Plant-based foods contain sources of fiber, an important element in your well-balanced diet. Dietary fiber comes from natural food sources, whereas functional fiber is an isolated or extracted fiber from plant foods that is added to foods or supplements. The common classifications of fiber as either "soluble" or "insoluble" refer to the properties and functions it has in your body; most foods contain mixtures of both forms.
Soluble Fiber
The solubility of fiber refers to its ability to dissolve in water. The terms "viscous" and "fermentable" further delineate the physiological effect of fiber, and are often used interchangeably with the term soluble; however, solubility does not necessarily predict fiber's physiological effect. Soluble fibers include gums, beta-glucans, pectins, mucilages and hemicelluloses. Soluble fibers such as pectin or beta-glucans form a gelatinous, or viscous property, that helps you stay full longer, stabilizes blood sugar and reduces cholesterol in your bloodstream. These types of fiber also nourish the good bacteria in your colon through fermentation. The soluble portion of a food is often the center of the fruit or vegetable underneath the peel.
About Insoluble Fiber
Insoluble fibers do not dissolve in water, but they do provide softness and bulk to stool by trapping water in your colon. Cellulose, lignin and some hemicelluloses, which provide structure to plants, are insoluble forms of fiber. This type of fiber is important for bowel regularity and regular consumption can prevent constipation, hemorrhoids and digestive diseases. The insoluble form of fiber is generally the outer portion of a fruit or vegetable like the peel of an apple, prune or potato.
Foods with Soluble and Insoluble Content
Cooked broccoli, Brussels sprouts, spinach and sweet potatoes contain 0.5 g to 2.0 g of soluble fiber and 1.1 g to 2.2 g of insoluble fiber per 1/2 cup serving. Raw celery, carrots, onions and tomatoes have 0.1 g to 1.1 g of soluble fiber and 0.9 g to 1.2 g of insoluble fiber per 1 cup serving. Apples, apricots, grapes and peaches all with skins contain 0.2 g to 1.8 g of soluble fiber, and 0.3 to 1.8 g of insoluble fiber.
Whole grains including bran cereals, wheat breads or pastas are a good source of both types of fiber but these generally have a higher quantity of insoluble fiber.
Daily Fiber Recommendation
According to the University of Arizona, plant-based foods are a good source of both forms of fiber and when you add fresh fruits, vegetables, legumes or grains to your diet, you get the benefit of soluble and insoluble fiber. The daily fiber recommendation is 25 g to 35 g and you can achieve this by eating a variety of foods. Fiber supplements are an option but should not be taken without physician consultation.
Member Comments