Fiber: The Most Important Plant Component? Maybe…
As is true with many dietary issues, we find
variability in recommendations for optimal food consumption. And, it is
important to keep in mind that there are individual differences in tolerance
for a whole variety of foods. And, finally, research is ongoing and as a result
we see a reversal in some historic findings.
Types of Fiber
Soluble Fiber
Complex carbohydrates are high in fiber which
can be at least partially digestible and calorie free, but still takes up
considerable space in our stomachs. Soluble fiber also known as viscous fiber is abundant in oats,
barley, legumes, beans, fruits and vegetables. It is really our ‘Best Fiend’ because it slows the entry
of sugar and fats into our bloodstream. This enhances feelings of fullness from
any given portion, which may prevent overeating and confers metabolic benefits,
including lower blood sugar and blood insulin levels. Lower blood lipids/cholesterol
and lower blood pressure are positive results.
Soluble fiber slows the absorption of glucose and helps lower cholesterol; beans are especially high in soluble fiber. Resistant starch (fiber) is resistant to stomach acid and digestive enzymes. It is important for good health and has beneficial effects for Diabetics. Oats, beans and other legumes, and some fruits and vegetables are all good sources of soluble fiber. Soluble fiber makes up about one-quarter of the fiber in food. It dissolves in water, slows digestion by slowing down the time it takes for the stomach to empty, and helps the body absorb nutrients from food. Soluble fiber can help lower blood cholesterol, particularly if you have elevated cholesterol levels, and may help control blood sugar levels in people with Diabetes.
Polydextrose Polyols
This is a soluble fiber that is added to processed foods as a bulking agent and sugar substitute. It is made from dextrose, sorbitol, and citric acid. It adds bulk to stools and helps prevent constipation. May cause bloating or gas.
Psyllium
A soluble fiber extracted from rush seeds or husks of the plantago ovata plant. Used in supplements, fiber drinks, and added to foods. Helps lower cholesterol and prevent constipation.
Insoluble Fiber
It tends to keep things moving efficiently through our digestive system. As you can tell, both soluble fiber and insoluble fiber are good for you.
Insoluble fiber is roughage and it is important also; it holds water and provides bulk to our stool and keeps us regular. It makes up about three-quarters of the fiber in food.
The water-holding quality of insoluble fiber creates a feeling of fullness in the stomach and helps foods pass through the stomach and intestines. It's made up from the structural material of the cell walls of plants. It consists of cellulose, hemicellulose, and lignin. With sufficient amounts of fluid, insoluble fiber can help prevent or alleviate constipation.
Insoluble fiber is found liberally in grapes, prunes, apple skins, pear skins, berries, celery, beets, carrots, Brussels sprouts, turnips, cabbage, cauliflower, broccoli, rhubarb, red chard, asparagus, corn, popcorn, kidney beans, potato skins, and bran.
Insoluble fiber passes through the gastrointestinal tract mostly undigested; the human body does not have the enzymes to break down insoluble fiber. Additionally, unlike soluble fiber, insoluble fibers are not metabolized by intestinal bacteria.
Resistant Starch Fiber
Resistant starch is
a carbohydrate that acts like a fiber also.
It is resistant to stomach acid and digestive enzymes. It is important for good health and has beneficial effects for Diabetics. Although resistant starch is technically a starch, it acts more like fiber and resists digestion. It passes through the small intestine undigested so, much of the carbohydrate calories are not absorbed.
Fiber passes through your digestive system undigested whereas resistant starch gets digested by good bacteria in the large intestine into short-chain fatty acids that provide additional health benefits. Because resistant starch is digestible to some degree, it also provides some caloric value.
Beta Glucan Fiber
Oats is a rich
source of a water-soluble fiber called β-glucan.
Oat β-glucans are the only dietary fiber currently recognized by the European Food Safety Authority (EFSA) to be able to reduce a disease risk!
This fiber protects against heart disease and revs up the immune system. It helps lower bad LDL cholesterol and reduces the risk of coronary heart disease and type 2 Diabetes. Use with caution if you have celiac disease or are gluten intolerant.
Guar Gum
This is a fiber from the seed of the guar plant. In foods and beverages, guar gum is used as a thickening, stabilizing, suspending, and binding agent. Guar gum comes from the seed of a bean-like (legume) plant, sometimes referred to as the Indian tree.
Guar gum is a fiber that normalizes the moisture content of the stool, absorbing excess liquid in diarrhea, and softening the stool in constipation. It also might help decrease the amount of cholesterol and glucose that is absorbed in the stomach and intestines.
The guar bean is principally grown in India, Pakistan, U.S., Australia and Africa. India produces 2.5 - 3.5 million tons of guar annually.
Cellulose
Cellulose is the most abundant insoluble dietary fiber in plant food. Found in
whole grain flour, wheat bran, whole-grain breakfast cereals, seeds, and many
vegetables including carrots, broccoli, celery, peppers, and cabbage. This is a
type of carbohydrate that is made up of chains of glucose bonded together by
indigestible linkages. It is found in the cell walls of plants, and in wood and
in other organic matter. Cellulose is made up of long -branching chains of glucose
molecules.
Our digestive system does not have the enzymes to break down cellulose to use it for fuel. Although we get no energy from these indigestible carbohydrates they are valuable to us for their dietary fiber.
Hemicellulose
This is a food fiber composed of various sugars, including xylose, glucose, and mannose. Hemicelluloses absorb and retain water in the gut but have little effect on stool size, and are largely digested by gastrointestinal bacteria.
Lignin
Lignin fiber acts as a binder for cellulose. It adds strength and stiffness to the cell walls found in wheat and some green, leafy vegetables. Lignin is found in all vascular plants, mostly between the cells, but also within the cells, and in the cell walls. It makes vegetables firm and crunchy, and gives us what we call "fiber" in our food.
Pectin
Pectin is a fiber found in fruits. It is used to make medicines. People use pectin for high cholesterol, high triglycerides, and to prevent colon cancer and prostate cancer. It is also used for diabetes and gastroesophageal reflux disease (GERD).
Some people use pectin to prevent poisoning caused by lead, strontium, and other heavy metals. Pectin binds substances in the intestine and adds bulk to the stools.
Lignans
Lignans are a large group of low molecular weight polyphenols found in plants, particularly seeds, whole grains, and vegetables. The name derives from the Latin word for "wood.” Lignans are precursors to phytoestrogens. They may play a role as antifeedants in the defense of seeds and plants against herbivores. Antifeedants are naturally occurring substances in certain plants which adversely affects insects or other animals which eat them. Plant lignans are co-passengers of dietary fiber. Fiber-rich food items are often good sources of lignans. Flax seed and sesame seed contain higher levels of lignans than most other foods. Foods containing plant lignans include whole grains, nuts and seeds, legumes, fruits, and vegetables. They have been consistently associated with reductions in risk of cardiovascular disease.
Inulin Oligo Fructose
Is extracted from onions and byproducts of sugar production from beets or chicory root. It is added to processed foods to boost fiber. May increase "good" bacteria in the gut and enhance immune function.
Miscellaneous Findings
· A study by the European Perspective Investigation into Cancer and Nutrition, EPICN, looked at 452,000 men and women and found that those with higher fiber intake had a lower mortality rate, particularly from circulatory, respiratory and inflammatory diseases over a 12-year period.
· Complex carbohydrates are whole grains, which tend to be high in fiber and contain healthy oils, health promoting phytochemicals, plant-based compounds, vitamins, and minerals. Consuming a diet rich in whole grains has been linked to a decreased risk of developing cholesterol abnormalities, Type-2 Diabetes, heart disease, stroke, obesity, and various cancers. It’s best to have at least three daily servings of whole grains; options include amaranth, barley, brown rice, cracked wheat, Farro, millet, oats, quinoa, spelt and whole wheat
· All of your grain food servings should come from whole grains as opposed to refined grains.
· Most Americans get less than half the recommended minimum fiber intake a day and the benefits of fiber go way beyond bowel regularity. Constipation can hurt, causing “abdominal discomfort and pain, straining, hard stool, infrequent bowel movements, bloating and nausea. No wonder laxatives are among the most commonly used drugs and they are one of the most common causes of adverse drug reactions. Constipation is an epidemic among the elderly; but it is not a problem among those centering their diet around fiber rich foods, whole unrefined plant foods.
· Dr. Burkitt: The famous British surgeon and medical researcher, Dr. Denis Burkitt, better known for his discovery of a childhood cancer now known as Burkitt's lymphoma, than for his 1979 international bestseller Don't Forget the Fiber in Your Diet. Burkitt’s dietary fiber theory remains intact and it is worthwhile to consume high-fiber diets, not just to prevent large bowel cancers but also to promote a variety of other positive health conditions. He spent many years in Africa working to better understand why diseases typically found in Western countries were rare in Africa. Diets high in fiber were associated with reduced cancer incidence of the large bowel, as well as the incidence of many other diseases common to Western countries.
· Animal-based foods contain no dietary fiber; all whole plant-based foods contain fiber.
· Fiber – In the past, dietary fiber was thought to be indigestible and only beneficial in promoting gut health. We now know that fiber can be at least partially digested by bacteria living in our guts. When we eat foods containing fiber, these bacteria digest the fiber, and they produce by-products (e.g. short chain fatty acids) that are known to have beneficial effects on the immune system. Similar to phytonutrients, fiber is only found in whole plant foods such as fruit, vegetables, legumes, and whole grains.
· Legumes: Common edible legumes include lentils, peas, chickpeas, beans, soybeans, and peanuts. Beans can make you feel full without adding all of their calories to your waistline. Legumes contain three kinds of fiber: soluble fiber, insoluble fiber, and resistant starch. Beans are especially high in soluble fiber and have ample insoluble fiber too. Beans are among the world's most perfect foods and they stabilize blood sugar, blunt your desire for sweets and prevent afternoon cravings. Beans contain both soluble and insoluble fiber and are very high in resistant starch.
· We feed the good bacteria in our gut, and they take the prebiotics we eat, like fiber, and in return provide the vital fuel source that feeds the cells that line our colon.
· 5 to 1 guideline: Look at the ratio of grams of carbohydrates to grams of dietary fiber. We're looking for about 5:1 or less. Whole-wheat Wonder Bread: divide the carbohydrates by the dietary fiber. 20 divided by 2.7 is about 7, that’s more than five, so goes back on the shelf!
· High fiber in natural plant foods binds cholesterol in the digestive tract and helps remove it.
· Dietary fiber intakes reduce risk for diabetes, heart disease, certain cancers, weight gain, obesity, and diverticular disease, as well as constipation.
· Fiber is broken down in our colon by our friendly flora, which release all sorts of beneficial substances into our bloodstream that can have anti-inflammatory effects.
· Some sources say that it is best to consume 50 to 100 g of fiber daily from real, high fiber plant foods, not supplements.
References
Fuhrman, Joel: ‘The End of Heart Disease,’ Harper Collins Publishers, 2016
Katz, David L.: ‘Disease
proof, slash your risk of heart disease, cancer, diabetes, and more by 80%,’
The Penguin Group, 2014.
Kelly, John and Shull, Jeni: Foundations of lifestyle medicine: the
lifestyle medicine board review manual, Second Edition, American College of
lifestyle medicine, 2019.
McDougall, John: ‘McDougall’s medicine: a challenging second opinion, ‘New Century
Publishers, inc, 1985.
Null, Gary: ‘Gary Null’s ultimate anti-aging program’: Kensington books, 1999.
‘Eat On: Crunch Crunch’
William
(Bill) Zahler, MSW, MPA, DipACLM
Website
& Blog: lifestyle – interventions.com
YouTube:
William Zahler
Email: wazahler@gmail.com
November,
2021
3 John
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