Helping others and building social relationships certainly make for a more satisfying life. Now there's reason to believe that they can help protect a person from the risk of developing high blood pressure in the mature adult years.

The National Institutes of Health says that 90 percent of Americans 50 or older are likely to suffer from hypertension at some point during the rest of their lives. The risk of developing hypertension can be reduced by eating a healthy diet and maintaining a healthy weight, and if you have high blood pressure, it can be controlled by medication.

Researchers at Carnegie Mellon University think they may have found a non-pharmaceutical way to reduce the risk. In a recent study, they concluded that older Americans who perform at least 200 hours of volunteer work a year are 40 percent less likely to develop hypertension, said the lead researcher, Rodlescia S. Sneed, a Ph.D. candidate in psychology at Carnegie Mellon.

The condition is serious: People who have hypertension are four times as likely to die from a stroke and three times as likely to die from heart disease, according to the U.S. Centers for Disease Control and Prevention. Nearly a third of Americans have high blood pressure, and half of them don't have it under control.

Blood pressure is determined by how much blood our hearts pump, and how much resistance to blood flow there is in our arteries. The more blood the heart pumps and the narrower the arteries, the higher the blood pressure.

Blood pressure tends to increase as we get older. The reasons aren't entirely clear, but as we age, our arteries tend to become less flexible and more constricted. Hormonal changes associated with menopause also appear to be a factor. Women are more likely to have hypertension than are men, African-Americans more likely than whites.

At Carnegie Mellon, Sneed and psychology professor Sheldon Cohen, her faculty adviser, studied 1,164 adults between the ages of 51 and 91. Each was interviewed twice, in 2006 and 2010. All had normal blood pressure at the time of the first interview.

At the second interview, those who did 200 or more hours of volunteer work were 40 percent less likely to report high blood pressure than those who did none. It was the volume, not the kind of volunteer work that mattered, Sneed said.

The reason, she thinks, is that seniors who volunteer have more social connections.

"There is strong evidence that having good social connections promotes healthy aging and reduces risk for a number of negative health outcomes," Sneed said.

Reinforcing that is the Carnegie Mellon study, funded in part by the National Institutes of Health and published in June in the American Psychological Association's Psychology and Aging journal.

(Reach Pittsburgh Post-Gazette reporter Jack Kelly at jkelly@post-gazette.com. Distributed by Scripps Howard News Service, www.shns.com.)

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