Healthy fats — eat ’em and they’ll somehow boost your HDL or “good cholesterol.” They’ll also cancel out the bad type of cholesterol and keep our hearts healthy, right?
Not everybody with high HDL is protected from heart disease.
HDL does have a protective role, but it’s been “hyped up,” said Dr. Michael Miller, a professor of cardiovascular medicine at the University of Maryland School of Medicine and a preventive cardiologist at the University of Maryland Medical Center.
Our HDL levels may not be as good as we thought at protecting us from heart disease, he told LifeZette.
Miller and a team of cardiologists from the University of Maryland Medical Center have just wrapped up a new study on lipids. Their findings are published in Circulation: Cardiovascular Quality and Outcomes.
The researchers looked at all three lipid levels in nearly 3,600 men and women who had no known risk factors for heart disease over nearly 25 years. Upon isolating HDL levels and putting them in either a high or low category, they found that high levels were not enough to protect a person from heart disease.
When Good Cholesterol Goes Bad
Managing cholesterol involves knowing three different numbers. Bad cholesterol is low-density lipoproteins (LDL), which add fat to the thick deposits that can clog arteries and lead to clots, heart attacks and strokes. Good cholesterol is known as high-density lipoproteins (HDL), which helps remove LDL by carrying cholesterol away from the arteries and back to the liver, where it’s filtered out of the body. Triglycerides are another form of fat that’s used to store the extra and unused calories from our diet. Each plays a vital role in keeping our hearts healthy.
Doctors have believed for a long time that HDL is protective, said Dr. Dennis A. Goodman, a cardiologist who specializes in preventative medicine and lipidology at the New York University’s Langone Medical Center in New York City.
But "not everybody with high HDL is protected," Goodman said. In general, it may be true, but people need to pay attention to getting LDL and triglycerides into normal ranges.
He mentioned that some people have dysfunctional HDL, which occurs when HDL doesn't clear plaque and instead causes inflammation in vessel walls.
People should talk with their doctors when reviewing blood work to make sure HDL, which is protective, has not become dysfunctional and therefore harmful. A separate blood test — and advanced lipid panel testing — can be done to find out if HDL is dysfunctional, Goodman said. Miller contended, however, that the test is not yet completely reliable.
Know Your Numbers
An optimal LDL level is less than 100 mg/dL (milligrams per deciliter), while a high level is considered more than 160 mg/dL. An HDL level of 60 mg/dL and higher is considered protective against heart disease. Normal triglycerides mean there are less than 150 milligrams per deciliter (mg/dL), the Mayo Clinic reported on its website.
"We used to believe that if HDL levels were high [above 50 for men and 60 for women], then you were generally at lower risk of heart disease," Miller said. "However, the new study does not support this cardio-protective effect of a high HDL when LDL and triglycerides levels are above 100."
Miller said doctors know that lowering LDL reduces risk of a heart attack. Ongoing studies are testing whether lowering triglycerides also reduces the risk of heart disease. Ideal LDL and triglyceride levels may both be less than 100, he added.
Heart disease is the leading cause of death in the U.S. Knowing your numbers and making both lifestyle changes and possibly even getting on the right medications can greatly reduce the risks to your health.
Last Modified: May 23, 2016, 8:31 am