Understanding your cholesterol levels

Eating too much saturated fat leads to high cholesterol, which can clog arteries and cause heart attacks. But cholesterol isn't necessarily a villain. Your liver, intestines and skin manufacture cholesterol to help build cell membranes and produce sex hormones, vitamin D and fat-digesting bile acids. Here're some pointers for understanding your cholesterol levels.

The real key to heart-healthy cholesterol levels, experts now say, is a balance between two basic types:

• "lousy" or "bad" low-density lipoproteins (LDLs);
• and "healthy" or "good" high-density lipoproteins (HDLs).

The latest news is that heart experts are finding that the higher your HDLs and the lower your LDLs, the lower your risk of blocked coronary arteries and heart attack. This balance reflects the "natural" cholesterol balance observed in hunter-gatherer societies.

LDL cholesterol is bad for you, so you want to aim for a low reading, preferably under 3.5 mmol/l (millimoles per litre of blood).

If you already have heart disease, your doctor will want to reduce LDL even further to less than 2.0 mmol/l.

The other cholesterol — HDL — is good for you, and you want a reading above 1 mmol/l.

Ideally, your total cholesterol — including LDL levels of 3.5 mmol/l or lower — should be below 5 mmol/l. If your levels are persistently higher, your doctor is likely to suggest measures to help to reduce it and may offer drug treatment too.

In other words:

• If you have less than 5 mmol/l, your cholesterol is deal.
• Cholesterol levels of 5.2 mmol/l–6.4 mmol/l are moderately high.
• If your cholesterol levels are above 6.5 mmol/l, then they're high.

New research also suggests that one type of LDLs — small, dense LDLs — is especially lethal. Free radicals (highly active molecules in your body that can proliferate and cause serious damage) can easily damage these tightly packed particles in your bloodstream.

The then even tinier LDL particles can then penetrate artery walls with ease, laying the foundation for the plaque buildup of atherosclerosis.

The bottom line is that high amounts of LDLs in your bloodstream increase your risk of atherosclerosis; low levels reduce it.

So what's the cholesterol safety zone?

All research indicates that the lower your LDL levels, the lower your risk of heart disease.

In a provocative study published in March 2004 in the Journal of the American Medical Association, researchers found that high doses of cholesterol-lowering medications (statins) that targeted LDLs halted the progression of heart disease and cut mortality rates by 28 per cent. But no drug is without side-effects, some people develop muscle pain and other problems when they take statins.

Keep these important pointers in mind and you'll be better able to understand what your cholesterol levels mean. This knowledge can also come in handy when you're talking with your doctor about your own cholesterol levels.