Dietary fibre, also known as roughage or bulk, refers to the plant foods you eat but your body can’t digest or absorb the nutrients. Whiles other food components like carbohydrates, proteins or fats are broken down by digestive enzymes and the nutrients are absorbed by your body, fibre can’t be broken down by your body. However, they still perform some very important function in your body system as they pass through your stomach, small intestine, large intestine and finally out of the body when you stool.
Soluble and Insoluble Fibre
Fibre can either be soluble or insoluble. Both have very important benefits in the body, therefore, it is good to have both of them featuring in your regular diet.
Soluble fibre, as the name implies, dissolves in water. When this happens, it forms a gel-like material. This gel-like material binds to cholesterol in the intestine and slows down the absorption of glucose in the intestine. Hence, soluble fibre can help lower blood cholesterol and glucose levels. In addition, soluble fibre also promotes the growth of friendly micro-organisms that keep the intestines healthy. Plant foods rich in soluble fiber include oats, peas, beans, apples, citrus fruits, carrots, barley and psyllium.
On the other hand, insoluble fibre does not dissolve in water. This type of fiber promotes the movement of material through your digestive system and increases stool bulk. As a result, it can be of benefit to those who struggle with constipation or irregular stools. Good sources of insoluble fibre include whole-wheat flour, wheat bran, nuts, beans and vegetables, such as cauliflower, green beans and potatoes.
Benefits of a High-Fibre Diet
It’s easy to get more fibre in your diet but this must be done with caution so as to avoid abdominal bloating which can occur at first if taken too much. Introducing too much fibre too quickly or eating too much can cause constipation or diarrhoea in some people.
A high-fibre diet can help reduce your risk of some diseases. Part of the amazing health benefits of fibre are as follows.
Normalizes bowel movements : Dietary fibre helps soften your stool and also increases the weight and size of your stool. This decreases your chances of constipation. And if you are having diarrhea, fibre may help to solidify the stool because it absorbs water and adds bulk to stool.
Reduce risk of bowel diseases : A high-fibre diet lowers your risk of developing hemorrhoids and small pouches in your colon (diverticular disease). Studies have also found that a high-fiber diet likely lowers the risk of colorectal cancer.
Lowers cholesterol levels : As stated above, soluble fibre may help lower total blood cholesterol levels. Studies also have shown that high-fibre foods may have other heart-health benefits, such as reducing blood pressure and inflammation.
Control blood sugar levels : Again, soluble fibre slows down the absorption of glucose in the intestine and help improve blood sugar levels. They form part of a healthy diet for diabetics. A high fibre may also reduce the risk of developing type 2 diabetes.
Weight management : High-fibre foods tend to be very helpful in maintaining a healthy weight. This is because they are more filling than low-fiber foods, which means you’re likely to eat less and stay satisfied longer.
- Kim Y, et al. Dietary fibre intake and mortality from cardiovascular disease and all cancers: A meta-analysis of prospective cohort studies. Archives of Cardiovascular Disease.
- Duyff RL. Carbs: Sugars, starches, and fiber. In: Academy of Nutrition and Dietetics Complete Food and Nutrition Guide. 5th ed. New York, N.Y.: Houghton Mifflin Harcourt; 2017.
- U.S. Food and Drug Administration – Nutrition facts label: Dietary fiber.
- Veronese N, et al. Dietary fiber and health outcomes: An umbrella review of systematic reviews and meta-analyses. American Journal of Clinical Nutrition. 2018.
- Song M, et al. Fiber intake and survival after colorectal cancer diagnosis. Journal of the American Medical Association: Oncology. 2018;41:71.
- Dietary reference intakes (DRIs): Recommended dietary allowances and adequate intakes, total water and macronutrients.