Can we reduce vascular plaque buildup?

The key is lowering LDL and making lifestyle changes.

High blood levels of cholesterol encourage the formation and growth of vascular plaques that put you at risk for heart attack and stroke. So can we reduce plaque buildup? "Making plaque disappear is not possible, but we can shrink and stabilize it," says cardiologist Dr. Christopher Cannon, a Harvard Medical School professor.

Image: Thinkstock

Plaque forms when cholesterol (above, in yellow) lodges in the wall of the artery.

All about plaque

Plaque forms when cholesterol lodges in the wall of the artery. To fight back, the body sends white blood cells to trap the cholesterol, which then turn into foamy cells that ooze more fat and cause more inflammation. That triggers muscle cells in the artery wall to multiply and form a cap over the area. But the soft plaque beneath the cap is dangerous. "For example, if your blood pressure spikes, it puts pressure on the thin wall of the plaque, which breaks open, forms a clot, and causes a heart attack," says Dr. Cannon. About three of every four heart attacks occur when plaques rupture.

Larger plaques can block blood flow. But they are typically covered by thick, fibrous caps that can resist breaking apart. These are often treated by inserting a wire mesh tube (stent) near the blockage to widen the artery.

Treatment

Doctors target smaller, unstable plaque. "If we have a 30% blockage in the artery from soft plaque, the goal is to try to suck out the cholesterol from the inside so the plaque shrivels down to 15% but doesn't have anything inside it," says Dr. Cannon.

How do you get the cholesterol out of the plaque? By adjusting levels of cholesterol in the blood, where it travels inside particles called lipoproteins. Low-density lipoprotein (LDL) deposits cholesterol into blood vessel walls. Its counterpart, high-density lipoprotein (HDL), removes the deposited cholesterol and carries it away in the bloodstream. "Good" HDL is difficult to change, but "bad" LDL can be lowered in a variety of ways. Statins—such as lovastatin (Mevacor) and pravastatin (Pravachol)—block the liver enzyme that promotes cholesterol production. Another medication called ezetimibe (Zetia) may be added to block cholesterol in the digestive tract. "Shrinking plaques with strong statins has been seen when you get LDL below 70 (mg/dL)," says Dr. Cannon.

Other means

Very intensive lifestyle changes have also been shown to shrink plaque. Dr. Cannon recommends that you:

  • Eat a Mediterranean diet. It can reduce heart disease risk by 30%. It is rich in olive oil, fruits, vegetables, nuts and fish; low in red or processed meats; and moderate in the amounts of cheese and wine you can consume.

  • Kick the habit. Smoking damages the lining of the arteries. Quitting can help raise HDL levels.

  • Exercise. Aerobic exercise can raise HDL, lower blood pressure, burn body fat, and lower blood sugar levels. Exercise combined with weight loss can also lower LDL levels. Aim for 150 minutes per week of moderate-intensity exercise. 

Busting the cholesterol myth

Why you can't live without this tricky substance.

Cholesterol is often vilified as the bad guy, but we need this waxy, fatty substance to make vitamin D, hormones, bile that aids digestion, and the coverings of our cells. The liver produces 75% of the body's cholesterol, but all cells have the ability to make it.

When cells need more cholesterol, the liver sends it via the bloodstream in packages made of cholesterol on the inside and protein on the outside. These cholesterol-laden particles are known as low-density lipoprotein, or LDL. Too much LDL in the blood can cause cholesterol to lodge in the artery walls and form plaques. That's why LDL is known as "bad" cholesterol.

Not surprisingly, high levels of cholesterol in the diet raise blood levels of LDL. But high levels of saturated fat and trans fat in the diet are even more important: they cause the liver to produce lots of LDL cholesterol and send it into the blood.

Whereas LDL particles deposit cholesterol into plaques of
atherosclerosis, high-density lipoprotein (HDL) particles
remove cholesterol from plaques. That's why it's often referred to as "good" cholesterol. How much HDL and LDL should you aim for? An HDL of 60 milligrams per deciliter (mg/dL) or greater may protect you against heart disease. Many doctors prescribe statins and lifestyle changes to get LDL levels below 70 mg/dL in people at high risk of having a heart attack in the next 10 years. Recent guidelines recommend that statins be prescribed regardless of the LDL level in people at high risk of heart attack because of cardiac risk factors (such as high blood pressure, diabetes, and smoking).