The results of the survey are good news for those campaigning for a healthier population in the U.S. The data comes from eight separate surveys, each running for two years, which form part of the on-going U.S. National Health and Nutrition Examination Survey. The findings relate to adults aged 20 or over.
With the different measures, total cholesterol is a measure of the total amount of cholesterol in the blood. The assessment covers low-density lipoprotein (LDL, or “bad”) cholesterol and high-density lipoprotein (HDL, or “good”) cholesterol. Triglycerides are a form of dietary fat found in meats, dairy produce and cooking oils. They are a key health measure because some people have more difficulty in clearing triglycerides from the blood following a fatty meal. Low-density lipoprotein (LDL) is one of the five major groups of lipoprotein. LDL particles pose a risk for cardiovascular disease when they invade the endothelium and become oxidized.
In total some 39,049 adults were studies for TC levels analysed; 17,486 adults for triglycerides and 17,096 for LDL-C levels. The findings showed that of total cholesterol levels fell between the years 1999 and 2014, where the average level decreased from 204 mg/dL to 189 mg/dL. The biggest decrease was between 2011 and 2013.
In addition, age-adjusted geometric average triglyceride levels fell from 123 mg/dL in 1999 to 97 mg/dL in 2014. The largest drop occurred in 2011-2012. Similarly, typical LDL-C levels dropped from 126 mg/dL to 111 mg/dL across the survey period.
In the survey report, the medics state: “Removal of trans-fatty acids in foods has been suggested as an explanation for the observed trends of triglycerides, LDL-C levels, and TC levels.”
As for the reason, they put this down to health promotion and education. In a rarer example of positive health-related news they conclude their assessment by saying this “represents an important finding and may be contributing to declining death rates owing to coronary heart disease since 1999.”
The research has been published in the journal JAMA Cardiology, in a paper headed “Trends in Total Cholesterol, Triglycerides, and Low-Density Lipoprotein in US Adults, 1999-2014.”
