Cholesterol is a waxy, fatlike substance that the body needs to function properly. It is involved in producing the hormones estrogen and testosterone, vitamin D and bile acids that help to digest fat. Cholesterol needs to attach to carriers to travel through the bloodstream. The two main types of carriers are low-density lipoproteins (LDL) and high-density lipoproteins (HDL). When trying to control cholesterol, LDL and HDL levels, it is important to understand the main sources of cholesterol and what foods influence the levels.
The Liver
The liver and other cells make about 75 percent of the cholesterol found in the blood, according to the American Heart Association. The exact amount made can be influenced by genetics. There are cases where a genetic defect inherited from parents or grandparents--called familial hypercholesterolemia--can cause the body to produce too much cholesterol. In these cases, lifestyle changes may not be enough to control cholesterol levels, and medication may be necessary.
Foods
Food contributes to the other 25 percent of cholesterol found in the blood. Cholesterol is in many foods, so it is important to learn to read food labels and choose foods low in cholesterol. According to the National Heart, Lung and Blood Institute, people at risk for heart disease should consume no more than 200 mg of cholesterol each day. In addition to watching total cholesterol levels, it is important to stay on top of LDL and HDL levels as well. Limiting foods high in cholesterol, such as liver and other organ meats, egg yolks and full-fat dairy products, can help. Whole grains and foods that are low in fat and high in fiber are smarter choices.
Trans Fats and Saturated Fats
Almost all foods, including some vegetables and fruits, contain fat and cholesterol. Since cholesterol cannot dissolve in the bloodstream, special carriers made by the body must help it travel through the blood. One of these carriers is LDL. High levels of LDL cause deposits of plaque to stick to the artery walls, making them hard and narrow. In addition, pieces of plaque can break off and form clots, which can block arteries. Both raise the risk for a heart attack or stroke.
Trans fats and saturated fats are the main culprits when it comes raising LDL levels. Trans fats are unhealthy byproducts of hydrogenating foods, and the body makes enough saturated fat on its own, so there is no need to eat either, warns the Harvard School of Public Health. To control LDL levels, people should avoid or limit consumption of meat, poultry with skin, whole-milk dairy products, coconut and coconut oil, palm oil and palm kernel oil. The goal is to limit saturated fat intake to less than 7 percent of total daily calories and limit trans fat intake to less than 1 percent of total daily calories.
Fish
The other cholesterol carrier is HDL, which is considered the good kind. HDL takes cholesterol to the liver so that it can be excreted by the body. The goal is to take steps to lower LDL and raise HDL. While HDL is made by the body and not actually found in foods, there are certain foods that can help to boost the amount the body has. Monounsaturated and polyunsaturated fats can raise HDL. Consuming several meals of fish such as salmon, sardines, herring, mackerel and sea bass weekly has been shown to raise HDL levels, reports the University of Massachusetts Medical School. Fish oil supplements, flaxseed, soy foods, green leafy vegetables and walnuts can also help to boost the good kind of cholesterol.
