Feeling stressed? Get a pet! Companionship with a dog or cat can tame the "stress response" that leads to high blood pressure, according to a study presented at the American Heart Association Scientific Sessions.

Researchers studied 48 male and female stockbrokers who were using medication to control high blood pressure. The stockbrokers who owned a pet were only half as likely as those without a pet to experience a rise in blood pressure under stress.

The results are similar to many previous studies that have found it is  beneficial to be with a pet when you're under stress. But this study went a step further by evaluating blood pressure under conditions of stress, which provided an objective measurement of the impact of having pets.

The researchers tried to reproduce a stressful situation to mimic the everyday stresses that stockbrokers typically face. They caused stress for the subjects by asking them to count backwards rapidly and to give a five-minute speech to talk their way out of a shoplifting charge. In response to stress, their average blood pressure shot up to 184/129 mm Hg. (Blood pressure over 140/90 mm Hg is considered "high.")

The stockbrokers then received medication for high blood pressure, and half the subjects agreed to get a cat or dog for a pet. Six months later, the researchers performed additional stress tests. Those who took the medication but had no pet experienced a rise in blood pressure that was much lower than the original test—because they had started taking antihypertensive medication. But stockbrokers who took medication and owned pets had a blood pressure level that was only half the level of the non-pet owners. These subjects were allowed to have their pet with them when they took the test.