Healthy "Artful Living" Moment #21: What's the Deal With Fiber?

Fiber has been discussed in previous blogs (for example, see Healthy Artful Living Moment #4 in which there is a discussion of fiber’s role in helping to prevent cancers and strokes and Healthy Artful Living Moment #5 which highlights fiber’s role in helping to avoid esophageal cancer).  Most people know that fiber is good for you and that we should consume more of it. This has led our enormous food industry to figure out how to add fiber to many processed foods. The best example of this trend may be the Smart Sweets Gummy Bears which promise 100% of a day’s suggested fiber consumption (28 grams minimum) in each serving.

Wow! All the fiber I need for a day in a gummy bear! Well, somewhere in the back of your mind you are probably thinking, “This is too good to be true.” And you are correct. Let’s take a closer look.

Fiber is a variety of nondigestible carbohydrates that are not broken down in the stomach or small intestine. Because they don’t break down fiber is often recommended for helping you to stay “regular” and avoiding constipation, helping you feel more “full” and reducing your appetite, and helping to keep your cholesterol and blood sugar levels healthy. But it turns out that there are a variety of processed fibers that are used in by these food companies, and different fibers help you manage different bodily functions. And under the current Food and Drug Administration rules, processed foods can count any type of fiber used in their products as “fiber” on the Nutrition Facts Label without regard to the specific type of fiber used, or its particular benefit.

So what are the different types of fibers used? Some fibers are soluble or non-soluble in water, some become viscous (i.e. thicken) in water and some don’t, and some are fermentable in the large intestine and some aren’t. Many processed fibers are soluble, non-viscous, and fermentable, and that combination may not be helpful for your health. Let’s see why.

Staying Regular

The best fiber for improving regularity is a fiber that increases stool mass and frequency, therefore the best fiber would be soluble, viscous, and nonfermentable so it retains moisture in the large bowl without breaking down (fermenting). Most processed fibers (like inulin, polydextrose and soluble corn fiber) are fermentable and won’t help you very much stay regular.

Feeling Full, Eating Less

Little evidence exists that processed fibers can help you control your appetite.

Lowering Cholesterol

Soluble, viscous, nonfermentable fibers (like psyllium and beta-glucan, a fiber in oats and barley) work best by absorbing water from partially digested food and creating a sludge-like mass that traps bile acids and eliminates them in the stool. The body uses cholesterol to make bile acids, so the more bile that you eliminate in your stool, the more cholesterol the body must use to make more, thus lowering the LDL cholesterol in your blood stream.

Controlling Blood Sugar

Soluble, viscous, nonfermentable fibers are desirable because the sludge-like mass slows down the absorption of nutrients and glucose into the blood stream, helping to maintain a more steady level of sugar in the blood.

So, this fiber thing is a lot more complicated than initially understood. And buying fiber-enhanced processed foods may not provide the health benefits that led you to purchase the items in the first place, because the fibers used don’t necessarily have the characteristics needed for health benefits. But there is a simple prescription for consuming the right kind of fiber for your various needs. And that is to consume more intact fiber, that is the fibers that are obtained from real fruits and vegetables rather than processed fibers made in a lab. Natural fruits and vegetables have the various types of fiber that your body needs. And there is no need to read a Nutrition Label!

Here are some intact fiber recommendations:

Bran cereals are a good source (6 to 13 grams per serving, depending upon the cereal)

Beans (black beans, lentils, pinto beans, chickpeas, kidney beans and split peas) are a good source (6 to 8 grams per serving)

Whole wheat pasta (5 to 6 grams)

Whole wheat bread (3 grams per slice)

Blackberries and raspberries (8 grams)

Broccoli and sweet potatoes (3 to 4 grams)

Almonds, pistachios and peanuts (2 to 4 grams)

There you have it. Try to get your fiber through consuming natural foods like these. Your body will ultimately thank you for it.