A physician at the Medical University of South Carolina (MUSC), and his colleagues, have found that fiber can affect a major heart attack risk indicator called C-reactive protein (CRP).

Results of the study, lead by Dana King, MD, a family medicine physician with an interest in preventive cardiology, appeared in a recent issue of Archives of Internal Medicine. The findings indicate that both a high-fiber diet and a fiber-supplemented diet significantly reduced baseline CRP levels over a three-week period.

"The study adds prospective trial data to the previous literature on dietary fiber and CRP," King told Heartwire, a Web MD publication. "The findings support current guidelines from the American Heart Association and other groups that promote adequate intake of fiber in the diet to promote good health. Clinicians should continue to counsel patients to eat foods high in fiber or take a supplement to reach their fiber-intake goals."

CRP is a plasma protein that rises in the blood with the inflammation from certain conditions. While LDL or "bad" cholesterol levels have long been known to be associated with an increased risk of heart attack, more studies show the same is often true for elevated CRP levels. People whose CRP levels are in the upper third of the population have twice the risk of a heart attack than people with lower CRP levels.

The study is one of the first to specifically examine a cause-and-effect role for fiber and CRP level in a randomized fashion.

The study enrolled 28 women and seven men whose baseline fiber intake was approximately 12 g/day, measured over a three-week run-in period. The participants were then randomized to either the DASH high-fiber diet (nearly 28 g of fiber per day) or to a fiber supplement (psyllium) on top of their regular diet (totaling 27 g/day). After three weeks on one diet, participants crossed over to the other fiber diet.

On both diets, CRP levels dropped below baseline values, a statistically significant change in both groups. Researchers were surprised to find that changes in CRP levels were greater in lean, normotensive subjects than in obese, hypertensive subjects because previous studies predicted a different outcome.

They suggest future studies may show whether a longer intervention period or increases in fiber intake in obese subjects might have a greater impact on CRP levels. However, the researchers are optimistic about the potential benefits for cardiovascular risk.

King says that while there has been no cause-and-effect link proven between CRP and cardiovascular risk, if a link is more firmly established, dietary fiber may play a role in helping to reduce the cardiovascular risk attributable to CRP and inflammation, he says.

About Medical University of South Carolina (MUSC)

Founded in 1824 in Charleston, The Medical University of South Carolina is the oldest medical school in the south. Today, MUSC continues the tradition of excellence in education, research, and patient care. MUSC is home to over 3,000 students and residents, as well as nearly 10,000 employees, including 1,300 faculty members. As the largest non-federal employer in Charleston, the University and its affiliates have collective budgets in excess of $1.3 billion per year. MUSC operates a 600 bed medical center, which includes a nationally recognized Children's Hospital and a leading Institute of Psychiatry. For more information on academic information or clinical services visit musc.edu or muschealth.

About MUSC Heart and Vascular Center

The Medical University of South Carolina's Heart and Vascular Center offers a complete range of cardiovascular services with subspecialty services. Our expert staff includes a highly specialized surgical team whose experience ranges from valve replacements and coronary bypasses to aortic aneurysms and heart transplants. MUSC performed South Carolina's first heart transplant in 1987 and remains the only comprehensive transplant center in the state. Additionally, the MUSC Heart and Vascular Center offers the full spectrum of detection, monitoring and therapies for circulatory disorders, including arteriosclerosis, aneurysm and carotid stenosis, and advanced venous disorders. Visit muschealth/heart for more information on MUSC's Heart and Vascular Center.

Tim Gehret
MUSC
Public Information Specialis