Food Freedom Friday Edition 312 - The Fiber Myth

For decades the fiber myth that your body cannot run efficiently without plants has been pervasive. Plants contain fiber and fiber prevents colon problems, constipation, high cholesterol, heart attacks, and more.

Men are recommended to consume  38 grams of fiber and 25 grams of fiber a day is recommended for women.  Newer, more objective research is showing that dietary fiber is often unnecessary and it might even be harmful. 

What Is Fiber

Dietary fiber is a non-digestible carbohydrate that can come from either natural or synthetic sources. Common types of dietary fiber include:

·       Cellulose

·       Psyllium Husk, 

·       Chitin, 

·       Fructo-oligosaccharides, 

·       Dextrin.

Fiber is commonly found in plant foods including fruits and vegetables. 

There are 2 types of fiber:

Insoluble fiber

Fiber is by definition mostly indigestible. Insoluble fiber is completely indigestible, meaning it passes through your entire digestive tract untouched.  This type of fiber is purported to speed up digestion. 

However, insoluble fiber does not dissolve in water or stomach acid. It is abrasive to the large intestine and mostly incompatible with your entire digestive tract. 

Soluble fiber

Soluble fiber distinguishes itself from insoluble fiber by being slightly digestible. 

This type of fiber is supposed to slow down digestion by absorbing water and keeping the entire GI tract well-hydrated. Soluble fiber gives the intestines a gel-like coating that some experts believe is beneficial.

Bacteria actually thrive in this gel coating and new research has shown that soluble fiber can make it easier for harmful bacteria to proliferate, potentially leading to conditions like small intestine bacterial overgrowth (SIBO).

Do You Need Fiber?

Humans do not need fiber to survive or thrive. The origins of the need for fiber began as a supply chain solution as opposed to a scientific breakthrough. In the late 1800s, grain processors learned how to efficiently separate the bran from the grain, creating ultra-fine, ultra-refined products in the process. 

Fiber-free grains and flours quickly became popular due to the smooth, chewy mouthfeel. 

Epidemiologists began to notice that countries with higher refined wheat consumption tended to be sicker, whereas countries or areas that didn’t have access to these new grains remained relatively free from modern diseases. 

People assumed that the newly missing fiber was responsible for this difference. Grain processors were happy to profit off their waste products by remarketing husks as fiber supplements. 

These early epidemiologists mistook correlation with causation and drew the wrong conclusion. A lack of fiber was not the factor deficient in modern diets! 

The real problem was a lack of fat-soluble vitamins, as Dr. Weston A. Price would later show. 

Fiber And Cholesterol

Fiber’s apparent utility is showcased in its ability to lower cholesterol levels. 

One review found that plant-based, high-fiber diets reduced LDL cholesterol by up to one third. 

Looking deeper, this is not as beneficial as it may seem. Many substances that are known to be toxic reduce cholesterol. High cholesterol usually indicates that there is a deeper underlying issue, and is not necessarily a problem in and of itself. 

Fiber And Blood Sugar

Fiber can also reduce the glycemic index of certain foods and help keep blood sugar stable. Studies show that fiber’s ability to slow digestion can reduce blood sugar spikes by between 10 and 20%. 

This benefit, however, is also limited by its context and the glycemic moderation of fiber becomes completely unnecessary when you eat a low carb  keto/carnivore diet.

Fiber And Weight Loss

The research on the link between dietary fiber with weight loss has also been unimpressive. Most studies so far have provided mixed results, and even the studies that do appear to show benefits have been poorly designed.

Research has found that “The limited number of clinical trials comparing high-fiber foods with low-fiber foods have not provided consistent data indicating that these diets are more efficacious for weight loss than low-fiber control diets.” 

Certain types of fiber can in fact cause enough bloating and pain to interfere with weight loss. A popular fiber supplement and food additive called guar gum has been connected with abdominal pain, flatulence, diarrhea, stomach cramps, and more. 

Fiber In The Body

While your body cannot digest fiber, the bacteria in your large intestine can. These bacteria ferment fiber and create gases like hydrogen and methane.  The exothermic (heat-producing) reaction can also damage local organs and tissues. 

Fiber intake may even impair fertility. One study found that women who consumed large amounts of fiber were less fertile. Fiber can also cause tremendous flatulence. 

As fiber consumption increases, so does the risk of developing diverticular diseases and colon disease. Studies have also shown no relief from bowel polyps when study participants were placed on a high-fiber, low-fat diet.

When taking a closer look at the healthy fiber myth, fiber may actually be considered a junk food. Insoluble fiber has been referred to as “the ultimate junk food”, as it is “neither digestible nor absorbable and therefore devoid of nutrition.”  

More recent studies have further affirmed the view that many types of fiber are not supportive of health, concluding that “the previous strongly-held belief that the application of dietary fiber to help constipation is but a myth. Our study shows a very strong correlation between improving constipation and its associated symptoms after stopping dietary fiber intake.” 

Excess insoluble fiber can also bind to minerals like iron, zinc, magnesium, and calcium and prevent the absorption of these nutrients. Excess insoluble fibers can inhibit enzyme activity enough to impair protein absorption, essentially acting as an antinutrient. 

One final myth regarding fiber’s health benefits lies in its ability to boost the production of certain types of fatty acids. Some soluble fiber is fermented by gut bacteria producing short-chain fatty acids like butyrate and proportionate. These fatty acids can fight against neurodegeneration, cancer, and obesity. 

This fiber-butyrate conversion has led some gut health experts to continue recommending high fiber diets. 

However, butyrate and other gut-friendly fatty acids can be obtained in much simpler and safer ways. Collagen rich foods and full fat dairy are all rich in anti-inflammatory butyrate and, unlike fiber, they cause little to no gut irritation. 

Added Fiber

Sadly, official guidelines perpetuating the fiber myth lag behind the latest research.

Functional fiber continues to be added to processed foods as a way to increase fiber content and satisfy consumers who wish to meet these official guidelines. 

Many health-conscious consumers continue to purchase products that contain added synthetic fiber and grain-based, high-fiber food products continue to be highly popular. 

Going Fiber Free

Some consideration when reducing or removing fiber from your diet:

Making the shift may result in temporary changes to your bowel patterns. Many people who begin a carnivore diet find that their digestion slows down. This is normal and natural, but it might still take some getting used to. If you begin to experience carnivore diet constipation, ensuring adequate water and electrolyte intake can help. 

Some experts feel that following low or no carbohydrate diets can harm the gut bacteria. While beneficial in the short term as a way to reduce overgrowth of unhealthy gut bacteria, in the long term, a fiber-free VLC diet may be unhealthy. 

The theory follows that a low/zero fiber diet, when followed for long periods of time might harm the gut’s normal gel lining. Studies looking at low-carb dieters have found an unusually high rate of colon cancer. (Note that research does not support the idea that this link is anything but correlative.) 

If you are active, and happy with your body composition, you may want to experiment with adding small portions of raw honey or fruit to your diet. Only a small amount of carbohydrates is needed to keep the digestive tract well ‘lubricated.’ If you are trying to lose excess weight or deal with a health or fertility issue, feel free to remove the carbs/fiber entirely for at least a few months. 

The fiber in low-carb berries may also boost the production of short-chain fatty acids.  Butyrate, in turn, can help maintain the integrity of the gut lining and maintain a high metabolic rate.

What To Expect

Surprisingly, many people experience better digestion when reducing fiber intake. You might experience easier bowel movements and reduced bloating/gas as you make the switch.  

Looking back over the sum of the research, it’s clear that dietary fiber has been greatly overrated. Fiber is not usually beneficial and large amounts of fiber can quickly become harmful. 

Experiment with cutting your insoluble fiber intake to a minimum and if you do choose to eat fiber, make sure it is a soluble fiber from whole-food sources including: 

·       Potatoes

·       Sweet potatoes

·       Fruits (especially low-carb berries)

·       Mushrooms

Small amounts of these foods may keep your digestive tract well ‘lubricated’ and boost your body’s production of beneficial short-chain fats. This is especially true when combined with healthy fats like tallow or butyrate-rich butter.

If you don’t enjoy fruits and vegetables, don’t feel obligated to eat them. The research is clear that humans evolved to do best with a hypercarnivore diet centered around animal products.

Animals, after all, have digestive tracts specifically designed to process plant fibers and convert them into more usable energy.