Over the past several decades, many careful studies have identified personal traits and habits that increase the risk of developing heart disease. Some of these risk factors are stronger than others; some are under your control, and some are beyond it. The impacts of some risk factors have been well documented, while others are just emerging.

No matter which risk factors you have, it’s important to remember that they reinforce one another: the more you have, the greater your chances of developing heart disease. There are some things that raise your risk for heart disease that you cannot control, but you can reduce their impact by working on the many avoidable risk factors.

Age

Heart disease becomes more prevalent with age. Simply put, older people have more heart attacks than younger people do. About 80 percent of people who die from heart attacks are over age sixtyfive. In America, the risk for heart attack begins to accelerate in men after they reach the age of forty-five and in women after age fifty-five.

Gender

In younger people, gender is a major predictor of risk. Before age sixty, one in five American men—but only one in seventeen women—will have had a coronary event. The naturally produced female hormone, estrogen, may be one of the reasons for this gender difference.

But after a woman goes through menopause, this advantage is lost. Beyond age sixty, equality is the rule, and coronary artery disease kills 25 percent of women and men alike. In the United States, heart disease is the leading killer of both women and men. However, there are a few concerns that pertain only to women.

First, although the death rate from heart disease has declined for both genders, it is declining in women less rapidly than in men. Currently, 38 percent of women who’ve had heart attacks die within a year, compared with 25 percent of men. Second, most women who die suddenly from coronary artery disease don’t have typical warning symptoms.

Some may have had symptoms that they didn’t recognize as signs of heart attack because women’s symptoms often differ from men’s. Sometimes doctors pay less attention to women’s symptoms than they do to men’s because they know that younger women are less likely to develop heart disease.

Academic medical centers are spending more time educating young doctors to pay attention to women’s heart symptoms so that those symptoms are not dismissed as a less serious complaint, such as heartburn. Given these issues, what should women do? Perhaps most important, they need to focus on prevention.

For many years, doctors recommended hormone replacement therapy to women who were entering menopause because of evidence that it reduced the risk for heart disease as well as osteoporosis. But the heartprotective benefits of HRT have come under fire.

Clinical trials have found that women with heart disease who take HRT do not have fewer heart attacks than women who don’t take it. In fact, it actually slightly raises the risk of heart disease in both healthy women and women who have had previous episodes of atherosclerotic heart trouble.

It’s a different story for men and heart disease. While female hormones appear to provide some heart-protective benefits—at least for younger women—male hormones may contribute to heart disease in five ways:

• Boosting LDL and lowering HDL
• Promoting the accumulation of abdominal fat, which can lead to high triglyceride levels and diabetes
• Increasing the number of red blood cells and activating the clotting system
• Triggering spasms that narrow arteries
• Enlarging and possibly damaging heart muscle cells

Scientists have discovered some of these effects after giving testosterone to laboratory animals. It will take time for researchers to determine whether a normal amount of testosterone increases a man’s risk for heart disease. Testosterone isn’t all bad for the heart—it appears to reduce the level of one newly identified cardiac risk factor, lipoprotein(a).

Family History

Coronary artery disease runs in families. While families share genes, they also share lifestyles such as smoking, diet, inactivity, or stress. Which is to blame, genetics or lifestyle? Both. About a dozen genetic abnormalities have been identified that seem to increase the risk for different kinds of heart problems.

For instance, defects in nine different genes can cause cardiomyopathy, a form of heart failure in which the heart is unable to pump blood efficiently. In 2002, researchers reported in the journal Circulation that a variant of a gene called the peroxisome proliferator alpha may predispose people to develop a dangerously enlarged heart after intensive exercise or as a side effect of high blood pressure.

Genetic research is in its infancy, but the hope is that genetic testing will enable doctors to identify people at high risk for heart problems and perhaps help them avoid heart disease with preventive treatment. But, in any case, genes are not the final word in determining who will develop heart disease.

Researchers for the Framingham Heart Study, a long-term observational study that has tracked the health of more than five thousand people in a Massachusetts town since the late 1940s, estimate that having a family history of heart disease increases an individual’s risk by about 25 percent.

To put this in perspective, smoking increases your risk ten times this rate. Moreover, not every family history is equally worrisome; it takes a strong history (for example, a father or brother afflicted before age fifty-five or a mother or sister stricken before age sixty-five) to increase your risk.

Many people with a family history of coronary artery disease have early signs of the disease. The American Heart Association now recommends that everyone undergo cholesterol profile screenings for heart disease at age twenty. If you have a family history, it’s vital for you to address risk factors like high blood pressure and elevated cholesterol, and to adopt a heart-healthy lifestyle in your youth.