Cholesterol is required by humans for cell membranes and to produce bile and steroid hormones. The human body produces cholesterol and the fat, and cholesterol we get from our diet contributes to serum levels. While a necessary component of the body, high levels are associated with cardiovascular disease and stroke. In addition to total cholesterol, it is important to know how it breaks down into low-density lipoprotein, known as LDL, and high-density lipoprotein, or HDL cholesterol.
Total Cholesterol
Cholesterol is transported in the blood bound to proteins. These particles are known as lipoproteins and vary in size and density. Density is determined by the ratio of protein to fat. Particles with the highest level of protein are denser. Total cholesterol measurements include high-density lipoproteins and low-density lipoproteins. These individual numbers are more important than the total, although total cholesterol should be below 200 mg/dL. Serum cholesterol is affected by genetics, stress, smoking, caffeine, age, exercise and diet.
High-Density Lipoproteins
High-density lipoproteins are responsible for removing cholesterol from the blood and taking it to the liver to be removed from the body. It is considered "good" cholesterol. HDL is believed to contain apolipoprotein which act as an anti-inflammatory and helps remove cholesterol from the arterial wall to the liver. HDL is the cholesterol number doctors want to see increase on the lipid panel. Levels above 60 mg/dL are considered protective against heart disease.
Increasing HDL
Lifestyle changes can be made to help increase HDL numbers. Quitting smoking can raise HDL up to 10 percent in smokers. For overweight individuals, HDL can be increased by 1 mg/dL for every six pounds lost. Frequent aerobic exercise can increase HDL by 5 percent within two months in currently sedentary individuals. Eating healthy fats, such as those found in olive and canola oils, fish, and nuts, and drinking a moderate amount of alcohol can improve the HDL to LDL ratio.
Low-Density Lipoproteins
Low-density lipoproteins are responsible for taking cholesterol from the liver to the cells. It is considered "bad" cholesterol because it can slowly build up on artery walls, causing atherosclerosis, which could lead to a heart attack or stroke. Optimal LDL levels are below 100 mg/dL. Levels above 159 mg/dL are considered high.
Decreasing LDL
Being overweight can increase LDL cholesterol levels, so losing 5 to 10 pounds can help get cholesterol under control. Decreasing saturated fat intake to no more than 10 percent of total calories and eliminating trans fat from the diet will help lower LDL. Increasing whole grains, fruits and vegetables and decreasing cholesterol from food to no more 200 mg per day can help improve numbers.
References
- American Heart Association: Cholesterol
- Mayo Clinic: High Cholesterol
- Centers for Disease Control and Prevention: LDL and HDL
- "Krause's Food & Nutrition Therapy"; L. Kathleen Mahan, Sylvia Escott-Stump, editors; 2008
