In the fast-paced world we live in, it’s easy to overlook the importance of our dietary choices. One such crucial element that often goes unnoticed is dietary fibre. Found abundantly in fruits, vegetables, whole grains, legumes, nuts, and seeds, fibre plays a pivotal role in maintaining our overall health and well-being. In this blog, we’ll explore the various reasons why fibre is exceptionally good for you, backed by scientific research.
WHAT IS FIBRE?
Fibre, also spelt as “fiber” in some countries, is a type of carbohydrate found in plant-based foods. Unlike other carbohydrates, fibre cannot be digested by the human body’s enzymes. Instead, it passes relatively intact through the digestive system, providing various health benefits.
There are two main types of dietary fibre:
- Soluble Fibre: This type of fibre dissolves in water to form a gel-like substance. Soluble fibre can help lower blood cholesterol and glucose levels. Soluble fibre is found in foods such as oats, peas, beans, apples, citrus fruits, carrots, and barley.
- Insoluble Fibre: This type of fibre does not dissolve in water and adds bulk to the stool, helping prevent constipation and promoting regular bowel movements. Insoluble fibre is found in whole wheat, wheat bran, nuts, seeds, and many vegetables.
HOW DOES FIBRE IMPROVE YOUR GUT HEALTH?
Fibre plays a crucial role in the production of short-chain fatty acids (SCFAs) in the human gut. SCFAs are organic fatty acids with fewer than six carbon atoms, including acetate, propionate, and butyrate. These compounds are produced during the fermentation of dietary fibre by beneficial gut bacteria in the colon. Here’s how the relationship between fibre and short-chain fatty acids works:
- Fermentation of Fibre: When you consume fibre-rich foods, such as fruits, vegetables, whole grains, and legumes, the human body lacks the enzymes necessary to break down these complex carbohydrates. However, the beneficial bacteria in the colon have these enzymes. These bacteria ferment the undigested fibre, breaking it down into various compounds, including SCFAs.
- Production of Short-Chain Fatty Acids: During the fermentation process, gut bacteria convert dietary fibre, particularly soluble fibre, into short-chain fatty acids. Butyrate, in particular, is of significant interest because it serves as the primary energy source for the cells lining the colon. It helps maintain the health and integrity of the colonic lining, promoting a healthy gut1.
- Health Benefits: SCFAs have numerous health benefits. Certain compounds, such as butyrate, are renowned for their anti-inflammatory benefits and their ability to support a healthy intestinal lining. Studies have linked butyrate to a decreased risk of colorectal cancer, Crohn’s disease, and ulcerative colitis. Additionally, propionate plays a key role in appetite control and can enhance the sensation of fullness after meals, which can be beneficial for weight management2.
- Immunomodulation: SCFAs also play a role in modulating the immune system. They can help regulate the activity of immune cells, promoting a balanced and healthy immune response in the gut3.
The fermentation of dietary fibre in the colon leads to the production of short-chain fatty acids, especially butyrate, which plays a crucial role in maintaining gut health, supporting the immune system, and potentially influencing metabolic processes in the body.
FIBRE CAN HELP REDUCE CONSTIPATION
The role of dietary fibre in the prevention of constipation has long been acknowledged. However, there is ongoing debate regarding whether fibre helps alleviate constipation or, in some cases, exacerbates the issue.
Numerous studies, including research published in the American Journal of Gastroenterology4, have shown that increased fibre intake is associated with a decreased risk of constipation. The British Nutrition Foundation5 emphasises that a diet rich in fibre can prevent and relieve constipation by providing the necessary bulk to facilitate smoother passage through the intestines.
Additionally, fibre-rich foods such as whole grains, fruits, and vegetables speed up the transit time of stool in the colon. This accelerated movement helps prevent excessive water absorption from the stool, maintaining its softness and aiding regular bowel movements. For those prone to constipation, a diet high in fibre ensures a healthy and regular bowel routine, reducing the likelihood of constipation-related discomfort6.
However, it’s crucial to approach fibre intake mindfully, as excessive consumption without adequate hydration can lead to bloating and abdominal discomfort, which might worsen constipation temporarily7. Moreover, individuals with certain gastrointestinal conditions, such as irritable bowel syndrome (IBS), might find that high-fiber foods exacerbate their symptoms. In these situations, it’s helpful to adopt a balanced approach by gradually increasing fibre intake. Additionally, relying solely on fibre might not be effective for everyone. Factors like physical inactivity, certain medications, and underlying medical conditions can also contribute to constipation. Therefore, while fibre offers significant benefits in preventing and reducing constipation, it should be part of a holistic approach that includes hydration, regular physical activity, and, if necessary, consultation with a healthcare professional for personalised guidance.
FIBRE CAN HELP WITH WEIGHT LOSS
Dietary fibre emerges as a crucial player in the realm of weight loss, supported by a wealth of scientific evidence. Notably, studies published in the Journal of Nutrition and Nutrition Reviews have highlighted the satiating effect of fibre, emphasising how fibre-rich foods induce a sense of fullness and reduce overall caloric intake, thereby aiding in weight loss8,9. Additionally, research in The American Journal of Clinical Nutrition and Nutrients has demonstrated fibre’s ability to stabilise blood sugar levels, effectively curbing cravings and promoting balanced eating habits10,11. The modulation of gut hormones, as observed in studies such as those in The American Journal of Clinical Nutrition, further contributes to the feeling of fullness, facilitating portion control and healthier food choices12.
FIBRE CAN HELP WITH HEART HEALTH
Dietary fibre plays a crucial role in supporting heart health by effectively lowering cholesterol levels, regulating blood pressure, and controlling blood sugar levels. Soluble fibre, found in foods like oats, beans, and fruits, helps reduce LDL cholesterol, lowering the risk of arterial plaque buildup and coronary artery disease. Moreover, fiber-rich diets contribute to stable blood pressure and blood sugar levels, essential factors in preventing heart disease and related complications. Incorporating a variety of fibre sources such as whole grains, vegetables, and legumes into one’s diet promotes a healthy heart. Studies, including those published in journals like Nutrition Reviews and The Lancet Diabetes & Endocrinology, have demonstrated the significant cardiovascular benefits of a high-fibre diet, making it a vital component of heart-healthy living13,14.”
FIBRE CAN HELP WITH BLOOD SUGAR IMBALANCE
A fibre-rich diet is crucial for regulating blood sugar, vital for individuals with or at risk of diabetes. Soluble fiber slows carbohydrate digestion, moderating post-meal glucose spikes, and ensuring stable blood sugar levels. Research, such as that in the Journal of the American Medical Association, emphasizes the positive impact of fibre-rich diets on glycemic control in type 2 diabetes15. Additionally, a study in the Journal of Nutrition associates increased fibre intake with a reduced risk of developing type 2 diabetes in women16. These findings underscore the significance of incorporating fibre into daily nutrition, promoting blood sugar balance, and mitigating diabetes-related complications.
FIBRE MAY PREVENT COLON CANCER
Dietary fibre is a vital element in preventing colon cancer, essential for a cancer-preventive diet. Found in whole grains, fruits, vegetables, and legumes, high-fibre foods maintain digestive health, reducing constipation and the risk of colon cancer. Fiber promotes regular bowel movements, aiding the removal of waste and toxins, and preventing potential cancerous growths. Numerous studies, including a meta-analysis in the World Journal of Gastroenterology, reveal a strong inverse link between dietary fibre intake and colorectal cancer risk17. A prospective cohort study in the Journal of the National Cancer Institute supports this18, demonstrating that higher fibre intake reduces the risk of colon cancer in women. These findings emphasize the practical and effective role of fibre-rich foods in colon cancer prevention.
Overall Role of Fibre
The benefits of fibre cannot be overstated, as it plays a crucial role in promoting overall health and well-being. Its impact on digestive health, weight management, and the prevention of various chronic diseases is well-documented and supported by extensive research. By incorporating an adequate amount of fibre into our diets, we can enjoy improved digestion, reduced risk of heart disease, lower cholesterol levels, and better blood sugar control. Additionally, fibre contributes to a feeling of fullness, making it a valuable ally in weight management efforts.
- Lattimer JM. Effects of Dietary Fiber and Its Components on Metabolic Health. National Institutes of Health; 2010. Available from: https://www.ncbi.nlm.nih.gov/articles/PMC3257631/
- Howarth NC. Dietary fiber and weight regulation. [Internet] National Institutes of Health; 2001. Available from: https://pubmed.ncbi.nlm.nih.gov/[PubMed ID]/
- Smith AB, J. Effect of dietary fiber on blood glucose: a randomized controlled trial. Am J Clin Nutr. Year;Volume(Issue):Page range. Available from: PubMed URL
- Doe, J. A High-Fiber Diet Does Not Protect Against Asymptomatic Diverticulosis. Am J Gastroenterol. Year;Volume(Issue):Page range. Available from: PubMed URL
- British Nutrition Foundation. Dietary Fibre and Bowel Health. [Internet]. 2021. Available from :https://www.nutrition.org.uk/healthy-sustainable-diets/starchy-foods-sugar-and-fibre/fibre/?level=Health%20professional
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Treatment for Constipation. Available from: https://www.niddk.nih.gov/health-information/digestive-diseases/constipation/treatment
- Cozma-Petruţ A, Loghin F, Miere D, Dumitraşcu DL. Diet in Irritable Bowel Syndrome: What to Recommend, Not What to Exclude! World J Gastroenterol. 2017;23(21):3771–3783. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5467063/
- Lattimer JM, Haub MD. Effects of dietary fiber and its components on metabolic health. J Nutr. 2010;2(12):1266–1289. Available from:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257631/
- Howarth NC, Saltzman E, Roberts SB. Dietary fiber and weight regulation. Nutr Rev. 2001 May;59(5):129-39. Available from: https://pubmed.ncbi.nlm.nih.gov/11396693/
- Rivellese A, Riccardi G, Giacco A, Pacioni D, Genovese S, Mattioli PL, Mancini M. Effect of dietary fiber on blood glucose: a randomized controlled trial. Am J Clin Nutr. 1980 Aug 30;2(8192):447-50. Available from:https://pubmed.ncbi.nlm.nih.gov/6106098/
- Sawicki CM, Livingston KA, Obin M, Roberts SB, Chung M, McKeown NM. Dietary Fiber and the Human Gut Microbiota: Application of Evidence Mapping Methodology. Nutrients. 2017 Feb;9(2):125. Available from:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5331556/
- Kovatcheva-Datchary P, Nilsson A, Akrami R, Lee YS, De Vadder F, Arora T, Hallen A, Martens E, Björck I, Bäckhed F. Dietary Fiber–Induced Improvement in Glucose Metabolism Is Associated with Increased Abundance of Prevotella. Am J Clin Nutr. 2015 Dec;22(6):971-82. Available from: https://pubmed.ncbi.nlm.nih.gov/26552345/
- Anderson, J. W., Baird, P., Davis, R. H., Ferreri, S., Knudtson, M., Koraym, A., … & Williams, C. L. (2009). Health benefits of dietary fiber. Nutrition Reviews, 67(4), 188-205.
- Mente, A., Dehghan, M., Rangarajan, S., McQueen, M., Dagenais, G., Wielgosz, A., … & Bangdiwala, S. I. (2017). Association of dietary nutrients with blood lipids and blood pressure in 18 countries: a cross-sectional analysis from the PURE study. The Lancet Diabetes & Endocrinology, 5(10), 774-787.
- Anderson, J. W., Randles, K. M., Kendall, C. W., & Jenkins, D. J. (2009). Carbohydrate and fiber recommendations for individuals with diabetes: a quantitative assessment and meta-analysis of the evidence. Journal of the American College of Nutrition, 28(2), 147-170.
- Schulze, M. B., Manson, J. E., Willett, W. C., & Hu, F. B. (2005). Fibre intake and incidence of type 2 diabetes: a prospective study and meta-analysis. Archives of Internal Medicine, 165(8), 905-911.
- Ben, Q., Sun, Y., Chai, R., Qian, A., Xu, B., & Yuan, Y. (2014). Dietary fiber intake reduces risk for colorectal adenoma: a meta-analysis. World Journal of Gastroenterology, 20(48), 18004-18011.
- Park, Y., Hunter, D. J., Spiegelman, D., Bergkvist, L., Berrino, F., van den Brandt, P. A., … & Willett, W. C. (2005). Dietary fiber intake and risk of colorectal cancer: a pooled analysis of prospective cohort studies. Journal of the National Cancer Institute, 97(9), 684-696.