Advice on managing cholesterol has traditionally emphasized the value of higher HDL cholesterol levels for better heart health, but recent research questions that wisdom. Until now, we've thought of HDL, or high-density lipoprotein cholesterol — the "good" cholesterol — as a dump truck that hauls away excess LDL (or low-density lipoprotein) cholesterol — the "bad" cholesterol — taking it back to your liver so your body can get rid of it. That's why doctors and patients, especially those with high LDL cholesterol and low HDL cholesterol, have been focused on raising the good level and lowering the bad.
But it's not unreasonable to question this logic, says cardiologist Arthur Agatston, MD, creator of the South Beach Diet and an associate professor of medicine at the University of Miami Miller School of Medicine in Florida. Using the dump truck analogy, he explains that aiming for high HDL is the same as putting more dump trucks on the road, but that doesn't necessarily mean the dumping of excess cholesterol is efficient. Consider that many people who have relatively low HDL also have low heart disease risk factors. Low HDL could be unhealthy, but it can also be a measure of efficiency, says Dr. Agatston. If a smaller number of dump trucks are keeping everything tidied up, do you really need more? "It's not just the amount of HDL in your blood at any time that matters," he says. "It's how the HDL is functioning."
The Latest HDL Research
A Harvard research study, published in April 2012 in the Journal of the American Heart Association, argues that a specific subtype of HDL cholesterol, marked by the inflammatory protein apolipoprotein C-III (apoC-III), is actually damaging to heart health. This little tag-along protein, which can also attach to LDL cholesterol, seems to be correlated with increased heart disease risk and is present in about 13 percent of HDL cholesterol. According to the researchers' analysis, the presence of apoC-III increased heart disease risk. The results suggest that testing for apoC-III could provide a better heart risk assessment. But study author Frank M. Sacks, MD, a professor at the Harvard School of Public Health and Harvard Medical School, says this is preliminary research.
"The HDL type that we identified is not yet measured by clinical laboratories, and it is a research measurement now," says Dr. Sacks. "When our findings are confirmed in additional populations, specific apoC-III tests could be routinely included in screening testing panels for heart disease."
In a second, unrelated study published in The Lancet, researchers looked at specific genes from participants in 20 heart-health studies, drawing data from more than 110,000 adults. They found that in a minority of cases, certain genetic markers were related to high HDL cholesterol — but the level of HDL among people with that genetic history did not seem to protect against heart attack.
Lifestyle Changes Still Work
Though some research questions the value of high HDL, recommended heart-healthy habits remain the same. These lifestyle changes do seem to increase the efficiency of the cardiovascular system, making your existing HDL work effectively to help your heart, says Agatston:
- Exercising. Exercise works to improve HDL, and it only takes a little, at a level most people can do regularly, says Sacks. Don't feel like you have to go run a marathon.
- Losing weight. Aim for a healthy weight, but know that abdominal fat is the most worrisome where cholesterol levels are concerned. A heart-healthy diet and regular exercise will help reduce belly fat.
- Smoking cessation. If you smoke, the best thing you can do for your overall cholesterol profile is to quit. "Smoking decreases HDL, so stop," Agatston says.
- Eating better. "High-carbohydrate diets lower HDL — research these days supports using unsaturated oils in cooking and reducing carbohydrates," says Sacks. Go for lean proteins, lots of fruits and veggies, and whole grains. A little alcohol, especially red wine, is fine, too.
Each of these changes will result in an overall improved health profile, not just higher HDL. And it's that "slew of metabolic changes," Agatston says, that can lead to your best shot at lowering heart disease risk factors.
If you're taking medication to raise HDL levels, don't stop without consulting with your doctor. These recent studies are too new for a sweeping statement about prescribed medications. Talk to your doctor if you have questions, and stay tuned for more research news.
Last Updated: 10/9/2012