Fibre is the indigestible part of carbohydrates. It is found in many foods including fruits, vegetables, whole grains and legumes. There are two types of fibre:

Insoluble fibre does not dissolve in water. It is found in whole wheat carbohydrates, wheat bran, nuts, seeds, beans and many vegetables.

Soluble fibre dissolves in water and helps feed the good bacteria, or probiotics, that live in your digestive system. These bacteria have the enzymes required to break down fibre, but humans don’t. Fibre feeds these bacteria and is called a prebiotic. Probiotic bacteria are important for colon health, weight management, blood sugar control, immune function and brain function (1, 2, 3, 4, 5, 6). It is found in oats, peas, beans, apples, citrus fruits, carrots, barley and psyllium.

How does fibre benefit the body?

Fibre is an important part of the diet and has positive health benefits for many organ systems.

Weight loss

Fibre-rich foods are filling because they tend to be bulky and occupy space in the stomach. This helps you feel fuller faster to prevent overeating. Fibre slows digestion because it takes longer to break down than other foods. This keeps you feeling fuller longer after eating which can be helpful for weight loss (7). These foods are generally more calorically dense which means you can consume fewer calories with smaller amounts of food.

Diabetes

Fibre-rich foods take more time to be broken so they tend to cause a smaller increase in blood sugar after eating. They also tend to be whole foods that have been minimally processed with added sugar, salt and chemicals. This may be helpful for preventing or treating Type 2 diabetes (8).

Heart Disease

Soluble fibre in particular has been shown to bind cholesterol for elimination and reduce these levels in the blood (9, 10). This is especially true for LDL cholesterol (or bad cholesterol) so this may contribute to reduced risk of heart disease (11). Fibre may also benefit the cardiovascular system by lowering blood pressure and reducing inflammation.  

Digestion

Since fibre-rich foods are bulky and difficult to break down, they provide volume to your stools. The stretching of your bowel is one of the signals that waste is ready to be eliminated. Fibre can increase the frequency and consistency of bowel movements by signaling your bowels to move more regularly. This may reduce the risk of colon cancer in some individuals since cancer-causing molecules have less time to contact the intestinal walls. Fibre also softens hard stools which makes stools easier to pass for those who are constipated. For those with a tendency for loose stools, fibre can make the stool more solid by absorbing water and adding bulk.

How much fibre do I need?

How can I increase my fibre intake?

Increasing the amount of fibre in your diet can have a huge impact on your health. Foods that are high in fibre include

·        Fruits and vegetables

·        Whole grain products

·        Beans, peas, lentils, legumes

·        Nuts and seeds

Incorporating these foods into your meals and snacks can help you increase your daily fibre intake. Whole foods are the best way to improve the fibre in your diet, but there are also a number of fibre supplements available if you aren’t getting enough from your diet alone. It is important to discuss your fibre needs with your Naturopathic Doctor before adding a fibre supplement to your diet to ensure you are supplementing with the right form, in the right amount, at the right time.

Is it possible to have too much fibre in my diet?

Adding too much fibre too quickly can cause gas, bloating, cramping and general abdominal discomfort. Gradually increasing your fibre over a few weeks allows your body to adjust and reduce these symptoms. It is also important to drink lots of water to provide enough fluid for the fibre to absorb. This will keep your stools soft and easily passed to prevent constipation.

References:

1. Guarner F, Malagelada JR. (2003). Gut flora in health and disease. Lancet, 361(9356):512-9. 
2. Ley RE, Turnbaugh PJ, Klein S, Gordon JI. (2006). Microbial ecology: human gut microbes associated with obesity. Nature, 444(7122):1022-3.
3. Giovanni M, Gambino R, Cassader M. (2010). Obesity, diabetes and gut microbiota. Diabetes Care, 33(10):2277-2284.
4. Steinhoff, U. (2005). Who controls the crowd? New findings and old questions about the intestinal microflora. Immunology letters, 99(1):12-6.
5. Cryan, JF, O’Mahony, SM. (2011). The microbiome-gut-brain axis: from bowel to behavior. Neurogastroenterology and Motility, 23(3):187-92.
6. Wong JM, de Souza R, Kendall CW, Emam A, Jenkins DJ. (2006). Colonic health: fermentation and short chain fatty acids. Journal of Clinical Gastroenterology, 40(3):235-43.
7. Burton-Freeman, B. (2000). Dietary fiber and energy regulation. Journal of Nutrition, 130(2):272S-275S.
8. Weickert MO, Pfeiffer AF. (2008). Metabolic effects of dietary fiber consumption and prevention of diabetes. Journal of Nutrition, 138(3):439-42.
9. Arvill A, Bodin L. (1995). Effect of short-term ingestion of konjac glucomannan on serum cholesterol in healthy men. American Journal of Clinical Nutrition, 61(3):585-9.
10. Gato N, Kadowaki A, Hashimoto N, Yokoyama S, Matsumoto K. (2013). Persimmon fruit tannin-rich fiber reduces cholesterol levels in humans. Annals of Nutrition and Metabolism, 62(1):1-6.
11. Pereira MA, O’Reilly E, Augustsson K, Fraser GE, Goldbourt U, et al. (2004). Dietary fiber and risk of coronary heart disease: a pooled analysis of cohort studies. Archives of Internal Medicine, 164(4):370-6.
12. Government of Canada. (2017). Fibre. Retrieved from https://www.canada.ca/en/health-canada/services/nutrients/fibre.html