Does thinking about fiber conjure up images in your head of bran muffins and those thick fiber supplements you stir into a glass of water when you’re feeling “backed up”?
It’s not exactly the most exciting of topics, but it is an important one nonetheless. In fact, while you probably know that fiber is “good for you,” chances are you’re not really sure why – or, for that matter, how to take advantage of the simple steps to use fiber to your optimal health advantage.
What Exactly Is Fiber?
Fiber is the component of plant foods that your body can’t digest or absorb. It’s unique because other parts of the foods you eat, such as fats, protein and carbohydrates, are broken down and absorbed by your body. Fiber, on the other hand, passes through your digestive system relatively untouched.
There are two types of fiber, each with important benefits to your health:
1. Soluble Fiber
As the name implies, soluble fiber dissolves partially in water, ending up in a gel-like consistency that helps to slow your digestion. This can help you feel full longer, which may help with weight control. Soluble fiber is also known to be beneficial for diabetes, as it helps improve insulin sensitivity, and may make it harder for your body to absorb dietary cholesterol, which can help lower your LDL (bad) cholesterol levels.
Examples of soluble fiber foods include:
|Oat bran and Oatmeal||Strawberries||Nuts||Flaxseeds|
2. Insoluble Fiber
Insoluble fiber does not dissolve in water, making it useful for adding bulk to your stool and helping food pass more quickly through your digestive tract. This is beneficial not only if you’re struggling with constipation, but also for your gut health in general.
Examples of insoluble fiber foods include:
|Whole grains||Wheat bran||Seeds and nuts||Brown rice|
|Green beans||Dark leafy vegetables||Raisins and grapes||Fruit|
If you noticed some repeats on these lists, it’s because many foods, such as many fruits, beans and vegetables, contain both soluble and insoluble fibers, making them ideal fiber sources to try to add to your diet.
Did You Know Fiber Could Do THIS?
The benefits of fiber extend far beyond your digestive tract. In fact, fiber has been found to impact ALL of the following:1
- Heart Disease: People who eat a lot of dietary fiber have a lower risk of heart disease than those who do not (in one study, the risk was 40 percent lower among those eating a high-fiber diet2). A high fiber intake is also protective against metabolic syndrome, a cluster of symptoms (high blood pressure, high insulin levels, excess weight, high triglycerides and low levels of HDL (good) cholesterol), which increases your risk of heart disease and diabetes.3
- Type 2 Diabetes: Eating a diet high in fiber is beneficial for reducing your risk of diabetes. In fact, if you eat a low-fiber diet that’s also high in high-glycemic index foods (like white sugar and bread), it more than doubles your risk of developing diabetes, compared to those who eat a high-fiber diet that’s low in high-glycemic index foods.4 If you have diabetes, eating fifer can also help you to improve and control your blood sugar levels.
- Diverticulitis: Your risk of developing this condition, an inflammation of your intestine, may drop by about 40 percent if you eat a lot of dietary fiber, particularly insoluble fiber.5
- Weight: Foods high in fiber make you feel full and satisfied, even though they tend to be less calorie-dense than eating similar quantities of other foods. Including high-fiber foods in your diet is a simple “trick” to help keep your weight under control. In fact, among obese individuals, fiber supplementation has been shown to significantly enhance weight loss.6
In short, adding fiber-rich foods to your diet is one of the simplest ways to give your all-around health a major boost. Researchers noted:7
“Individuals with high intakes of dietary fiber appear to be at significantly lower risk for developing coronary heart disease, stroke, hypertension, diabetes, obesity, and certain gastrointestinal diseases. Increasing fiber intake lowers blood pressure and serum cholesterol levels. Increased intake of soluble fiber improves glycemia and insulin sensitivity in non-diabetic and diabetic individuals … Increased fiber intake benefits a number of gastrointestinal disorders including the following: gastroesophageal reflux disease, duodenal ulcer, diverticulitis, constipation, and hemorrhoids. Prebiotic fibers appear to enhance immune function.”
Why Fiber is Becoming “Controversial”
While the idea that fiber is an essential part of a healthy diet is quite engrained in modern nutritional advice and research, this is an area of growing controversy. There are some experts, such as advocates of the Paleo style of eating (which focuses on eating whole foods available to our ancient ancestors to eat right from an evolutionary standpoint), who believe too much dietary fiber may actually cause many of the health problems it is claimed to prevent.
And, indeed, there is some research showing, for instance, that excess fiber may increase your risk of diverticulosis,8 whereas certain high-fiber foods, such as grains, may worsen diabetes.
Much of the controversy surrounds the intake of excess low-quality sources of fiber, such as bread, pasta, cereals, and processed foods enhanced with “added fiber.” These should be only minimal sources of fiber in your diet.
On the other hand, eating whole foods that are naturally rich in fiber, including green leafy vegetables, carrots, berries, fruits with edible peels (apples, pears, etc.), nuts, and sweet potatoes, is very likely to not only enhance your fiber intake, but also boost your health.
1. Harvard School of Public Health, The Nutrition Source, Fiber: Start Roughing It!
2. JAMA. 1996 Feb 14;275(6):447-51.
3. Diabetes Care. 2004 Feb;27(2):538-46.
4. Am J Clin Nutr. 2004 Aug;80(2):348-56.
5. J Nutr. 1998 Apr;128(4):714-9.
6. Nutr Rev. 2009 Apr;67(4):188-205.
7. Nutr Rev. 2009 Apr;67(4):188-205.
8. Gastroenterology Volume 142, Issue 2, Pages 266-272.e1, February 2012