Why The Medical Establishment Opposes Fiber Supplements

Executive Summary

  • There is a widespread fiber deficiency in the population.
  • This information is not incorporated into the advice provided by health authorities when they discuss fiber supplements.


Most health authorities and MDs oppose fiber supplements, although confusingly, they acknowledge there is widespread fiber deficiency, and fiber is strongly associated with disease prevention.

Therefore, this article covers the degree of widespread fiber deficiency and the inconsistency of this with recommendations by health authorities.

Our References for This Article

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On the Topic of Fiber

The following quotes provide an excellent explanation of fiber.

A big reason for that has to do with what we now eat. Instead of munching on fruits, vegetables, beans, nuts, and seeds, more than half of the calories Americans consume come from ultra-processed foods. On any given day, nearly 40 percent of Americans eat fast food. These prepared and processed meals tend to be low in fiber, or even fiber free. (A cup of cooked oatmeal has 4 grams of fiber and a pear has 6 grams, while a McDonald’s hamburger has one gram and soda has none.)

This pattern of eating is not just leading to weight gain and obesity-related health issues; it’s hurting our gastrointestinal health in ways researchers are only beginning to understand. That’s because fiber’s benefits are a lot more complicated than our prune-peddling moms and grandmothers appreciated.

Fiber doesn’t just help us poop better — it also nourishes our gut microbiome. The science, while still pretty nascent, is fascinating and it points to the fact that the fiber gap may be even more damaging than we’ve realized.

Take cellulose, a type of fiber in fruits and vegetables: it’s insoluble and it’s not fermentable. Hemicellulose, found in bran, can’t be dissolved in water and it’s not gel-forming (viscous) but it is fermentable. Psyllium, in Metamucil, is water soluble, gel-forming and less fermentable than other fibers.

Understanding this variety is relevant to our health because different fibers have different health effects on our gastrointestinal tract, said William Chey, a professor of gastroenterology and nutrition at the University of Michigan. Gel-forming fibers like psyllium, for example, hold on to water.

Today, studies of Tanzania’s Hadza people, one of the few remaining hunter-gatherer groups on the planet, are a useful model for understanding just how much fiber early humans probably ate. Tribe members consume 100 to 150 fiber grams per day — enough to fill some 50 bowls of Cheerios, and 10 times what Americans take in, as NPR reported. Their daily diet is rich in roughage — tubers, berries, baobab fruits — and the Hadza people don’t eat any ultra-processed foods.

Researchers who study the health effects of fiber, including Jens Walter at the University of Alberta, say the Hadza’s enthusiasm for roughage should remind us of how much the human diet has shifted away from fiber.

“It’s really just within the last 5,000 years, and definitely within the last 100 years, that we basically took all the fiber away,” he said. “The average amount of fiber consumed by now is a small fraction to what we evolved with.”

This change isn’t just attributable to the advent of fiber-free processed and fast foods in advanced economies. More than 10,000 years ago, before agriculture and selective plant breeding, early fruits and vegetables were almost unrecognizable by today’s standards. – VOX

The following quote describes the types of fiber.

There are numerous fiber products on the market today. Some contain a natural fiber, such as inulin (i.e., chicory root), psyllium (i.e., husk of blond psyllium seed), or β‐glucan (i.e., oat or barley; McRorie & Fahey, 2015). Others contain an artificially created product, such as polydextrose (synthetic polymer of glucose and sorbitol), wheat dextrin (heat/acid treated wheat starch), or methylcellulose (semisynthetic, chemically treated wood pulp; McRorie & Fahey, 2015). Wheat dextrin, an artificially created “fiber” made by altering the chemical bonds of wheat starch with heat or acid, actually resulted in an increase in peak postprandial blood glucose concentrations after each meal in pediatric patients being treated for type 1 diabetes and continuously monitored for blood glucose (Nader, Weaver, Eckert, & Ltief, 2014). The artificial process for turning wheat starch into wheat dextrin is incomplete, leaving some of the products readily degraded and absorbed as sugar, which resulted in higher peak postprandial blood glucose concentrations (Nader et al., 2014; Vermorel et al., 2004). Introduction of a gel‐forming fiber (e.g., psyllium, β‐glucan) will significantly increase the viscosity of chyme in a dose‐dependent manner, making it thicker. This increase in viscosity slows the interactions of digestive enzymes with nutrients (slowing degradation) and slows the absorption of glucose and other nutrients (McRorie, 2015a). In the short term, this can lead to a reduced peak postprandial blood glucose concentration. – NCBI

And this on the benefits of fiber.

High-viscosity, gel-forming fibers like beta-glucan (Quaker Oats), psyllium (Metamucil, Konsyl), and guar gum have been shown to improve glycemic control and lower cholesterol levels.5,10-13 These agents significantly increase the viscosity of the intestinal chyme, slowing the interaction of the digestive enzymes with nutrients.

When discussing fiber for self-care with patients, it is important to distinguish intrinsic, intact dietary fiber, which is found in fruits, vegetables, whole grains, legumes, and nuts, from isolated or synthetic fibers that are added to foods or found in supplements. Much of the data that associate fiber with a reduced risk of stroke, heart attack, cardiovascular disease, and cancer are based on high intakes of intrinsic, intact dietary fiber. Therefore, these benefits should not be attributed to the use of fiber supplements and patients seeking these benefits should be counseled on ways to increase fiber through food.

Fiber supplements have demonstrated health benefits, including lower LDL-cholesterol and improved regularity and glycemic control. High-viscosity, gel-forming fibers like beta-glucan (Quaker Oats), psyllium (Metamucil, Konsyl), and guar gum have been shown to improve glycemic control and lower cholesterol levels, whereas nonviscous and insoluble fibers do not confer these benefits. – NCBI

This quote explains a bit about the small intestine.

The small intestine is approximately 7 m long and the mucosa is studded with millions of villi, each of which is covered with approximately 1000 microvilli per 0.1 μm2 (i.e., brush border; McRorie & Fahey, 2015). With roughly the surface area of a tennis court, the small intestine is our largest surface area exposed to the outside world. With roughly the surface area of a tennis court, the small intestine is our largest surface area exposed to the outside world. – NCBI

The NCBI is hosted from the NIH’s website. However, while there are many articles at the NCBI, the NIH does not focus on fiber or on fiber supplements. That is they don’t apply the research being done, which is published on their own website. This is because the NIH is a drug puppet. Their objective is not public health, but maximizing the profits of the pharmaceutical industry.

Fiber Supplements

Let us take another example. I have been taking a fiber supplement called Optifiber, both a fiber and a probiotic that supports gut bacteria. Again, is this a supplement or a food? Do I need to tell my MD if I am taking this?

Health authorities are quite dismissive of supplements, but some supplements are part of a healthy “well-balanced diet.” Furthermore, the US diet is deficient in Omega 3s, 6s, and 9s, yet health authorities are constantly critiquing supplementation. The same goes for dietary fiber.

This is the current deficiency of fiber.

What does that look like? Adult men consume just 18.4 grams of fiber per day while women consume 15.5 grams, according to the most recent 2017-2018 What We Eat in America, National Health and Nutrition Examination Survey (NHANES). The recommended intake is 38 grams of fiber for men, and 25 grams of fiber for women.

Diets higher in dietary fiber can increase the frequency of bowel movements by bulking up stool, promote weight loss by slowing digestion, reduce your risk of diabetes by controlling levels of blood glucose, and can reduce the risk of developing cardiovascular disease by lowering low-density lipoprotein (LDL or “bad”) cholesterol levels in the blood, according to a review published in Nutrition Reviews. A higher fiber intake has also been linked to increasing positive mood, cognition, and alertness as well as supporting gut health.

A Journal of Nutrition study found that increasing fiber by just 4 grams per day over what participants consumed before the study was associated with an additional 3 ¼ pounds of weight loss over 6 months. – Eat This and Not That

According to a study presented at the Nutrition Live 2020 event, 5% of men and 9% of women meet the guidelines for fiber, which is a tiny fraction of the population.

After using several official sources on the recommended amount of daily fiber, I found an article on the history of discovering the need for fiber.

The Lancet took a leading role in the development and dissemination of the fibre hypothesis, which was subsequently named Burkitt’s hypothesis after its major protagonist, Denis Burkitt.1,2 Many others, including Cleave, Walker, Campbell, Trowell, Painter, and Cummings, contributed to its development between 1960 and 1989.3 One of the initiating factors behind the theory was Cleave’s recognition of the association between diets in high-income countries (HICs) and the development of diabetes, obesity, coronary heart disease, constipation, diverticulosis, and colon cancer (western diseases). Diets in HICs are characterised by increased consumption of meat, fat, and refined, fibre-deficient carbohydrates.

However, Burkitt, Trowell, and Walker suggested that the cause of high-income lifestyle-associated diseases was the refinement of grains and the removal of fibre during that process, which has become much more commonplace in developed countries since the Industrial Revolution (starting with the first industrial revolution in 1760 in the UK).

The establishment of the fibre hypothesis occurred from 1966–71 when Burkitt returned to England from Africa and was supported by the UK Medical Research Council to develop his theory. Burkitt was credited with the fibre hypothesis, despite the hypothesis being a synthesis of his experience and the research of others.

Trowell helped Burkitt expand the fibre hypothesis to include extra-colonic diseases, specifically type 2 diabetes, cardiovascular disease, and obesity, which culminated in their joint publication of the landmark book: Refined Carbohydrate, Foods and Disease: Some Implications of Dietary Fibre—published in 1975. – NCBI

Type 2 diabetes, cardiovascular disease, and obesity are three of the most prevalent diseases in high-income countries or developed countries. However, the medical establishment does not recommend higher fiber for people that see them with these conditions, and instead, they push them towards drugs. How many of these diseases could be significantly reduced by simply increasing dietary and supplementary fiber?

Processed foods dramatically reduce the fiber of food.

Furthermore, this initial publication of the relationship between multiple diseases and fiber was in 1975, now 47 years ago. And it recommends an average of 50 G of fiber for adults. And however, the commonly published recommendation is 38 G for men and 25 G for women.

That is an average of (38 + 25)/2 = 31.5 G. This is 1 – (31.5/50) = 37% lower than the initial estimate. And the actual consumption in the US is (18.4 + 15.5)/2 = 16.95 or let us say 17. 17/50 = 34% of the amount recommended in 1975.

The answer as to why the current recommended level is so much lower than in 1975 is explained as the quotation continues.

50 years on, fibre intake in HICs remains well below the greater than 50 g/day advocated by Burkitt, which is of grave concern; moreover, the number of disease cases are increasing in HICs, and, with the spread of HIC-associated diets, these diseases are making an appearance in middle-income and low-income countries around the world, including African countries (eg, Zimbabwe).

In the UK, the average fibre intake is about 18 g/day11 and in the USA the average intake is 16 g/day.12 So, why has progress been so slow? The simple answer is that by producing and advertising tasty, low-cost, fibre-deficient fast-foods the food industry is doing a better job at influencing attitudes than health-care professionals are.

Concern is also growing that fibre intake recommendations are about half what they should be. The UK’s National Health Service recommendations of 30 g/day and US Department of Agriculture (USDA) recommendations of 22 g/day for women and 38 g/day for men, are well below Burkitt’s 50 g/day recommendation.

In a review of fibre intake recommendations, published in 2017, across 24 European countries, the USA, and Australia and New Zealand by Stephen and colleagues,13 only the recommendations in the Netherlands came close (32–45 g/day fibre) to the proposed 50 g/day.

The discrepancy can be explained by the fact that requirements in the UK were first calculated from the quantity of fibre needed to prevent constipation, but those accepted by the USDA were based on the quantity of fibre needed to prevent cardiovascular disease. – NCIB

And that is amazing. Who would set the fiber level at just enough to prevent constipation? I know that I am personally not interested in only not being constipated, and I am interested in optimal health. However, all of the RDAs are set this way. They are set only to stop deficiency, which is an unstated aspect of RDAs. They are not selected for optimal health. However, multiple health authorities state the RDAs are the “maximum upper limit.” However, recall that the Hadza consume between 100 and 150 G of fiber. This means that 50 G should probably be seen as the lower level.

Fiber Causation #1: Fiber and Cancer Prevention

And according to this same article, the evidence for what was discovered in the 1970s has become even stronger.

Since Burkitt died in 1993, evidence supporting the protective effects of a fibre-rich diet against colon cancer has increased dramatically. The 2010 Continuous Update Report from the World Cancer Research Fund systematic review and meta-analysis of 43 cohort or randomised controlled trials graded the evidence linking high dietary fibre with a decreased risk of colorectal cancer as convincing—the strongest grade assignable.23 From this database, a 10% increase in fibre consumption was estimated to confer a 10% reduction in cancer risk,24 which is lower than that calculated by Bingham of a 40% reduction in risk by doubling fibre intake in low intake populations.25 The Bingham estimate25 was based on data from the European Prospective Investigation into Cancer and Nutrition Study (EPIC), which included 519 978 individuals recruited from ten European countries. In support of the common cause hypothesis, a high-fibre diet has also been found to be associated with a lower risk of breast,26 liver,27 all cancer mortality,28–30 and death from other high-income lifestyle associated diseases (specifically cardiovascular, infectious, and respiratory diseases,29 diabetes, and all non-cardiovascular non-cancer30) in multinational studies. Finally, in 2019, Reynolds and colleagues31 published a systematic review and meta-analysis based on nearly 135 million person-years of data from 185 prospective studies and 58 clinical trials with 4635 adult participants that suggested a 15–30% decrease in all-cause and cardiovascular-related mortality, and incidence of coronary heart disease, stroke incidence and mortality, type 2 diabetes incidence and mortality, and colorectal cancer incidence and mortality when comparing the highest dietary fibre consumers with the lowest.31 Furthermore, they noted that fibre intakes higher than 35 g/day appeared to be even more effective than lower intakes in reducing risk cardiovascular diseases, type 2 diabetes, and colorectal, and breast cancer.

In summary, good evidence exists from epidemiological studies that suggests that high dietary fibre might not only reduce colon cancer risk and deaths, but also all-cancer deaths, and all-cause mortality, thus increasing lifespan. The reduced effect of other diseases associated with high-income lifestyles can then be expected to improve the quality of life gained. – NCIB

Therefore, now cancer is connected to fiber as well. I went out to the American Cancer Society and found the following recommendations on diet.

Follow a healthy eating pattern
Eating well is an important part of improving your health and reducing your cancer risk. Take a good hard look at what you typically eat each day, and try to build a healthy diet plan for yourself and your family.

A healthy eating pattern includes…

Foods high in vitamins, minerals, and other nutrients
Foods that are not high in calories, and that help you get to and stay at a healthy body weight
A colorful variety of vegetables – dark green, red, and orange
Fiber-rich beans and peas
A colorful variety of fruits
Whole grains (in bread, pasta, etc.) and brown rice – American Cancer Society

However, I found nothing on fiber supplementation at the American Cancer Society. Yet increasing fiber with not only a diet but a fiber supplement should be a high priority on the American Cancer Society. However, it is clear from reading the American Cancer Society website that they don’t even bring up the topic. Instead, I found the standard scare tactics regarding supplements on virtually all of the websites of establishment entities.

Although supplements are not required to go through clinical trials, companies that make them are supposed to:

Have data showing the products are safe
Make sure that the details on product labels are truthful
Avoid making false claims
Correctly show what is in the supplement. – American Cancer Society

One of the essential supplements to reduce cancer is fiber supplements, which have a zero risk, and the ACS won’t even bring up the topic.

Fiber Causation #2: Fiber and Obesity

The following quote describes the relationship between fiber and obesity.

Numerous studies in adults and children have now confirmed the association between low fibre and high glycaemic index diets with type 2 diabetes and obesity.32–35 Using cross-sectional weighted data from the National Health and Nutrition Examination Survey (NHANES) among adults, King and colleagues36 reported that obese participants consistently reported lower fibre intake than did individuals with a healthy weight (14·6–15·4 g/day fibre) or overweight (15·6–16·8 g/day fibre) participants. Using the same database, Albertson and colleagues37 found that high grain consumption was associated with lower bodyweights in both adults and children. – NCIB

Fiber Causation #3: Fiber and Inflammatory Bowel Disease

Crohn’s disease and ulcerative colitis are also associated with high-income lifestyles. Their incidence increased dramatically in North America and Europe during the second half of the 20th century. Although rare in less developed countries, concern exists that these diseases are becoming more common in more developed parts of Africa, including South Africa.46 Like colon cancer, diabetes, and cardiovascular disease, Crohn’s disease and ulcerative colitis are classic complex diseases generated by a combination of factors in the luminal micro-environment and genetic aberrations in epithelial responses. As reviewed by Rasmussen and Hamaker,46 numerous studies have documented low consumption of fibre-rich foods by patients with inflammatory bowel diseases (IBD), with other studies identifying common patterns of colonic microbial dysbiosis, or signatures, characterised by depletions of high butyrate producing microbes. – NCIB

Some great sources of fiber are listed and explained here.

The explanation for Why the Medical Establishment De-Emphasizes Fiber Supplementation

This quote is highly educated on this topic.

The diseases of civilization – so-called because pre-industrial cultures all over the world to this day do not suffer from them – include most cancers, heart disease, stroke, diabetes, kidney disease, Alzheimer’s and more. That list is >80% of the leading causes of death in Western countries.

A mountain of evidence compiled over the last 60 years shows that routine consumption of refined carbs such as sugar and flour causes hyperinsulinemia, which leads to obesity and the diseases of civilization.

As a note, refined or white flour does not have fiber.