2006-03-30
Chris Rosenbloom, Ph.D., R.D.

Editor's note: In this weekly column, Atlanta registered dietitian and Georgia State University nutrition instructor Chris Rosenbloom offers advice on how to maintain a healthy diet and active lifestyle. And she's prepared to answer your questions as well — whether you're trying to shed pounds, lower your cholesterol, fuel yourself to excel at your favorite sport or simply eat better and live longer.

Several readers have asked for dietary advice to lower triglycerides. A typical question is: "My total cholesterol and low-density lipoproteins (LDL) are normal, but my triglyceride level is very high — what foods can lower triglycerides?" Another frequent question is whether supplementation of the B vitamin niacin is an effective treatment.

Elevated blood triglyceride level (called hypertriglyceridemia — "hyper" means high and "emia" means blood) is a risk factor for heart disease. The National Cholesterol Education Program recommends that blood triglyceride levels be less than 150 milligrams. It is important to fast from food and alcohol for at least 12 hours before you get your triglycerides measured.

Triglyceride is a general term for fat; 95 percent of the fat we eat is in the form of triglycerides. The triglyceride molecule looks like the letter E. The backbone of the letter is glycerol, and each arm of the letter is a fatty acid. Some of the fatty acids are saturated fatty acids (foods like sausage, butter, shortening and the fat in whole-milk dairy foods). Other "arms" of the triglyceride could contain polyunsaturated fatty acids (corn oil, soybean oil and soft tub margarines), while others contain monounsaturated fats (olive oil, canola oil, avocados and nuts).

In addition to the triglycerides we get from foods, the liver makes triglycerides from the fat we eat but also from extra carbohydrates and from alcohol. By "extra" carbohydrates I mean the carbohydrates that exceed daily energy needs. The extra carbs get converted to triglycerides and can be stored as body fat.

The first recommendation for lowering triglycerides is to decrease calorie intake, if you're overweight. If you are at a healthy weight, decrease carbohydrate-rich foods to less than 50 percent of your calories and substitute heart-healthy fats for carbohydrates. Heart-healthy fats include canola oil, olive oil and liquid margarine. Nuts, olives and avocados also contain good fats.

Another dietary strategy to manage triglycerides is to substitute fatty fish for some beef, pork and poultry.

Fish with high levels of omega-3 fatty acids include herring, sardines, trout, salmon and albacore tuna. Halibut, Alaskan king crab, mackerel, shrimp and scallops also contain omega-3 fats, but in lesser amounts. A recent report found that consumption of fatty fish lowered triglycerides by an average of 29 percent. The American Heart Association recommends eating two fish meals a week to increase intake of these "good" fats.

Another strategy to lower triglycerides is to reduce or eliminate all types of alcohol. Alcohol, even small amounts, can elevate triglycerides.

Niacin can lower triglycerides, but only when used in very large amounts. The recommended dietary allowance for niacin is 14 milligrams a day for women, 16 milligrams for men, with an upper limit of 35 milligrams. To lower triglycerides, levels of 2,000 to 6,000 milligrams (2 to 6 grams) of niacin are needed. At this level, niacin is no longer a vitamin but a drug. Dietary supplements are not tightly regulated by the Food and Drug Administration, so if your doctor recommends niacin, you should use the prescription version of niacin. The prescription form is regulated by the FDA and is formulated to reduce side effects and deliver the vitamin in a time-released way to minimize skin flushing.

• Chris Rosenbloom, Ph.D., R.D., is a member of the nutrition faculty in the College of Health and Human Sciences at Georgia State University. She'll answer nutrition questions of general interest at dietitian@ajc.com. Or send your questions to her c/o The Atlanta Journal-Constitution, Eighth Floor, 72 Marietta St. N.W., Atlanta, GA 30303.

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http://www.ajc.com/living/content/living/food/fit/stories/033006.html