What Happens When Your HDL Is Below 40?

About Lipoproteins

That greasy cheeseburger at the local diner will give you a heavy dose of cholesterol, but your body also makes cholesterol naturally to maintain healthy cell function. Lipoproteins act as cholesterol transporters in your blood, carrying cholesterol to and from your cells. High levels of low-density lipoprotein -- LDL, or "bad" cholesterol -- cause plaque to build up in your blood vessel walls, increasing your risk of heart disease. HDL, your "good" cholesterol, acts as a security guard, carrying cholesterol away from your arteries and back to your liver, where it's passed from your body, thereby lowering your risk of heart disease.

HDL Levels

Higher is better when it comes to your HDL levels. According to the National Cholesterol Education Program, HDL levels below 40 milligrams per deciliter increase your risk of developing heart disease. Estrogen tends to boost HDL levels, so young women often have higher HDL levels than men. Due to this natural advantage, the American Heart Association considers HDL levels below 50 milligrams per deciliter to be a risk factor for women. Ideally, you should aim for HDL levels of 60 milligrams per deciliter and higher.

Research

In several major research studies, HDL levels accurately predicted the risk of heart disease for women. In the Framingham Heart Study, as reported in an article in "Arteriosclerosis" in 1988, women with low HDL levels had a risk of death from heart disease that was three times greater than women with high HDL levels. According to the Nurses' Health Study conducted by Harvard University, as reported in "Circulation" in 2004, low HDL levels were the strongest predictor of future heart disease in women, compared to other known risk factors. Another article in “Circulation,” published in 1989, analyzed four studies that looked at the relationship between HDL and cardiovascular disease. One of those studies found that increasing HDL levels benefited women more than men. An increase in HDL of 1 milligram per deciliter reduced the risk of heart disease in women by 3 percent, compared to 2 percent for men.

Tips

If your HDL levels need a boost, lace up your sneakers and hit the trail. MayoClinic.com reports that 30 minutes of exercise five days a week can increase your HDL levels by 5 percent. If you you stop smoking cigarettes, you could increase your levels by 10 percent. At the grocery store, add fiber-rich fruits, veggies and whole grains to your cart. Fiber helps to regulate cholesterol levels, and a high-fiber diet reduces your risk of heart disease. According to the Harvard Nurses' Health Study, as reported in "The Journal of the American Medical Association" in 1999, a high-fiber diet reduced the risk of heart disease in women significantly. Aim for at least 25 grams of fiber a day, as recommended by the Institute of Medicine.