Pop quiz: Name the substance your body manufactures that is an essential part of every cell in your body (from your skin to your brain) and is used to create hormones and vitamin D.

Answer: Cholesterol. It sounds like such a dirty word, but in the right amounts, cholesterol helps your body function. Unfortunately, your genes and your diet may leave you with way more than your system can handle.

When there is too much cholesterol in your blood, it builds up in your arteries and can eventually cut off the blood supply to your heart. The higher your cholesterol, the greater your chances are of developing heart disease.

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Wow fact

Getting two to 2.5 grams of plant sterols (good-for-you chemicals that occur naturally in plants) from fortified products, like Smart Balance spread and Minute Maid Heart Wise orange juice, may lower LDL by 10 to 14 percent.

There are several types of cholesterol in your body, but the ones in the spotlight at the doctor’s office are “lousy” low-density lipoprotein (LDL) and “healthy” high-density lipoprotein (HDL). The general guidelines say that your LDL should be less than 130, and HDL should be greater than 45 in men (the higher, the better) and higher than 55 in women.

If you’re at high risk for heart disease, your LDL should be lower than 100. People with very high risk factors such as diabetes should aim for less than 70. Triglycerides, another type of fat in the bloodstream, should be below 150.

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So what makes LDL really so lousy? “Bad” cholesterol (LDL) stealthily seeps into the lining of critical arteries that supply life-giving blood to the heart. This LDL can then cause all kind of havoc by sending messages to inflammatory cells to set up shop in that area. As this invasion progresses, it can cause the artery to narrow by forming plaque (think of it as a time bomb) inside the artery. At some point, the plaque can rupture and a clot forms, which is the genesis of an acute heart attack. These changes can begin as early as in your twenties!

The silver lining: Even if you do have high cholesterol, it is largely manageable through lifestyle behaviors, such as a heart-healthy diet, not smoking, regular exercise and stress reduction.