Although "serum cholesterol" refers to all three kinds of cholesterol now recognized by medical science, many people still use the term to mean only the harmful cholesterol. LDL and HDL cholesterols have different effects on your circulatory health. According to Dr. Mehmet Oz in "You: The Owner's Manual," it's the ratio between the two that's most important.
LDL Cholesterol
Cholesterol is a substance naturally secreted in your body. It plays a vital role in building, maintaining and repairing your body's tissues. LDL cholesterol, also called low-density lipoproteins, carries material to building sites within your body. Once they complete their task, they tend to aggregate inside your bloodstream, which can restrict blood flow. Enough restriction can lead to high blood pressure, heart disease and even heart attack or stroke.
HDL Cholesterol
HDL cholesterol, also called high-density lipoproteins, cleans your blood stream by carrying waste material back to your liver for processing and disposal. Among the waste materials HDL carries are the clumps of harmful LDL cholesterol. According to Harvard nutritionist Walter Willett, this means that HDL cholesterol in your blood directly counteracts the harmful effects of LDL serum cholesterol.
Total Cholesterol
Your total cholesterol count takes into account the interaction of LDL and HDL cholesterol. To calculate your total cholesterol, first subtract your HDL count from your LDL count. To this total, add 1/5 of your triglyceride count. Triglyceride is a third kind of cholesterol. According to the Mayo Clinic website, a total cholesterol of 200 or less is desirable. Scores above 240 are very high and indicate you are at a greater risk for health problems.
Ratio of LDL to HDL
The higher your HDL count, the higher your LDL count can be while your heart health remains good. In general, according to the Mayo Clinic site, an HDL vs LDL ratio of 1 to 2 or better is optimal for good circulatory health.
Improving Your Ratio
To improve your cholesterol ratio, you need to reduce your LDL cholesterol and/or increase your HDL cholesterol. The key is to watch the fat profile of foods you eat, according to Willett. Reduce your intake of saturated fats, which stimulate your body to produce more LDL cholesterol, and increase your intake of unsaturated fats, which stimulate production of HDL cholesterol. According to Oz, eating foods high in dietary fiber, such as whole grains, also improves your body's ability to cleanse itself of LDLs.
References
- Mayo Clinic: Cholesterol Numbers
- "Eat, Drink and Be Healthy"; Walter Willett MD, et al; 2006
- "You: The Owner's Manual"; Dr. Mehmet Oz; 2006
