Among more than 2,500 people aged 65 or older, the higher a person scored on a questionnaire measuring positive emotions, the lower was his or her blood pressure.

"Our thoughts and emotions do affect our physical processes," Dr. Glenn V. Ostir of the University of Texas Medical Branch in Galveston, the study's lead author, told Reuters Health. "The nice thing is that we have some control over that."

There is evidence that positive emotions can help keep a person's chemical and neural responses in balance, and help people handle stress better, Ostir and his team note in the latest issue of Psychosomatic Medicine.

To investigate whether happiness might be related to blood pressure as well, they surveyed 2,654 Mexican-Americans. About half were men and half were women, and the study participants were an average of 72.5 years old. All of the subjects completed a questionnaire that ranked their degree of positive emotions on a scale of 0 to 12.

The higher a person scored on the test, the lower their blood pressure was, the researchers found. The effect was strongest among people who weren't taking drugs to lower their blood pressure, but it was still significant for men and women who were taking antihypertension medications.

The findings suggest that targeting people's emotional well-being could be an effective way to help control their blood pressure, Ostir and his team suggest.

In an interview, Ostir emphasized the importance of knowing one's blood pressure, and also suggested that people try to gain perspective when they're feeling unhappy. When "we're worried or anxious or stressed out over things, maybe we should take a step back and be aware of why we're feeling that way," he said.