Lipoproteins are transport mechanisms that carry cholesterol throughout your blood. Lipoproteins have an outer shell that contains protein and an inner compartment that contains cholesterol. Lipoproteins are categorized based on their cholesterol and protein ratio. The term HDL stands for high-density lipoprotein and the term LDL stands for low-density lipoprotein. HDL contains a high percentage of protein and a low amount of cholesterol, whereas LDL contains a high percentage of cholesterol and a low amount of protein.
Function of HDL
Approximately one-third to one-fourth of the cholesterol in your blood is carried by HDL, according to the American Heart Association. HDL helps to remove cholesterol from the blood by picking up excess amounts and bringing it back to the liver, where it is broken down and removed from the body. Because of its role in cholesterol removal, HDL helps to prevent the accumulation of plaque on the walls of your arteries and is considered protective against heart disease. This is why HDL is often referred to as good cholesterol.
HDL Values
The goal with HDL is to get your numbers as high as possible. HDL levels of 60 mg/dL or higher are considered ideal. If a woman's HDL level falls below 50 mg/dL and a man's HDL level falls below 40 mg/dL, it significantly increases the risk of heart disease. If your HDL level is not 60 mg/dL or higher, there are a number of things you can do to increase your numbers. Some beneficial lifestyle changes include quitting smoking, increasing physical activity, losing weight, decreasing alcohol intake and incorporating healthy fats into your diet.
Function of LDL
LDL carries most of the cholesterol in your blood. LDL is responsible for delivering cholesterol to your tissues so that your body can make bile acids, build cell membranes and synthesize certain hormones. Because it has such a high percentage of cholesterol, when LDL moves through your bloodstream, it deposits some of this cholesterol on the walls your arteries. If your blood contains too much LDL, the accumulation of cholesterol on your arteries can be severe and lead to atherosclerosis, or hardening of the arteries. Atherosclerosis can interfere with proper blood flow and lead to the development of heart disease. Because of this, LDL is often referred to as bad cholesterol.
LDL Values
Because LDL can cause atherosclerosis, the goal is to decrease LDL values. The ideal LDL value for healthy individuals is less than 100 mg/dL, although levels between 100 and 129 mg/dL are considered near ideal. If you have existing heart disease or have several risk factors for heart disease, you should aim for an LDL value of less than 70 mg/dL. If you have high LDL, you can lower your numbers by decreasing the amount of saturated fat, trans fat and cholesterol in your diet and increasing the amounts of fruits, vegetables and fiber. Increased physical activity and avoiding alcohol can also help decrease LDL values.
