High fiber foods: The good and the bad

I previously discussed the glycemic index and disease, namely metabolic syndrome, (insulin resistance) and obesity, and other chronic diseases.

Before reading and concerning yourself with which vegetables or fruits have high carbohydrate amounts (since I have been hammering the concept that excessive sugars are harmful to health), please remember this: complex carbohydrates, which from whole-food sources, are complexed with dietary fibers (starch, cellulose, lignans, etc.), which create health in the body.

Now let’s look at the powerful health benefits of high fiber food and which ones you’ll want to be wary of.

Fiber: What kinds and in what foods

If you’re like me, soluble versus insoluble fiber (and the foods containing each) can be a bit confusing. However, let me explain the general differences. Good effects of soluble fiber are that it:

• Binds fat in the intestinal tract, thereby lowering cholesterol
• Prolongs (slows) stomach emptying time so that sugar is absorbed more slowly into the bloodstream
• Normalizes insulin surges, therefore lowering the tendency toward metabolic syndrome and diabetes

Soluble fiber is found predominately in fruit (e.g. strawberries, apples, pears, oranges, lemons) and most non-starchy vegetables. It is also found in grains, nuts, seeds, beans, and lentils.

Insoluble fiber is a bit different. Insoluble fiber doesn’t become absorbed easily, so it cleans out the intestinal system by moving stool on through. In this way, it also balances intestinal pH so that healthy organisms are maintained there. Insoluble fiber is highest, starchy and leafy vegetables, and whole grains. Foods high in fiber will generally have some of both fiber types.

Fiber: How much for disease prevention

While it is estimated that on average Americans eats 13 grams (for women) to 17 grams (for men) of fiber daily, the U.S. Government recommends from 28 (for women) to 38 grams (for men).

If you are reading this, then you know that for real health changes to occur, your daily fiber intake must be much higher. Leading experts on health (me included) recommend 75 or more grams of dietary fiber daily to reverse or prevent disease. That could equal as few as nine large total daily fiber food servings.

Let’s look at some of the higher fiber foods and you can do the math:

FOOD                                             GRAMS

Fruits

Honeydew melon 1 cup (pieces)                    1.0

Peach 1 medium                                             1.7

Pineapple 1 cup (pieces)                                2.0

Orange 1, medium                                          3.0

Apple with skin                                                3.3

Pear 1, medium                                              4.0

Vegetables

Brussels sprouts, 1/2 cup                               2

Spinach, 1/2 cup                                             2.2

Carrot, 1/2 cup                                                2.3

Broccoli, 1/2 cup                                             2.6

Potato, baked w/ skin 1 medium                    5.0

Winter squash, 1 cup                                      5.7

Whole-grain products

White rice 1 cup                                              1

Oatmeal, 3/4 cup                                            3

Brown rice, 1 cup                                            3.5

Spaghetti, whole wheat 1 cup                        6.3

Quaker Shredded Wheat 3 biscuits               7

All-Bran, Kellogg’s ½ cup                              10

Beans, peas and other legumes

Kidney beans, 1/2 cup                                    5.7

Baked beans, 1/2 cup                                     6.3

Black beans boiled, 1/2 cup                           7.5

Nuts and seeds

Split peas/lentils boiled, 1 cup                        16

Chia seeds, 1 ounce                                       10

Almonds, 1 ounce (23 nuts)                             3

Pistachios, 1 ounce (49 nuts)                           3

Sunflower kernels, 1 ounce                              3

Let me add that this is not the case with fiber supplements such as psyllium of Metamucil, Citrucel, and Fibercon, etc. These insoluble fiber supplements treat constipation well but are devoid of almost all nutrients.

Related: How the food industry fools you into settling for fake fiber

High fiber food–claims to fame

It has been proven that high fiber foods have the following health benefits:

• Normalizes bowel movements; increases weight/size and softens stool. Also, if you have loose or watery stools, it bulks stool as it absorbs water.
• Reduces hemorrhoids by reducing the need for straining.
• Treats ulcerative colitis.
• Reduces IBS symptoms.
• Lowers your risk of colorectal cancer.
• Lowers cholesterol levels (soluble fiber found in beans, oats, flaxseed, oat bran).
• Lowers your heart disease risk significantly.
• Reduces stroke risk: It has been estimated by researchers that for every 7 grams more fiber you consume daily you reduce your stroke risk 7 percent.
• Helps control blood sugar levels in people with diabetes (slows sugar absorption).
• Reduces excess body: Fiber-rich foods are more filling, take longer to eat, and have fewer calories for the same volume of food.
• Improves rashes: Psyllium husk helps move yeast and fungus out of your body, thought to trigger the skin reaction of acne or rashes.
• Reduces the risk of gallstones and kidney stones.

Fiber from grains may make you sicker

Contrary to what you’ll read on Mayo Clinic websites, grains may not be a good source of fiber for everyone.

That’s because not only are grains relatively poor in vitamin and mineral content compared to fruits and vegetables (and even compared to meat and fish), they contain what some call “anti-nutrient” substances such as gluten and lectins.

These proteins are well known to be responsible for immune hypersensitivity through the mechanism of increased intestinal permeability (aka leaky gut syndrome). Gluten and lectins are known to cause fatigue, skin rashes, arthritic pain, allergies, autism, psychological symptoms, and more — and removal of grains often reverses these conditions.

Moreover, high fiber foods could make you feel worse at first. This happens if your gut is filled with yeast and fungi, or overloaded with the gas-producing bacteria. In this case, high fiber in your diet can actually worsen your intestinal symptoms as pathogenic organisms will feed on fiber and proliferate.

For example, the Gut and Psychology Syndrome (GAPS) diet calls for carefully eliminating fiber for a period of time to starve out pathogens by implementing probiotic-rich fermented vegetables and soups, along with well-cooked, peeled and de-seeded vegetables (e.g. zucchinis and squash).

I am also curious as to how high fiber food heals intestinal diseases such as ulcerative colitis, which I suffered with for many years and ultimately resulted in my total proctocolectomy surgery in 1997. Therefore, I’d like to share with you some very interesting studies about this in my next article.

To healing through foods and feeling good,

Michael Cutler, M.D.

Sources:

1.  Kanauchi O, Suga T, Tochihara M, et al. Treatment of ulcerative colitis by feeding with germinated barley foodstuff: first report of a multicenter open control trial — J Gastroenterol. 2002 Nov;37 Suppl 14:67-72. PubMed PMID: 12572869.
2. Kanauchi O, Iwanaga T, Mitsuyama K. Germinated barley foodstuff feeding. A novel neutraceutical therapeutic strategy for ulcerative colitis — Digestion. 2001;63 Suppl 1:60-7. PubMed PMID: 11173912.
3. Reynolds A, Mann J, Cummings J, Winter N, Mete E, Te Morenga L. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses — Lancet. 2019 Feb 2;393(10170):434-445. PubMed PMID: 30638909.
4. Dietary fiber: Essential for a healthy diet — Mayo Clinic
5. Gut and Psychology Syndrome by Dr. Natasha Campbell-McBride’s
6. https://www.med.umich.edu/mott/pdf/mott-fiber-chart.pdf
7. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/high-fiber-foods/art-20050948