Cholesterol can increase the risk of heart disease when you have too much of it in your body. About 75 percent of blood cholesterol comes from your liver and other cells in the body, according to the American Heart Association. Your body produces all the cholesterol it needs and uses it to make hormones, vitamin D and substances to aid in digestion. Food accounts for the other 25 percent.
LDL Function
Cholesterol, a soft, fatty substance, travels through the bloodstream to perform its various functions in lipoproteins. Low-density lipoproteins, called LDL cholesterol, can build up on the inner arterial walls when excess amounts accumulate. They form plaques that narrow the arteries and affect blood flow that can lead to heart disease. In some cases, the plaques can burst and completely block blood flow, causing a heart attack or stroke.
HDL Function
High-density lipoproteins, or HDL cholesterol, pick up excess cholesterol and bring it to the liver for disposal as waste. Doctors sometimes call LDL the "bad" cholesterol and HDL the "good" cholesterol. To reduce the risk of heart disease you need low levels of LDL and high levels of HDL.
Saturated Fats
Because the body makes the necessary cholesterol, problems arise when too much cholesterol gets into the bloodstream from foods. Saturated fats can raise LDL cholesterol levels that may eventually clog the arteries. Meat, poultry with skin, fish and whole-milk dairy products contain saturated fats. You can choose lean meats, poultry without skin and low-fat dairy products. Sources of saturated fats also include palm oil, palm kernel oil, coconut and coconut oil.
Trans Fats
Trans fats result from processed foods with partially hydrogenated oils to make them last longer. Commercially baked products, such as cookies and cakes, and foods from restaurants, including french fries and onion rings, may contain trans fats. Trans fats not only raise unhealthy LDL cholesterol, but also lower protective HDL levels.
Healthy Fats
Unsaturated fats may reduce harmful cholesterol levels, according to the Harvard School of Public Health. A Dutch analysis of 60 trials reported in the May 2003 issue of the "American Journal of Clinical Nutrition" found that unsaturated fats reduced LDL levels and raised healthy HDL cholesterol. Almonds, hazelnuts, pecans, avocados and olive, peanut and canola oils contain monounsaturated fats, one of the two types of unsaturated fats. You can find polyunsaturated fats, the other unsaturated fat, in fish with omega-3 fatty acids, including salmon, tuna, herring and mackerel. Walnuts and sunflower, corn, soybean and flaxseed oils also contain polyunsaturated fats.
References
- American Heart Association: About Cholesterol
- National Heart Lung and Blood Institute: High Blood Cholesterol
- Harvard School of Public Health: Fats and Cholesterol-Out with the Bad, In with the Good
- PubMed.gov: Effects of Dietary Fatty Acids and Carbohydrates on the Ratio of Serum Total to HDL Cholesterol
