Fiber 101
Fiber is a type of carbohydrate found in plant foods.
Found mostly in fruits, vegetables, legumes, grains, and nuts, fiber’s calorie amount varies depending on the source. Unlike other types of carbohydrates, fiber isn’t digested in the small intestine. So, while the carbs in dairy desserts and sugar-sweetened beverages are broken down into simple sugars and then absorbed in the small intestine, fiber has two routes: fermented by bacteria in the large intestine or not fermented at all. This is due to the two different types of fiber: soluble and insoluble. Both types provide different benefits for our GI tract.
References:
[1] Nutrition facts label: Dietary fiber. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/InteractiveNutritionFactsLabel/#intro. Accessed Oct. 1, 2018.
[2] Lattimer, James M, and Mark D Haub. “Effects of dietary fiber and its components on metabolic health.” Nutrients vol. 2,12 (2010): 1266-89. doi:10.3390/nu2121266
Found mostly in fruits, vegetables, legumes, grains, and nuts, fiber’s calorie amount varies depending on the source. Unlike other types of carbohydrates, fiber isn’t digested in the small intestine. So, while the carbs in dairy desserts and sugar-sweetened beverages are broken down into simple sugars and then absorbed in the small intestine, fiber has two routes: fermented by bacteria in the large intestine or not fermented at all. This is due to the two different types of fiber: soluble and insoluble. Both types provide different benefits for our GI tract.
References:
[1] Nutrition facts label: Dietary fiber. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/InteractiveNutritionFactsLabel/#intro. Accessed Oct. 1, 2018.
[2] Lattimer, James M, and Mark D Haub. “Effects of dietary fiber and its components on metabolic health.” Nutrients vol. 2,12 (2010): 1266-89. doi:10.3390/nu2121266
There are two types of fiber: soluble and insoluble.
Soluble fiber is fermented by bacteria in the large intestine and, as its name suggests, is water-soluble. This means that it interacts with water in our GI tract, forming a gel-like substance. Once this gel is formed, soluble fiber provides many benefits, for example:
Insoluble fiber is not fermented by bacteria in the large intestine and it isn’t water-soluble. It travels through the gastrointestinal tract fairly intact. Although it doesn’t enrich the microbes in the GI tract like soluble fiber does, unfermented insoluble fiber can: add substance/bulk to the stool and assist movement of food down the digestive system, promoting bowel movements.
Examples of foods containing insoluble fiber:
Note: most plant foods contain both soluble and insoluble fiber, but in varying amounts.
References:
[1] Nutrition facts label: Dietary fiber. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/InteractiveNutritionFactsLabel/#intro. Accessed Oct. 1, 2018.
[2] Lattimer, James M, and Mark D Haub. “Effects of dietary fiber and its components on metabolic health.” Nutrients vol. 2,12 (2010): 1266-89. doi:10.3390/nu2121266
Soluble fiber is fermented by bacteria in the large intestine and, as its name suggests, is water-soluble. This means that it interacts with water in our GI tract, forming a gel-like substance. Once this gel is formed, soluble fiber provides many benefits, for example:
- - oatmeal
- - beans (kidney, pinto/black, soy)
- - peas (split, green)
- - apples
- - citrus fruits (orange)
Insoluble fiber is not fermented by bacteria in the large intestine and it isn’t water-soluble. It travels through the gastrointestinal tract fairly intact. Although it doesn’t enrich the microbes in the GI tract like soluble fiber does, unfermented insoluble fiber can: add substance/bulk to the stool and assist movement of food down the digestive system, promoting bowel movements.
Examples of foods containing insoluble fiber:
- - whole wheat products (cereals, bread, pasta, crackers)
- - green beans
- - potatoes
- - nuts (almonds, pistachios, pine)
- - seeds (chia, flax, psyllium)
Note: most plant foods contain both soluble and insoluble fiber, but in varying amounts.
References:
[1] Nutrition facts label: Dietary fiber. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/InteractiveNutritionFactsLabel/#intro. Accessed Oct. 1, 2018.
[2] Lattimer, James M, and Mark D Haub. “Effects of dietary fiber and its components on metabolic health.” Nutrients vol. 2,12 (2010): 1266-89. doi:10.3390/nu2121266
A major benefit of fiber intake is its effect on the gut microbiome.
The gut microbiome is made up of microbes in our gastrointestinal tract. Its involvement in “human metabolism, nutrition, physiology, and immune function” makes the microbiome’s wellbeing an integral role in overall health and disease prevention [3].
To create a healthy microbiome profile, we need dietary fiber. With fiber, we can “increase the potentially beneficial bacterial genomes” and enrich the microbiome [4]. A flourishing microbiome can greatly improve our gut health (i.e. digestion, absorption, disease prevention).
References:
[3] Bull, Matthew J, and Nigel T Plummer. “Part 1: The Human Gut Microbiome in Health and Disease.” Integrative medicine (Encinitas, Calif.) vol. 13,6 (2014): 17-22.
[4] Filippo, Carlotta De, et al. “Impact of Diet in Shaping Gut Microbiota Revealed by a Comparative Study in Children from Europe and Rural Africa.” PNAS, National Academy of Sciences, 17 Aug. 2010, https://www.pnas.org/content/107/33/14691.
The gut microbiome is made up of microbes in our gastrointestinal tract. Its involvement in “human metabolism, nutrition, physiology, and immune function” makes the microbiome’s wellbeing an integral role in overall health and disease prevention [3].
To create a healthy microbiome profile, we need dietary fiber. With fiber, we can “increase the potentially beneficial bacterial genomes” and enrich the microbiome [4]. A flourishing microbiome can greatly improve our gut health (i.e. digestion, absorption, disease prevention).
References:
[3] Bull, Matthew J, and Nigel T Plummer. “Part 1: The Human Gut Microbiome in Health and Disease.” Integrative medicine (Encinitas, Calif.) vol. 13,6 (2014): 17-22.
[4] Filippo, Carlotta De, et al. “Impact of Diet in Shaping Gut Microbiota Revealed by a Comparative Study in Children from Europe and Rural Africa.” PNAS, National Academy of Sciences, 17 Aug. 2010, https://www.pnas.org/content/107/33/14691.
Adequate fiber intake can help prevent:
Diabetes [2]
Slow-digesting carbohydrates, which is dietary soluble fiber, can control blood glucose. Thus, improved dietary fiber intake has been related to a decreased risk of diabetes.
Constipation [1,2,5]
The two go-to nutrition interventions for constipation are: sufficient fluid intake and a high-fiber diet. (5) While fluids help soften the stool for passing, both soluble and insoluble fiber diets add bulk to the stool and promote bowel movements [1,2]. Thus, fiber prevents and relieves constipation.
Cardiovascular diseases [6,7,8,28,43,44]
Heart disease is the leading cause of death in the United States [28]. Thus, the benefit of soluble fiber on preventing cardiovascular diseases is extremely noteworthy: Soluble fiber is broken down in the large intestine (not small intestine) and produces short-chain fatty acids (SCFA’s). Among these SCFA’s are acetate, which promotes cholesterol synthesis, and propionate, which inhibits cholesterol synthesis. If we could “decrease the acetate:propionate ratio… [we] may reduce serum lipids” [6]. Therefore, a lower cholesterol synthesis rate, that lowers overall blood lipid levels, could help prevent cardiovascular diseases. In addition to the effects of soluble fiber itself, foods high in dietary fiber (i.e. “fresh fruits, vegetables, and legumes”) provide many more benefits to our cardiovascular health [8]. For example, edamame is a good source of both fiber and health omega-6 and omega-3 fats. These healthy fats protect cardiovascular health by lowering LDL (“bad”) cholesterol levels [44]. Also, fiber has been shown to help lower blood pressure in hypertensive patients [43]. Lowering hypertension can reduce the risk of heart attack and stroke, which are two major components of cardiovascular diseases.
Cancer [6,9-14]
Diverticulosis [6,16,29-33]
Diverticulosis is a condition in which the colon wall weakens due to pressure and forms small pouches that protrude out of those weakened spots of the colon wall [32]. Although there are no specific causes of diverticulosis, it is mostly associated with a low-fiber diet.
A high-fiber diet, therefore, can help prevent diverticulosis mainly by alleviating constipation [16,29]. Fiber absorbs water while traveling through the intestine and creates bulky stool that decreases pressure applied to the colon. Decreased pressure to the colon prevents diverticulosis and eases discomfort or pain associated with constipation.
Yet, fiber cannot treat diverticulosis once it has been developed. It can prevent diverticulosis developing into diverticulitis, in which one or a few of the pouches of the colon wall become inflamed. However, a high-fiber diet is not a treatment for diverticulosis--only a means of preventing diverticulitis, which can cause abdominal pain, fever, and nausea.
After surgery for or during a flare-up of diverticulitis, a high-fiber diet is not recommended [30]. Instead, a low-fiber, liquid diet is recommended until the flare-up subsides and the patient recovers from surgery [31]. Afterwards, a high-fiber diet is once again recommended to prevent subsequent flare-ups and need for surgery.
A low-fiber diet includes [33]:
Inflammatory bowel diseases: Crohn’s disease and Ulcerative colitis [6,39,40-42]
Crohn’s disease and ulcerative colitis is under a group of gastrointestinal diseases called inflammatory bowel diseases (IBD) [39]. These conditions cause chronic inflammation in the GI tract, which impairs proper functions of our digestive organs. The symptoms include: abdominal pain, weight loss, diarrhea, rectal bleeding, and cramping.
Absorption of nutrients is also compromised. With Crohn’s disease, the small intestine becomes inflamed, leading to incomplete digestion of food. As this poorly digested food travels through the colon, diarrhea and abdominal pain may occur. With ulcerative colitis, the colon becomes inflamed. Since water is mostly absorbed in the colon, the malabsorption of water causes diarrhea and frequent bowel movements.
Several studies have shown that IBD is associated with “impairment in short-chain fatty acid (SCFA) production, mainly acetate, propionate, and butyrate” [40]. This is where dietary soluble fiber plays a role in IBD: soluble fiber is broken down in the large intestine and produces SCFA’s [6]. Butyrate, for example, “decreases the inflammatory response” of IBD conditions as it is produced via fermentation of fiber [41]. Also, soluble fiber can reduce diarrhea by forming a gel-like consistency and delaying gastric emptying. Insoluble fiber, on the other hand, is not recommended because it is “more difficult to digest,” which can cause a “blockage in the intestinal tract” and worsen symptoms of IBD [39].
Many current researchers believe dietary soluble fiber promotes the “prevention and/or alleviation of IBD”; fibers “should have positive effects on the microbiota, deliver the fiber to the site of inflammation for local fermentation, and limit the rate of undesirable reactions”. Some research even claim that intake of dietary fiber is “significantly associated” with a decreased risk of IBD [42]. Yet, the overall outlook on dietary fiber seems “promising but not definitive” [41]. Thus, many still recommend a high-fiber diet to alleviate symptoms of IBD.
References:
[1] Nutrition facts label: Dietary fiber. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/InteractiveNutritionFactsLabel/#intro. Accessed Oct. 1, 2018.
[2] Lattimer, James M, and Mark D Haub. “Effects of dietary fiber and its components on metabolic health.” Nutrients vol. 2,12 (2010): 1266-89. doi:10.3390/nu2121266
[5] Gordon, Barbara. “Tips for Preventing Constipation.” EatRight.org, Academy of Nutrition and Dietetics, 22 Oct. 2019, https://www.eatright.org/health/wellness/digestive-health/tips-for-preventing-constipation.
[6] Wong, Julia M W, et al. “Colonic Health: Fermentation and Short Chain Fatty Acids.” Journal of Clinical Gastroenterology, U.S. National Library of Medicine, Mar. 2006, https://www.ncbi.nlm.nih.gov/pubmed/16633129.
[7] National Research Council (US) Committee on Diet and Health. Diet and Health: Implications for Reducing Chronic Disease Risk. Washington (DC): National Academies Press (US); 1989. 10, Dietary Fiber. Available from: https://www.ncbi.nlm.nih.gov/books/NBK218764/
[8] M Stasse-Wolthuis, H F F Albers, J G C van Jeveren, J Wil de Jong, J G A J Hautvast, R J J Hermus, M B Katan, W G Brydon, M A Eastwood, Influence of dietary fiber from vegetables and fruits, bran or citrus pectin on serum lipids, fecal lipids, and colonic function, The American Journal of Clinical Nutrition, Volume 33, Issue 8, August 1980, Pages 1745–1756, https://doi.org/10.1093/ajcn/33.8.1745
[9] Health claims: fiber-containing grain products, fruits, and vegetables and cancer, 21 C.F.R. §101.76 (1993)
[10] Kunzmann, Andrew T et al. “Dietary fiber intake and risk of colorectal cancer and incident and recurrent adenoma in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial.” The American journal of clinical nutrition vol. 102,4 (2015): 881-90. doi:10.3945/ajcn.115.113282
[11] Zhang, Zhizhong et al. Dietary Fiber Intake Reduces Risk for Gastric Cancer: A Meta-analysis. Gastroenterology, Volume 145, Issue 1, 113 - 120.e3
[12] Risch, H A, et al. “Dietary Factors and the Incidence of Cancer of the Stomach.” American Journal of Epidemiology, U.S. National Library of Medicine, Dec. 1985, https://www.ncbi.nlm.nih.gov/pubmed/2998182.
[13] Li, Q., Holford, T.R., Zhang, Y. et al. Dietary fiber intake and risk of breast cancer by menopausal and estrogen receptor status. Eur J Nutr 52, 217–223 (2013). https://doi.org/10.1007/s00394-012-0305-9
[14] Baghurst, P.A. and Rohan, T.E. (1994), High‐fiber diets and reduced risk of breast cancer. Int. J. Cancer, 56: 173-176. doi:10.1002/ijc.2910560204
[16] Harvard Health Publishing. “Diverticular Disease Prevention and Treatment.” Harvard Health, Harvard Medical School, Feb. 2011, Chttps://www.health.harvard.edu/diseases-and-conditions/diverticular-disease-prevention-and-treatment
[28] “FastStats - Leading Causes of Death.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 17 Mar. 2017, www.cdc.gov/nchs/fastats/leading-causes-of-death.htm.
[29] “Eating, Diet, & Nutrition for Diverticular Disease.” National Institute of Diabetes and Digestive and Kidney Diseases, U.S. Department of Health and Human Services, 1 May 2016, www.niddk.nih.gov/health-information/digestive-diseases/diverticulosis-diverticulitis/eating-diet-nutrition.
[30] Dahl, C.; Crichton, M.; Jenkins, J.; Nucera, R.; Mahoney, S.; Marx, W.; Marshall, S. Evidence for Dietary Fibre Modification in the Recovery and Prevention of Reoccurrence of Acute, Uncomplicated Diverticulitis: A Systematic Literature Review. Nutrients 2018, 10, 137.
[31] “Diverticulitis.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 1 Aug. 2019, www.mayoclinic.org/diseases-conditions/diverticulitis/diagnosis-treatment/drc-20371764.
[32] “Diverticulitis.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 1 Aug. 2019, www.mayoclinic.org/diseases-conditions/diverticulitis/symptoms-causes/syc-20371758.
[33] “The Do's and Don'ts of a Low-Fiber Diet.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 25 July 2017, www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/low-fiber-diet/art-20048511.
[39] Dalessandro MS, RD, CDN, Tracie, and Lynne Christensen. “Diet, Nutrition, and Inflammatory Bowel Disease.” Edited by Beth Arnold, MA, RD, LD and Faten Aberra, MD, MSCE, Diet, Nutrition, and Inflammatory Bowel Disease, Crohn's & Colitis Foundation of America, 2013, Diet, Nutrition, and Inflammatory Bowel Disease.
[40] Galvez, J., Rodríguez‐Cabezas, M.E. and Zarzuelo, A. (2005), Effects of dietary fiber on inflammatory bowel disease. Mol. Nutr. Food Res., 49: 601-608. doi:10.1002/mnfr.200500013
[41] Devin J. Rose, MS, Mark T. DeMeo, MD, Ali Keshavarzian, MD, Bruce R. Hamaker, PhD, Influence of Dietary Fiber on Inflammatory Bowel Disease and Colon Cancer: Importance of Fermentation Pattern, Nutrition Reviews, Volume 65, Issue 2, February 2007, Pages 51–62, https://doi.org/10.1111/j.1753-4887.2007.tb00282.x
[42] Liu, Xiaoqin, et al. “Dietary Fiber Intake Reduces Risk of Inflammatory Bowel Disease: Result from a Meta-Analysis.” Nutrition Research, Elsevier, 3 June 2015, www.sciencedirect.com/science/article/pii/S0271531715001335.
[43] Whelton, Seamus P, et al. “Effect of Dietary Fiber Intake on Blood Pressure: a Meta-Analysis of Randomized, Controlled Clinical Trials.” Journal of Hypertension, U.S. National Library of Medicine, Mar. 2005, www.ncbi.nlm.nih.gov/pubmed/15716684.
[44] “Exceptional, Enjoyable Edamame - Today's Dietitian Magazine.” Today's Dietitian, www.todaysdietitian.com/newarchives/0417p24.shtml.
Diabetes [2]
Slow-digesting carbohydrates, which is dietary soluble fiber, can control blood glucose. Thus, improved dietary fiber intake has been related to a decreased risk of diabetes.
Constipation [1,2,5]
The two go-to nutrition interventions for constipation are: sufficient fluid intake and a high-fiber diet. (5) While fluids help soften the stool for passing, both soluble and insoluble fiber diets add bulk to the stool and promote bowel movements [1,2]. Thus, fiber prevents and relieves constipation.
Cardiovascular diseases [6,7,8,28,43,44]
Heart disease is the leading cause of death in the United States [28]. Thus, the benefit of soluble fiber on preventing cardiovascular diseases is extremely noteworthy: Soluble fiber is broken down in the large intestine (not small intestine) and produces short-chain fatty acids (SCFA’s). Among these SCFA’s are acetate, which promotes cholesterol synthesis, and propionate, which inhibits cholesterol synthesis. If we could “decrease the acetate:propionate ratio… [we] may reduce serum lipids” [6]. Therefore, a lower cholesterol synthesis rate, that lowers overall blood lipid levels, could help prevent cardiovascular diseases. In addition to the effects of soluble fiber itself, foods high in dietary fiber (i.e. “fresh fruits, vegetables, and legumes”) provide many more benefits to our cardiovascular health [8]. For example, edamame is a good source of both fiber and health omega-6 and omega-3 fats. These healthy fats protect cardiovascular health by lowering LDL (“bad”) cholesterol levels [44]. Also, fiber has been shown to help lower blood pressure in hypertensive patients [43]. Lowering hypertension can reduce the risk of heart attack and stroke, which are two major components of cardiovascular diseases.
Cancer [6,9-14]
- Colon cancer [6,9,10]:
SCFAs, produced by soluble fiber via fermentation in the large intestine, have been studied to show protective, nourishing effects to the distal colon for “prevention of cancer of the colon” [6]. Overall, studies on soluble fiber and cancer showed an inverse association between high-fiber intake diets and colon cancer. - Gastric (stomach) cancer [11,12]:
Soluble and insoluble fiber can reduce gastric nitrite concentration (nitrites are potentially carcinogenic to humans, and increased nitrite consumption increased risk of gastric cancer) [11]. Also, fiber’s ferulic acid and p-coumaric acid can delay cell cycle progression, which is an anti-cancer effect [12]. - Breast cancer [13,14]:
Early results show a correlation between foods rich in dietary soluble fiber and a reduced risk of breast cancer in premenopausal women [13]. These preliminary results, however, weren’t true for post-menopausal women and require additional studies to prove a stronger association between dietary soluble fiber and reduced breast cancer.
Diverticulosis [6,16,29-33]
Diverticulosis is a condition in which the colon wall weakens due to pressure and forms small pouches that protrude out of those weakened spots of the colon wall [32]. Although there are no specific causes of diverticulosis, it is mostly associated with a low-fiber diet.
A high-fiber diet, therefore, can help prevent diverticulosis mainly by alleviating constipation [16,29]. Fiber absorbs water while traveling through the intestine and creates bulky stool that decreases pressure applied to the colon. Decreased pressure to the colon prevents diverticulosis and eases discomfort or pain associated with constipation.
Yet, fiber cannot treat diverticulosis once it has been developed. It can prevent diverticulosis developing into diverticulitis, in which one or a few of the pouches of the colon wall become inflamed. However, a high-fiber diet is not a treatment for diverticulosis--only a means of preventing diverticulitis, which can cause abdominal pain, fever, and nausea.
After surgery for or during a flare-up of diverticulitis, a high-fiber diet is not recommended [30]. Instead, a low-fiber, liquid diet is recommended until the flare-up subsides and the patient recovers from surgery [31]. Afterwards, a high-fiber diet is once again recommended to prevent subsequent flare-ups and need for surgery.
A low-fiber diet includes [33]:
- - white bread, pasta, and crackers
- - refined cereal
- - canned vegetables without skins or seeds
- - fruit and vegetable juice with no pulp
- - meat, poultry, fish, eggs, tofu
- - milk products: yoghurt, pudding, milk, etc.
Inflammatory bowel diseases: Crohn’s disease and Ulcerative colitis [6,39,40-42]
Crohn’s disease and ulcerative colitis is under a group of gastrointestinal diseases called inflammatory bowel diseases (IBD) [39]. These conditions cause chronic inflammation in the GI tract, which impairs proper functions of our digestive organs. The symptoms include: abdominal pain, weight loss, diarrhea, rectal bleeding, and cramping.
Absorption of nutrients is also compromised. With Crohn’s disease, the small intestine becomes inflamed, leading to incomplete digestion of food. As this poorly digested food travels through the colon, diarrhea and abdominal pain may occur. With ulcerative colitis, the colon becomes inflamed. Since water is mostly absorbed in the colon, the malabsorption of water causes diarrhea and frequent bowel movements.
Several studies have shown that IBD is associated with “impairment in short-chain fatty acid (SCFA) production, mainly acetate, propionate, and butyrate” [40]. This is where dietary soluble fiber plays a role in IBD: soluble fiber is broken down in the large intestine and produces SCFA’s [6]. Butyrate, for example, “decreases the inflammatory response” of IBD conditions as it is produced via fermentation of fiber [41]. Also, soluble fiber can reduce diarrhea by forming a gel-like consistency and delaying gastric emptying. Insoluble fiber, on the other hand, is not recommended because it is “more difficult to digest,” which can cause a “blockage in the intestinal tract” and worsen symptoms of IBD [39].
Many current researchers believe dietary soluble fiber promotes the “prevention and/or alleviation of IBD”; fibers “should have positive effects on the microbiota, deliver the fiber to the site of inflammation for local fermentation, and limit the rate of undesirable reactions”. Some research even claim that intake of dietary fiber is “significantly associated” with a decreased risk of IBD [42]. Yet, the overall outlook on dietary fiber seems “promising but not definitive” [41]. Thus, many still recommend a high-fiber diet to alleviate symptoms of IBD.
References:
[1] Nutrition facts label: Dietary fiber. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/InteractiveNutritionFactsLabel/#intro. Accessed Oct. 1, 2018.
[2] Lattimer, James M, and Mark D Haub. “Effects of dietary fiber and its components on metabolic health.” Nutrients vol. 2,12 (2010): 1266-89. doi:10.3390/nu2121266
[5] Gordon, Barbara. “Tips for Preventing Constipation.” EatRight.org, Academy of Nutrition and Dietetics, 22 Oct. 2019, https://www.eatright.org/health/wellness/digestive-health/tips-for-preventing-constipation.
[6] Wong, Julia M W, et al. “Colonic Health: Fermentation and Short Chain Fatty Acids.” Journal of Clinical Gastroenterology, U.S. National Library of Medicine, Mar. 2006, https://www.ncbi.nlm.nih.gov/pubmed/16633129.
[7] National Research Council (US) Committee on Diet and Health. Diet and Health: Implications for Reducing Chronic Disease Risk. Washington (DC): National Academies Press (US); 1989. 10, Dietary Fiber. Available from: https://www.ncbi.nlm.nih.gov/books/NBK218764/
[8] M Stasse-Wolthuis, H F F Albers, J G C van Jeveren, J Wil de Jong, J G A J Hautvast, R J J Hermus, M B Katan, W G Brydon, M A Eastwood, Influence of dietary fiber from vegetables and fruits, bran or citrus pectin on serum lipids, fecal lipids, and colonic function, The American Journal of Clinical Nutrition, Volume 33, Issue 8, August 1980, Pages 1745–1756, https://doi.org/10.1093/ajcn/33.8.1745
[9] Health claims: fiber-containing grain products, fruits, and vegetables and cancer, 21 C.F.R. §101.76 (1993)
[10] Kunzmann, Andrew T et al. “Dietary fiber intake and risk of colorectal cancer and incident and recurrent adenoma in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial.” The American journal of clinical nutrition vol. 102,4 (2015): 881-90. doi:10.3945/ajcn.115.113282
[11] Zhang, Zhizhong et al. Dietary Fiber Intake Reduces Risk for Gastric Cancer: A Meta-analysis. Gastroenterology, Volume 145, Issue 1, 113 - 120.e3
[12] Risch, H A, et al. “Dietary Factors and the Incidence of Cancer of the Stomach.” American Journal of Epidemiology, U.S. National Library of Medicine, Dec. 1985, https://www.ncbi.nlm.nih.gov/pubmed/2998182.
[13] Li, Q., Holford, T.R., Zhang, Y. et al. Dietary fiber intake and risk of breast cancer by menopausal and estrogen receptor status. Eur J Nutr 52, 217–223 (2013). https://doi.org/10.1007/s00394-012-0305-9
[14] Baghurst, P.A. and Rohan, T.E. (1994), High‐fiber diets and reduced risk of breast cancer. Int. J. Cancer, 56: 173-176. doi:10.1002/ijc.2910560204
[16] Harvard Health Publishing. “Diverticular Disease Prevention and Treatment.” Harvard Health, Harvard Medical School, Feb. 2011, Chttps://www.health.harvard.edu/diseases-and-conditions/diverticular-disease-prevention-and-treatment
[28] “FastStats - Leading Causes of Death.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 17 Mar. 2017, www.cdc.gov/nchs/fastats/leading-causes-of-death.htm.
[29] “Eating, Diet, & Nutrition for Diverticular Disease.” National Institute of Diabetes and Digestive and Kidney Diseases, U.S. Department of Health and Human Services, 1 May 2016, www.niddk.nih.gov/health-information/digestive-diseases/diverticulosis-diverticulitis/eating-diet-nutrition.
[30] Dahl, C.; Crichton, M.; Jenkins, J.; Nucera, R.; Mahoney, S.; Marx, W.; Marshall, S. Evidence for Dietary Fibre Modification in the Recovery and Prevention of Reoccurrence of Acute, Uncomplicated Diverticulitis: A Systematic Literature Review. Nutrients 2018, 10, 137.
[31] “Diverticulitis.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 1 Aug. 2019, www.mayoclinic.org/diseases-conditions/diverticulitis/diagnosis-treatment/drc-20371764.
[32] “Diverticulitis.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 1 Aug. 2019, www.mayoclinic.org/diseases-conditions/diverticulitis/symptoms-causes/syc-20371758.
[33] “The Do's and Don'ts of a Low-Fiber Diet.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 25 July 2017, www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/low-fiber-diet/art-20048511.
[39] Dalessandro MS, RD, CDN, Tracie, and Lynne Christensen. “Diet, Nutrition, and Inflammatory Bowel Disease.” Edited by Beth Arnold, MA, RD, LD and Faten Aberra, MD, MSCE, Diet, Nutrition, and Inflammatory Bowel Disease, Crohn's & Colitis Foundation of America, 2013, Diet, Nutrition, and Inflammatory Bowel Disease.
[40] Galvez, J., Rodríguez‐Cabezas, M.E. and Zarzuelo, A. (2005), Effects of dietary fiber on inflammatory bowel disease. Mol. Nutr. Food Res., 49: 601-608. doi:10.1002/mnfr.200500013
[41] Devin J. Rose, MS, Mark T. DeMeo, MD, Ali Keshavarzian, MD, Bruce R. Hamaker, PhD, Influence of Dietary Fiber on Inflammatory Bowel Disease and Colon Cancer: Importance of Fermentation Pattern, Nutrition Reviews, Volume 65, Issue 2, February 2007, Pages 51–62, https://doi.org/10.1111/j.1753-4887.2007.tb00282.x
[42] Liu, Xiaoqin, et al. “Dietary Fiber Intake Reduces Risk of Inflammatory Bowel Disease: Result from a Meta-Analysis.” Nutrition Research, Elsevier, 3 June 2015, www.sciencedirect.com/science/article/pii/S0271531715001335.
[43] Whelton, Seamus P, et al. “Effect of Dietary Fiber Intake on Blood Pressure: a Meta-Analysis of Randomized, Controlled Clinical Trials.” Journal of Hypertension, U.S. National Library of Medicine, Mar. 2005, www.ncbi.nlm.nih.gov/pubmed/15716684.
[44] “Exceptional, Enjoyable Edamame - Today's Dietitian Magazine.” Today's Dietitian, www.todaysdietitian.com/newarchives/0417p24.shtml.
Dietary fiber is associated with improved cardiovascular (refer back to Question 4), lung, and kidney health [52-45,9], and Covid-19 can cause problems in all three organs [6,9-14,57-9,63-4].
For example, coronavirus can cause heart complications, such as “high inflammatory burden that can induce vascular inflammation, myocarditis, and cardiac arrhythmias” [64]. This list of acute cardiac injuries is the “most frequently reported cardiovascular abnormality in COVID-19,” [63] and is “strongly associated with mortality” [64]. Also, Covid-19 is associated with pneumonia [58] and decreased kidney function due to the possible lack of oxygen in the blood [59]. Thus, heart, lung, and kidney health is extremely important against Covid-19. To ensure optimal health, an adequate daily intake of dietary fiber will help to protect our cardiovascular, lung, and kidney health.
Lungs [52-4,57,60]
Allergic inflammation
A study found that dietary fiber and its major metabolite, short-chain fatty acids (SFCA), are able to “influence the severity of allergic inflammation” of the lungs [52]. The study also showed that a diet low in dietary fiber and SCFA’s “increased allergic airway disease” [52].
Chronic Obstructive Pulmonary Disease (COPD)
In addition, dietary fiber, especially cereal and fruit fibers [53], can “reduce risk of developing COPD” [54]. This is related to the by-product of “immune-modulating effects derived from the by-products of dietary fiber fermentation” [60]. Important to note that “existing health problems, such as chronic obstructive pulmonary disease” will worsen the symptoms of Covid-19 [57].
Although further research is needed, many existing research approves of dietary fiber’s role in helping reduce risk of lung disease.
Kidneys [61-2]
Fiber-rich diets have shown to “improv[e] renal function and lower risk of chronic kidney disease” due to fiber’s beneficial effects on the gut microbiota and lessening risk of weight gain [61].
Also, dietary fiber can lead to a “reduction in serum urea and creatinine,” which are markers of chronic kidney disease [62].
References:
[6] Wong, Julia M W, et al. “Colonic Health: Fermentation and Short Chain Fatty Acids.” Journal of Clinical Gastroenterology, U.S. National Library of Medicine, Mar. 2006, https://www.ncbi.nlm.nih.gov/pubmed/16633129.
[9] Health claims: fiber-containing grain products, fruits, and vegetables and cancer, 21 C.F.R. §101.76 (1993)
[10] Kunzmann, Andrew T et al. “Dietary fiber intake and risk of colorectal cancer and incident and recurrent adenoma in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial.” The American journal of clinical nutrition vol. 102,4 (2015): 881-90. doi:10.3945/ajcn.115.113282
[11] Zhang, Zhizhong et al. Dietary Fiber Intake Reduces Risk for Gastric Cancer: A Meta-analysis. Gastroenterology, Volume 145, Issue 1, 113 - 120.e3
[12] Risch, H A, et al. “Dietary Factors and the Incidence of Cancer of the Stomach.” American Journal of Epidemiology, U.S. National Library of Medicine, Dec. 1985, https://www.ncbi.nlm.nih.gov/pubmed/2998182.
[13] Li, Q., Holford, T.R., Zhang, Y. et al. Dietary fiber intake and risk of breast cancer by menopausal and estrogen receptor status. Eur J Nutr 52, 217–223 (2013). https://doi.org/10.1007/s00394-012-0305-9
[14] Baghurst, P.A. and Rohan, T.E. (1994), High‐fiber diets and reduced risk of breast cancer. Int. J. Cancer, 56: 173-176. doi:10.1002/ijc.2910560204
[52] Trompette, A., Gollwitzer, E., Yadava, K. et al. Gut microbiota metabolism of dietary fiber influences allergic airway disease and hematopoiesis. Nat Med 20, 159–166 (2014). https://doi.org/10.1038/nm.3444
[53] Kan, Haidong et al. “Dietary fiber, lung function, and chronic obstructive pulmonary disease in the atherosclerosis risk in communities study.” American journal of epidemiology vol. 167,5 (2008): 570-8. doi:10.1093/aje/kwm343
[54] Raphaëlle Varraso, Walter C. Willett, Carlos A. Camargo, Jr, Prospective Study of Dietary Fiber and Risk of Chronic Obstructive Pulmonary Disease Among US Women and Men, American Journal of Epidemiology, Volume 171, Issue 7, 1 April 2010, Pages 776–784, https://doi.org/10.1093/aje/kwp455
[55] Scarlata, Kate, and Dede Wilson. Low-FODMAP Diet Step by Step: a Personalized Plan to Relieve the Symptoms of IBS and Other Digestive Disorders--with More than 135 Deliciously Satisfying Recipes. Da Capo, Perseus Books/Hachette Book Group, 2018.
[57] “What Coronavirus Does to the Lungs.” What Coronavirus Does to the Lungs | Johns Hopkins Medicine, Http://Www.wikidata.org/Entity/Q50363516, 13 Apr. 2020, www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus/what-coronavirus-does-to-the-lungs.
[59] Cheng, Yichun, et al. “Kidney Disease Is Associated with in-Hospital Death of Patients with COVID-19.” Kidney International, Elsevier, 20 Mar. 2020, www.sciencedirect.com/science/article/pii/S0085253820302556.
[60] Young, RP, et al. “The Gut–Liver–Lung Axis. Modulation of the Innate Immune Response and Its Possible Role in Chronic Obstructive Pulmonary Disease.” American Journal of Respiratory Cell and Molecular Biology, American Thoracic Society, 16 Oct. 2015, www.atsjournals.org/doi/full/10.1165/rcmb.2015-0250PS.
[61] Dreher, Mark L. “Fiber-Rich Diets in Chronic Kidney Disease.” SpringerLink, Humana Press, Cham, 1 Jan. 1970, link.springer.com/chapter/10.1007/978-3-319-50557-2_15.
[62] Chiavaroli, L, et al. “Dietary Fiber Effects in Chronic Kidney Disease: a Systematic Review and Meta-Analysis of Controlled Feeding Trials.” Nature News, Nature Publishing Group, 12 Nov. 2014, www.nature.com/articles/ejcn2014237.
[63] Paramasivam, A., Priyadharsini, J.V., Raghunandhakumar, S. et al. A novel COVID-19 and its effects on cardiovascular disease. Hypertens Res, 30 Apr. 2020, https://doi.org/10.1038/s41440-020-0461-x.
[64] Madjid M, Safavi-Naeini P, Solomon SD, Vardeny O. Potential Effects of Coronaviruses on the Cardiovascular System: A Review [published online ahead of print, 2020 Mar 27]. JAMA Cardiol. 2020;10.1001/jamacardio.2020.1286. doi:10.1001/jamacardio.2020.1286.
Based on a 2000 calorie diet, the FDA recommends 25 g of fiber per day from foods, not supplements. However, most Americans do not eat the recommended amount of fiber. Thus, the FDA has labeled fiber a "nutrient of public health concern,” because low fiber intake is related to potential health risks. Adequate fiber consumption can lower health risks, such as intestinal irregularity and cardiovascular diseases.
References:
[1] Nutrition facts label: Dietary fiber. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/InteractiveNutritionFactsLabel/#intro. Accessed Oct. 1, 2018.
References:
[1] Nutrition facts label: Dietary fiber. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/InteractiveNutritionFactsLabel/#intro. Accessed Oct. 1, 2018.
Food and supplements.
As mentioned before, fiber is found in plant foods. Some major sources of fiber include:
Since fiber is found only in plant foods, this means that dairy and meat products have no dietary fiber.
It is important to note that natural fiber is present in whole, plant foods, not refined foods. Refined foods include refined white bread, white rice, cereals, and processed apple juice. Their dietary fiber composition is modified during processing, lacking natural fiber from whole foods.
Besides food sources, there are also fiber supplements. Fiber sources from supplements include guar gum and psyllium tablets. Psyllium supplements are extracted from the husks of psyllium seeds, and are one of the most popular forms of fiber supplements. Because fiber supplementation isn’t considered a natural, whole source of dietary fiber, it is called ‘functional fiber’.
References:
[1] Nutrition facts label: Dietary fiber. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/InteractiveNutritionFactsLabel/#intro. Accessed Oct. 1, 2018.
[17] Harvard Health Publishing. “Surprising Sources of Dietary Fiber.” Harvard Health, Harvard Medical School, Dec. 2017, https://www.health.harvard.edu/staying-healthy/surprising-sources-of-dietary-fiber.
[18] Lambeau, Kellen V, and Johnson W McRorie. “Fiber Supplements and Clinically Proven Health Benefits: How to Recognize and Recommend an Effective Fiber Therapy.” Journal of the American Association of Nurse Practitioners, John Wiley and Sons Inc., Apr. 2017, https://www.ncbi.nlm.nih.gov/pubmed/28252255.
As mentioned before, fiber is found in plant foods. Some major sources of fiber include:
- - Legumes (lentils, black beans, soybeans, chickpeas, peanuts, quinoa, bulgur)
- - Whole wheat products
- - Peas
- - Fruits
- - Vegetables
- - Oatmeal
- - Nuts
- - Seeds
Since fiber is found only in plant foods, this means that dairy and meat products have no dietary fiber.
It is important to note that natural fiber is present in whole, plant foods, not refined foods. Refined foods include refined white bread, white rice, cereals, and processed apple juice. Their dietary fiber composition is modified during processing, lacking natural fiber from whole foods.
Besides food sources, there are also fiber supplements. Fiber sources from supplements include guar gum and psyllium tablets. Psyllium supplements are extracted from the husks of psyllium seeds, and are one of the most popular forms of fiber supplements. Because fiber supplementation isn’t considered a natural, whole source of dietary fiber, it is called ‘functional fiber’.
References:
[1] Nutrition facts label: Dietary fiber. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/InteractiveNutritionFactsLabel/#intro. Accessed Oct. 1, 2018.
[17] Harvard Health Publishing. “Surprising Sources of Dietary Fiber.” Harvard Health, Harvard Medical School, Dec. 2017, https://www.health.harvard.edu/staying-healthy/surprising-sources-of-dietary-fiber.
[18] Lambeau, Kellen V, and Johnson W McRorie. “Fiber Supplements and Clinically Proven Health Benefits: How to Recognize and Recommend an Effective Fiber Therapy.” Journal of the American Association of Nurse Practitioners, John Wiley and Sons Inc., Apr. 2017, https://www.ncbi.nlm.nih.gov/pubmed/28252255.
Fiber additives and fiber pills (functional fiber) help reach the recommended intake of dietary fiber. However, dietary fiber is recommended over functional fiber; functional fiber not only lacks holistic health benefits generally associated with fiber, but also causes unhealthy, excess intake of fiber.
Also, dietary fiber increases satiety, which can promote weight loss [20]. If taken straight from whole, unprocessed foods, dietary fiber can significantly increase a meal’s satiety. However, fiber pills are not recommended as a weight loss treatment, which they are often wrongly used as. While some studies point out that glucomannan pills, fiber extracted from the konjac root, “beneficially affect” [34] and “may promote weight loss” [35], most studies [36,37] claim that weight loss effects of most fiber supplementation is “not convincing” [36] enough to be considered an appropriate weight loss treatment.
In addition, many fiber pills contain fiber sources that are more prone to bloating and gastrointestinal discomfort. For instance, many studies on glucomannan were conducted using a low dosage of fiber [35,37] because of its “high viscosity” [35], which was taken with 8 oz of water [37]. Also, many fiber pills contain inulin and chicory root fiber, which are highly fermentable. Highly fermentable fibers can create an excess of gas when fermented by the bacteria in our gut, hence the bloat and discomfort [19]. Therefore, yes—fiber additives and fiber pills are good for meeting the recommended intake of fiber. However, fiber pills can easily go over the recommended intake, and lead to a fiber overdose, of sorts. Excess fiber, especially with pills that commonly use inulin and chicory root fiber, can create the opposite of fiber’s desired effects. Overall, dietary fiber is a better source with a more expansive set of benefits.
References:
[18] Lambeau, Kellen V, and Johnson W McRorie. “Fiber Supplements and Clinically Proven Health Benefits: How to Recognize and Recommend an Effective Fiber Therapy.” Journal of the American Association of Nurse Practitioners, John Wiley and Sons Inc., Apr. 2017, https://www.ncbi.nlm.nih.gov/pubmed/28252255.
[19] Hannah D. Holscher (2017) Dietary fiber and prebiotics and the gastrointestinal microbiota, Gut Microbes, 8:2, 172-184, DOI: 10.1080/19490976.2017.1290756
[20] Ma Y, Olendzki BC, Wang J, et al. Single-Component Versus Multicomponent Dietary Goals for the Metabolic Syndrome: A Randomized Trial. Ann Intern Med. 2015;162:248–257. doi: https://doi.org/10.7326/M14-0611
[34] Sood, Nitesh, et al. “Effect of Glucomannan on Plasma Lipid and Glucose Concentrations, Body Weight, and Blood Pressure: Systematic Review and Meta-Analysis.” The American Journal of Clinical Nutrition, U.S. National Library of Medicine, Oct. 2008, www.ncbi.nlm.nih.gov/pubmed/18842808.
[35] Keithley, Joyce, and Barbara Swanson. “Glucomannan and Obesity: a Critical Review.” Alternative Therapies in Health and Medicine, U.S. National Library of Medicine, 2005, www.ncbi.nlm.nih.gov/pubmed/16320857.
[36] Pittler, Max H, and Edzard Ernst. “Dietary Supplements for Body-Weight Reduction: a Systematic Review.” The American Journal of Clinical Nutrition, U.S. National Library of Medicine, Apr. 2004, www.ncbi.nlm.nih.gov/pubmed/15051593.
[37] Keithley, Joyce K, et al. “Safety and Efficacy of Glucomannan for Weight Loss in Overweight and Moderately Obese Adults.” Journal of Obesity, Hindawi Publishing Corporation, Dec. 2013, www.ncbi.nlm.nih.gov/pubmed/24490058.
Also, dietary fiber increases satiety, which can promote weight loss [20]. If taken straight from whole, unprocessed foods, dietary fiber can significantly increase a meal’s satiety. However, fiber pills are not recommended as a weight loss treatment, which they are often wrongly used as. While some studies point out that glucomannan pills, fiber extracted from the konjac root, “beneficially affect” [34] and “may promote weight loss” [35], most studies [36,37] claim that weight loss effects of most fiber supplementation is “not convincing” [36] enough to be considered an appropriate weight loss treatment.
In addition, many fiber pills contain fiber sources that are more prone to bloating and gastrointestinal discomfort. For instance, many studies on glucomannan were conducted using a low dosage of fiber [35,37] because of its “high viscosity” [35], which was taken with 8 oz of water [37]. Also, many fiber pills contain inulin and chicory root fiber, which are highly fermentable. Highly fermentable fibers can create an excess of gas when fermented by the bacteria in our gut, hence the bloat and discomfort [19]. Therefore, yes—fiber additives and fiber pills are good for meeting the recommended intake of fiber. However, fiber pills can easily go over the recommended intake, and lead to a fiber overdose, of sorts. Excess fiber, especially with pills that commonly use inulin and chicory root fiber, can create the opposite of fiber’s desired effects. Overall, dietary fiber is a better source with a more expansive set of benefits.
References:
[18] Lambeau, Kellen V, and Johnson W McRorie. “Fiber Supplements and Clinically Proven Health Benefits: How to Recognize and Recommend an Effective Fiber Therapy.” Journal of the American Association of Nurse Practitioners, John Wiley and Sons Inc., Apr. 2017, https://www.ncbi.nlm.nih.gov/pubmed/28252255.
[19] Hannah D. Holscher (2017) Dietary fiber and prebiotics and the gastrointestinal microbiota, Gut Microbes, 8:2, 172-184, DOI: 10.1080/19490976.2017.1290756
[20] Ma Y, Olendzki BC, Wang J, et al. Single-Component Versus Multicomponent Dietary Goals for the Metabolic Syndrome: A Randomized Trial. Ann Intern Med. 2015;162:248–257. doi: https://doi.org/10.7326/M14-0611
[34] Sood, Nitesh, et al. “Effect of Glucomannan on Plasma Lipid and Glucose Concentrations, Body Weight, and Blood Pressure: Systematic Review and Meta-Analysis.” The American Journal of Clinical Nutrition, U.S. National Library of Medicine, Oct. 2008, www.ncbi.nlm.nih.gov/pubmed/18842808.
[35] Keithley, Joyce, and Barbara Swanson. “Glucomannan and Obesity: a Critical Review.” Alternative Therapies in Health and Medicine, U.S. National Library of Medicine, 2005, www.ncbi.nlm.nih.gov/pubmed/16320857.
[36] Pittler, Max H, and Edzard Ernst. “Dietary Supplements for Body-Weight Reduction: a Systematic Review.” The American Journal of Clinical Nutrition, U.S. National Library of Medicine, Apr. 2004, www.ncbi.nlm.nih.gov/pubmed/15051593.
[37] Keithley, Joyce K, et al. “Safety and Efficacy of Glucomannan for Weight Loss in Overweight and Moderately Obese Adults.” Journal of Obesity, Hindawi Publishing Corporation, Dec. 2013, www.ncbi.nlm.nih.gov/pubmed/24490058.
Studies have shown that too much fiber can cause adverse effects, such as bloating, constipation and gas [15,16,19]. Therefore, eating the recommended amount of fiber (25 g per day, based on a 2000 calorie diet) then increasing 5 grams every day, if needed, is advised to alleviate and prevent unpleasant side effects of excess fiber [1].
Also, as mentioned before, fiber pills could cause bloating due to their composition of fiber. Thus, it is recommended to eat fiber through whole, plant foods that can prevent you from taking in too much fiber in one sitting.
References:
[1] Nutrition facts label: Dietary fiber. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/InteractiveNutritionFactsLabel/#intro. Accessed Oct. 1, 2018.
[15] Müller-Lissner, Stefan A, et al. “Myths and Misconceptions About Chronic Constipation.” The American Journal of Gastroenterology, U.S. National Library of Medicine, Jan. 2005, https://www.ncbi.nlm.nih.gov/pubmed/15654804.
[16] Harvard Health Publishing. “Diverticular Disease Prevention and Treatment.” Harvard Health, Harvard Medical School, Feb. 2011, Chttps://www.health.harvard.edu/diseases-and-conditions/diverticular-disease-prevention-and-treatment
[19] Hannah D. Holscher (2017) Dietary fiber and prebiotics and the gastrointestinal microbiota, Gut Microbes, 8:2, 172-184, DOI: 10.1080/19490976.2017.1290756
Also, as mentioned before, fiber pills could cause bloating due to their composition of fiber. Thus, it is recommended to eat fiber through whole, plant foods that can prevent you from taking in too much fiber in one sitting.
References:
[1] Nutrition facts label: Dietary fiber. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/InteractiveNutritionFactsLabel/#intro. Accessed Oct. 1, 2018.
[15] Müller-Lissner, Stefan A, et al. “Myths and Misconceptions About Chronic Constipation.” The American Journal of Gastroenterology, U.S. National Library of Medicine, Jan. 2005, https://www.ncbi.nlm.nih.gov/pubmed/15654804.
[16] Harvard Health Publishing. “Diverticular Disease Prevention and Treatment.” Harvard Health, Harvard Medical School, Feb. 2011, Chttps://www.health.harvard.edu/diseases-and-conditions/diverticular-disease-prevention-and-treatment
[19] Hannah D. Holscher (2017) Dietary fiber and prebiotics and the gastrointestinal microbiota, Gut Microbes, 8:2, 172-184, DOI: 10.1080/19490976.2017.1290756
A diet high in fiber has been proven to promote weight loss [20]. One of the major reasons is due to fiber’s ability to increase satiety; dietary fiber, both soluble and insoluble, promotes fullness post-meal, which prevents unnecessary snacking and eating. The reduction of extra calories from excessive snacking and eating significantly promotes weight loss. An added benefit: encouraging healthy eating habits.
Another major reason is fiber’s role in blood glucose control [21-25]. Especially for insoluble fiber, a high-fiber diet was shown to help stabilize blood glucose post-meal [22]. When blood glucose increases, our pancreas produces insulin [38]. Insulin signals our body to either use glucose as energy or store it as fat. If our body can’t control blood glucose, our body’s insulin production goes into overdrive, encouraging glucose to be stored at fat. Extra glucose stored as fat can lead to extra weight gain. Thus, fiber’s ability to control blood glucose and slow glucose absorption promotes weight loss.
These benefits are particularly helpful for those struggling with obesity, diabetes, metabolic syndrome, cardiovascular disease, unhealthy relationship with food, etc.
References:
[20] Ma Y, Olendzki BC, Wang J, et al. Single-Component Versus Multicomponent Dietary Goals for the Metabolic Syndrome: A Randomized Trial. Ann Intern Med. 2015;162:248–257. doi: https://doi.org/10.7326/M14-0611
[21] Ellis, Esther. “What Is Glycemic Index?” EatRight, Nov. 2019, www.eatright.org/food/nutrition/dietary-guidelines-and-myplate/what-is-glycemic-index.
[22] T M Wolever, Relationship between dietary fiber content and composition in foods and the glycemic index, The American Journal of Clinical Nutrition, Volume 51, Issue 1, January 1990, Pages 72–75, https://doi.org/10.1093/ajcn/51.1.72
[23] Salmerón J, Manson JE, Stampfer MJ, Colditz GA, Wing AL, Willett WC. Dietary Fiber, Glycemic Load, and Risk of Non—insulin-dependent Diabetes Mellitus in Women. JAMA. 1997;277(6):472–477. doi:10.1001/jama.1997.03540300040031
[24] Matthias B Schulze, Simin Liu, Eric B Rimm, JoAnn E Manson, Walter C Willett, Frank B Hu, Glycemic index, glycemic load, and dietary fiber intake and incidence of type 2 diabetes in younger and middle-aged women, The American Journal of Clinical Nutrition, Volume 80, Issue 2, August 2004, Pages 348–356, https://doi.org/10.1093/ajcn/80.2.348
[25] Salmerón, Jorge, et al. “Dietary Fiber, Glycemic Load, and Risk of NIDDM in Men.” Diabetes Care, American Diabetes Association, 1 Apr. 1997, care.diabetesjournals.org/content/20/4/545.abstract.
[38] Wilcox, Gisela. “Insulin and insulin resistance.” The Clinical biochemist. Reviews vol. 26,2 (2005): 19-39.
Another major reason is fiber’s role in blood glucose control [21-25]. Especially for insoluble fiber, a high-fiber diet was shown to help stabilize blood glucose post-meal [22]. When blood glucose increases, our pancreas produces insulin [38]. Insulin signals our body to either use glucose as energy or store it as fat. If our body can’t control blood glucose, our body’s insulin production goes into overdrive, encouraging glucose to be stored at fat. Extra glucose stored as fat can lead to extra weight gain. Thus, fiber’s ability to control blood glucose and slow glucose absorption promotes weight loss.
These benefits are particularly helpful for those struggling with obesity, diabetes, metabolic syndrome, cardiovascular disease, unhealthy relationship with food, etc.
References:
[20] Ma Y, Olendzki BC, Wang J, et al. Single-Component Versus Multicomponent Dietary Goals for the Metabolic Syndrome: A Randomized Trial. Ann Intern Med. 2015;162:248–257. doi: https://doi.org/10.7326/M14-0611
[21] Ellis, Esther. “What Is Glycemic Index?” EatRight, Nov. 2019, www.eatright.org/food/nutrition/dietary-guidelines-and-myplate/what-is-glycemic-index.
[22] T M Wolever, Relationship between dietary fiber content and composition in foods and the glycemic index, The American Journal of Clinical Nutrition, Volume 51, Issue 1, January 1990, Pages 72–75, https://doi.org/10.1093/ajcn/51.1.72
[23] Salmerón J, Manson JE, Stampfer MJ, Colditz GA, Wing AL, Willett WC. Dietary Fiber, Glycemic Load, and Risk of Non—insulin-dependent Diabetes Mellitus in Women. JAMA. 1997;277(6):472–477. doi:10.1001/jama.1997.03540300040031
[24] Matthias B Schulze, Simin Liu, Eric B Rimm, JoAnn E Manson, Walter C Willett, Frank B Hu, Glycemic index, glycemic load, and dietary fiber intake and incidence of type 2 diabetes in younger and middle-aged women, The American Journal of Clinical Nutrition, Volume 80, Issue 2, August 2004, Pages 348–356, https://doi.org/10.1093/ajcn/80.2.348
[25] Salmerón, Jorge, et al. “Dietary Fiber, Glycemic Load, and Risk of NIDDM in Men.” Diabetes Care, American Diabetes Association, 1 Apr. 1997, care.diabetesjournals.org/content/20/4/545.abstract.
[38] Wilcox, Gisela. “Insulin and insulin resistance.” The Clinical biochemist. Reviews vol. 26,2 (2005): 19-39.
Foods high in fiber have a low glycemic index (GI) because it is digested and absorbed at a slower rate, causing a slower increase in blood glucose levels [21]. Foods with a high total dietary fiber and insoluble fiber, especially, were significantly related to GI [22]. For example, fiber from whole grains, such as unrefined, whole cereal, has a low GI. With a low GI, high-fiber foods can decrease risk of diabetes because it causes a slower rise in blood glucose [23,24,25].
References:
[21] Ellis, Esther. “What Is Glycemic Index?” EatRight, Nov. 2019, www.eatright.org/food/nutrition/dietary-guidelines-and-myplate/what-is-glycemic-index.
[22] T M Wolever, Relationship between dietary fiber content and composition in foods and the glycemic index, The American Journal of Clinical Nutrition, Volume 51, Issue 1, January 1990, Pages 72–75, https://doi.org/10.1093/ajcn/51.1.72
[23] Salmerón J, Manson JE, Stampfer MJ, Colditz GA, Wing AL, Willett WC. Dietary Fiber, Glycemic Load, and Risk of Non—insulin-dependent Diabetes Mellitus in Women. JAMA. 1997;277(6):472–477. doi:10.1001/jama.1997.03540300040031
[24] Matthias B Schulze, Simin Liu, Eric B Rimm, JoAnn E Manson, Walter C Willett, Frank B Hu, Glycemic index, glycemic load, and dietary fiber intake and incidence of type 2 diabetes in younger and middle-aged women, The American Journal of Clinical Nutrition, Volume 80, Issue 2, August 2004, Pages 348–356, https://doi.org/10.1093/ajcn/80.2.348
[25] Salmerón, Jorge, et al. “Dietary Fiber, Glycemic Load, and Risk of NIDDM in Men.” Diabetes Care, American Diabetes Association, 1 Apr. 1997, care.diabetesjournals.org/content/20/4/545.abstract.
References:
[21] Ellis, Esther. “What Is Glycemic Index?” EatRight, Nov. 2019, www.eatright.org/food/nutrition/dietary-guidelines-and-myplate/what-is-glycemic-index.
[22] T M Wolever, Relationship between dietary fiber content and composition in foods and the glycemic index, The American Journal of Clinical Nutrition, Volume 51, Issue 1, January 1990, Pages 72–75, https://doi.org/10.1093/ajcn/51.1.72
[23] Salmerón J, Manson JE, Stampfer MJ, Colditz GA, Wing AL, Willett WC. Dietary Fiber, Glycemic Load, and Risk of Non—insulin-dependent Diabetes Mellitus in Women. JAMA. 1997;277(6):472–477. doi:10.1001/jama.1997.03540300040031
[24] Matthias B Schulze, Simin Liu, Eric B Rimm, JoAnn E Manson, Walter C Willett, Frank B Hu, Glycemic index, glycemic load, and dietary fiber intake and incidence of type 2 diabetes in younger and middle-aged women, The American Journal of Clinical Nutrition, Volume 80, Issue 2, August 2004, Pages 348–356, https://doi.org/10.1093/ajcn/80.2.348
[25] Salmerón, Jorge, et al. “Dietary Fiber, Glycemic Load, and Risk of NIDDM in Men.” Diabetes Care, American Diabetes Association, 1 Apr. 1997, care.diabetesjournals.org/content/20/4/545.abstract.
FODMAPs are short-chain carbohydrates [46] that stand for “fermentable oligo-, di-, monosaccharides and polyols” [45]. They are known to significantly affect gastrointestinal symptoms, such as bloating, cramping, diarrhea, and flatulence [46]. For example, high FODMAPs diet worsened the GI symptoms in patients with GI conditions, like Celiac disease, non-celiac gluten sensitivity [45], and Irritable Bowel Syndrome [46-7].
FODMAPs create these symptoms by “increas[ing] delivery of readily fermentable substrate and water to the distal small intestine” [48]. This leads to decreased absorption of short-chain carbs in the small intestine, which exacerbate GI symptoms.
Although FODMAPs were originally targeted to alleviate GI symptoms of patients with functional GI disorders [48], the low-FODMAPs diet has risen in popularity for anyone who experiences GI discomfort.
What are the six FODMAPS?
Fructose [49]
Galactans [50]
Polyols [49, 50]
What is the Difference between fiber and FODMAPs? [1,19, 45-50,55-6, 65,66]
The low FODMAPs diet has been successful for many of those who experience GI discomfort/disorders. However, it is not a one-size-fits-all diet. For instance, this diet counters one of the main benefits of dietary fiber: fiber isn’t digested in the small intestine and quickly passses through to the large intestine where it adds bulk to stool [1]. This is why a low-FODMAPs diet “requires expert delivery by a dietitian” [48]. Without proper planning, the popular low-FODMAPs diet can end up harming the gut microbiome of someone who already lacks sources of dietary fiber [48].
Rich sources of fiber also found in the ‘low FODMAPs diet’ include [51,55-6]:
Our FYBR Bars: are FODMAPs present?
Here are FYBR's ingredients, explained:
Edamame [55]:
Chia seeds [56]
Dates [65,66]
Cacao powder [66-7]
References:
[1] Nutrition facts label: Dietary fiber. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/InteractiveNutritionFactsLabel/#intro. Accessed Oct. 1, 2018.
[19] Hannah D. Holscher (2017) Dietary fiber and prebiotics and the gastrointestinal microbiota, Gut Microbes, 8:2, 172-184, DOI: 10.1080/19490976.2017.1290756
[45] Dieterich, Walburga et al. “Influence of low FODMAP and gluten-free diets on disease activity and intestinal microbiota in patients with non-celiac gluten sensitivity.” Clinical Nutrition Journal, Volume 38, Issue 2, 697 - 707, https://www.clinicalnutritionjournal.com/article/S0261-5614(18)30129-8/fulltext
[46] de Roest, R.H., Dobbs, B.R., Chapman, B.A., Batman, B., O'Brien, L.A., Leeper, J.A., Hebblethwaite, C.R. and Gearry, R.B. (2013), The low FODMAP diet improves gastrointestinal symptoms in patients with irritable bowel syndrome: a prospective study. Int J Clin Pract, 67: 895-903. doi:10.1111/ijcp.12128
[47] Halmos, Emma P. et al. A Diet Low in FODMAPs Reduces Symptoms of Irritable Bowel Syndrome. Gastroenterology Journal, Volume 146, Issue 1, 67 - 75.e5. https://www.gastrojournal.org/article/S0016-5085(13)01407-8/fulltext
[48] Gibson, P.R. and Shepherd, S.J. (2010), Evidence‐based dietary management of functional gastrointestinal symptoms: The FODMAP approach. Journal of Gastroenterology and Hepatology, 25: 252-258. doi:10.1111/j.1440-1746.2009.06149.x
[49] Fedewa, Amy, and Satish S C Rao. “Dietary fructose intolerance, fructan intolerance and FODMAPs.” Current gastroenterology reports vol. 16,1 (2014): 370. doi:10.1007/s11894-013-0370-0
[50] Scarlata, Kate. “The FODMAPs Approach — Minimize Consumption of Fermentable Carbs to Manage Functional Gut Disorder Symptoms.” Today's Dietitian, Aug. 2010, p. 30, https://www.todaysdietitian.com/newarchives/072710p30.shtml.
[51] Harvard Health Publishing. “Try a FODMAPs Diet to Manage Irritable Bowel Syndrome.” Harvard Health, Oct. 2014, www.health.harvard.edu/diet-and-weight-loss/a-new-diet-to-manage-irritable-bowel-syndrome.
[55] Scarlata, Kate, and Dede Wilson. Low-FODMAP Diet Step by Step: a Personalized Plan to Relieve the Symptoms of IBS and Other Digestive Disorders--with More than 135 Deliciously Satisfying Recipes. Da Capo, Perseus Books/Hachette Book Group, 2018.
[56] Bustamante, Mariela, et al. “Effective Lactobacillus Plantarum and Bifidobacterium Infantis Encapsulation with Chia Seed (Salvia Hispanica L.) and Flaxseed (Linum Usitatissimum L.) Mucilage and Soluble Protein by Spray Drying.” Food Chemistry, Elsevier, 9 Aug. 2016, www.sciencedirect.com/science/article/abs/pii/S0308814616312493?via=ihub.
[65] “FODMAPs and Irritable Bowel Syndrome.” About FODMAPs and IBS | Monash FODMAP - Monash Fodmap, www.monashfodmap.com/about-fodmap-and-ibs/.
[66] Hewawasam, Samapriya P, et al. “Dietary Practices and FODMAPs in South Asia: Applicability of the Low FODMAP Diet to Patients with Irritable Bowel Syndrome.” Wiley Online Library, John Wiley & Sons, Ltd, 26 Jan. 2018, onlinelibrary.wiley.com/doi/full/10.1111/jgh.13885.
FODMAPs create these symptoms by “increas[ing] delivery of readily fermentable substrate and water to the distal small intestine” [48]. This leads to decreased absorption of short-chain carbs in the small intestine, which exacerbate GI symptoms.
Although FODMAPs were originally targeted to alleviate GI symptoms of patients with functional GI disorders [48], the low-FODMAPs diet has risen in popularity for anyone who experiences GI discomfort.
What are the six FODMAPS?
Fructose [49]
- - Simple sugars found in fruits and vegetables
- - Corn (yields high fructose corn syrup)
- - Carbohydrates from dairy products
- - Soft cheeses (ricotta, cottage cheese, cream cheese)
- - Milk, butter, cream, yoghurt
- - Carbohydrates that include fructose units (49)
- - Inulin and chicory root fiber, which are highly-fermentable soluble fibers (19)
- - Wheat products (bread, pasta, couscous, etc)
- - Barley, scallions, shallots, brussel sprouts, broccoli, cabbage, pistachio
Lactose [49]
Fructans [19, 49]
Galactans [50]
- - Carbohydrates made up of sugar galactose
- - Soy-based products (veggie-burgers, soy milk, soy protein isolate, miso)
- - Lentils, chickpeas, kidney beans, black-eyed peas
Polyols [49, 50]
- - Sugar alcohols/sugar-free sweeteners (erythritol, xylitol, sorbitol)
- - Apples, plums, cherries
- - Snow peas, mushrooms
What is the Difference between fiber and FODMAPs? [1,19, 45-50,55-6, 65,66]
The low FODMAPs diet has been successful for many of those who experience GI discomfort/disorders. However, it is not a one-size-fits-all diet. For instance, this diet counters one of the main benefits of dietary fiber: fiber isn’t digested in the small intestine and quickly passses through to the large intestine where it adds bulk to stool [1]. This is why a low-FODMAPs diet “requires expert delivery by a dietitian” [48]. Without proper planning, the popular low-FODMAPs diet can end up harming the gut microbiome of someone who already lacks sources of dietary fiber [48].
Rich sources of fiber also found in the ‘low FODMAPs diet’ include [51,55-6]:
- - Quinoa, oats
- - Oranges, bananas, grapefruit
- - Carrots, cucumbers, bok choy, eggplant, potatoes
- - Almonds, peanuts, walnuts, pine nuts
Our FYBR Bars: are FODMAPs present?
Here are FYBR's ingredients, explained:
Edamame [55]:
- - Considered low-FODMAPs in small servings, compared to other soy products
- - Contains two FODMAPs: galacto-oligosaccharides and fructans
- - Still, highly FODMAP-sensitive consumers should take note of FYBR products’ serving size for precaution
Chia seeds [56]
- - Low in all FODMAPs
Dates [65,66]
- - High in FODMAPs
Cacao powder [66-7]
- - Low in FODMAPs in “2 teaspoon (8g) portions”, which is less than the portion in each FYBR bar
- - Reaches high FODMAP level with a 200g portion in galacto-oligosaccharides and fructans
References:
[1] Nutrition facts label: Dietary fiber. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/scripts/InteractiveNutritionFactsLabel/#intro. Accessed Oct. 1, 2018.
[19] Hannah D. Holscher (2017) Dietary fiber and prebiotics and the gastrointestinal microbiota, Gut Microbes, 8:2, 172-184, DOI: 10.1080/19490976.2017.1290756
[45] Dieterich, Walburga et al. “Influence of low FODMAP and gluten-free diets on disease activity and intestinal microbiota in patients with non-celiac gluten sensitivity.” Clinical Nutrition Journal, Volume 38, Issue 2, 697 - 707, https://www.clinicalnutritionjournal.com/article/S0261-5614(18)30129-8/fulltext
[46] de Roest, R.H., Dobbs, B.R., Chapman, B.A., Batman, B., O'Brien, L.A., Leeper, J.A., Hebblethwaite, C.R. and Gearry, R.B. (2013), The low FODMAP diet improves gastrointestinal symptoms in patients with irritable bowel syndrome: a prospective study. Int J Clin Pract, 67: 895-903. doi:10.1111/ijcp.12128
[47] Halmos, Emma P. et al. A Diet Low in FODMAPs Reduces Symptoms of Irritable Bowel Syndrome. Gastroenterology Journal, Volume 146, Issue 1, 67 - 75.e5. https://www.gastrojournal.org/article/S0016-5085(13)01407-8/fulltext
[48] Gibson, P.R. and Shepherd, S.J. (2010), Evidence‐based dietary management of functional gastrointestinal symptoms: The FODMAP approach. Journal of Gastroenterology and Hepatology, 25: 252-258. doi:10.1111/j.1440-1746.2009.06149.x
[49] Fedewa, Amy, and Satish S C Rao. “Dietary fructose intolerance, fructan intolerance and FODMAPs.” Current gastroenterology reports vol. 16,1 (2014): 370. doi:10.1007/s11894-013-0370-0
[50] Scarlata, Kate. “The FODMAPs Approach — Minimize Consumption of Fermentable Carbs to Manage Functional Gut Disorder Symptoms.” Today's Dietitian, Aug. 2010, p. 30, https://www.todaysdietitian.com/newarchives/072710p30.shtml.
[51] Harvard Health Publishing. “Try a FODMAPs Diet to Manage Irritable Bowel Syndrome.” Harvard Health, Oct. 2014, www.health.harvard.edu/diet-and-weight-loss/a-new-diet-to-manage-irritable-bowel-syndrome.
[55] Scarlata, Kate, and Dede Wilson. Low-FODMAP Diet Step by Step: a Personalized Plan to Relieve the Symptoms of IBS and Other Digestive Disorders--with More than 135 Deliciously Satisfying Recipes. Da Capo, Perseus Books/Hachette Book Group, 2018.
[56] Bustamante, Mariela, et al. “Effective Lactobacillus Plantarum and Bifidobacterium Infantis Encapsulation with Chia Seed (Salvia Hispanica L.) and Flaxseed (Linum Usitatissimum L.) Mucilage and Soluble Protein by Spray Drying.” Food Chemistry, Elsevier, 9 Aug. 2016, www.sciencedirect.com/science/article/abs/pii/S0308814616312493?via=ihub.
[65] “FODMAPs and Irritable Bowel Syndrome.” About FODMAPs and IBS | Monash FODMAP - Monash Fodmap, www.monashfodmap.com/about-fodmap-and-ibs/.
[66] Hewawasam, Samapriya P, et al. “Dietary Practices and FODMAPs in South Asia: Applicability of the Low FODMAP Diet to Patients with Irritable Bowel Syndrome.” Wiley Online Library, John Wiley & Sons, Ltd, 26 Jan. 2018, onlinelibrary.wiley.com/doi/full/10.1111/jgh.13885.
Longevity hotspots (a.k.a. Blue Zones) are areas around the world in which people live healthier and longer. The Blue Zone centenarians report eating diets high in fiber, which include vegetables, fruits, whole grains and nuts. Their focus on a plant-based diet explains their high consumption of fiber [26].
Specific examples of fibrous foods eaten by the 5 Blue Zone centenarians include [26,27]:
References:
[26] Buettner, Dan, and Sam Skemp. “Blue Zones: Lessons From the World’s Longest Lived.” American Journal of Lifestyle Medicine, vol. 10, no. 5, Sept. 2016, pp. 318–321, doi:10.1177/1559827616637066.
[27] Buettner, D. (2017). The Blue Zones Solution: Eating and Living Like the World's Healthiest People. Washington, DC: National Geographic.
Specific examples of fibrous foods eaten by the 5 Blue Zone centenarians include [26,27]:
- Sardinia, Italy: Beans, flatbreads, garden vegetables, fruits, chickpeas, barleys, fennel
- Okinawa, Japan: Sweet potatoes, soybeans, brown rice
- Loma Linda, CA, USA: Leafy greens, nuts, legumes, oatmeal, dates
- Nicoya, Costa Rica: Bananas, legumes, black beans, yams, squash, rice
- Ikaria, Greece: Fruits, vegetables, whole grains, beans, potatoes, leafy greens, nuts
References:
[26] Buettner, Dan, and Sam Skemp. “Blue Zones: Lessons From the World’s Longest Lived.” American Journal of Lifestyle Medicine, vol. 10, no. 5, Sept. 2016, pp. 318–321, doi:10.1177/1559827616637066.
[27] Buettner, D. (2017). The Blue Zones Solution: Eating and Living Like the World's Healthiest People. Washington, DC: National Geographic.