For the Love of Fiber
What if I told you there is a food that can help improve skin health, balance hormones, aid detoxification, prevent obesity, heart disease, diabetes, and colon cancer? Then if I told you it’s very easy to find and affordable on any budget, would you start to include more if it in your diet today? I hope so!
I’m happy to report that dietary fiber is the “magic” ingredient that can contribute to all these health benefits.
Following is information presented in a handout I developed for my patients. This guide will inform you about types of dietary fiber, food sources, and health benefits of each fiber type.
Personal dietary fiber needs and tolerance vary, so it’s important to have a conversation with your physician before substantially changing your intake of fiber. Some folks with gut dysfunction conditions like IBS and SIBO, or those with stringent fluid restrictions will not tolerate increased fiber and other treatments may need to be considered.
Dietary fibers work to protect our bodies against:
- Digestive System Diseases:
- diverticulosis, diverticulitis
- colon cancer
- ulcerative colitis, irritable bowel syndrome, Crohn’s disease
- appendicitis
- kidney stones, gallstones
- dental caries (cavities)
- Metabolic Diseases:
- obesity
- diabetes mellitus
- gout
- Cardiovascular Diseases:
- hemorrhoids, varicose veins
- cerebrovascular disease
- hypertension
- pulmonary embolism
- ischemic heart disease
- Dermatological (skin) Conditions
- Autoimmune Diseases
- Hormone Imbalances
Categories of fiber:
- Soluble –
- reduce blood sugar levels
- reduce blood cholesterol and other lipid levels
- bind hormones for elimination
- Insoluble –
- require more chewing, which causes more production of saliva = better digestion and protection for tooth enamel
- Fermentable –
- more slowly fermentable fibers feed beneficial gut bacteria
- beneficial gut bacteria play many important roles in our health, one of which is to increase bulk and soften stool so wastes can be more rapidly eliminated
- more rapidly fermentable fibers support production of short chain fatty acids (acetic, butyric, and propionic acids) which feed the cells of the large intestine/colon
- propionic acid also lowers the body’s production of cholesterol
- more slowly fermentable fibers feed beneficial gut bacteria
- Non-fermentable – increase bulk and soften stool, leading to more rapid elimination of wastes
Types of dietary fiber:
- Cellulose
- Hemicellulose
- Mucilage
- Pectin
- Inulin
- Lignin
- Algal polysaccharides
Sorted By Benefit:
- Bind hormones for elimination (for hormone balance): Mucilage, Pectin, Algal polysaccharides, Hemicellulose, and Inulin
- Delay glucose absorption (improve blood sugar and insulin control): Mucilage and Pectin
- Lower cholesterol in bloodstream: Mucilage, Pectin, Hemicellulose, Inulin, and Lignin
- Chelate heavy metals: Mucilage, Pectin, and Algal polysaccharides
- Laxative/Prevent constipation: Algal polysaccharides, Hemicellulose, Cellulose, and Lignin
- Substrate for bacteria to produce SCFAs (feeds intestinal cells): Hemicellulose, Cellulose, Inulin
- Delay stomach emptying time (feel full longer): Mucilage and Algal polysaccharides
- Decrease absorption of fat from foods eaten: Mucilage and Pectin
- Antioxidant: Lignin
- Anti-cancer: Lignin
Because these are contained in different types of foods, eating a variety of foods every day to get all the beneficial fibers is preferred over supplements alone.
Furthermore, studies of the benefits of fiber have been largely done using whole foods. Nutrition researchers note that it’s difficult to separate out the effect of fiber per se from the effect of the high fiber food.
Specifics of each fiber type:
- Mucilage
- Categories: soluble, rapidly fermentable
- Main area of action: Small Intestine
- Benefits:
- decrease absorption of fat from foods eaten
- delay glucose absorption (reduces blood sugar spikes and improves insulin function)
- lower cholesterol in bloodstream
- delay stomach emptying time (feel full longer)
- chelate heavy metals
- Sources include:
- chia seeds, flax seeds, psyllium seeds, guar
- slippery elm bark powder, marshmallow root powder
- legumes: beans, peas, lentils, peanuts
- Pectin
- Categories: soluble, rapidly fermentable
- Main area of action: Small Intestine
- Benefits:
- decrease absorption of fat from foods eaten
- delay glucose absorption (reduces blood sugar spikes and improves insulin function)
- lower cholesterol in bloodstream
- chelate heavy metals
- Sources include:
- apples, strawberries, apricots, cherries, plums (prunes)
- citrus rinds
- cabbage, cauliflower
- dried peas
- green beans
- carrots, potatoes
- squash
- Algal polysaccharides
- Categories: soluble, rapidly fermentable
- Main area of action: Small Intestine
- Benefits:
- laxative
- delay stomach emptying time (feel full longer)
- chelate heavy metals
- Sources include:
- algin/alginate
- seaweeds: agar, arame, carageenan, dulse, hijiki, kelp, kombu, nori, spirulina, etc.
- Hemicelluloses
- Categories: some are insoluble, some soluble; moderately fermentable
- Main areas of action: Small Intestine and Large Intestine/Colon
- Benefits:
- increase size/bulk of stool
- important substrate for bacteria to produce short chain fatty acids (preferred food source of the intestinal cells)
- bind bile acids (lowers cholesterol in bloodstream)
- Sources include:
- chia seeds, flax seeds
- whole grains, oat bran
- Brussels sprouts
- mustard greens
- beet roots
- Inulin
- Categories: soluble, fermentable
- Main area of action: Large Intestine/Colon
- Benefits:
- important substrate for bacteria to produce short chain fatty acids (preferred food source of the intestinal cells)
- Sources include:
- artichokes, asparagus
- leeks, garlic, onions
- jicama
- chicory root, dandelion root
- bananas
- Cellulose
- Categories: insoluble; non-fermentable in grains, moderately fermentable in legumes
- Main area of action: Large Intestine/Colon
- Benefits:
- ensure proper function of the colon/large intestine by
- absorbing water, increasing size/bulk of stool
- decreasing transit time (faster elimination of wastes)
- helping prevent constipation
- important substrate for bacteria to produce short chain fatty acids (preferred food source of the intestinal cells)
- Sources include:
- chia seeds, flax seeds
- whole grains, bran (from rice, oat, corn, or wheat)
- cell walls of plants, such as:
- legumes: beans, peas, lentils, peanuts
- cabbage
- young peas, green beans, wax beans
- broccoli, Brussels sprouts
- cucumber skins
- peppers
- carrots
- apples
- Lignin
- Category: insoluble, non-fermentable
- Main area of action: Large Intestine/Colon
- Benefits:
- bind bile acids (lowers cholesterol in bloodstream)
- decrease transit time
- antioxidant
- anticarcinogenic (anti-cancer)
- Sources include:
- chia seeds, flax seeds
- whole grains, bran (from rice, oat, corn, or wheat)
- older vegetables
- apples, pears
- strawberries (fruits with edible seeds)
- cabbage
- eggplant
- green beans
- radishes
Intake Goals: (these are generalized goals – ask your doctor for your individual needs)
Women: 30g per day
Men: 40g per day
To lower high cholesterol/triglycerides: 50g per day
Examples of dietary sources (highest to lowest fiber per serving):
| Whole oats, raw | 8.5 g | per ½ cup |
| Kidney beans | 8 g | per ½ cup |
| Pinto or black beans | 7.5 g | per ½ cup |
| Chickpeas or hummus | 6 g | per ½ cup |
| Edamame or peas | 4 g | per ½ cup |
| Pita, whole wheat, 6½” | 5 g | each |
| Quinoa, cooked | 5 g | per 1 cup |
| Brown rice, cooked | 4 g | per 1 cup |
| Oat bran | 4 g | per 1 oz. |
| Peanuts | 2 g | per 1 oz. |
| Almond butter | 2 g | per 2 Tbs. |
| Green beans | 4 g | per 1 cup |
| Okra, sliced | 2 g | per ½ cup |
| Marinara sauce | 3.5 g | per ½ cup |
| Asparagus | 3 g | per 1 cup |
| Eggplant, cooked | 2 g | per 1 cup |
| Beet, cooked | 2 g | per ½ cup |
| Carrot, chopped | 2 g | per ½ cup |
| Romaine lettuce | 2 g | per 1 cup |
| Kale, raw, chopped | 2 g | per 1 cup |
| Celery, chopped | 2 g | per ½ cup |
| Tomato, 2½” diameter | 1 g | each |
| Asian pear | 4 g | each |
| Apple, 3” diameter | 4 g | each |
| Blueberries | 2 g | per ½ cup |
| Raisins | 1 g | per 1 oz |
Example meals:
| Breakfast | |
| ½ cup oats (~1 cup cooked) with ½ cup blueberries | 10.5 g |
| 1 3” apple or Asian pear with 2 Tbs almond butter and 1 oz. raisins | 7 g |
| Lunch | |
| 1 cup quinoa with 1 cup asparagus and 1 cup kale | 9 g |
| 1 6½” whole wheat pita with ½ cup hummus | 11 g |
| Dinner | |
| Salad: 1 cup romaine, 1 2½” tomato, ½ cup each: carrots, celery, beets | 7 g |
| 1 cup brown rice with ½ cup black beans | 11.5 g |
| Total for the day | 46 g |
*Tip* If you eat like the average American, you probably get 12-16 grams or less of fiber per day. When increasing your intake, go slowly; add no more than 5 grams fermentable fiber per day. This will help you avoid the discomfort of increased gas production that can result from your newly well-fed gut bacteria fermenting a lot of extra fiber.
