TL:DR: Fiber, the long-touted digestive aid daytime television always told us we needed more of and should supplement, may not be as essential as once thought to human wellness. Reexamine your diet to determine if fiber is really all that necessary for optimizing your health.
*We are not doctors. Please consult your physician before changing your diet or health practices. All claims throughout are made for research purposes and should not be taken as dietary advice.*
With that out of the way…
Introduction
Welcome back, biohacker. Today we will be discussing a topic that has recently exploded in popularity as people around the world begin to self-inform regarding nutrition. While this article will begin by illustrating the typical mainstream view towards dietary fiber, it will also introduce readers to the other side of the aisle that believes fiber is utterly unnecessary. We do this in the aim of providing you, the reader, with an opportunity to make your mind up for yourself instead of simply going with the grain (pun intended).
This article will be structured by first explaining what fiber is and where to find it. Subsequently, we will raise four of the most pressing issues regarding fiber as categorized by their popularity in Google search results, in order to bring you the information you are most likely interested in. In each of the four main questions, we will first introduce the traditional western view, followed by an alternative argument, which offers an opposing perspective for your reflection. If you have an opinion you would like to voice regarding any of the content found herein, please make your opinion heard on our ‘Fiber’ forum thread. We take great pleasure in discussing with you and responding to any and all comments.
With that said, let’s now jump into what dietary fiber actually is.
What Is Dietary Fiber?
Strictly speaking, fiber is a type of carbohydrate that the human body cannot digest. Found in plant-food products, fibers are considered diverse in their chemical composition and are therefore categorized based on several different properties. The main three differentiating properties are their viscosity (think asparagus, sweet potato, and mangos), their solubility (their abilities to dissolve in water or not), and their fermentability (beans and legumes). Each one of these factors determines how that particular fiber will be processed by the body and accordingly classified.[1]
If you look on google, the first link you’ll likely find when searching “what is dietary fiber?” is a link to MayoClinic where they tell us the following information regarding fiber: [fiber] is probably best known for its ability to prevent or relieve constipation. But foods containing fiber can provide other health benefits as well, such as helping to maintain a healthy weight and lowering your risk of diabetes [and] heart disease…[2]
Furthermore, if you do more research, you’ll find additional characterizations of dietary fiber’s job in the body along the lines of: scraping the body of plaque and generally ridding the body of waste. With all these definitions in mind, it is easy to take dietary fiber as an essential component of the human diet. However, when looked into more deeply, relevant and pressing questions arise. These questions may be presented as follows:
- Is constipation only solved by consuming fibrous foods?
- Is fiber essential in maintaining a healthy weight?
- Are the diabetes-improving properties of fiber unique to dietary fiber?
- Is dietary fiber the best way of lowering one’s risk of developing heart disease?
While proponents of the typical western diet would mostly answer in the affirmative to all of these questions, thereby enshrining dietary fiber in the nutritional hall-of-fame, proponents of a more ancestral diet among others would respond otherwise. We will soon get into this discussion. For now, though, let’s look at where we actually find fiber in our natural environment.
Where Is Dietary Fiber?
As briefly mentioned above, dietary fiber is categorized based on its distinct chemical characteristics. However, while most fiber does have certain predominant attributes – which results in their primary categorization (water soluble vs water-insoluble, for example), most of them share secondary features that may be the defining feature of another fiber. With that in mind, we will give you a brief list of some of the most generally fibrous foods found in the typical western diet:
(represented in grams of dietary fiber per cup)
- Beans → 18g (edamame)
- Broccoli → 5g
- Berries → 4g (blueberries)
- Avocados → 10g
- Popcorn → 1g
- Whole Grains → 3.8g in 2 slices of bread
- Apples → 4g per apple
- Dried Fruits → 12g (prunes)
- Potatoes → 3g per small white potato with skin
- Nuts → 3.5g per 1 oz (almonds)
As you can readily see, in the typical western diet, there is no shortage of fiber. One thing to note is that fiber does not appear in animal based foods including fish, red meat, or poultry (this will become relevant soon).
Q1. Fiber and Constipation
First off, if you’re generally concerned about your bowel movements and what they can tell you about your health, or simply a tea-leaf reader who has decided to turn their skills to the toilet bowl, please check out UpRiver’s article here on poop! Moving right along.
Now that we have an understanding of what fiber is and where to find it, we will begin to look at the arguments from both sides when it comes to the question of constipation.
On the modern western side of the aisle, (which we will now give the blue corner of the ring), we hear pretty frequently that the solution to constipation is to drink prune juice or eat some other sort of fibrous food to relieve us. The idea here is that the fiber, as it cannot be absorbed by the body, will cause us to have a bowel movement to excrete it, forcing other things to be expelled too, thereby solving our constipation.
* Rocky Balboa theme music plays*
“Aaaaaaand in the red corner, we have the Caaaarrnniiivooorreee.”
Carnivores or animal-based diet practitioners have an entirely different view when it comes to dietary fiber, especially its relationship to constipation. As such, this is the group we will call the ‘red corner’ and will represent the blue corner’s primary opposition. To note, the red corner believes that dietary fiber is not essential to optimal digestion, nor health writ large. Moreover, if you want to check out our deep-dive on the carnivore diet for more context, please feel free to do so as we will not be doing an extensive overview of the carnivore diet here in this article.
The red corner makes the very simple and intuitive argument that something our bodies cannot absorb does not seem to indicate any sort of essential property to an organic organism that depends on the mechanism of absorption for its health. Put another way, we absorb water; we absorb food; we absorb oxygen; heck, we even absorb sunlight. All these things are essential, but intuitively, our body does not seem to want to take in fiber. [3]
It is important here to not mistake the modus ponens here and assume that if we absorb something, then it must be essential. This is not the point being made. The red corner is simply saying that if we do not absorb something, then it seems spurious of being essential.
The red corner classically believes that if we avoid foods that cause constipation (like the host of processed and plant-foods our bodies are not adequately equipped to eat regularly), we will not require fiber. No cause of problem, no need for ‘solution.’
NOTE: total fiber elimination diets have also been shown to cure constipation. Perhaps this shows that fiber is not nearly as important as we once thought to keep us regular. For more information on this, check out Paul Saladino’s The Carnivore Code Ch. 9.
Q2. Is Fiber Essential for Maintaining a Healthy Weight?
The argument here from the blue corner relies on a string of premises. We will present them to you plainly as follows:
P1. Fiber helps certain kinds of ‘good’ bacteria in your gut
P2. Good bacteria help fight inflammation in the body
P3. More Inflammation in the body leads to weight gain; less inflammation in the body leads to weight loss
———————————————————————-
C. More fiber leads to weight loss
While this argument from the blue corner is straightforward enough, the red corner starts by examining the problem before suggesting a solution. By and large, the carnivore brings into question both the bodily inflammation and its concomitant weight gain. In a similar vein to the last response the red corner gave, the carnivore investigates the presence of inflammation in the first place. Remember, the argument for fiber’s alleged ‘essential’ consumption, relies on their being chronic inflammation in the body.[4]
Unlike the typical western diet of the blue corner, the red corner’s eating approach claims to be one that is naturally anti-inflammatory. If this is the case (find out HERE), the red corner may have delivered a blow from which the blue corner cannot recover. In fact, whether or not you agree with an animal-based diet being anti-inflammatory, the blue corner would have to defend the same argument from any diet that in actuality, is anti-inflammatory.
Q3. Are the Diabetes-Improving Properties of Fiber Unique to Fiber?
Here is where the blue corner may have a bit of a comeback…
While this is not an article about diabetes in general, here is how diabetes enters this discussion. Diabetes, both type I and type II, affects the entire body and are largely anchored to one’s blood sugar.[5] However, in people with diabetes or even pre-diabetes, fiber – particularly soluble fiber – can slow the absorption of sugar and help improve blood sugar levels.[6] Additionally, it has been shown that insoluble fiber may actually help prevent the onset of type II diabetes. [7]
Again, the counter-punch from the red corner is that if we do not consume a diet where diabetes is a risk for us then we can address the problem before it requires a cure. We can, in a sense, take the vaccine, circumventing the need for a cure.
Of course, though, this does not help people who develop hereditary cases of diabetes. In these cases then, fiber may actually be an important part of one’s overall health regimen. However, it is worth noting that while fiber may have unique properties to it that benefit some diabetics, there are of course other things that sufferers can do to positively influence their blood sugar. These can include regular aerobic exercise, anaerobic exercise, proper diet, adequate water intake, and adequate supplementation.[8]
In summary, then, fiber may offer beneficial properties to the body that helps in very particular cases. Although, that is not to say that fiber itself is mandatory to consume for diabetics, as there are other ways to improve the ailment, rendering fiber potentially helpful, but not unique when it comes to it’s beneficial effects on diabetes.
One study illustrating that fiber may even harm our nutrient absorption claims:
The bioavailability of vitamin B6, from animal products is quite high, reaching 100% for many foods. In general the bioavailability from plant foods is lower. The presence of the fiber reduces the bioavailability by 5-10% whereas the presence of pyridoxine glucoside reduces the bioavailability by 75-80%. This glucoside is found in a variety of plant foods, with the highest content occurring in the crucifers.[9]
Q4. Is Dietary Fiber Consumption the Best Way of Lowering One’s Risk of Developing Heart Disease?
The argument from the blue corner has been published in numerous studies on fiber and its connection to heart disease. Largely, this argument depends on the idea that in cases of heart disease, we see very high levels of a person’s low-density lipoprotein (LDL), and that fiber has been shown to lower LDL levels in the body.[10] While this point quickly becomes convoluted and esoteric, we will give you a quick rundown of what the blue corner thinks and how the red corner responds.
Cholesterol: a word that haunts and unduly scares the bejesus out of the casual bingo player, actually serves an incredibly important function in the human body. It forms the building blocks of your hormones.[10] In a sense, cholesterol is the grandaddy of your endocrine system.
Now, there are two main types of cholesterol:
- low-density lipoprotein (LDL); and
- high-density lipoprotein (HDL)
Unfortunately, the former has come to be known as the “bad cholesterol” and the latter as the “good cholesterol.” One reason for thinking this is that typically when doctors have observed heart disease and many other kinds of bodily issues, LDL is very high. This, historically, has led to a correlative finding becoming treated as a causal relationship. What’s worse, is that the direction of the relationship has also been inferred. Did the high LDL cause the heart disease or did the heart disease call for the high LDL?
Thankfully, this becomes pretty clear when we actually take the time to look at what LDL does in the body. LDL serves lots of functions, but one of the main ones is that it actually binds with endotoxins in an attempt to eradicate them.[12] Well, the funny thing about endotoxins is…
They. Cause. Heart. Disease.[13]
Emerging, we see the red corner’s final knockout uppercut incoming. What the red corner will argue is that to accuse LDL of causing heart disease, is like accusing the fireman of starting the fire, or the detective of committing the murder. Sure they’re there at the scene of the crime – as it is their job to be – but simply looking at the scene and inferring causation is to likely misrepresent the scenario entirely. The red corner simply looks to the biological function of LDL in order to acquit this unsung hero of its alleged crimes.
Ultimately then, if heightened LDL is not the cause of heart disease, then lowering LDL whether good or bad for other reasons, is not relevant to the matter in question. Therefore, the connection between fiber and heart disease may be entirely misunderstood and dogmatically touted as valuable.
Moreover, despite our view in the west that fiber is essential, there are lots of examples of other cultures who consume trace amounts or no fiber whatsoever. The one that most readily comes to mind is the Eskimo’s and the Inuits, who have reportedly statistical longevity and good health.
Author’s Motivation
When I was younger, I never gave much thought to fiber until I came across a diet approach called IIFYM (check that out HERE.) This approach recommended that I intake 10g of fiber per every 1000 or so kcals. At the time, I didn’t pay too much attention to why, but I kind of just went along with it. Since this diet was primarily a diet focused on body composition over health per se, when I got older and began to care about health over body comp, I actually looked into fiber. One place I found a lot of information was in Dr. Paul Saladino’s Carnivore Code. He detailed a lot of information regarding why people think dietary fiber is essential and represents the primary voice in this article’s “red corner.”
At first, I was pretty skeptical about ditching fiber altogether, because I had heard that to do so was to ditch pooping altogether too. I found out through Saladino’s book that this is not the case, and I found out through experience that Saladino was right. In his book, he speaks about how your gut flora (intestinal ecosystem) changes to ultimately adapt to what you’re consuming. Additionally, as on a carnivore diet you are consuming what many believe to be the most innate diet to the homo sapien, your gut actually improves manyfold. This beneficial change definitely showed in my own experience and thus gave me the motivation to write this article. In reading this, I sincerely hope you learned both about fiber, and to question the traditional and largely debunked western food pyramid.
Dr. Saladino’s Website: https://carnivoremd.com
Conclusion
Fiber has traditionally been thought of as vital in the west. Generally speaking, fiber is brought up in the context of bowel movement and constipation, weight maintenance, diabetes, and heart disease. Throughout this article, we introduce the classic western perspectives on fiber and pin them against a new fighter who takes his wisdom from ancestral knowledge backed by a review of modern science.
Ultimately, this leads to some interesting findings. For instance, something that we cannot absorb, may simply not be designed for our ingestion; inflammation may be solved in a variety of ways; the diabetic population may benefit from fiber more than others; and LDL may not be the criminal it was once thought to be. While we believe that there are some good arguments for eating fiber, in the context of a non-western typical diet, there may be better arguments against fiber’s general consumption.
This article was written in order to encourage your further investigation into the ideal diet for your own goals and to encourage your bottom-up thinking when it comes to nutrition as a whole.
Food for thought.
Best of luck biohacker, and keep moving UpRiver.
References
[1]https://en.wikipedia.org/wiki/Dietary_fiber
[2]https://www.mayoclinic.org/fiber/art-20043983
[3]Saladino, Paul, and Mark Sisson. The Carnivore Code: Unlocking the Secrets to Optimal Health by Returing to Our Ancestral Diet. Fundamental Press, 2020. (43-47)
[4]Ibid.
[5]https://www.diabetes.ca/about-diabetes/causes-of-diabetes
[7]Ibid.
[8]https://www.healthline.com/nutrition/15-ways-to-lower-blood-sugar#TOC_TITLE_HDR_5
[9] The Carnivore Code, Dr. Paul Saladino, pg. 122
[10]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5731843/
[12]https://www.nature.com/articles/s41598-018-28777-0
[13]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5452150/
