It turns out being lonely may be hazardous to your health. A new University of Chicago study has found that over time feelings of loneliness can have a marked impact on blood pressure.

Researchers studied 229 individuals aged 50 through 68 who were part of a long-term study on aging. At the beginning of the study, participants were asked a series of questions to determine whether they perceived themselves as lonely.

During the five-year study, researchers found a clear connection between feelings of loneliness reported at the beginning of the study and rising blood pressure over that period. Among all the people in the sample, the loneliest people saw their blood pressure go up by 14.4 mm more than the blood pressure of their most socially contented counterparts.

"Loneliness behaved as though it is a unique health-risk factor in its own right," wrote researcher Louise Hawkley.

High blood pressure increases the risk for heart attack and stroke, and impairs kidney function. A systolic blood pressure measurement greater than 140 mm, also called hypertension, is the most common primary diagnosis in the U.S. and is the primary or contributing cause of about 18 percent of deaths in this country.

In addition to lifestyle changes like weight loss and exercise, supplements containing potassium, calcium, fish oil, magnesium and garlic may help prevent high blood pressure.