Close to 20% of young adults have high blood pressure, a new government-funded study reports.

For the National Longitudinal Study of Adolescent Health, researchers from the University of North Carolina-Chapel Hill asked 14,000 men and women between the ages of 24 and 32 about their high blood pressure history and then took blood pressure readings of participants.

High blood pressure (hypertension) was defined as 140/90 millimeters of mercury or higher. According to the National Heart, Lung, and Blood Institute, a normal blood pressure is 120/80 or less.The researchers found that 19% of participants had high blood pressure.

"We were surprised by the figure," says Kathleen Mullan Harris, a principal investigator of the study and professor of sociology at UNC. "Nobody really knows or had known what the prevalence was of high blood pressure among young adults. This is the first estimate we have on this."

The findings, published online in Epidemiology today, are significantly higher than other recent research from another large, ongoing health study, the National Health and Nutrition Examination Survey (NHANES), which found only 4% of adults 20 to 39 have high blood pressure.

"We explored several possible explanations for the difference between this study and NHANES, including participant characteristics, where they were examined, and the types of devices for measuring their blood pressure," says Harris, but none of those factors could account for the differences.

The results concern heart experts. "These statistics are certainly worrisome ," says Chip Lavie, medical director of Cardiac Rehabilitation and Prevention at the John Ochsner Heart and Vascular Institute, in New Orleans. "A prevalence of 19% at such a young age is already a high prevalence that will certainly lead to substantial cardiovascular disease as aging occurs."

The study authors wrote that many young people are unaware that they have high blood pressure. Eleven percent of participants said they had been told they had high blood pressure prior to the research, fewer than the 19% found to have high blood pressure during the study.

"We've usually thought of this population as being healthy and these are people that shouldn't be sick and they are," says Steinbaum. She blames salt- and sugar-packed processed foods and says young adults need to get moving and making healthier food choices. If they don't address it, this group of young adults will get cardiovascular disease.

Steinbaum says you can't change risk factors for heart disease like family history, age, and your sex, but you can address other risk factors that lead to heart disease including high blood pressure, high cholesterol, a sedentary lifestyle, stress, smoking, and diabetes.

Source:Mary Brophy Marcus, USA TODAY 5/25/11

"Eighty percent of the time, heart disease is preventable," Steinbaum says.