Cholesterol is then returned to the liver by multiple routes. In the first route, cholesterol esters may be transferred from HDL to the apo B–containing lipoproteins, such as very–low-density lipoprotein (VLDL) or intermediate-density lipoprotein (IDL), by CETP. These lipoproteins undergo metabolism and subsequent uptake by the liver, primarily by a process mediated by the B,E receptor. In the second route, HDL particles may be taken up directly by the liver. In the third, free cholesterol may be taken up directly by the liver. Finally, HDL cholesterol esters may be selectively taken up via the scavenger receptor SR-B1.
HDL serves as a chemical shuttle that transports excess cholesterol from peripheral tissues to the liver. This pathway is called the RCT system. In this system, plasma HDL takes up cholesterol from the peripheral tissues, such as fibroblasts and macrophages. (A study by El Khoury et al indicated that in persons with HALP, macrophages have an increased plasma cholesterol efflux capacity.  ) This may occur by passive diffusion or may be mediated by the adenosine triphosphate (ATP)–binding cassette transporter 1. The latter interacts directly with free apo A-I, generating nascent, or so-called discoidal, HDL. Cholesterol undergoes esterification by lecithin-cholesterol acyltransferase (LCAT) to produce cholesteryl ester, which results in the production of the mature spherical HDL. Cholesterol is also taken up from triglyceride-rich lipoproteins in a process mediated by a phospholipid transfer protein (ie, CETP). [19, 20, 21, 22]
The most important mechanism by which HDL exerts its antiatherogenic role is the removal of excess cholesterol from peripheral cells and its transport to the liver, a process commonly termed the reverse cholesterol transport system (RCT). Several proteins are involved in this process, including ATP-binding cassette transporter 1, LCAT, CETP, and hepatic triglyceride lipase (see Pathophysiology). 
Could one of your current prescriptions be a cause of your low HDL levels? Possibly! Medications such as anabolic steroids, beta blockers, benzodiazepines and progestins can depress HDL levels. If you take any of these medications, I suggest talking to your doctor and considering if there is anything you can do that could take the place of your current prescription.
Thanks everyone for all of your comments. If you have specific inquiries, please feel free to contact us at firstname.lastname@example.org. While we cannot give you medical advice, we may be able to help you find an FH specialist. Otherwise, continue to check back to our discussions, or consider joining our FH Support Group here: https://community.thefhfoundation.org/welcome
The information provided here is for informational purposes only and is not intended as a substitute for professional medical advice, diagnosis and treatment. Please consult your healthcare provider with questions concerning any medical condition. While we try to update our content often, medical information changes rapidly. Therefore, some information may be out of date. All images are copyright protected and must not be reproduced in any manner.
Controlling your weight is an important part of getting to healthy cholesterol levels, so it’s crucial to know your portion sizes if you're trying to lower cholesterol. A portion of starchy carbohydrate, like potato or pasta, should be only about half the size of a baseball. A heart-healthy portion of meat should be about the size of a deck of playing cards, or about three ounces.
Plant stanols and sterols (such as beta-sitosterol and sitostanol) are naturally-occurring substances found in certain plants. Stanols are also found as dietary supplements or are added to margarine, orange juice, and dressings. Research suggests that plant stanols and sterols may help to lower cholesterol. They are similar in structure to cholesterol and may help block the absorption of cholesterol from the intestines.
Altering your diet is the easiest way to lower your elevated LDL cholesterol, and should be your first course of action, as every cholesterol-lowering strategy starts with your dietary habits. A balanced diet consisting of fruits, vegetables, whole grains, fish, and various plants will significantly help you lower your LDL cholesterol level. It’s best to limit the amount of red meat, eggs, and dairy you consume. Plant-based diets not only help lower your LDL, but they can also help clear plaque buildup from your arteries.
Where HDL is concerned, “you can’t be too thin,” Castelli says. One report found about a 1 percent rise in HDL for every pound of fat lost. This doesn’t mean you have to turn yourself into a toothpick, but that you should work on getting rid of excess flab as you add muscle. (Use a body-fat monitor rather than a scale to chart your progress.) Fortunately, fat loss is likely to go hand in hand with the exercise and dietary modifications that also raise HDL levels.
1. Oats. An easy first step to improving your cholesterol is having a bowl of oatmeal or cold oat-based cereal like Cheerios for breakfast. It gives you 1 to 2 grams of soluble fiber. Add a banana or some strawberries for another half-gram. Current nutrition guidelines recommend getting 20 to 35 grams of fiber a day, with at least 5 to 10 grams coming from soluble fiber. (The average American gets about half that amount.)
Research has shown the health benefits of eating seafood rich in omega-3 fatty acids, especially when it replaces less healthy proteins that are high in saturated fat and low in unsaturated fat. Including seafood high in omega-3 fatty acids as part of a heart-healthy diet can help reduce the risk of heart failure, coronary heart disease, cardiac arrest and the most common type of stroke (ischemic).
Hayek T, Chajek-Shaul T, Walsh A, Agellon LB, Moulin P, Tall AR, Breslow JL. An interaction between the human cholesteryl ester transfer protein (CETP) and apolipoprotein A-I genes in transgenic mice results in a profound CETP-mediated depression of high density lipoprotein cholesterol levels. J Clin Invest. 1992 Aug;90(2):505–510. [PMC free article] [PubMed]
3. Beans. Beans are especially rich in soluble fiber. They also take awhile for the body to digest, meaning you feel full for longer after a meal. That's one reason beans are a useful food for folks trying to lose weight. With so many choices — from navy and kidney beans to lentils, garbanzos, black-eyed peas, and beyond — and so many ways to prepare them, beans are a very versatile food.
As defined by the US National Cholesterol Education Program Adult Treatment Panel III guidelines, an HDL cholesterol (HDL-C) level of 60 mg/dL or greater is a negative (protective) risk factor.  On the other hand, a high-risk HDL-C level is described as being below 40 mg/dL. Randomized, controlled clinical trials have demonstrated that interventions to raise HDL-C levels are associated with reduced CHD events. A prospective analysis by Mora et al investigated the link between cholesterol and cardiovascular events in women and found that the baseline HDL-C level was consistently and inversely associated with incident coronary and coronary vascular disease events across a range of LDL-C values. 
Pick Purple Produce – Did you know that eating purple-colored vegetables and fruits can potentially increase your HDL cholesterol? That’s because these specific foods contain antioxidants called anthocyanins, which have been shown to help fight inflammation and protect your cells from free radicals. When you can, fill up your plate with purple produce like eggplant, purple corn, red cabbage, blueberries, blackberries, and black raspberries.
And according to some powerful experiments by software engineer-turned-biohacker Dave Feldman, you can actually increase and decrease your cholesterol at will. It all depends on how much fat you eat — and, directly against mainstream dietary knowledge, the correlation is inverted. In other words, eating more fat will actually lower your cholesterol.