What can you do to lower your heart disease risk? Only so much, according to research.

Studies have identified several risk factors that contribute to heart disease -- some more than others. And while some of the risk factors can be modified, treated or controlled -- some can't. The more risk factors you have, the greater your chance of developing coronary heart disease, according to the American Heart Association. Also, the greater the level of each risk factor, the greater the risk.

Some major risk factors that can be controlled include:

High blood pressure (Hypertension)
High blood cholesterol
Diabetes
Obesity/overweight
Smoking
Physical inactivity/sedentary lifestyle

However, some major risk factors are not controllable. They include:

Gender: This risk factor cannot be changed or eliminated. Overall, men have a higher risk of heart attack than women. The difference narrows after women reach menopause. After the age of 65, the risk of heart disease is about the same between the sexes when other risk factors are similar.
Heredity: Heart disease tends to run in families. For example, if your parents or siblings had a heart or circulatory problem before age 55, then you are at greater risk for heart disease than someone who does not have that family history.
Age: Older age is a risk factor for heart disease. In fact, about four of every five deaths due to heart disease occur in people older than 65.
Race: Blacks and Mexican-Americans are more likely to have heart disease than whites.

Studies have found several secondary risk factors, but it is unclear how much these contribute to heart disease risk. They include:

Stress: Scientists have found that individual responses to stress might increase heart attack risk. For example, people under stress may overeat, start smoking or smoke more than they otherwise would, according to the AHA.
Sex hormones: Sex hormones appear to play a role in heart disease. Among women younger than 40, heart disease is rare. But between the ages 40 and 65, the chances that a woman will have a heart attack greatly increase. From 65 onward, women make up about half of all heart attack victims.
Excessive Alcohol Consumption: Drinking too much alcohol can raise blood pressure, cause heart failure and lead to stroke. It can contribute to high triglycerides, cancer and other diseases, and produce irregular heartbeats.
However, studies have found that the risk of heart disease in people who drink moderate amounts of alcohol -- an average of one drink for women or two drinks for men per day -- is lower than in nondrinkers.