When it comes to lowering cholesterol, Americans seem to be getting the message.
Researchers at the Centers for Disease Control and Prevention (CDC) looked at trends in serum lipid levels among adults age 20 and older who participated in national health surveys between 1988 and 2010. They looked at the average levels of the participants’ total cholesterol, “bad” LDL cholesterol, “good” HDL cholesterol and artery-clogging triglycerides.
Overall, the researchers report in the Journal of the American Medical Association (JAMA) that the cholesterol trends are moving in the right direction. Total cholesterol as well as LDL cholesterol levels were down, and levels of “good” HDL cholesterol were up. “It’s certainly good news that there are improvements in lipids,” says lead study author Margaret Carroll of the CDC’s National Center for Health Statistics. Individuals with high LDL levels and low HDL levels are at a greater risk for developing coronary heart disease.
Looking at the measurements from the most recent study period, the researchers found total cholesterol among adults fell from 206 mg/dL in 1988-1994 to 196 mg/dL between 2007-2010. Overall LDL levels also dropped from 129 mg/dL to 116 mg/dL between the same survey periods and triglyceride levels had similar declines, from 123 mg/dL to 110 mg/dL. Lastly, HDL levels inched up between 1988 to 2010 from 50.7 mg/dL to 52.5 mg/dL.
Most of the positive trends can be traced to lipid-lowering medications known as statins, as more people began to take advantage of the drugs; while only 3.4% of the participants were statin users between 1988-1994, that percentage increased five-fold to 15.5% in 2007-2010. And for men and women over 50, who are at highest risk of heart disease, there was a 35% bump.
Even more encouraging for public health campaigns that emphasize diet and exercise to lower heart disease, Carroll says the similar declines in total cholesterol were seen among individuals not using lipid-lowering medications. “The cholesterol levels have been on the decline for many decades, and I think this partly has to do with healthier lifestyles and a variety of advancements in treatment,” says Dr. David Gordon, special assistant for clinical studies at the National Heart Lung and Blood Institute (NHLBI), who was not involved in the study. “More people are aware of cholesterol levels and doctors take it more seriously.”
The authors also credit government efforts to cut trans fats out of American diets. Since 2006, manufacturers have listed trans fat content in their foods, and in 2008 New York City banned artificial trans fats in city restaurants. A July study reported the ban led to a 86% increase in healthy food options in New York restaurants.
Although cholesterol levels are down, the authors note that Americans’ saturated fat consumption has not declined in 22 years, and progress in boosting physical activity remains slow. More than one-third of the population qualifies as obese, putting them at risk for developing heart disease.
Total LDL cholesterol declined among obese adults, but the authors did not see improvements in HDL cholesterol among this group. More research is needed, they say, to better understand the right combination of lifestyle changes, lipid lowering medications and lower trans-fat consumption can further lower cholesterol levels.