For centuries, fiber has been recognized as a super-nutrient. But what exactly is fiber and why is it an essential part of a healthy diet?
Fiber is made up from the indigestible parts of plants, e.g. gums, waxes, pectins, mucilage, cellulose, lignins, or oligosaccharides. In a nutshell, it is the closest thing we have to a true superfood because as fiber passes through our digestive tract, it undergoes fermentation, which provides many health benefits.
A fiber-rich diet is associated with reduced risk of cardiovascular disease, coronary heart disease, stroke, hypertension, certain gastrointestinal disorders, obesity, and metabolic dysfunctions, including prediabetes and type 2 diabetes, and colorectal, gastric as well as breast cancers. In addition, fiber is associated with digestive benefits, such as increased stool bulk, decreased transit time, and fermentation by colonic microflora.
Other Health Benefits of Fiber
There are two main types of fiber: soluble and insoluble fiber. Insoluble fiber includes cellulose, hemicellulose, and lignins, which do not dissolve in water. Examples of soluble fiber include gums, pectin, and mucilage, which combine with water to form a gel-like texture in the intestines. Since soluble fibers are more fermentable they provide more beneficial byproducts. Insoluble fibers, on the other hand, are great bulking agents that improve the mechanics of elimination and help prevent constipation.
Other health benefits of fiber include:
It increases fecal bulk
It decreases transit time
It supports healthy blood sugar by slowing its absorption into the bloodstream
It decreases cholesterol by decreasing its absorption and enhancing its elimination
And, what is emerging to be one of its most important functions – it interacts positively with the gut flora.
Recommended Fiber Intake
Currently, the Institute of Medicine recommends 25-30 grams of fiber daily. The average US adult intake is 16 grams.
What Are Good Sources of Fiber?
Whole grains, vegetables, and some fruits are good sources of insoluble fiber, while soluble fiber is predominantly found in beans, peas, lentils, apples, and oats. Here are the average amounts of fiber found in common foods:
1 cup cooked black beans – 17 grams
1 cup cooked lentils – 16 grams
1 cup cooked garbanzo or pinto beans – 14.7 grams
1 cup cooked lima beans - 13.2 grams
2 tablespoons chia seeds – 10 grams
1 cup guava – 9 grams
1 cup collard greens – 8 grams
1 cup raspberries – 8 grams
1 cup butternut squash – 7 grams
1 cup blackberries – 7 grams
¼ cup almonds – 7 grams
1 cup oatmeal – 5 grams
1 cup barley – 5 grams
1 apple with skin - 3.7 grams
1 medium banana - 2.7 grams