It's well known that measures such as exercise, a healthy diet and not smoking can help reduce high blood pressure, but researchers at the University of Michigan Health System have determined the very air we breathe can be an invisible catalyst to heart disease.
Inhaling air pollution over just two hours caused a significant increase in diastolic blood pressure, the lower number on blood pressure readings, according to new U-M research.
The study findings appear in the current issue of Hypertension, a publication of the American Heart Association.
Nearly one in three Americans suffer from hypertension, a significant health problem that can lead to heart attack, heart failure, stroke, and other life-threatening problems.
"Although this increase in diastolic blood pressure may pose little health risk to healthy people, in people with underlying coronary artery disease this small increase may actually be able to a trigger heart attack or stroke," says Robert D. Brook, M.D., lead author and vascular medicine physician at the U-M Cardiovascular Center.
In the study, researchers hoped to identify which air pollutants are harmful and how the pollutants work to damage the cardiovascular system.
Eighty-three people in Ann Arbor and Toronto were involved in testing and breathed air pollution, concentrated by a mobile air quality research facility, that was similar to what would be found in an urban environment near a roadway.
"We looked at their blood vessels and then their responses before and after breathing high levels of air pollution," explains Robert Bard, M.S., overall research project manager.
Ozone gases, a well-known component of air pollution, were not the biggest culprit. Rather, small microscopic particles about a 10th of the diameter of a human hair caused the rise in blood pressure and impaired blood vessel function, tests showed. The blood pressure increase was rapid and occurred within two hours, while the impairment in blood vessel function occurred later but lasted as long as 24 hours.