Lipid Disorders and Fiber

Water-soluble fiber supplements (such as psyllium, hydroxymethylcellulose and its relatives, and beta glucan from oats) are thought to lower cholesterol, and the FDA has permitted products containing this form of fiber to carry a "heart-healthy" label.³¹ It must be kept in mind, however, that the bulk of the supporting evidence for this theory comes from studies of oats conducted by manufacturers of oat products.²⁵⁵

Glucomannan, a dietary fiber derived from the tubers of Amorphophallus konjac, has been shown to significantly reduce total and LDL cholesterol levels.

Chitosan, a type of insoluble fiber derived from crustacean shells, has been proposed for reducing cholesterol levels. Research is not yet very encouraging for using chitosan for this purpose.

Experts believe that soluble fiber reduces cholesterol levels by increasing excretion of cholesterol from the digestive tract. This affects two forms of cholesterol: cholesterol from food, and, more importantly, cholesterol from the blood “recycled” by the liver through the intestines.

Read more details about Fiber.

A comprehensive review combining the results of 14 studies found that glucomannan significantly reduced total and LDL cholesterol levels.²⁸⁹

Many studies indicate that water-soluble fiber supplements lower cholesterol.^253,263,291 Keep in mind that the bulk of the supporting evidence for this theory comes from studies of oats conducted by manufacturers of oat products.²⁵⁵

Current evidence suggests that if chitosan does offer any benefits, they are minimal at best.^{84-92,147,148,187,197,225-226,285}

See the chitosan article and the glucommanan article for more information on these forms of fiber.

As for soluble fiber, you can incorporate more into your diet by taking supplements and/or increasing your intake of foods that are good sources of soluble fiber, such:

• Oats and barley
• Beans and peas
• Nuts
• Flax seeds
• Fruits such as oranges and apples
• Vegetables such as carrots

A typical dose of oat bran is 5 to 10 g with each meal and at bedtime; psyllium is taken at 10 g with each meal. For improving total and LDL cholesterol, studies have found benefit with beta-glucan at doses ranging from 3 to 15 grams daily. However, benefits have been seen more consistently at the higher end of this range, and one carefully designed study found no benefit at 3 grams daily.³³

Beta-glucan products can contain molecules of various average lengths (molecular weight). Some manufacturers claim superior benefits with either high or low molecular weight versions. However, one study failed to find any difference between high molecular weight and low molecular weight beta-glucan for normalizing cholesterol and blood sugar levels.³⁴

• Integrative MD
• Nutritionist or dietitian
• Naturopathic doctor

Because it occurs naturally in foods and is a part of most people's regular diet, fiber is considered to be generally safe at normal amounts. Some people do experience digestive upset (stomach ache, cramps, and/or diarrhea) when they increase their intake of fiber. To avoid this, increase your intake gradually so your body has time to adjust.

There are some theoretical concerns about the use of beta-glucan and its potential effects on the immune system. For more information, see the the Side Effects & Warnings section of the beta glucan article.

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