By Michael Thompson, Contriubting writer

Heart disease itself isn't genetic, but risk of heart disease is.

The American Heart Association and an array of researchers say that statistics compiled through generations show that when parents develop heart disease or fatty artery blockages, their offspring are more likely to do the same.

But heart disease risk can involve both genetics and behaviors. This is illustrated in what many people have observed: One health-conscious acquaintance exercises every day, avoids fatty foods, does all the right things and still keels over early in life. Another person sits on the couch, drinks and smokes to excess, does all the wrong things, yet lives to become an octogenarian.

Obviously, if behavior were the only factor, this sort of disparity would not occur. All marathon runners would live longer than all couch potatoes, and all abstainers would live longer than all drinkers and smokers. Genetics obviously plays its own role in heart disease.

Another illustrative point is that African Americans have a higher risk of developing high blood pressure, which in turns increases their chances of heart disease and stroke. A myth is that the higher risk for African Americans is rooted in unhealthy diets that took root generations ago when slavery limited food choices to the fattiest portions of meat.

Diet indeed is a statistical factor, but medical researchers have found that genetics also plays a role similar to the genetic factor in sickle cell anemia.

Genetic Risks May Vary

Just because this is the 21st century doesn't mean that medics know everything. Just as some experts continue to seek cures for cancer, others still are trying to learn about the genetic causes of heart disease.

The American Heart Association explains, "A number of genes have been reported to be associated with heart disease, stroke and high blood pressure in large population-based studies. However, the impact of each individual gene on an individual person is not fully understood."

Some diseases, such as sickle-cell anemia, can be traced to a single gene.

Genetic Tests

No similar answer is available in terms of measuring a genetic risk of heart disease.

However, a "blood test to see if your genetic makeup puts you at having a high risk of a heart attack" could become common practice within five years, according to reports that quote Dr. Sekar Kathiresan, director of preventive cardiology at Massachusetts General Hospital.

Kathiresan heads a research group with members who believe they have identified three new genetic variants linked to heart attack risk.