How Fiber Protects Us Against the Negative Health Effects of Sugar Consumption

How Fiber Protects Us Against the Negative Health Effects of Sugar Consumption

Fiber plays an important role in the digestion of our food and offers a myriad of health benefits. Its consumption has been shown to improve blood glucose levels, promote satiety, help to maintain weight, improve digestion, helps to normalize bowel habits, and even protect your heart.

Fiber is a type of complex carbohydrate found in fruits, vegetables, whole grains, and legumes. In contrast to sugar, these carbohydrates are neither digested nor absorbed by the gut, so they don’t contribute to calories or “total carbs.” 

There are two types of fiber: soluble and insoluble fiber. Soluble fiber, found in foods such as beans, Brussels sprouts, oats and apples, dissolves in water and slows digestion by creating a gel-like substance in your stomach. This gel slows the emptying from the stomach, as well as the digestion and absorption of sugar. Insoluble fiber, found in foods such as nuts, seeds, green beans and potatoes, does not dissolve in water so it moves through your digestion intact. Both types of fiber have unique benefits and are necessary for optimal health. 

When you consume foods that contain carbohydrates (aside from fiber), these carbohydrates are broken down into sugar molecules, which are rapidly absorbed in the first section of your small intestine and enter the bloodstream as glucose. Your pancreas then releases the hormone insulin to move glucose from the blood into your cells for use for energy. When consuming foods high in carbohydrates or sugars, fiber is exceptional at slowing the digestion of glucose to prevent blood sugar spikes. It also supports insulin sensitivity, which promotes a healthier insulin response and minimizes fat storage. 

The perfect example of the benefits of fiber when paired with sugar consumption is the example of whole fruit versus fruit juice. Consuming fruit in its whole form, such as an apple versus a glass of apple juice, includes the consumption of the fiber content found in fruit. Since apples contain soluble fiber, the fiber will help to slow digestion and prevent a blood sugar spike from the natural sugar molecules sucrose, fructose and glucose found in the apple.  The same is true about the sweet freshly squeezed orange juice which many people consider a healthy part of their breakfast.

When fruit is juiced, it is stripped of the fiber that helps to slow the absorption of sugar, consequently leading to a larger spike in blood sugar. A larger spike in blood sugar means your body will need to release more insulin to draw the glucose into your cells and triggering this pathway too frequently can lead to insulin resistance.  These glucose and insulin spikes occur with fruit juices in the same way as they are happening in response to sweetened sodas, and some reports suggest that they may even happen when drinking artificially sweetened drinks

A study found that “nearly 40 percent of young adults without diabetes experience insulin resistance.” Insulin resistance and blood sugar dysregulation impact a great deal of the population, which is believed to increase an individual’s risk of developing more serious medical issues including type 2 diabetes and cardiovascular disease.

Additionally, heightened blood sugar levels can increase the rate of aging, both physically and cognitively. Excess blood sugar may react with proteins to create advanced glycation end products which lead to brown “age spots” and the loss of elasticity of the skin. This glycation can cause negative cognitive effects as well including the destruction of nerve cells in the brain and the formulation of free radicals.

Making sure to include ample amounts of fiber (both soluble and insoluble) in your diet is one of the keys to optimal metabolic and cognitive health. Eating fruits and vegetables in their whole form, instead of juicing them, will keep the fiber intact. 

Similarly, try keeping the skin on your fruits and vegetables when you eat them. Kiwi, for example, is high in fiber and supports healthy digestion, however peeling the skin off removes a majority of its fiber content. Simply rinse the skin to remove any dirt and enjoy the kiwi whole (it may take some time to get used to the fuzzy skin). The same can be done with sweet potatoes, cucumbers, apples and most other produce. This way, you’ll be pairing the natural sugars and carbohydrates with the full amount of intended fiber to slow glucose absorption and minimize blood glucose levels.  And as an additional benefit, the skin of many fruits not only contains the highest amount of fiber, but the highest amounts of polyphenols as well!


Fiona Riddle is a Certified Health Coach with a degree in Psychology from UCLA. She is passionate about a holistic approach to health when working with her private coaching clients. She is an avid cook, constantly creating and sharing new recipes on her Instagram (@feelgoodwithfi) to showcase simple clean home cooking. She has helped clients take their health into their own hands and successfully boost their energy and confidence through sustainable lifestyle changes. www.feelgoodwithfi.com