did not own pets were obese.

Keeping blood pressure low and staying active is great for the heart. One analysis of 3.4 million people spanning 12 years revealed that those who owned pets had a significantly lower risk of cardiovascular disease than those who were pet-less.

Research shows that pets also improve people's mental health.

In one Israeli study, scientists deliberately elevated participants' stress levels by telling them that they might have to hold a tarantula. Then, to calm the participants down, researchers gave them either toy rabbits, toy turtles, real rabbits, or real turtles. The toys did nothing to relieve stress. But petting both the hard shell of real turtles and the soft fur of real bunnies calmed participants effectively.

A survey of veterinary school students produced similar results. Investigators asked students to report their stress levels on a scale from one to ten, as well as whether they had a pet at home. Six in ten people who did not own pets reported stress levels of eight or higher; only four in ten pet-owners said that they were similarly stressed.

Another review of 17 studies found that people with mental illnesses – including post-traumatic stress disorder, schizophrenia, and bipolar disorder – derive health benefits from owning pets.

Some hospitals and schools are acting on this research. At Indiana University Health North Hospital, dogs wander the hallways and spend time with patients who request a visit. Jon Goble, president of IU Health North, noted that when patients go in for surgery, "the dog will completely take their mind off what's happening or about to happen."

Virginia Commonwealth University offers therapy dogs to students during finals week. Experts there found that the dogs significantly reduced pre-exam jitters.

All this research exemplifies the interconnection between human health, animal health, and the environment. That interconnection is the foundation of the One Health movement, to which a number of universities, including St. George's, adhere in their teaching and research efforts.

Medical research shows that pets are the perfect antidote to all sorts of illnesses and ailments. It's time to unleash this knowledge across our healthcare system.