Why is Dietary Fiber Important

Discover the major benefits of dietary fiber and why it is important for your health.

Dietary fiber is important for the health of your gastrointestinal system, and plays a major role in helping your digestion and improving your bowel movement.

Many physicians recommend a high-fiber diet; however, most people consume less than half of the recommended amount. There are many health problems associated with a low-fiber diet. Research shows that you may be able to lower your risk of colon cancer if you eat foods high in fiber. Fibers also keep food moving through your body and prevent constipation.

Dietary fiber is the part of plant foods that cannot be digested by humans. Soluble fiber dissolves in water so it can thicken or glue other things together while insoluble fiber may act like a scrub to clean our digestive tract. Both types of fiber are important for good health. The recommended dietary allowance (RDA) for fiber in American adults is 14 grams per 1,000 calories consumed each day — which works out to between 25 and 38 grams daily for most women and men, respectively.

Both soluble and insoluble fiber are equally important for health, digestion, and the prevention of various diseases (heart disease, diabetes, obesity, constipation).

Soluble fiber

Soluble fiber dissolves in water and forms a gelatinous structure. Soluble fiber includes gum, pectins, and some hemicelluloses. Gum is mainly used as an additive in the food industry. Pectins are found in vegetables and fruit, mostly apples and citrus. They are used in the production of jams and jellies.

Hemicelluloses are mostly found in cereals. In diet, fiber slows down the passage of food through the digestive system, meaning it improves the feeling of satiety and allows better absorption of nutrients. In addition to the above fruit and vegetables, soluble fiber is found in legumes, some other fruit (plum pulp, berries, bananas, pear peels), nuts, asparagus, psyllium, broccoli and carrots. They lower blood cholesterol levels and slow down glucose absorption.

Insoluble fiber

Insoluble fiber does not dissolve in water. Insoluble fiber includes most hemicelluloses, cellulose, and lignin. Cellulose is the primary building block of cell membranes, made up of glucose units. It is indigestible in the human digestive system.

Lignin is found in some vegetables (carrots) and fruit (strawberries). In diet, insoluble fiber mainly stimulates digestion, increases food volume and slows glucose absorption. They prevent constipation and are therefore good for gut health.

In addition to these foods, insoluble fiber is present in whole grains, legumes (beans and peas), potato peel, zucchini, celery and dark green leafy vegetables, cauliflower and in the peel of some fruit (kiwi, grapes, tomatoes).

You should be aware that most fruit and vegetables are a mixture of soluble and insoluble fiber. While plum peel is rich in insoluble fiber, soluble fiber is found in the pulp. It is similar with other plants. You should not bother yourself with the amount of soluble and insoluble fiber in a particular food, unless you are looking to solve a specific problem (e.g. if you want to lower your blood cholesterol level you will choose more soluble fiber).

To make the most of your fiber intake, it is important to drink enough water so that the soluble fiber can ‘bulk’. Increasing fiber intake will initially lead to increased gas production due to fermentation, however the body will get used to it over time.

Phytates

Phytic acid is not a fiber, but is found in foods in which fiber is also present. It has the ability to bind certain minerals (zinc, iron, calcium, magnesium and copper) which are then excreted from the body unused.

If fiber intake is adequate (not excessive), there is no need to be afraid of mineral deficiency. Phytates are mostly present in cereals, legumes and seeds.

The Benefits of Fiber in the Digestive System

Fiber helps with digestion – it increases the stool volume and softens it. That way stool passes more easily through the digestive system and thus reduces the occurrence of constipation. Also, in diarrhea, the fibers absorb excess fluid and creates a harder stool.

Fiber lowers blood cholesterol levels – soluble fiber in beans, oatmeal, flaxseed can help lower total blood cholesterol by lowering LDL (bad) cholesterol.

Fiber helps control blood sugar – to slow down digestion and absorb glucose, there are no sudden spikes in blood glucose levels after a meal.

Fiber helps to maintain the desired weight – in general, they require more time to digest, from the very beginning (chewing) to the end, but by increasing the volume, they give a feeling of satiety.

Intake Recommendations

Recommended fiber intake ranges around 30-38 g of fiber for men under the age of 50 and 25 g for women. The minimum recommended fiber intake is 18 g.

I hope you understand why dietary fiber is important part of keeping yourself fit and healthy.