Is dietary fiber actually bad for you? When it comes to diet, many people are often too quick to label a specific food as “good” or “bad” for health. Aside from the obvious culprits of processed and refined flours, sugar, and trans fats, there are other seemingly beneficial foods and nutrients that can do damage in specific individuals.
One such food is fiber. Although there are countless research articles that tell us about all the benefits that fiber can have, such as decreasing the risk of diseases such as diabetes, heart disease, and cancer, for some people, fiber can create more of a problem than a solution.
The reality is that, whether dietary fiber is really beneficial or not depends on the individual and the status of their gut health.
Why Too Much Dietary Fiber Can Cause Issues:
1. Some Dietary Fiber Exacerbates SIBO and IBS
SIBO or Small Intestinal Bacterial Overgrowth is a condition in which gram-negative bacteria (which can exist happily in the large intestine) overgrow in the small intestine. This is a problem because these bacteria can damage the lining of the small intestine and lead to an array of digestive problems. Dr. Allison Seibecker, Naturopathic physician, acupuncturist, and SIBO specialist, claims that SIBO has been shown to exist in up to 84 percent of patients with IBS or Irritable Bowel Syndrome and is therefore theorized to be the underlying cause.
Symptoms of SIBO can include:
- Abdominal bloating (gas)
- Abdominal pain, cramps
- Constipation, Diarrhea, both
- Heartburn (Reflux or GERD)
Leaky Gut Symptoms
- Food Sensitivities
- Joint Pain
- Skin symptoms (such as eczema or rashes)
- Respiratory symptoms (such as asthma)
- Mood symptoms (such as depression)
- Brain symptoms (such as Autism)
- Steatorrhea (fatty stools)
- Anemia (Iron or B12)
- Weight Loss1
For SIBO sufferers, all fibers are not created equal. Specific fibers that are easily fermented and therefore feed the bacteria that cause SIBO, are eliminated in dietary protocols used to help treat SIBO. A variation of the SCD (Specific Carbohydrates Diet) and the Low FODMAP diet are used in integrative treatment of SIBO.
In this case, soluble fibers found in grains, beans, and nuts and seeds or prebiotics found in roots or herbs are eliminated in order to offer symptom relief. According to experts, SIBO is typically treated with diet and antibiotics or herbal antibiotics. Diet (free from fibers that cause IBS symptoms) is usually used in combination with antibiotics or one month after treatment of SIBO in order to allow the damaged small intestinal lining to heal.
2. The Wrong Kind of Dietary Fiber Can Cause Chronic Disease
For years, conventional wisdom has led us to believe that eating whole grains is the secret to a long, healthy life. However, if one were to choose whole grain oats or wheat over fruits and vegetables, he or she is actually choosing a nutritionally inferior food, which can also spike blood sugar levels and interfere with healthy insulin levels. Fruits and vegetables, on the other hand, are rich in phytochemicals that help the body in its detoxification processes and fight off free radicals.
3. Food Additives Derived From Fiber Can Damage the Gut
Food additives like guar gum, carageenan, and resistant starch are almost always included in foods like yogurt, sour cream, ice cream, soy milk, cakes, and snack bars. The food companies want you to believe that you are getting more fiber, but what you are really getting are cleverly disguised food additives that damage the lining of the gut.
In animal studies, animals given carraggeenan, a common food additive derived from seaweed and used as a thickener, in their feed developed ulcerations in the gut lining in as little as a month. Human studies showed that carraggeenan caused inflammation within the gut, which led to intestinal permeability or a leaky gut.2
4. Dietary Fiber Supplements Can Actually Worsen Problems Like Constipation
If you have an ongoing issue with not being able to go to the toilet, turning to a fiber supplement like Metamucil, may seem like the right thing to do. The main ingredient in Metamucil is psyllium, which is a bulk-forming laxative shown by studies to alleviate constipation.3 However, the truth is that supplements like Metamucil also contain additives that worsen digestive symptoms. One example is maltodextrin, which is a cheap filler in a lot of packaged foods. However, it can affect the gut microbiome negatively by suppressing the activity of good bacteria in the gut, further adding to the problem of constipation.
How to Choose Dietary Fiber that is Safe for Your Gut
If you have an Inflammatory Bowel Disease (Like IBS, Diverticulitis or Crohn’s), Leaky Gut or many of the digestive or immune symptoms mentioned above, you can turn to the following tips in order to get the right amount and right type of fiber in your diet:
- Choose dark leafy green vegetables like kale, spinach, and collard greens, carrots, broccoli, and beets instead of vegetables like potatoes, sweet potatoes, yams, and corn. The latter are not included in an SCD protocol.
- Choose fruits like berries, melon, citrus fruits like oranges or lemon, kiwi, pineapple, and pomegranate over fruits like peaches, pears and plums. The latter are high FODMAP foods.
- A more detailed list of the foods to include or avoid to help with IBS can be found here. It is a list developed by Dr. Allison Seibacker incorporating the SCD and low FODMAPS protocol.
- Nourish your intestinal lining with a grass-fed collagen supplement, a glutamine supplement, or home-made bone broth. Taking these supplements or drinking bone broth on a daily basis are definitely conducive to healing the intestinal tract.
- Be wary of probiotics before SIBO is treated. If you have SIBO, make sure to work with a health care professional knowledgeable in gut health to help you with when and how to use a probiotic. In some cases, it can exacerbate SIBO.
- If you know that you have an inflamed intestine caused from autoimmune conditions such as ulcerative colitis or Crohn’s disease, following the AIP diet can also help.
At the end of the day, a highly processed diet and the wrong kinds of fibers lend themselves to damaging the intestinal tract, which lead to malabsorption of nutrients and nutrient deficiencies. On the flip side, a damaged intestinal tract cannot tolerate soluble fibers and additives, leading to an increase in IBS symptoms. If anything, one should understand that all the information about the health benefits of fiber should be taken “with a grain of salt”. Ultimately, it is the health of your gut that will dictate how much and what kind of fiber you should include into your daily diet.
About Tina Christoudias, The Thyroid Dietician
Tina Christoudias is a Harvard-trained registered dietitian with nearly 18 years of experience as a nutrition counselor. Having had personal experience with hypothyroidism, she specializes in diet protocols for Hashimoto’s thyroiditis and hypothyroidism and has recently finished her book, Tired of Feeling Tired? She is a strong advocate of the Paleo diet and is currently getting certified as an autoimmune protocol certified practitioner.