Your cholesterol measurements provide you with three numbers that tell you a lot about your risk for heart-related illnesses. The first tells you about how much total cholesterol you have circulating in your bloodstream. Another provides you with a measure of your good cholesterol, and the third tells you about your level of bad cholesterol. The good news is that in the United States, average cholesterol levels are trending downward as of the time of publication. However, some subsets of the population have dangerously high levels of cholesterol. According to the Centers for Disease Control and Prevention, 1 in every 6 American adults has high blood cholesterol.
Cholesterol Measurements
Cholesterol is a fatlike waxy substance that performs several important functions in your body. It's not soluble in water, however, so it's transported around your body through special carriers called lipoproteins. The blood measurements of cholesterol actually measure these carriers. There's high-density lipoprotein, known as HDL and "good" cholesterol, and low-density lipoprotein, also known as LDL and "bad" cholesterol.
Total Cholesterol
Your total cholesterol is usually the sum of HDL and LDL, and sometimes it includes a remnant carrier known as very low-density lipoprotein that mostly transports triglycerides. Using 2005 to 2008 data from the National Health and Nutrition Examination Survey, the CDC reports that the mean total cholesterol level for adults of both sexes older than age 20 is 198 mg/dL. That's a downward trend from data just three years earlier, when it was 203 mg/dL. According to the National Cholesterol Education Program, having a total cholesterol level below 200 mg/dL is considered "desirable." Greater than that is considered "borderline high" or "high."
Bad Cholesterol
The most recently published and attributable data on average LDL cholesterol comes from 2002, and it was reported by CDC researchers in the Oct.12, 2005, "Journal of the American Medical Association." The average LDL was reported as 123 mg/dL for both sexes, 126 for men and 120 for women. According to the report, that's down from an overall average of 129 mg/dL based on data from 1988 to 1994. The American Heart Association's website was reporting in May 2011 that the average LDL reading was 115 mg/dL, but it was not clear where that data came from and what time frame it referenced. Each of these figures falls within the "near optimal" category based on the NCEP guidelines. Once your LDL surpasses 130, you are in "borderline high" territory.
Good Cholesterol
The JAMA report said good cholesterol hadn't changed much in the past few decades. The latest data point to a mean of 51.3 mg/dL: 45.9 for men and 56.2 for women. In the case of HDL, the higher the number, the better. To be precise, greater than 60 is high and lower than 40 is problematic. The American Heart Association reports that the mean HDL level is 54.3 mg/dL.
References
- CDC: Health, United States, 2010
- National Heart, Lung, and Blood Institute; High Blood Cholesterol: Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III); May 2001
- "Journal of the American Medical Association"; Trends in Serum Lipids and Lipoproteins of Adults, 1960-2002; Margaret D. Carroll, et al.; October 2005
- American Heart Association: What Your Cholesterol Levels Mean
- CDC: Cholesterol
- MayoClinic.com; VLDL Cholesterol: Is It Harmful?; Thomas Behrenbeck, M.D.; April 2010
