If you are anything like me when I was when I was a kid, any mention of fiber sent me running for the hills. Upon hearing the word my brain would conjure up an image of a bowl of All-Bran cereal that looked as appetizing as a pile of twigs. This is a meal which seemed more fitting for a colony beaver pups than skinny, brown-eyed lass. As a seasoned adult, I now have a more informed opinion of dietary fiber. Through the years I have gleaned tidbits of information through investigation and experience which I wish to share with you today. I promised you in a blog post a few months back that I would highlight some of the wonderful benefits of fiber, and I aim to deliver.
Fiber is part of the complex carbohydrate macromolecule family. Carbohydrates are composed of sugar molecules (saccharides). Simple carbohydrates consist of single sugars (monosaccharides) and two sugar molecules linked together (disaccharides). Three to fifteen sugars linked together become oligosaccharides, whereas the term polysaccharide is typically applied to carbohydrates composed of more than 15 sugars. Oligosaccharides and polysaccharides are designated as complex carbohydrates.
Dietary fiber comes in two forms: soluble and insoluble. This basically means that one will dissolve in water and the other will not. Soluble fiber molecules have sugars that are linked in straight chains whereas insoluble fiber molecules have linkages that cause kinks or bends in the polysaccharide chain. These terms can be found on food nutrition labels. Having a better understanding of those terms will help you make more informed choices about what to eat.
Both types of fiber have important roles in promoting good health. Research studies indicate individuals who increased dietary fiber intake had more stable blood glucose and lower cholesterol levels at the end of the testing period. The health benefits of soluble fiber may come because it swells in the intestinal tract and slows the digestive process. As a result, carbohydrates are absorbed into the blood stream more slowly.
Insoluble fiber stays in the intestine, drawing water into the digestive tract, preventing constipation, and reducing the risk of developing diverticula. Insoluble fiber also helps the body eliminate toxic waste in the gastro-intestinal tract, reducing the risk colon cancer. Increasing dietary fiber intake also has even been shown to improve acid reflux symptoms.
Insoluble fiber is the main food source for fermenting bacteria in the colon. Lacto and bifido bacterial strains produce acetate, proprionate and butyrate from fiber. These are short chain fatty acids which are anti-inflammatory in nature and contribute to energy production and modulate metabolism. You may have heard some discussion around beta-hydroxybutyrate or (BHB) lately. The liver produces BHB from butyrate and influences fat burning, increasing weight loss.
These short chain fatty acids can then be converted into ketone bodies and feed the brain or other cells and can be used by the mitochondria to produce ATP. The cells of the small intestine use them to make the mucosal membrane that protects you from harmful substances in the food you eat. In short, dietary fiber can do a lot more than just keep you regular.
What are the best sources of dietary fiber you ask? There are many more options than just prune juice. Fruits such as apples, oranges, raspberries and dates. Dates have more fiber content when compared to most fruits and have a much lower glycemic index. If you are trying to eat a low carbohydrate diet, here is a list of ketogenic friendly food that contain fiber: nuts, avocado, coconut, collard greens, kale, chia seeds, flax seed, cauliflower, and cabbage.
The recommended daily intake of dietary fiber for all adults is 25 to 30 grams. If eating dietary fiber causes gut irritability, bloating or gas, then you most likely have microbiome imbalance. You should get a comprehensive stool analysis to determine what protocol is needed to remedy your unique situation. We have now come to the end of my short treatise on dietary fiber and neither of us has run for the hills. We have remained for the entire discussion as mature adults. I hope you have found it informative and enlightening. I encourage you to try out just one new fiber-rich food you had not thought about previously. Your brain, metabolism, heart, and gastro-intestinal tract will thank you.
Yours in Health,
Biochemist and Certified Health Coach