Main content starts here, tab to start navigating

Health Hack #15 - Soluble Fiber: A Vital Component of a Balanced Diet

Distractions From the Topic of Fiber

In our modern world where diet talk has become part of everyday water cooler chat, the various types of elimination diets tend to dominate the conversation. “I’m thinking of going Vegan.” “How’s that Paleo thing working out?” “Are you familiar with Keto? My wife is considering it.” (In a prior Health Hack we touched on this subject more deeply; for a refresher or for a first time read, click here.)

One tier down in conversational prevalence is talk of Macronutrients. Is low-carb the way to go? If you’re vegan, how are you going to consume enough protein? Is it really true that eating dietary fat doesn’t necessarily make you fat? And it’s these macronutrients (fat, carbohydrate, protein) that dictate much of the talk about another ubiquitous topic, which is probably third in the ranks of most discussed: calories. Many focus intently on caloric intake, and there are certainly good reasons for this. We’ll actually be covering the notion of caloric restriction in next week’s post, so stay tuned.

What is Often Overlooked

If there’s any dietary topic that receives far less attention than it should, it’s fiber. Mostly everyone knows what it is to some degree, in that it assists in digestion and in the regularity of our bowel movements. Probably makes sense why it’s not a hotter topic around the water cooler...

Fiber is actually an extremely vital component of a balanced diet. Yes, it aids in digestion. And yes, it helps regulate our bowel movements. But it also helps to:

-Lower cholesterol

-Control blood sugar levels

-Achieve satiation after a meal

-Fight against cancer, primarily of the bowel

-Reduce the risk of heart disease 

-Feed the healthy bacteria residing in the gut

Broadly speaking, fiber comes in two dietary forms: insoluble and soluble.

Insoluble Fiber

Insoluble fiber is the version that most of us are already familiar with. This is what we all equate with helping things “pass through us”. Insoluble fiber does not dissolve in water, allowing it to travel through our digestive tract more or less unchanged. En route to its exit, it collects bulk and makes for a more pleasant and more recurring release. And as we’ll delve into more next week with all things calories, insoluble fiber is non-caloric. Focusing here on insoluble fiber for a final moment, consider the range of benefits here purely from a body weight stabilization context: a food substrate that aids in digestion, increases satiety signaling, contains zero calories, and helps move things along more comfortably. While the focus of this article is primarily Soluble fiber, it’s important to give insoluble its proper due. Making it a dietary staple is a no-brainer.

Moving on now from all of the bowel-related euphemisms...

Soluble Fiber

Soluble fiber, unlike its counterpart, is able to dissolve in water as well as in some other gastrointestinal fluids. During this process it’s converted into a gel-like substance that then serves as a food source for the bacteria that resides in our large intestine (which is also known as our colon). Many of us these days are familiar with probiotics. They’re strongly linked with gut health and are now often prescribed as a first line of defense against gastrointestinal distress. We find probiotics in fermented foods like sauerkraut and kombucha, and we find them in supplemental form in virtually all health food and drug stores. But what do probiotics have to do with soluble fiber?

Soluble fiber provides prebiotics to our microbiome. This is essentially food for our probiotics to feast on. When you supplement with traditional probiotics (or consume them via fermented foods) you’re wishfully hoping that these beneficial bacteria will colonize in your gut and crowd out the less desirable bacteria that we wish to eradicate. Without a steady stream of prebiotics - which we derive from soluble fiber - these beneficial bacteria will be left without a food source. This is when things become dangerous. In one scenario, these welcome bacteria will simply die off, leaving space for those unwelcome invaders to increase residence. This can agitate our gut and stunt our immune system. Taking this a step further, it then becomes difficult for new probiotics to colonize.

What’s worse, however, is the scenario when our starved bacteria begins exploring for food in a desperate attempt to survive. When this occurs, our gut bacteria will auto-digest the mucin layer that sits on the surface of our intestinal epithelial cells. In layman’s terms, this process runs the risk of puncturing holes into our gut, as the mucin layer is meant to provide a protective barrier. Ramifications begin at irritation, but extend to conditions such as leaky gut syndrome and more severe GI issues like Colitis and Crohn’s Disease. Fiber consumption is hugely important.

How Best to Find Nutritious Fiber in Your Diet

As usual, it all harkens back to real food. Processed foods - meaning virtually all foods with labels on them - see degradation of the fiber matrix at every step of the processing. So the safest bet is to seek out real food, keeping in mind that fiber is found in plant foods only. Fruits, Vegetables, Nuts, Seeds, and especially in unprocessed Whole Grains and Legumes is where you’ll find the most. The more raw upon purchase, the better.

All fiber-containing foods contain at least some soluble and some insoluble portions. Nature has an intuitive design process for all things, and it’s nicely aggregated these fiber siblings for us. This is untrue of many supplements, including the most widely prescribed fiber supplement: psyllium husk. Psyllium supplements contain exclusively soluble fiber. Without working in tandem with its insoluble counterpart, the magic is unfortunately lost. Fiber One bars therefore fall flat in their advertised benefits.

It’s noteworthy to be mindful of the dual relationship since it’s virtually impossible to parse out the soluble/insoluble split while on the fly. Food labels aren’t broken down this elegantly, to separate the two. Compounding confusion further is the fact that the fresh produce you buy doesn’t come equipped with a nutrition label. So what you’re really keeping an eye out for when label scouring is a high total fiber content (matched with minimal processing), which can be found as a subcategory to carbohydrates. And when buying produce, try to eat the rainbow and consume a diverse array of plant foods. But for starters, consider focusing on some of the fiber leaders in each real food category, aiming for a total fiber intake above 25g daily for women and above 38g daily for men:

-Fruits: Avocado (14g of fiber in one avocado!) & Raspberries

-Vegetables: Artichokes, Broccoli, Carrots

-Nuts: Almonds & Pistachios

-Seeds: Chia & Flax

-Unprocessed Grains: Virtually all suffice, but we recommend Quinoa due to it’s Gluten-free distinction

-Legumes: Lentils, Beans, Peas; you really can’t go wrong with the Legumes

A Final FYI on Fiber

Many of us find it helpful to up our fruit/vegetable intake via liquifying these foods. It should be noted, however, that the process of juicing extracts the fiber content that lives in the pulp of the food, leaving only the pure sugar behind. If you find drinking your fruits/vegetables the best way to get your fix, then consider making smoothies instead, in an effort to preserve that all-important fiber.

Until next week,