Animal products, including eggs, contain cholesterol. Too much bad (LDL) cholesterol in the blood can contribute to formation of plaque and the narrowing of the arteries that feed the heart. A medium-size egg has about 185 milligrams of cholesterol, and a large egg has about 215 milligrams. All the cholesterol in eggs is in the yolks. Egg whites without the yolks are a heart-healthy source of protein.