Comparing Soluble and Insoluble Fiber

Type of Fiber

Sources

Functions

Soluble

Apples (mainly in the flesh of the apple)

Barley

Beans

Citrus fruits

Lentils

Oat bran

Oatmeal

Pectin (from fruit)

Rice bran

Strawberries

Helps reduce cholesterol levels

May reduce the risk of atherosclerosis (including coronary artery disease)

Insoluble

Apples (mainly in the skin of the apple)

Brown rice

Pears

Prunes

Many vegetables, including cabbage, root vegetables, and zucchini

Whole grains and whole-grain breads and pastas

Provides bulk to feces and thus helps food move through the digestive tract, preventing constipation

Helps eliminate cancer-causing substances produced by the bacteria in the large intestine

Reduces pressure in the intestine, helping prevent diverticular disease

Makes people feel less hungry because it adds bulk to the diet, makes people chew more slowly, and keeps food in the stomach longer—and is thus helpful in losing weight

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