Heart Health High Cholesterol What Is Oxidized Cholesterol? Definition, Effects, Food Sources, and Ways to Prevent Future Buildup By Jennifer Moll, PharmD Jennifer Moll, PharmD Facebook Jennifer Moll, MS, PharmD, is a pharmacist actively involved in educating patients about the importance of heart disease prevention. Learn about our editorial process Updated on September 15, 2022 Medically reviewed by Michael Menna, DO Medically reviewed by Michael Menna, DO Michael Menna, DO, is a board-certified, active attending emergency medicine physician at White Plains Hospital in White Plains, New York. Learn about our Medical Expert Board Print Oxidized cholesterol is made in the body when low-density lipoprotein (LDL), sometimes called “bad” cholesterol, goes through a chemical reaction. Oxidized cholesterol is what builds up on the artery walls, the muscular tubes that carry blood away from the heart. Too much oxidized cholesterol can lead to atherosclerosis, or hardening of the arteries. The resulting decrease in blood flow in your arteries raises your risk for heart attack and stroke. What is cholesterol? Cholesterol is a waxy substance in the blood, one of a group of non-water-soluble molecules called lipids. Cholesterol is used to build healthy cells in the body, which help with bodily structure, nutrient processing, and making energy. Westend61 / Getty Images This article explains what oxidized cholesterol is, what causes it, and how it can impact your overall health. It will also discuss what can help reduce and prevent oxidized LDL buildup. Atherosclerosis, Arteriosclerosis, and Heart Surgery What Causes LDL to Oxidize? LDL cholesterol can buildup due to: Eating foods high in trans fats, like salty fried foods and pastries Smoking tobacco products, like cigarettes When LDL cholesterol reacts with free radicals (unstable molecules made during normal cell metabolism), it can become oxidized. While oxidation is a normal process, it is possible for your body to make too much oxidized cholesterol. This can lead to inflammation and other health concerns. LDL cholesterol molecules are not all the same size. Smaller LDL particles are more likely to become oxidized, making them more dangerous to your health. What Are The Effects of Oxidized LDL? Oxidized LDL can cause inflammation in the arteries. Platelets, which normally help to stop bleeding by producing blood clots, can stick to areas of inflammation within the arteries. When they do, they create sticky, hardened areas inside blood vessels called plaques. Over time, fat, cholesterol, and other substances build up in the walls of the arteries. This causes the plaques to grow. Plaque buildup can partially or completely block blood flow within an artery. This is referred to as atherosclerosis. Atherosclerosis increases a person’s risk for: Coronary heart disease, or damage in the heart’s blood vessels due to plaque Peripheral vascular disease, or a progressive circulation condition that can impact blood flow to the limbs Cerebrovascular disease, or a condition that impacts the brain’s blood vessels Stroke, or a condition that occurs when the brain doesn’t get enough oxygen Heart attack, a condition that occurs when a part of the heart doesn’t get enough blood flow While research has largely indicated that oxidized LDL cholesterol has a negative effect on the body, some studies suggest mild oxidation of LDL may have some protective factors. How Do You Reduce Oxidized LDL? You can test for cholesterol levels through routine cholesterol blood tests. These determine levels of LDL, HDL, and triglycerides, or a type of fat in the blood. Routine cholesterol tests do not measure the concentration of small versus large LDL molecules or oxidized LDL levels, though advanced lipoprotein tests can measure these. If you have elevated or high cholesterol, lifestyle changes can help you reduce your level of small LDL. This can help prevent the formation of oxidized LDL. According to the American Heart Association (AHA), cholesterol testing should be done every four to six years for people age 20 or older who are at low risk for cardiovascular disease. People with cardiovascular risk factors may need more frequent testing.LDL cholesterol levels should be less than 100 mg/dL. How to Reduce Your Small, Dense LDL Cholesterol What Foods Remove Oxidized Cholesterol? What you eat can play a significant role in preventing oxidized LDL.Oxidized cholesterol-lowering foods include: Fruits and vegetables: Produce is rich in antioxidants with natural anti-inflammatory properties that may help reduce the oxidation of LDL. Healthy fats: Healthy fats, like those in nuts, avocados, and seafood, help raise HDL. This is believed to have an antioxidant effect because of its ability to neutralize an enzyme that plays a role in oxidation. Antioxidants Antioxidants are substances that help prevent oxidation and reduce or slow cell damage. Foods That Cause Oxidized Cholesterol Foods that cause oxidized cholesterol that should be limited or avoided include: Trans fats: Foods higher in trans fats include pastries, deep-fried foods, potato chips, and any food cooked with lard.Sugary foods: Refined sugars have been linked to higher levels of oxidized cholesterol. Natural sugars, like those found in fruits, have not been shown to increase cholesterol. What Else Can Help Reduce Oxidized LDL? You can further boost your efforts to prevent oxidized cholesterol by: Quitting or avoiding smoking. Smoking exposes you to chemicals that promote free radical formation, increasing oxidative damage. Controlling your blood sugar. If you have been diagnosed with diabetes, a group of conditions that impact blood sugar, or metabolic syndrome, a group of conditions that increase your risk of stroke, heart disease, and diabetes, it’s important to keep your sugar levels in check. In some cases, your healthcare provider may prescribe medication. Exercising. Regular physical activity can help raise HDL, or the “good” cholesterol. Some cholesterol-lowering medications, such as statins, also have anti-inflammatory properties that may help prevent the inflammation that promotes plaque buildup in the arteries. At normal levels, LDL and HDL cholesterol do not cause problems. Ways You Can Lower Your High Cholesterol Summary Oxidized cholesterol forms in the body when LDL goes through a chemical reaction. Oxidized LDL can build up on the artery walls due to eating certain foods high in trans fats. Smoking tobacco products is also linked to high levels of oxidized LDL. Oxidized LDL can lead to inflammation in the arteries and eventually atherosclerosis, which is linked to other serious health concerns. A Word From Verywell Oxidized LDL is increasingly recognized as a contributor to heart disease, vascular disease, and stroke. If you’ve been diagnosed with elevated or high cholesterol, taking steps to eat healthier, exercise more, and to stop smoking can help. A lower level of LDL decreases the chance of plaque buildup. Speak with your healthcare provider about ways you can prevent or reduce LDL buildup. Frequently Asked Questions Do statins lower oxidized cholesterol? Statins, a type of drug, are associated with reduced oxidized cholesterol levels. Learn More: Be Aware of These Stain Drug Interactions What foods are bad for oxidized cholesterol? Highly processed foods, dairy, eggs, butter, meat, fish, and baked goods tend to cause a buildup of oxidized cholesterol. Learn More: Study: Eating Ultra-Processed Foods May Increase Your IBD Risk What is the difference between LDL and oxidized LDL? LDL is a type of cholesterol that is considered bad. LDL that has gone through a chemical reaction is called oxidized LDL. Oxidized LDL can lead to inflammation and other health concerns. Learn More: Signs of a Weak Heart and Common Causes What causes LDL to oxidize? Smoking, and eating foods high in trans fats can cause a buildup of oxidized LDL. Learn More: Which Foods Are High in Trans Fats? 10 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Rhoads JP, Major AS. How oxidized low-density lipoprotein activates inflammatory responses. Crit Rev Immunol. 2018;38(4):333-342. doi:10.1615/CritRevImmunol.2018026483 Badrnya S, Schrottmaier WC, Kral JB, et al. Platelets mediate oxidized low-density lipoprotein-induced monocyte extravasation and foam cell formation. Arterioscler Thromb Vasc Biol. 2014;34(3):571-580. doi:10.1161/ATVBAHA.113.302919 Brites F, Martin M, Guillas I, Kontush A. Antioxidative activity of high-density lipoprotein (HDL): mechanistic insights into potential clinical benefit. BBA Clin. 2017;8:66-77. doi:10.1016/j.bbacli.2017.07.002 Trpkovic A, Resanovic I, Stanimirovic J, et al. Oxidized low-density lipoprotein as a biomarker of cardiovascular diseases. Crit Rev Clin Lab Sci. 2015;52(2):70-85. doi:10.3109/10408363.2014.992063 Meyer JM, Ji A, Cai L, van der Westhuyzen DR. Minimally oxidized LDL inhibits macrophage selective cholesteryl ester uptake and native LDL-induced foam cell formation. J Lipid Res. 2014;55(8):1648. doi:10.1194/jlr.M044644 Laboratory Corporation of America. LDL particle testing (LDL-P). National Library of Medicine: MedlinePlus. LDL: The "bad" cholesterol. Grundy SM, Stone NJ, Bailey AL, et al. 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA guideline on the management of blood cholesterol: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation. 2019;139(25):e1082-e1143. doi:10.1161/CIR.0000000000000625 DiNicolantonio JJ, Lucan SC, James H. O’Keefe JH. The evidence for saturated fat and for sugar related to coronary heart disease. Prog Cardiovasc Dis. 2016;58(5):464-472. doi:10.1016/j.pcad.2015.11.006 Singh P, Goncalves I, Tengryd C, et al. Reduced oxidized LDL in T2D plaques is associated with a greater statin usage but not with future cardiovascular events. Cardiovasc Diabetol. 2020;19(1):214. doi:10.1186/s12933-020-01189-z By Jennifer Moll, PharmD Jennifer Moll, MS, PharmD, is a pharmacist actively involved in educating patients about the importance of heart disease prevention. 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