Bowel health

Types of fiber

Insoluble and soluble fiber: what each does and where to find it.

There are two main types of fiber: insoluble and soluble. Both can prevent and relieve constipation and diarrhea, although some people find one or the other easier to digest.

Insoluble fiber

Functions: moves bulk through the intestines, and controls and balances the pH (acidity) in the intestines.

Benefits:

• Promotes regular bowel movements and prevents constipation
• Removes fecal waste through the colon in less time
• Keeps an optimal pH in the intestines to prevent microbes from producing cancer-causing substances, helping prevent colon cancer

Food sources:

• Whole-wheat products
• Wheat bran (miller’s bran)
• Corn bran
• Flax seed and other seeds
• Green beans, broccoli, cauliflower, and potato skins
• Fruit skins and root vegetable skins
• Popcorn
• Brown rice

Soluble fiber

Functions: holds water in the colon to bulk and soften the stool, and prolongs stomach emptying time so that sugar is released and absorbed more slowly.

Benefits:

• Lowers total cholesterol and LDL (bad) cholesterol, reducing the risk of heart disease
• Regulates blood sugar for people with diabetes

Food sources:

• Oats and oat bran
• Dried beans and peas
• Nuts
• Barley
• Flax seed and other seeds
• Oranges, pears, peaches, and apples
• Carrots
• Psyllium husk
• Prunes