HDL levels below 40 mg/dL are associated with an increased risk of CAD, even in people whose total cholesterol and LDL cholesterol levels are normal. HDL levels between 40 and 60 mg/dL are considered "normal," and do not very much affect the risk of CAD one way or the other. However, HDL levels greater than 60 mg/dL are actually associated with a reduced risk of heart disease.
Plasma HDL is a small, spherical, dense lipid-protein complex that is half lipid and half protein. The lipid component consists of phospholipids, free cholesterol, cholesteryl esters, and triglycerides. The protein component includes apo A-I (molecular weight, 28,000) and apo A-II (molecular weight, 17,000). Other minor, but important, proteins are apo E and apo C, including apo C-I, apo C-II, and apo C-III.
Dr. Pacold notes that exercise has a greater effect on raising HDL cholesterol, which protects you from heart disease, than on lowering the LDL cholesterol that puts you at risk. It's good to know that even if you don’t see the numbers changing right away, regular exercise strengthens your heart and protects you from heart disease. If you’re not a big fan of exercise and not in great shape to begin with, remember that all you need to do to start reaping the heart-healthy benefits of exercise is 30 minutes of walking at a moderate pace every day. If you have a heart condition, talk with your doctor first about how much exertion is right for you when you begin, and then work your way up to your fitness goals for heart health.
As a result of all this, doctors don’t just want you to lower your total cholesterol count; they want you to change the ratio as well, so you have more HDL and less LDL. “When we looked at the data, we found that the higher your HDL went, the lower your risk of heart attack,” says cardiologist William Castelli, M.D., former director of the Framingham Heart Study in Massachusetts. An HDL level of 75 or more seems to convey extra longevity for many people, while a count of 100 or more is so beneficial that it was dubbed the “Methuselah syndrome” by one researcher. HDL less than 35 or so, meanwhile, can carry significant risk of heart disease. Genetics plays a large role in HDL. A few guys have naturally low levels and need to keep their LDL low as well to make up for it. (As Castelli puts it, you don’t need a substance that removes cholesterol from your blood if you don’t have much to begin with.) But there’s plenty that everyone else can do to pump up their HDL. Never one to shirk from a task that doesn’t involve housecleaning, I managed to find two handfuls of ways to turn my “good” numbers into great numbers.
George T Griffing, MD is a member of the following medical societies: American Association for the Advancement of Science, International Society for Clinical Densitometry, Southern Society for Clinical Investigation, American College of Medical Practice Executives, American Association for Physician Leadership, American College of Physicians, American Diabetes Association, American Federation for Medical Research, American Heart Association, Central Society for Clinical and Translational Research, Endocrine Society
You've probably heard that fried foods of all kinds, hydrogenated oils, and full-fat dairy products are cholesterol bombs that are best avoided (and not just by those watching their cholesterol levels). The American Heart Association recommends that everyone restrict these foods, as they contain trans and saturated fats, the "bad" kind that raises LDL cholesterol and leads to plaque buildup in the arteries.