The Nation's Health

Triglycerides: Low-fat diets raise triglycerides

Martin, a hospital employee, knowing that I fuss a great deal with lipids and lipoproteins, showed me his lipid panel because the result triggered a "panic value" for triglycerides at 267 mg/dl. He asked if he should go on a serious low-fat diet.

I asked Martin what he had for breakfast: a whole wheat bagel with no-added-sugar jam. Lunch: a turkey sub on whole grain bread, no mayonnaise. Snacks: baked chips, pretzels ("a low-fat snack!").

In years past, if person developed high triglycerides levels, a very low-fat diet was prescribed. Someone would come to the hospital, for instance, with abdominal pain from pancreatitis (an inflamed pancreas)due to the damaging effects of triglyceride levels >1000 mg/dl. For this reason, many people still believe that all instances of elevated triglycerides should be treated with a reduction in fat intake.

This is absolutely wrong. While a fat restriction may reduce triglycerides in genetically-programmed responses when triglycerides are >1000 mg/dl, lesser levels of high triglycerides of, say 250 or 300 mg/dl, do not respond to dietary fat restrictions as a sole strategy.

Yes, a reduction in unhealthy fats (saturated, trans, polyunsaturated) helps. But a reduction in fats of all sorts is not necessary and can, in fact, worsen the problem. We learned this lesson years ago with the Ornish diet and similar ultra low-fat approaches. When you reduce fat intake significantly to <10% of calories, triglycerides go way up. In those days, it wasn't uncommon to see triglycerides skyrocket past 200 or 300 mg/dl on these diets.

Why are triglycerides important? Triglycerides are an ingredient in creating the lipoproteins VLDL, IDL, small LDL. Elevated triglycerides trigger a drop in HDL, a shift towards small, ineffective HDL, and contribute to heightened inflammation. Higher triglycerides also tend to go hand in hand with lipoproteins that persist for extended periods (12-24 hours or longer) in the blood after a meal.

Triglycerides respond very nicely to a dramatic reduction in processed carbohydrates, especially wheat and corn. Of course, wheat is the bulk of the problem, since it has grown to occupy an enormous role in many people's diet, not uncommonly eaten 3,4, or 5 times per day in various forms, as it has in Martin's diet. Eliminating all sources of high-fructose corn syrup is also helpful, since high-fructose corn syrup shoots triglycerides way up. (Recall that high-fructose corn syrup is everywhere: ketchup, beer, low-fat or non-fat salad dressings, breads, fruit drinks, sports drinks, breakfast cereals, etc.)

Curiously, it is a fat that also powerfully reduces triglycerides in the form of fish oil. In the Track Your Plaque program, fish oil, taken at truly effective doses of 4000 mg per day or more (to provide at least 1200 mg EPA+DHA), is our number one choice after reduction of processed carbohydrates for reduction of high triglycerides.