Fiber: Friend or Foe?
Greetings, Intuits. (Is that a thing? Can I call you that now that you're intuition masters?)
Glad you're back for more.
In the last series of posts, you learned a little about essential nutrition and how to wake up your body's inner health guide. But there are certain buzz words and hailed superfoods out there that need some exploration to see if they actually enrich our lives. So today, we're going to shine a light on one of the most prevalent and recommended ones.
Fun, right? Come on now, don't get too excited. Our examination of the conventional wisdom surrounding fiber may just have you crapping your pants by the time we're finished. So hold on to your britches.
In the last couple of decades, fiber has emerged as its own unique superhero. Do you want to slash your risks of colon cancer? Elevated blood sugar? Toxic build-up? Obesity? Constipation? Brittle bones? Stroke? Heart Disease? Fiber is the answer. Duh! Everyone knows this. WebMD summarizes it so well when they say, "It's hard to believe that something we can't even digest can be so good for us!"
Government and industry around the world preach the fiber message as gospel. Beginning in 2005, the American Heart Association (AHA), bless their hearts, even began to recommend that you get at least 25-30 grams of fiber in your daily diet. You can find the guidelines here. They don’t skimp on providing lots of examples on how you can reach that imposed goal either. Whole grain cereals, whole grain breads, whole grain pasta, whole grain this, whole grain that... And they stress, this 25-30 grams is far above what the average American gets. So in case you were not aware, we're in a fiber deficit, my friends. Yikes! What can we do?
EAT MORE FIBER, of course! Hmm... not so fast.
The fiber movement was largely influenced by the observational (aka epidemiological) studies of an Irish surgeon named Denis Burkitt. After observing various African natives, Burkitt concluded that the their good health was primarily a result of the consumption of the fiber found in their traditional diets. This was certainly an interesting finding, and one worth pursuing. But as with all epidemiology studies, more controlled research was needed to isolate fiber as the magical ingredient.
Fast forward to today, and it's clear that information available concerning fiber is hardly conclusive. As you can see, coming from public health bodies, it's quite glorified. It's especially touted to slow your blood glucose absorption, move your stools through your body more quickly, and "scrub" the intestinal walls squeaky clean so you minimize your risk for colon cancer. But make note, for as many scientists that agree on its superpowers, there are just as many who do not.
So what do we do with such controversy? Once again, we have to cut through the noise. Going back to what we're trying to accomplish here, it's important to take all the information you hear (including mine) and put it on the back burner as you continue reframing your perspective on food and health to be natural and instinctive.
First, a warning. Whenever far away, faceless entities (like public health organizations and media outlets) isolate certain compounds in our food (like fiber) and tout them as lifesavers or killers, we should be wary. Remember, test everything.
So what exactly is fiber anyway?
Well, first off, fiber is NOT a nutrient. So don't get it twisted. Fiber is the roughage or bulk part of the plant that your body cannot digest or absorb. (Yes. By all means, be sure to eat more of that.) It contains substances such as cellulose, lignin, and pectin, that are resistant to the action of human digestive enzymes. There are two specific types classified as soluble fiber, which swells in water, and insoluble fiber, which does not.
We begin by going back to essential nutrients. What does my body NEED to function optimally? Unfortunately, fiber just doesn't make the cut. And this is not new information. The Institute of Medicine tells us straight up. "The lower limit of dietary carbohydrate compatible with life is apparently zero, provided that adequate amounts of protein and fat are consumed." (The Institute of Medicine, 2005)
Fiber falls into the carbohydrate category of the macros... No carbohydrate is essential for human life, therefore fiber is not essential. Now hear me out. Just because something isn't essential for life doesn't mean it can't be beneficial. (Take orgasms for example.) I am not saying there is no benefit to be gained by consuming fiber... I think there may be for some people. But upon review, it doesn't take long to see that the evidence for all these fibrous benefits is hard-pressed to hold up to scientific scrutiny. Especially when it comes to using it to advise the masses.
What's that you say? Right again! One size just does not fit all.
So let's get into the nitty gritty of how fiber tends to interact with the body, using the information we do know.
The human digestive system is not designed to use fiber as food. Unlike herbivores, we do not have the proper enzymes needed to break it down into energy or retrieve its nutrients. As a result, fiber passes right through the small intestine, where all other nutrients are broken down and absorbed, on into the colon where it encounters a variety of bacteria. It is here that the body will try and use the fiber, if possible, through fermentation by gut microbes. In someone who has healthy gut microbiota, the result of this fermentation is beneficial short-chain fatty acids such as butyrate, acetate and propionate. These are then converted into ketones before they are used to "nourish" or energize the cells lining the colon. (This whole process is pretty cool, don't you think? Gassy, bloat-iful, and maybe even explosive at times, but cool. The human body is amazing.)
Even so, a glaring thought remains... Is this the BEST we can do? Just because fiber seems to be beneficial for some people, doesn't necessarily mean it's the optimal choice. The fermentation of fiber in the colon is not the only way we get short-chain fatty acids. They can also be obtained from animal products containing no fiber at all. What's more, when we eat a natural, seasonal diet, the body can and does make its own ketone bodies to energize and nourish all our cells, not just the ones in our colon.
A person who eats the Standard American Diet (SAD) full of packaged, processed junk foods will likely benefit greatly from consuming high amounts of dietary fiber. If you're gnawing on celery stalks, you have less time to be shoving muffins in your mouth. So that's a good start. But, good lord, aren't we past that?
People who eat real, nutrient-dense food--such as meat, fish, eggs and whole fruits instead of fruit juice--do not need to focus their time and energy on getting their daily 25-30 grams of fiber (and all the sugar that tends to come along with it). These people do not have elevated blood sugars, insulin resistance or obesity. Their risks of heart disease, cancer and stroke are already low. Perhaps this is the kind of diet we should be recommending for the masses. Real, whole, nutrient-dense food. Not fiber-enriched, genetically modified, sugar-loaded, pesticide-ridden cereals, bars and pastas manufactured for profit.
Question: Is it better to forfeit bioavailable, nutrient-dense foods for the sake of increasing dietary fiber, of which we cannot absorb or digest? No. No it is not.
What's missing from the discussion is the reality that fiber can actually be harmful in some cases. (It is, after all, an anti-nutrient--something we'll discuss in great detail later.) Believe it or not, excess fiber intake can actually CAUSE constipation, diarrhea, and stomach pain. Even more disturbing, it can cause mineral deficiencies which is a root cause of many health problems. So for people who struggle with any of these things, contrary to popular belief, the answer may actually be a zero- to low-fiber diet instead. If that's you, do some experimenting and see what happens.
The point of all this is to show you that fiber may not be as miraculous as we've been led to believe. "Eat more fiber" is usually the advice given to people who are experiencing all kinds of ailments. But it's highly unlikely that consuming extra fiber will do anything to solve the underlying issues of people's poor health. That's like telling someone who's car isn't running properly to top off the windshield wiper fluid and hope for the best... Um, what?
So how do you relate to all this? Are you a fiber-focused junkie, worried you're not getting enough? Or is your diet already so full of nutrient-dense foods that you don't have room for whole grain pasta? If you decide that your body thrives on copious amounts of fiber, that's great. Just know that you can get it without consuming loads of mineral-robbing whole grains and the many sugars that come along with them. Instead of bread, cereal, granola bars and pasta, you can get good amounts of fiber through avocados, cauliflower, berries, and cabbage.
I encourage you to explore your eating habits and make personal decisions based on your own data. Here's a tip: Healthy digestion should not be painful or uncomfortable. And if you have more questions about fiber, leave a comment below. I'd love to hear from you!