Average US Total-Cholesterol Levels Fall Below 200 mg/dL

Shelley Wood

December 14, 2007

December 14, 2007 (Hyattsville, MD) - Average serum total-cholesterol levels in American adults over age 20 have fallen below 200 mg/dL, an analysis of 2005-2006 data from the National Health and Nutrition Examination Survey (NHANES) reports [1]. That's down from an average of 204 mg/dL in 1999–2000 and from an average of 222 mg/dL in 1960–1962, Dr Susan E Schober et al report.

But experts caution that the survey results should not be interpreted to mean Americans are innately healthier than they were in the past.

"The main reason the total cholesterol has gone down is just because so many more people are on statin therapy, especially those 60 and older," Dr Roger Blumenthal (Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD), who was not involved in the study, told heartwire . "If you took them out [of the analysis], there probably wouldn't be that much of a difference. With the population getting heavier and exercising less, the total cholesterol may have modestly have gone down, but it's likely that the triglycerides and HDL have worsened."

The 2005-2006 levels are the lowest reported in the US since the survey began; the proportion of US adults whose total-cholesterol levels are higher than 240 mg/dL now represents 16% of the population, down from 20% in the early 1990s.

Not the Full Story

Supporting the lipid-lowering-drug hypothesis, the greatest declines have been seen in men 40 years and older and in women over 60: the groups most likely to be taking statins. By contrast, total-cholesterol levels have remained more or less constant in men 20-39 and in women 40-59 years of age. In women 20-39, the numbers hint at a slight increase in total-cholesterol levels between 1999 and 2006.

The report also notes that roughly 70% of US adults have undergone the recommended cholesterol screening at least once, but tellingly, 7.6% of adults who had their cholesterol measured in the survey had high serum total-cholesterol levels but report never having been told by a healthcare provider that their levels were dangerously high.

The report does not contain information on LDL, HDL, and triglyceride levels, which may have helped flesh out the analysis. Blumenthal points out that this information has likely not been tracked as long as total-cholesterol levels. Still, he worries the survey results, which have been widely reported in the mainstream media, may be misinterpreted.

"The picture that the CDC report painted and the way that some newspapers picked up the story is rosier than it really should be, because if you just looked at people not on drug therapy, the total cholesterol numbers really haven't changed that much in the past 20 years."

The "low-fat-diet message" has also become ingrained in recent decades, and this may have led to greater consumption of sweets and carbohydrates, which would also tend to drive up triglyceride levels and decrease HDL, "which would be just as bad in the long run," Blumenthal observed.

"This is, unfortunately, very incomplete information and it doesn't really tell us what we'd like to know," he said.

  1. Schober SE, Carroll MD, Lacher DA, Hirsch R. High serum total cholesterol--an indicator for monitoring cholesterol lowering efforts; US adults, 2005–2006. NCHS data brief no 2, Hyattsville, MD: National Center for Health Statistics, 2007. Available at: http://www.cdc.gov/nchs/data/databriefs/db02.pdf .

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