QUESTION: I'm worried about getting heart disease. During the past four months, three of my friends have developed this disease. Two of them were treated with a balloon and one had to undergo bypass surgery. All of us are in our late 50s and have been active in sports all of our lives. Is there anything I can do to avoid getting it?

ANSWER: If it's any comfort, I'm worried about "getting" heart disease too. The problem is, we really don't just "get" heart disease. Instead, the heart disease process usually starts when we are young and progresses over the years, showing up when we get older.It is important to realize that there are many types of heart disease. The one you are worried about is called coronary artery disease (CAD) and is caused by a buildup of a fatty plaque in the arteries that feed the heart muscle. As the artery gets narrower, it can become blocked either by a blood clot or by a spasm that constricts and closes it. The lack of blood, with its supply of life-giving oxygen, can damage the heart muscle. If a large enough area of the muscle is damaged, the person may die. Amazingly, this process occurs in 1.5 million Americans every year, and 500,000 of them die.

Is there anything you can do to avoid getting heart disease? The answer to this question is still difficult to answer and experts sometimes disagree on what can be done. An article in the Oct. 29 issue of Time magazine discussed three recent studies showing a positive effect from lifestyle changes in terms of reversing the buildup of plaque.

In one study, 94 subjects were given a low-fat diet (22 percent fat) and treated with cholesterol-lowering drugs (colestipol and niacin). Another group lowered their fat intake. All the men in the drug-taking group had a spectacular reduction in total cholesterol and 16 percent showed a decrease in arterial plaque buildup. In another study, three groups of men were selected. One received niacin and colestipol, the second colestipol and another cholesterol reducer, lovastatin. A third group got only placebos. All the men were placed on a diet with less than 30 percent fat. After 21/2 years, those taking the lipid-lowering drugs had large drops in total cholesterol and 35 percent showed a decrease in arterial plaque.

Another researcher approached the problem using a very low fat diet (less than 10 percent) and added a stress reduction program of meditation, yoga and relaxation drills. Smoking was prohibited and exercise recommended. After just one year, 18 of 22 subjects had an increase of blood flow to the heart and a regression of blockages, on average, from 61 to 56 percent. This researcher thinks that reducing stress is at least as important as reducing cholesterol. Otherwise, the drug studies would have reversed the progress in more of the subjects who lowered their cholesterol.

Next week I will discuss some other views on this important subject.