What Is LDL Cholesterol and How Do You Lower It?

High cholesterol is one of those health problems that really sneaks up on you. Often called a “silent” condition, it doesn’t have any direct symptoms but quietly damages arteries over time.It’s exactly why more than 40% of US adults with high LDL cholesterol don’t know they have it, according to a 2023 study published in JAMA Cardiology. This means that there are a whole lot of people out there who are at an increased risk of having a heart attack, stroke, or getting heart disease, and they don’t even know it.“Heart disease doesn't suddenly appear when someone turns 60. It's a process that develops over decades,” says Dr. Jason Hoff, MD, a structural interventional cardiologist and assistant professor at Loma Linda University Health. He explains that every year that LDL cholesterol stays elevated, a little more plaque can build up in the arteries.Earlier this year, the American College of Cardiology and the American Heart Association released updated guidelines for managing cholesterol, primarily focusing on earlier intervention. “The biggest shift in these guidelines is recognizing that if we can identify people at higher risk earlier, we have a chance to prevent that damage instead of trying to fix it later after a heart attack or stroke. That's why we're screening people earlier and being more proactive about treatment in those with significant risk factors, like a strong family history or very high cholesterol,” Dr. Hoff says.Whether you’re 19 or 90, your cholesterol levels are something you can control. We talked to cardiologists about how to do exactly that.What is LDL cholesterol?Cholesterol is typically referenced generally and almost always negatively, but it’s actually a bit more nuanced. Dr. Ethan Korngold, MD, an interventional cardiologist who works with the health company Abbott, explains that cholesterol, which is a waxy fat-like substance found in the body, is essential to build cells and produce vitamins and hormones. “However, too much cholesterol can cause problems because it narrows the arteries, blocking blood flow, which increases the risk of heart disease,” he says.Cholesterol is transported through the blood by lipoproteins, including two types of lipoproteins: high-density lipoproteins (HDL) and low-density lipoproteins (LDL). HDL (often referred to as “good” cholesterol) transports cholesterol to the liver, where it’s then broken down and excreted. LDL transports cholesterol to cells, and as Dr. Korngold explained, too much of it can lead to plaque buildup in the arteries. That’s why LDL cholesterol is often referred to as “bad” cholesterol.What causes LDL cholesterol?Even if you’re relatively young and generally in good health, preventing high LDL cholesterol is still important. Hoff says that cholesterol plaque buildup is something that can happen over time without you even realizing it.“It’s not something you can feel. It can eventually lead to a heart attack or stroke, and the process often starts decades before symptoms appear, even as early as your 20s and 30s,” he says.Walk with a Doc CEO and cardiologist Dr. David Sabgir, MD, says being proactive about your heart health is key to staying healthy. “Even if you feel great, cholesterol can climb quietly, especially if you have a family history of heart disease,” says Dr. Sabgir. “High LDL cholesterol builds up over time and raises the risk for heart attack and stroke. The fix is simple. If we know our numbers and stay ahead of them, we can make a huge difference in our health.”How do you know if you have high cholesterol?Since you can’t feel LDL cholesterol slowly creeping up, how do you know if yours is too high? All three cardiologists say that it requires a blood test from your doctor and it’s something Dr. Korngold recommends everyone 20 and older have regularly checked. The American Heart Association says that optimal LDL cholesterol is at or below 100 mg/dL.In 2023, the American Heart Association introduced the PREVENT online calculator, which is a tool for estimating your chance of getting heart disease—especially when it comes to managing cholesterol. The acronym aptly stands for Predicting Risk of Cardiovascular Disease Events.“The older calculators were helpful, but they were built from research that started decades ago and didn't always reflect today's patients. PREVENT uses much more contemporary data and looks at a broader picture of cardiovascular health, including things like kidney function,” Dr. Hoff says. If the calculator suggests you’re at high risk for developing heart disease, it should be used as a conversation starter with your doctor.Dr. Sabgir explains that genetics play a big role in causing high LDL cholesterol. Research published in the Journal of Lipid Research estimates that 40 to 60% of high cholesterol is due to genetics. That means you could be working out regularly and hitting your nutrient goals and still have it.If you do have a family history of high cholesterol, consider asking your doctor for an ApoB test, which is different from measuring your cholesterol. Dr. Hoff explains that LDL indicates how much cholesterol is being carried in the bloodstream, while ApoB counts how many potentially harmful particles are circulating.“I often use an analogy of delivery trucks. LDL tells you how much cargo is being transported. ApoB tells you how many trucks are on the road. Even if each truck is carrying a smaller load, having more trucks still increases the chances they'll eventually end up delivering cholesterol into the artery wall,” Dr. Hoff explains.Something else that contributes to high LDL cholesterol that’s out of your control is aging. “As you age, your body becomes less efficient at clearing bad cholesterol from the bloodstream, which increases your risk,” Dr. Korngold says.But all three cardiologists say that diet and lifestyle majorly contribute to cholesterol levels too, which brings us to the habits that are in your control.How to lower LDL cholesterolWhile there are factors outside of your control that contribute to cholesterol, the doctors all emphasize that you can definitely make a noticeable impact through diet and lifestyle habits. Here are five you can start doing today.1. Minimize foods high in saturated fatsThis was the number one tip from all three cardiologists. Minimizing foods high in saturated fats means red meat, dairy, and sweets should all be enjoyed only occasionally. According to a 2020 meta-analysis published in Cochrane Review that took into account 15 scientific studies and more than 56,000 people, reducing saturated fat lowers LDL cholesterol by an estimated 17%—that’s a lot!Besides minimizing saturated fat, Dr. Sabgir recommends eating a primarily plant-based diet. PSA: A high-fiber diet and low LDL cholesterol go hand in hand. He adds that limiting alcohol can also help prevent or lower LDL cholesterol.2. Don’t use tobaccoReason number infinity not to smoke or vape: It ups your LDL cholesterol, something all three doctors made a point to mention. As an article in the Journal of Clinical & Diagnostic Research explains, the nicotine in tobacco decreases HDL cholesterol and increases LDL cholesterol. And a PSA to those of you that vape: it’s just as bad as smoking in this instance, as shown in a 2021 Vascular Medicine study.3. Get moving“Exercise not only lowers ‘bad’ cholesterol, but it also raises ‘good’ cholesterol,” Dr. Sabgir says, pointing to the American Heart Association’s guidelines of doing at least 150 minutes of cardio a week.Exercise reduces LDL cholesterol because it causes the body to use lipids for fuel, which leaves less LDL circling around and clogging your arteries, as explained by a scientific article in Sports Medicine.4. Learn how to deal with stressDr. Hoff says that two lifestyle habits that many people don’t realize contribute to high LDL cholesterol are chronically high levels of stress and not getting enough sleep—which often happen simultaneously. He explains that chronic stress and lack of sleep both release cortisol, and high levels of cortisol are linked to high LDL cholesterol.If you don’t know how to deal with stress in healthy ways or you’re running on fumes more days than not, consider this your sign to get to the bottom of it and make some long-overdue changes.5. Consider a cholesterol-lowering medicationEven if you treat your body like the temple that it is, sometimes high cholesterol is just the hand you were dealt, due to genetics. Typically, a doctor will recommend cholesterol-lowering medication if LDL cholesterol is over 190 mg/dL or someone has a history of heart attacks or stroke, says Dr. Korngold.“If your LDL stays high despite solid habits, you have diabetes, or you have known plaque, cholesterol meds can be game-changers,” Dr. Sabgir says. “Statins can plummet your LDL by up to 60%. They’ve been proven safe and effective for decades.” Statins lower cholesterol by blocking the body’s ability to make cholesterol. “This forces the liver to pull more cholesterol out of the blood,” he says.Remember, high cholesterol is something you can change, so if your cholesterol numbers aren’t where you want them to be, you can do something about it. And if you have no idea what your cholesterol numbers are, make sure you ask your healthcare provider to check at your next appointment. Doing so just might save your life.