"A skinless chicken breast, add mustard hold the mayonnaise, salad not French fries, and low-fat dressing"... the good news is your dietary efforts have paid off and your cholesterol level has dropped. The bad news is, it hasn't dropped quite low enough. But don't give up on dietary measures just yet. Two daily doses of a soluble fiber called psyllium combined with the low-fat diet you're already following may be just what your body needs to push cholesterol levels down to within a healthful range. This is what a group of researchers based in Lexington, Kentucky in the US recently reported in the American Journal of Clinical Nutrition.

In the first phase of this study, researchers invited men and women with elevated cholesterol levels (hypercholesterolemia) to follow the American Heart Association's Step I diet for 8 weeks. This diet-55% of calories from carbohydrate, 15% from protein, < 30% from fat with < 10% as saturated fat, and < 300mg cholesterol daily-is typically prescribed as the first step to lower elevated cholesterol levels. After 8 weeks, 200 people entered the next phase, in which they were divided into two groups. All of the study volunteers continued to follow the Step I diet for the 26-week long phase two, but one group was given two 5.1 gram doses a day of the soluble fiber psyllium in the form of Metamucil powder mixed with 8 ounces of fluid. Previous studies have found that soluble fiber can lower both total and LDL cholesterol levels in people with hypercholesterolemia. The placebo group was given an identical looking powder, but one devoid of soluble fiber and made instead of insoluble fiber, which does not appear to affect cholesterol levels.

While following the Step I diet during phase one, both total and LDL cholesterol levels dropped for all the volunteers. However, as phase two progressed, the total and LDL cholesterol levels of those in the psyllium group continued to drop, while the cholesterol levels in people taking the insoluble fiber increased. Over the course of the entire study, the people who combined the Step I diet with psyllium achieved about a 5% lower total cholesterol level and a 7% lower LDL level compared with those in the placebo group, who only followed the Step I diet. The researchers explain that such drops translate to a 10-15% reduced risk for heart disease.

Exactly how soluble fiber helps to tame cholesterol levels has not been clearly defined. It is believed to encourage bile acid synthesis, which in turn leads to a reduction in serum cholesterol levels. Commercial fiber supplements like Metamucil (the form used in this study) are a convenient way for some people to boost their soluble fiber intake, but it is not necessary to rely on such supplements. In fact, a number of studies demonstrate the positive effect of oats on serum cholesterol. Fruits, vegetables, and legumes are also good sources of soluble fiber. Note, though, that several servings of these foods per day are necessary to reach the soluble fiber intake shown to benefit the subjects in this study.

Commonly used as a laxative, psyllium comes with few safety concerns. However, bloating, indigestion, and other gastrointestinal side effects were reported by a quarter of volunteers in the psyllium group. To minimize such effects, psyllium, like any high-fiber food, should be added gradually to the diet and accompanied by an increased intake of fluid. So, if you're whittling away at your cholesterol level, know that psyllium can be a helpful tool combined with a low-fat diet.

Source

Long-term cholesterol-lowering effects of psyllium as an adjunct to diet therapy in the treatment of hypercholesterolemia.
JW. Anderson,  et al., American Journal of Clinical Nutrition. , 2000, vol. 71, pp. 1433--1438

Links

• The American
  Heart Association Step I and II diets
• The
  Cholesterol Quandary
• Fiber
  Facts: Soluble Fiber and Heart Disease, The American Dietetic Association