Why is dietary fiber an important part of our diet?
Dietary Fiber is the indigestible part of plant foods that travel through our digestive system easing bowel movements. The digestive enzymes produced by our body cannot digest dietary fiber foods. Abundant in many vegetables, fruits, whole grains, and legumes, fibers help reduce the risk of heart disease and diabetes. Read on to know about the different types of dietary fibers and their benefits!
What are Dietary Fibers?
Dietary fiber, also called roughage, includes non-digestible carbohydrates and lignin most commonly found in plants. Experts define total fiber in many ways, however, the most accepted definition is that total fiber is the sum of dietary fiber and functional fiber.
Functional fiber is defined as isolated, manufactured, or synthetic oligosaccharides with three or more degrees of polymerization found in both plants and animal products. They play an important role in several beneficial physiological functions that influence laxation, blood glucose, and cholesterol concentrations of the body.
What are the different types of dietary fiber?
There are two types of dietary fiber: soluble and insoluble.
Soluble fiber dissolves in water. It becomes gelatinous (after absorbing water) as it goes through the digestive tract, where it is fermented by bacteria.
They improve the immune and digestive health as well as overall wellbeing. They also reduce cholesterol, especially levels of low-density lipoproteins (also known as bad cholesterol). Soluble fibers regulate sugar intake, which is especially beneficial for people suffering from diabetes and metabolic syndrome.
Some good sources of soluble dietary fiber foods include kidney beans, pinto beans, brussels sprouts, broccoli, spinach, zucchini, apples, oranges, grapefruit, grapes, prunes, oatmeal, and whole-wheat bread.
Insoluble dietary fiber foods does not dissolve in water. As it goes through the digestive tract, it gets fermented by bacteria in the colon. Insoluble fibers promote regular bowel movements and prevent constipation. They speed up the elimination of waste through the colon. By keeping an optimal pH in the intestines, insoluble fiber helps prevent microbes from producing substances which can lead to colorectal cancer.
Some good sources of insoluble dietary fiber foods include vegetables – especially dark green leafy ones, root vegetable skins, fruit skins, whole-wheat products, wheat bran, corn bran, nuts, and seeds.
Both soluble and insoluble fibers are present in all plant foods, but rarely in equal proportions. Though both types of fiber have immense health benefits, insoluble fibers, however, can inhibit the absorption of certain minerals such as magnesium, calcium, iron and zinc.
On the other hand, soluble fibers such as β-glucan can promote such mineral absorption. β glucan, a soluble fibre component from bran of grains like barley, oats, and wheat, has gained utmost nutraceutical significance in the recent past.
Dietary Fiber Benefits
Here are some dietary fiber benefits:
- Protects against heart disease – According to the University of Maryland Medical Center, the consumption of soluble fiber can protect you against heart diseases by reducing cholesterol levels.
- Improves gut health – The consumption of fiber promotes regular bowel movements and prevents constipation. It may also reduce the risk of colitis and haemorrhoids. There is also evidence that suggests consuming fiber might help reduce the risk of colon cancer.
- Manages diabetes – People with diabetes who consume a lot of fiber tend to need less insulin than those whose fiber intake is low. Fiber also helps slow down the absorption of sugar, preventing blood sugar spikes after meals.
- Controls body weight – A high-fiber intake can significantly contribute towards controlling body-weight. Fiber produces a feeling of fullness without adding calories. This can help treat or prevent obesity. This is because fiber-rich foods take longer to digest and thus result in an increased feeling of fullness and satiety.
Most foods high in fiber are also very healthy for other reasons. Take, for example, fruit, vegetables, and whole grains; they are high in fiber but also rich in vitamins and other essential nutrients. Eating a high-fiber diet protects health through both the intake of fiber and other essential nutrients.
Can too much fiber be harmful?
Eating too much fiber (over 50-60 grams of fiber a day) may decrease the amount of vitamins and minerals your body absorbs. Consuming too much fiber too quickly may further cause gas, diarrhoea, and bloating. Therefore, if you want to add more fiber to your diet, increase the amount of fiber consumption gradually. This gives the stomach and intestines time to get used to the change.
Additionally, fiber supplements can lead to overconsumption quite easily, which may cause intestinal discomforts. Thus, it’s safer to increase dietary fiber foods intake naturally.
Studies suggest that proper hydration is essential in order for the fiber to be beneficial. Consequently, drinking at least 8 glasses of water and other liquids a day is ideal.
Adding fiber to the diets of young children should be done carefully. Too much fiber may interfere with the body’s ability to obtain enough vitamins and minerals. This can be a problem for adults as well but is more serious in children.
Should you take fiber supplements?
Excessive use of fiber supplements can increase the risk of intestinal problems. Some of the benefits from a high fiber diet may be from the food that provides the fiber and not from fiber alone. In other words, it is important to strike a balance between the amount of food you eat (or the calories you consume) and the amount of fiber you consume. It is best to get fiber naturally from the foods you eat on a day-to-day basis rather than from supplements.
Recommended Daily Intake
There have been no studies on evaluating the dietary fiber requirements in Indians. However, the WHO Committee on chronic degenerative diseases recommended a daily intake of 30g dietary fiber. An intake in excess of 60 g of fiber over a day can reduce the absorption of nutrients and may cause irritation in the bowel and also lead to diarrhoea.