You’ve probably heard high-density lipoprotein (HDL) cholesterol described as the “good” cholesterol and low-density lipoprotein (LDL) as the “bad” cholesterol. But when it comes to which type of cholesterol is most important to control, who wins the HDL vs. LDL matchup?
If only it were that simple.
There’s considerable debate in medical circles about the importance of reaching certain target levels of LDL, HDL, and a type of blood fat called triglycerides. These measurements comprise your lipid profile. And your lipid profile is one way doctors can determine your risk for cardiovascular disease and a heart attack.
Even though cardiologists and researchers have learned much about how cholesterol functions in the body and how it and other risk factors determine your likelihood of a heart attack, many questions continue to swirl. Is HDL vs. LDL the most important question? Are high triglyceride levels the real enemy? Is cholesterol ratio the key set of numbers? And just what should your levels be?
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While there may not be complete agreement in the medical community about answers to any of those questions, there are some basic concepts that aren’t up for debate.
Cholesterol is a waxy substance that helps form cells. Your body produces all the cholesterol you need, but you do consume additional cholesterol from your diet. Meat, full-fat dairy, and poultry contain cholesterol as well as saturated fat. Saturated fat can trigger your liver to produce more cholesterol. Tropical oils, such as palm oil and coconut oil, can also prompt more cholesterol production.
Too much cholesterol circulating in your bloodstream is a problem, because it can leave deposits in your arteries. These deposits become hardened plaques that narrow your arteries, restricting blood flow. Plaques also make your arteries less able to expand and contract in response to your body’s needs. When you’re exercising, for example, you want your arteries to widen a little to increase blood flow to your muscles.
LDL cholesterol is the kind that builds up in your arteries, which makes it the “bad” kind. HDL cholesterol is the “good” kind because it helps remove LDL molecules from your bloodstream and returns it to the liver, where it can be reprocessed or excreted from the body.
HDL vs. LDL: The Great Debate
Given how HDL and LDL operate in your body, it’s easy to see why your doctor wants your LDL levels low and your HDL levels high. But how low and how high? And aren’t there many other risk factors to consider?
In 2013, the American College of Cardiology (ACC) and the American Heart Association (AHA) published guidelines for the management of high cholesterol. One of the more controversial aspects of the new guidelines was the elimination of a specific LDL target. For a long time, doctors urged their patients to get their LDL levels under 100 mg/dL. An optional target of under 70 mg/dL was also recommended, especially if you had other cardiovascular risk factors, such as high blood pressure, smoking, diabetes, and a family history of heart disease.
But when the ACC/AHA guidelines came out, LDL targets had been replaced by risk scores. Taking into consideration several risk factors, a formula was used to determine your 10-year risk of a heart attack. High-risk individuals were advised to take high-intensity LDL-lowering statin medications in concert with other aggressive steps to reduce their risk. People determined to have a low 10-year risk were would be advised to follow a less-aggressive approach to cholesterol management.
Getting away from hard targets made sense in some ways. Research hasn’t proved that driving your LDL down well below 70 mg/dL is necessarily improving your risk. Also, LDL levels aren’t precise forecasters of cardiac health. A 2009 UCLA study had shown, for example, that nearly half of the patients hospitalized for a heart attack had LDL levels under 100 mg/dL. However, around that same percentage of patients had HDL levels below 40 mg/dL, which is considered too low and a contributor to greater heart attack risk.
“We found that less than two percent of heart attack patients had both ideal LDL and HDL cholesterol levels, so there is room for improvement,” says UCLA cardiologist Gregg Fonarow, the study’s principal investigator.
HDL vs. LDL: The Winner?
So in the HDL vs. LDL debate, could both levels be equally important? Not necessarily. A 2016 study that focused on the protective benefits of high HDL levels found that high HDL didn’t afford much heart attack protection if LDL and triglyceride levels were beyond their normal or healthy range.
“There’s no question that HDL does have a protective role, as we also confirm in the study, but HDL has been hyped-up,” says senior author Michael Miller, MD, professor of cardiovascular medicine at the University of Maryland School of Medicine and preventive cardiologist at the University of Maryland Medical Center. “HDL really should be viewed as a third priority, with LDL on top and triglycerides second.”
So that settles it. The winner of HDL vs. LDL is LDL… right? Maybe.
What About Triglycerides?
While doctors understand the cardiovascular risks posed by high triglycerides, these blood fats are still somewhat of a mystery. Triglycerides are fats made from calories that you consume but don’t use right away for energy. Triglycerides are stored in fat cells, and when they are needed for energy, they are available. But if you consume a lot more calories than you burn, your triglyceride levels are going to rise.
High triglyceride levels are 200 mg/dL or higher. While it’s not entirely clear how high triglycerides might affect the health of your arteries (and therefore affect your risk of heart attack or stroke), high levels are often associated with other risk factors strongly linked to higher heart attack risks. These include obesity, poorly controlled type 2 diabetes, kidney disease, and other problems.
Your triglyceride levels are usually checked along with your LDL and HDL levels. You may see on your lab report a figure called “total cholesterol.” That number is simply your LDL + HDL + half of your triglyceride level. A total cholesterol level of less than 200 mg/dL is considered desirable.
Some doctors say your cholesterol ratio is another helpful number. That ratio is your HDL divided into your total cholesterol. A healthy ratio is less than 3.5 to 1. A higher ratio means a higher heart attack risk.
Ultimately, maybe the way to think about your cholesterol isn’t a matter of HDL vs. LDL vs. triglycerides. They’re all important, and they all bear watching. But there is more to your heart health than numbers. You can also lower your heart attack risk by:
- Quitting smoking (talk with your doctor about therapies and programs that can help).
- Following a heart-healthy diet, such as the Mediterranean-style eating plan, which focuses on fruits, vegetables, whole grains, fish instead of red meat, nuts, seeds, and low-fat or non-fat dairy.
- Exercising at least 150 minutes a week—a mix of aerobic exercise, such as brisk walking (click here to read “The Benefits of Walking“), and resistance training is best.
- Losing weight if you are overweight or obese.
The best news of all is that all of those things will also help get your HDL, LDL, and triglycerides heading in the right direction.
“Basically, it’s common sense,” says Thomas Miller, MD, an internal medicine specialist with University of Utah Health. “Don’t eat a lot of animal products, because animal foods have cholesterol [while] plants don’t—they don’t have cholesterol. You’re not going to get cholesterol from plants, so the more vegetarian-based your diet is, the more leafy green vegetables you eat, the chances are you will help lower your LDL cholesterol.”
“And get your heart rate up to a moderately elevated level,” Dr. Miller adds. “We’re not talking about Olympian-athlete-type redlining heart rates; we’re just talking about getting out and doing a brisk walk or a swim or cycling.”
Of course, if you notice your LDL is above 100 mg/dL, your triglycerides are over 200 mg/dL, and your HDL is below 40 mg/dL, talk with your doctor about other lifestyle changes and medication possibilities to help stabilize your numbers and boost your cardiovascular health.
Finally, don’t let all these numbers overwhelm or confuse you. You can’t control your age or your family history. But your cholesterol is usually a heart disease risk factor you can control. It just takes some attention and a little bit of math.
This article was originally published in 2018. It is regularly updated.
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