America has a heart disease problem. It's the leading cause of death for men and women. Per the Centers for Disease Control and Prevention (CDC), heart disease kills, on average, one person every 33 seconds in the United States. The American Heart Association notes that nearly half of all Americans have some type of cardiovascular disease, some of them leading to heart attack, heart failure and stroke. 

While there are many causes and risk factors associated with heart disease that include high blood pressure, physical inactivity, and diabetes, one significant contributing factor is high cholesterol. 

What is cholesterol?

"High" is the optimal word there as lower cholesterol levels are Ok and some types of cholesterol are even considered to be "good" because they serve important basic functions. Cholesterol is a fatty, waxy substance that is produced in the body and is "used to make hormones and vitamin D," explains Jill Weisenberger, MS, RDN, a Virginia-based registered dietician and author of "Prediabetes: A Complete Guide."

Cholesterol is also instrumental in building cells, storing fat, assisting in bile production in the liver and in helping one's metabolism work more efficiently. 

How is cholesterol produced?

Much of the body's cholesterol is produced in the liver − "about 80%," says Caroline Susie, RD, a registered dietician and national spokesperson for the Academy of Nutrition and Dietetics. From there, she says it travels through the blood on proteins called lipoproteins and "helps sends signals all over your body." 

Though one's liver "can make all the cholesterol you need," says Weisenberger, another significant source of cholesterol comes from the food one eats. Any foods containing animal fat have some cholesterol, but "the highest sources of dietary cholesterol are beef, chicken and other livers," Weisenberger explains. Full-fat dairy products, fried foods, and baked goods are also high in cholesterol. 

How to lower cholesterol

Because one's diet significantly affects cholesterol levels, eating better is an important first step towards lowering cholesterol. Foods that are known to lower cholesterol include oats, barley, beans, nuts and fatty fish, according to Harvard Medical School. 

One general rule to follow in choosing the right foods is to replace "saturated fatty acids with unsaturated fats," suggests Weisenberger. Think cooking with oil instead of lard. And though the cholesterol in eggs gets a bad rap, the Cleveland Clinic notes that one egg contains only 8% of one's daily allowance for saturated fat. Still, if you're worried about the cholesterol in eggs, sticking to egg whites alone will give you the protein and nutritional benefits of eggs without the cholesterol downsides. 

Susie recommends consuming "high fiber foods," and getting plenty of fruits and vegetables. "No plants have cholesterol," echoes Weisenberger.

One's lifestyle also affects cholesterol levels. Losing weight or maintaining a healthy moderate weight will decrease the amount of cholesterol the liver produces and also lower one's chances of having "bad" cholesterol in one's blood. "Exercise can also increase levels of good cholesterol," offers Susie. 

Weisenberger says that other important strategies that can help one manage healthy cholesterol levels include "getting more sleep and avoiding tobacco." 

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