Doctors no longer predict your chances of suffering a heart attack by how high your total cholesterol is. The current guidelines recommend that everyone should have a blood level of the bad LDL cholesterol below 100. If you live in Canada, divide the American number by 40. That means that Canadians must have their bad LDL cholestrol levels below 2.5. If you have had a heart attack, you should try to get your bad LDL cholesterol below 70 (Canadian value below 1.75).
You can remember that HDL is the good cholesterol by thinking "H is for healthy"; and that LDL cholesterol is bad because "L is for lousy". The good HDL cholesterol carries cholesterol from your bloodstream to your liver where it can be removed from your body. The bad LDL cholesterol carries cholesterol to your arteries where it forms plaques. To some degree, your good HDL cholesterol protects you from the bad LDL cholesterol, so having a high level of the good HDL helps to protect you from having a heart attack from high levels of the bad LDL. However, this is sometimes not true. Some people with very high blood levels of the good HDL cholesterol still get heart attacks. Hence the new guidelines based purely on blood levels of the bad LDL cholesterol.
A heart-healthy diet can lower cholesterol levels in most people. You can lower your LDL cholesterol by restricting your intake of saturated and partially hydrogenated fats, refined carbohydrates and calories. The diet for lowering cholesterol is the same as the diet to control high blood pressure; see my modified DASH diet . If you are willing to make these lifestyle changes you may be one of the 80 percent who can control cholesterol and blood pressure without drugs.