What’s the deal with fiber?

By Rheanna Smith, Peer Nutrition Counselor

Dietary fiber is one of the most underrated nutrients. Other nutrients like Vitamin C and Iron tend to get a lot more attention in the media but no one seems to talk about fiber! Dietary fiber consists of all indigestible plant materials consumed in the diet, classified as either soluble or insoluble fiber. While it may not be digested by us fiber is still an essential nutrient that you need to consume every single day!

Let’s break down the top three reasons that dietary fiber is essential for overall health:

• Fiber helps regulate cholesterol levels in the body.

Have you ever wondered why Cheerios says “heart healthy, lowers cholesterol” on every cereal box? That claim is made because Cheerios are a good source of dietary fiber! Here’s how it works: bile is produced by the liver to assist in breaking down food within the digestive tract, specifically emulsifying fats, and interestingly enough, bile happens to be very close to cholesterol in molecular structure. In fact the liver uses cholesterol as a building block for bile production! So where does fiber come in? Dietary fiber effectively decreases overall cholesterol levels because it binds to bile which is then excreted with your next bowel movement. This requires the liver to manufacture more bile and it does so by pulling cholesterol from the bloodstream in order to convert it into bile. Therefore the more dietary fiber you eat the more regulated your cholesterol levels will be!

• Fiber plays an important role in digestive health.

This reason may be a little more obvious to some, but nonetheless is still a very valuable reason to include dietary fiber in your daily diet. Fiber adds bulk to stools and keeps digestive motility up. The intestines use what is referred to as peristalsis, wavelike muscular contractions, in order to move food throughout the digestive tract. Without proper force applied to the intestinal wall these muscular contractions can be much harder on the body. Fiber adds bulkiness to stools which allows for smooth and effective peristaltic movement. Lack of fiber in the diet can also lead to digestive diseases such as Diverticulosis, in which inflamed bulging pouches referred to as diverticula form around the intestinal wall due to build up of waste on sensitive parts of the intestinal wall or due to pressure caused with constipation – both of which can be avoided with adequate fiber intake!

• Fiber feeds beneficial microbes within the gut.

While fiber may be undigestible to us, that doesn’t mean it isn’t being broken down at all. Within our digestive tracts there are a plethora of microorganisms, many of which are beneficial to our health and recent research has found correlations between high fiber diets and higher levels of beneficial bacteria in the gut. So what’s the benefit to that? Fiber feeds bacteria in my gut? Not too sure how to feel about that, well here’s where it gets interesting! When these microbes break down the fiber they convert it into short chain fatty acids (SCFA) such as acetate and butyrate. These SCFA have shown to help nourish our colon cells and provide anti-inflammatory effects that protects the colon from disease onset. Some studies have even shown that SCFA help reduce glucose and cholesterol levels in the blood which can help protect against metabolic diseases such as obesity!

Now that you know the three main reasons why dietary fiber is important for your health here are some tips on how to increase your daily fiber intake!

• Switch out white bread for whole grain bread
• Have a bowl of oatmeal instead of cereal in the morning
• Eat a whole piece of fruit instead of drinking juice
• Snack on nuts and seeds
• Add vegetables to canned soup or ramen noodles
• Opt for brown rice instead of white rice
• Don’t peel potatoes
• Eat the skins of fruits
• Incorporate more lentils and beans into meals
• Add berries to yogurt

Sources:

Brown, et al. “Cholesterol-Lowering Effects of Dietary Fiber: a Meta-Analysis.” OUP Academic, Oxford University Press, 1 Jan. 1999, academic.oup.com/ajcn/article/69/1/30/4694117.

Campbell, Kristina, et al. “Breaking It down: Short-Chain Fatty Acids and Your Health.” Gut Microbiota for Health, 3 Apr. 2017, http://www.gutmicrobiotaforhealth.com/en/breaking-short-chain-fatty-acids-health/.

“Diverticulitis Diet: A List of Foods to Avoid.” Healthline, Healthline Media, http://www.healthline.com/health/diverticulitis-diet-list-of-foods-to-avoid.