By the way, doctor

Q. I have healthy cholesterol levels, but a high triglyceride level. What are triglycerides, and how dangerous is it to have high levels?

A. Triglycerides are the chemical form taken by most of the fat in our bodies and our diet, and they're important because they provide energy the body needs. The fats, carbohydrates, and proteins we eat are converted in the body into simple triglyceride molecules and repackaged with special proteins called lipoproteins, which ferry the triglycerides to the cells. Blood triglyceride levels spike right after we eat, when these triglyceride/lipoprotein packages get dumped into the bloodstream. Levels drop over the next few hours as the triglycerides are taken up and used for energy. Those not needed immediately are transported to fat cells for storage.

Excessive triglycerides are not good for the arteries. Research has found links between high triglyceride levels and a high risk of stroke and heart disease, especially in postmenopausal women.

Some people have an inherited predisposition to high triglycerides. Other contributing factors are obesity, excessive alcohol use, a diet high in saturated fats, and various medical conditions, such as poorly controlled diabetes, low thyroid hormone, or chronic kidney or liver disease. Triglyceride levels can also be raised by certain medications, including prednisone, estrogens used in oral contraceptives or hormone therapy, thiazide diuretics, isotretinoin (Accutane), tamoxifen, and some beta blockers.

It makes sense to try to lower triglycerides to normal levels, that is, below 150 milligrams per deciliter. If there are medical reasons for your high triglycerides, you'll need to work with your clinician to address them, possibly with medications. If not, concentrate on lifestyle strategies, including a diet that emphasizes whole grains, fruits, vegetables, and healthy fats. Also, get at least 30 minutes of moderate to vigorous-intensity exercise most days, and keep your alcohol intake to a minimum.

If lifestyle changes don't work, or if your triglyceride level is very high, you may need to take a medication, such as niacin, gemfibrozil (Lopid, generic), or fenofibrate (Antara, TriCor, others).

— Celeste Robb-Nicholson, M.D. Editor in Chief, Harvard Women's Health Watch