October 26, 2023 general

Insoluble fiber is what grandma may have called “roughage” and promoted to keep the bowels regular. She was right about that, but there is more to the story—there are other factors affecting regularity (e.g. see the September 22^nd newsletter about constipation) and who knew that fiber is a PREbiotic (the probiotic bacteria in our gut can digest some of that fiber that we can’t and turn it into fatty acids that promote health of the lining of the digestive tract). Also, there is another important category of fiber, soluble fiber.

A primitive natural diet contains lots of fiber from vegetables, fruits, seeds, and whole grains. However, modern processing of foods often purposely removes the fiber. An example is when whole wheat flour is turned into white flour by removing the bran layer. Curiously, if a manufacturer (for marketing reasons) wants to increase the fiber amount on the nutrition facts panel, they can add powdered trees, corn husks or cotton. That powder is called Cellulose gum. It is also used as a thickener and stabilizer in many food products and beverages as well as in personal care products like shampoo and in some laundry detergents.

Cellulose gum does not have nutritional value but appears to be relatively safe. However, it isn’t a food, and the studies on its safety were mostly done on animals. Some people who eat a lot of foods containing that fiber experience gas and bloating. It can interfere with nutrient absorption and for some lead to forgetfulness, exhaustion, and headaches. Another issue is the company the gum keeps. I.e. the processed foods that use cellulose gum may have removed other natural nutrients from the product ingredients and typically add in food processing chemicals like colors, flavors, conditioners, and preservatives which may have sketchy health effects.

Real foods that are rich in insoluble fiber:

• Fruits (1 cup of raspberries contains 2.4 grams)
• Nuts (1 ounce of walnuts contains 2.5 Grams)
• Seeds (1/2 cup of cooked quinoa contains 2.5 grams)
• Vegetables (1 cup of cooked Kale contains 5.1 grams)
• Legumes (1/2 cup cooked lentils contains 3.8 grams)
• Whole grain foods (1 cup whole wheat pasta has 2.2 grams)

The recommended daily fiber intake for men is between 30 and 38 grams. For women, it’s between 21 and 25 grams. You can see that if you ate the foods in the example list above (18.5 grams total), you are well on your way. Note that: a serving (2) Twinkies contains zero fiber, beer has none, bacon has none, a small personal size bag of Cheese Doritos does have 1 gram and 1 cup of Kraft mac and cheese contains 2 grams (you’d get a lot more if you ate the box).

Next week, we’ll look at soluble fiber.