By Jeni Baker

Atherosclerosis, commonly called “hardening of the arteries,” is a leading cause of life-threatening medical issues such as heart attack, stroke, and peripheral artery disease. Duke Heart Center preventive cardiologist William E. Kraus, MD, and vascular physiologist Jason Allen, PhD, discuss how simple lifestyle changes can help individuals prevent and manage this potentially dangerous condition.

Dr. Kraus (left) and Dr. Allen (right)

What Role Do Lifestyle Choices Play in Atherosclerosis?

Characterized by fatty deposits (plaque) within artery walls, atherosclerosis can obstruct blood flow and contributes to the formation of harmful blockages in the bloodstream. While some risk factors for atherosclerosis -- such as advancing age and family history -- can’t be controlled, many can, including:

• High-fat diet: Fat consumption can cause lipids (such as cholesterol and triglycerides) to accumulate in the bloodstream, promoting atherosclerosis.
• Sedentary lifestyle: Inactivity keeps people from reaping the benefits of exercise, which burns excess fat and increases production of nitric oxide, a chemical that promotes vascular health.
• Smoking: Cigarette smoking narrows and damages the arteries, promoting plaque buildup and blockages.

Tipping the Balance toward Health

Lifestyle recommendations to lower the risk of atherosclerosis include:

Eat a low-fat diet. Data show that diets best for long-term vascular health are low in saturated fats (which include cholesterol) and high in monounsaturated fats, such as those found in fish and olive oils. Dr. Kraus recommends the American Heart Association guidelines for fat consumption, which call for fats to comprise the following portions of daily caloric intake:

• Total fat: 25-35 percent
• Saturated fat: Less than 7 percent
• Trans fat: Less than 1 percent

“When high levels of lipids are circulating in our bodies, the balance is tipped toward atherogenesis [the buildup of fats in the arteries] instead of toward health,” says Dr. Allen.

Get more exercise. The 2003 results of the landmark Studies of Targeted Risk Reduction Interventions through Defined Exercise (STRRIDE) -- a federally funded, five-year randomized trial led by Dr. Kraus -- indicate that walking briskly for just 30 minutes a day burns a significant percentage of fat (and therefore promotes weight loss) in otherwise sedentary people.

STRRIDE II, currently under way at Duke, is examining the impact of weight and endurance training, alone or combined, on conditions that impact cardiovascular health, such as atherosclerosis.

“Not only has exercise been shown to reduce blood lipid levels effectively, it also can improve many other areas -- including arterial health, hypertension, blood glucose levels, weight loss, and mood -- that would require multiple medications,” says Dr. Allen.

Quit smoking and avoid secondhand smoke. Cigarette smoke can significantly accelerate atherosclerosis progression.

Making these changes can have a big impact on vascular health. “For many people, the first line of atherosclerosis defense should be lifestyle factors like diet and exercise,” says Dr. Allen. “These can be supplemented with medication in people who require a more aggressive approach.”

Lowering Lipids: The Exercise Connection

The importance of exercise in fighting atherosclerosis has become even clearer in recent years. Exercise not only improves lipid levels by burning fat molecules, it alters their distribution, the STRRIDE study suggested. Interestingly, some fat particles appear more likely to cause atherosclerosis, while others seem to protect against it.

While this link is well established in terms of high- versus low-density lipoproteins -- HDL and LDL (“good” and “bad” cholesterol, respectively) -- the STRRIDE study revealed that exercise appears to increase the size of HDL and LDL particles. Small, dense particles appear more likely to cause atherosclerosis than larger ones, perhaps because smaller particles can amass in the nooks and crannies of arteries more easily than larger ones can.

The bottom line, Dr. Kraus says, is that “inactivity is not an option. To prevent and manage atherosclerosis, people have to get out and do something.”

-- William E. Kraus, MD, is the director of Duke Heart Center’s cardiac rehabilitation program and a professor of medicine and assistant professor of cell biology at Duke.

-- Jason D. Allen, PhD, an assistant research professor of medicine at Duke, leads the Frederick R. Cobb Non-Invasive Vascular Research Laboratory as well as the vascular evaluation service of the Duke Executive Health Program.