Cholesterol level: Can it be too low?

Q: Can your cholesterol level be too low?

Warren / Illinois

A high blood cholesterol level increases your risk of coronary artery disease. Lower cholesterol is usually better — but not always.

Some research suggests that low levels of low-density lipoprotein (LDL), or "bad," cholesterol may be associated with an increased risk of certain types of cancer. Other studies associate a low total cholesterol level with depression and anxiety, perhaps because low cholesterol may reduce levels of the brain chemical serotonin. And pregnant women who have low total cholesterol may be more likely to give birth prematurely and have babies who have low birth weights.

Although the upper limits for total cholesterol and LDL cholesterol have been clearly established, the lower limits depend on the individual.

Ideally, keep your total cholesterol below 200 milligrams per deciliter (mg/dL), or 5.2 millimoles per liter (mmol/L), and your LDL cholesterol below 100 mg/dL (2.6 mmol/L) — or below 70 mg/dL (1.8 mmol/L) if you're at very high risk of heart disease. An adult who eats a low-fat, low-cholesterol diet may have an LDL cholesterol level between 40 and 50 mg/dL (1.0 and 1.3 mmol/L) and a total cholesterol level of 100 mg/dL (2.6 mmol/L).

It's also important to remember that high-density lipoprotein (HDL), or "good," cholesterol counts, too. A low HDL level increases the risk of heart disease. For women, a low HDL level coupled with excess weight after menopause may increase the risk of breast cancer as well. To help prevent heart disease, aim for an HDL level of 60 mg/dL (1.5 mmol/L) or higher.

If you're concerned about your cholesterol level, consult your doctor. He or she can determine the cholesterol range most appropriate for you.