Why Fiber Matters… Reduced Disease Risk! Are you getting enough?

By Mary Fraser, LIU-Post Dietetic Intern


Many chronic diseases and conditions can be reduced or alleviated by dietary and lifestyle changes. Adequate intakes of total dietary fiber are associated with reducing the risks of cardiovascular disease (by helping to lower cholesterol), type 2 diabetes (by helping to improve blood glucose levels and possible insulin sensitivity), some cancers, and alleviating constipation.


There is also mounting evidence that fiber may also help reduce inflammation and may have an inverse relationship with all-cause mortality. Unfortunately, generally only 5% of the population meets recommended guidelines. Many people don’t realize the benefits of having enough fiber in their diet or know how to incorporate it.


So are you getting enough?


The Institute of Medicine (IOM) recommends most adults daily total fiber consumption be

approximately 25 grams for adult women and 38 grams for adult men. This recommendation is also supported by The Academy of Nutrition and Dietetics (Academy). Daily fiber should be a combination of dietary and functional fiber from a variety of foods including whole grains, legumes, such as beans or peas, vegetables, fruits, and nuts. IOM defines dietary fiber as a naturally occurring non-digestible carbohydrate and lignin, that is intact or intrinsic in plants, and functional fiber as a non-digestible carbohydrate that has been isolated, extracted or manufactured with health benefits. Total fiber is dietary and functional fiber combined. Traditionally fiber was classified as either soluble or insoluble. Soluble fibers are dispersible in water, while insoluble fibers are not. Properties of dietary fiber such a fermentability and viscosity may also be important in reducing the risk of disease.


The types of fiber and disease risk reduction


Foods that can reduce the risk of heart disease, type 2 diabetes and help lower cholesterol,

include oats, oat bran, beans, peas, barley, flaxseeds, berries, soybeans, bananas, oranges,

apples, and carrots. These foods provide mucilage and beta-glucans soluble fibers.

Another type of soluble fiber that can lower cholesterol (LDL and total cholesterol) and may

reduce the risks of coronary heart disease and type 2 diabetes is wheat dextrin , which is

extracted from wheat starch. Wheat dextrin is widely used to add fiber in processed foods but

must be avoided if you have celiac disease or are gluten intolerant. Insoluble, cereal and

vegetable fiber are associated with reduced risk of both cardiovascular disease, by lowering

cholesterol levels, and chronic heart disease. Fruit fiber is only associated with lower

cardiovascular disease.


Pectins and gums , a soluble fiber, also helps to lower cholesterol and is found in fruits, berries, seeds. Pectins and gums can slow down the time between poops by keeping the food in the intestinal track longer, which is something to consider if you suffer from constipation. Some fibers also work as nature’s natural laxative, such as psyllium , a soluble fiber, and insoluble fibers cellulose & some hemicellulose . Frequently found in fiber drinks, like Metamucil or in supplements, psylilum also has the added benefit of helping to lower

cholesterol. Cellulose & some hemicellulose can also lower the risk of diverticulitis and may

help with weight loss. They are naturally found in nuts, whole wheat, whole grains, bran, seeds, brown rice, and the skins of produce. Other types of fiber that can help with constipation are the soluble fiber agents which can be added to processed foods, such as dextrose, sorbitol, citric acid , but these may also cause bloating and gas.


Resistant starch is another type of soluble fibers, which may also reduce the risk of type 2

diabetes, by helping to control blood sugar levels and increasing insulin sensitivity. It may also

help manage weight by increasing fullness. It is found in oatmeal and legumes and can be

extracted and added to processed foods to boost fiber content.


Another type of fiber is lignin , which appears good for heart health. Some foods with this type

of insoluble fiber are found naturally in flax, rye, and some vegetables.

What are some high fiber foods?


Some high dietary fiber foods are: ¼ cup of almonds with 4.5 grams of dietary fiber, 1 apple

with 5.4 grams, 1 half cup beans with 5.5 grams, and ½ cup raisin bran with 7.4 grams. Some

foods with no fiber include alcoholic beverages, milk, cheese, meat, poultry, and seafood.

September 26, 2019


References:

Gropper SS, Smith JL, Carr TP. Advanced Nutrition and Human Metabolism, 7th Edition.

Wadsworth, Cengage Learning, Belmont, CA. 2018.

Dahl, W. J., & Stewart, M. L. (2015). Position of the Academy of Nutrition and Dietetics: Health

Implications of Dietary Fiber. Journal of the Academy of Nutrition and Dietetics, 115(11),

1861–1870. doi: 10.1016/j.jand.2015.09.003