HDL
Related Terms
Atherosclerosis, cholesterol, diet, HDL, high-density lipoprotein, LDL, low-density lipoprotein, plaque.
Background
A low cholesterol diet involves the consumption foods that contain little cholesterol. Red meats, egg yolks, organ meats, whole milk and milk products are avoided, because they increase the low-density lipoprotein (LDL) that the body already makes. This cholesterol is absorbed through the intestines and added to what the liver makes.
According to the American Academy of Family Physicians, a low cholesterol diet is one of the three most important things a person can do to prevent heart disease. The other factors include quitting smoking and getting regular exercise.
There are two types of cholesterol in the body-low-density lipoprotein (LDL) and high-density lipoprotein (HDL). Diets that include large amounts of "unhealthy" cholesterol result in an over accumulation of LDL in the body. Excessive LDL binds to arteries.
Most American diets include an intake of much more LDL than HDL. This means that LDL accumulates in the arteries of the body and brain, forming what is known as a plaque. With continually high levels of LDL in the body, these plaques grow larger, and blood flow through the artery is increasingly restricted. The continued presence and accumulation of plagues in the body leads to a condition known as atherosclerosis. Atherosclerosis is a major cause of coronary heart disease, stroke, and other cardiovascular diseases, according to the American Heart Association. Because of its negative effects on the health of the body, LDL is known as "bad" cholesterol.
HDL escorts some of the excessive LDL back to the liver, where it is excreted through the body. HDL does not form plaques in the arteries. For this reason, HDL is known as "good" cholesterol.
When doctors talk about a "low cholesterol diet," they are referring to the ratio of "good" to "bad" cholesterol in the diet. In general, these levels should be consumed equal moderation, or more "good" cholesterol should be consumed than "bad."
Patients go on a low cholesterol diet because of excessive accumulation of LDL in the body. This diet helps to even out the proportion of LDL to HDL, while also preventing or slowing the accumulation of LDL in arteries.
Although a low cholesterol diet is often recommended by experts in the field to treat heart disease, it is important to note that dietary cholesterol has not been proven as a cause of heart disease. Rather it is strongly correlated with high quantities (LDL) in at risk patients, meaning that cholesterol may not be the cause of heart disease but it happens to be present in high levels in those with heart disease.
Theory / Evidence
The American Heart Association, as well as all other major health organizations, strongly supports a direct link between atherosclerosis and coronary heart disease. One out of every two American men will develop heart disease, and one in three American women will develop heart disease, according to the National Blood, Lung, and Heart Institute. Coronary heart disease is the number one cause of death in the United States today.
Despite the strong expert opinion and research in this field, it is still inconclusive whether heart disease is indeed directly caused by elevated cholesterol levels. Also, it remains a topic of discussion whether reducing dietary intake of cholesterol (found in foods) has an overall effect on systemic levels of cholesterol (cholesterol found in the body).
Author information
This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
Bibliography
American Academy of Family Physicians: Cholesterol. 16 May 2006.
American Heart Association: About Cholesterol. 16 May 2006.
National Blood, Lung, and Heart Institute. 16 May 2006.
Technique
Following a low cholesterol diet requires educating patients on healthy and unhealthy types of foods. The benefits of this diet are only realized if the patient consistently follows the diet plan.
Patients may experience difficulty adhering to the diet if someone else prepares their food or if their lifestyle includes the frequent consumption of foods, which are high in cholesterol. For this reason, many patients require ongoing education and support from a healthcare professional, partner, and other family members.
Lowering one's cholesterol often includes food substitutions. For instance, cooking leaner meats (such as chicken or turkey) instead of red meats, or using canola or olive oil instead of vegetable oil or butter. In many cases, more healthy versions of popular packaged foods are available. Patients may be overwhelmed at the process of changing a majority of their diets. Suggesting brands of popular foods, which contain lower levels of hydrogenated vegetable oils, should reassure the patient that they can eat some of their old favorites while still lowering cholesterol.