Loneliness in people over 50 greatly increases their risk of high blood pressure, researchers say in the latest study to underscore the health advantages of friends and family.

The loneliest people studied had blood pressure readings as much as 30 points higher than those who weren’t lonely, suggesting that loneliness can be as bad for the heart as being overweight or inactive, the researchers said.

“The magnitude of this association is quite stunning,” said University of Chicago scientist Louise Hawkley, the study’s lead author.

With earlier research suggesting that more than 11 million Americans over 50 often feel isolated, left out or lacking companionship, the study could have substantial public health implications if it can be shown that reducing loneliness can lower people’s blood pressure, said Richard Suzman, director of a behavioral research program at the National Institute on Aging, which helped fund the study.

Hawkley said the findings hint that one strategy for treating high blood pressure might be to get more involved, “do volunteer work, make yourself useful.”