Fiber: The Carb with Many Health Benefits

Over the years, carbohydrates have gotten a bad reputation as low-carb diets like Atkins and ketogenic diets gained more popularity. However, most people would read headlines like “Sugar Is Bad for You” without understanding one important fact — not all sugars are created equally.

The main types of carbohydrates (sugars)

There are three essential macronutrients: carbohydrates (sugars), proteins, and fats. Carbohydrates are naturally found in many foods, including grains, legumes, vegetables, and fruits, and come in various forms.

Simple sugars (simple carbs), starches, and fiber are the most abundant carbohydrates.

Simple carbs (sugars)

Simple carbs (sugars) spike blood sugar levels. Although some simple sugars occur naturally in food like milk or fruits, most of the simple carbs in Western diets are added to foods. For example, cookies and pastries, sodas, and fruit juice concentrate all include sugar, high fructose corn syrup, glucose, fructose, sucrose, and fruit concentrates. Anyone wanting to manage or prevent diabetes should limit simple sugars. Too many simple carbs contribute to weight gain and increase the risk of heart disease and high cholesterol levels.

Starches are complex carbohydrates

Beans, legumes, fruits, whole grains, and starchy vegetables like peas and sweet potatoes provide an abundance of starch and complex carbs. Unlike simple sugars, starches take longer to break down and do not spike blood sugar levels. Therefore, starches are part of a healthy diet when consumed in moderation — like a half cup of cooked beans or a slice of whole grain bread with a meal.

Fiber is a complex carbohydrate found in beans, nuts, seeds, whole grains, and vegetables. However, it does not metabolize like sugar. The body can’t break down fiber. Fiber passes through the digestive tract and provides several health benefits. Unfortunately, most Americans consume less than half of the recommended levels of dietary fiber daily — about 14 g/1000 kcal (which means about 25-30 grams daily for adults)

Types of fiber

Fiber is broadly classified as soluble or insoluble.

Soluble fiber

Soluble fiber dissolves in water and is best known for supporting healthy glucose and cholesterol levels. Oatmeal, chia seeds, nuts, beans, lentils, apples, and berries are all good sources of soluble fiber. Examples of soluble fiber include beta-glucans, guar gum, Inulin, oligofructose, oligosaccharides, fructooligosaccharides, and pectins. Resistant starches found in legumes, unripe bananas, cooked and cooled pasta and potatoes are also soluble fibers.

Insoluble fiber

Insoluble fiber does not dissolve in water but prevents constipation by promoting regularity. Examples of insoluble fibers include cellulose, hemicellulose, and lignin. Wheat bran, brown rice, quinoa, legumes, leafy greens, nuts and seeds, and fruits with skin (i.e., apples, pears) are rich in insoluble fibers.

Fiber’s many benefits

Cardiovascular health

Cardiovascular diseases like angina, heart attacks, strokes, and high blood pressure affect more than 80 million Americans and are a leading cause of death. Yet, heart diseases can be prevented, as an estimated 60% of the cases are attributed to dietary factors. High consumption of dietary fiber is associated with a significantly decreased risk of heart disease, high blood pressure, and stroke. Psyllium and oat β-glucan are the most common sources of soluble fiber, and FDA-approved health claims that these fibers protect against cardiovascular disease.

Diabetes prevention

Diabetes prevention and management. Eating healthy amounts of fiber helps reduce the risk of diabetes. Fiber improves insulin sensitivity and can prevent the development of diabetes in prediabetics. In one randomized controlled study, the participants with the highest fiber consumption levels witnessed a 62% decrease in the progression of diabetes compared with those who consumed less fiber. Diabetics consuming enough fiber are more likely to have better glycemic control and often reduce the need for diabetes medication.

Fiber improves cholesterol levels. Fiber’s benefits for improving blood cholesterol levels have been researched for decades. Soluble fibers are particularly beneficial. They lower blood cholesterol and LDL cholesterol by binding bile acids in the small intestine and promoting their elimination. Fiber also ferments in the large intestine, producing short-chain fatty acids, which contribute to healthy cholesterol levels.

Additionally, fiber promotes a healthy weight. Studies show that eating high amounts of fiber helps reduce the risk of weight gain or developing obesity by 30%. Fiber creates a sense of fullness and increases the gut hormones that promote satiety.

Furthermore, fiber aids in digestion and helps prevent or manage digestive conditions. High-fiber foods take longer to eat and, thus, people feel full for longer. Soluble fiber slows the transit of food through the digestive tract, improving the absorption of nutrients. In the colon, some fibers act as prebiotics, feeding the friendly bacteria — or probiotics. Based on research studies, high consumption of dietary fiber reduces the risk of acid reflux, hiatal hernia, peptic ulcer, gallbladder disease, appendicitis, esophageal and stomach cancers, constipation, and hemorrhoids. Some studies suggest that fiber may also reduce the risk of colon cancer. When it comes to irritable bowel syndrome (IBS), some fiber like, psyllium and methylcellulose, helps alleviate the symptoms, while wheat bran fiber may aggravate them.

Not all carbs are created equally. Fibers are healthy carbs. From lowering the risk of heart disease and diabetes to promoting optimal weight and digestion, there are plenty of reasons for consuming fiber regularly. The recommended daily intake is about 25-30 grams daily.

Tips for adding more fiber to your diet

Make sure to add more plant foods like fresh fruits and vegetables, cooked or canned beans, grains, nuts, and seeds to your diet.

Replace fruit juices with whole fruits and refined grains, like white rice and bread, with brown rice and whole grains.

Add high-fiber foods to meals. For example, add a couple of tablespoons of almonds, ground flaxseeds, or chia seeds to your bowl of oats or salads.

Although most fiber should be obtained from the diet, supplements can also be used to achieve the daily recommended 25-30 grams. Psyllium and methylcellulose are some of the most popular fiber supplements.

Increase the amount of daily fiber intake slowly to prevent gas and bloating. Also, drink plenty of water when consuming fiber supplements.