Listen to your mother when she tells you not to pass on the peas at dinner. Peas have long been hailed as an excellent source of protein, often considered a hypoallergenic, vegan alternative to whey protein supplements (see Dr. Hrkals comparison of pea and whey protein here). New benefits of pea protein hydrosylates as antioxidants, and support for cardiovascular and renal health have come to light in the last few years. Clinical and preclinical research suggests that peptides from pea protein may have some blood pressure lowering effects. Preclinical studies in hypertensive rats found there was a significant reduction in systolic blood pressure
Dietary fibre plays an important role in maintaining gut health and function. Fibre is useful in helping feel full after meals, ensuring our bowel movements are regular as well as stimulating the growth of healthy bacteria to allow the gut microbiome to thrive. It is important that fibre, both soluble and insoluble, is included in everyday consumption to ensure optimal gut health (1). These fibres are found in a variety of different foods as well as prebiotic and full fibre supplements that can be used in times of bowel irregularity or for general health and maintenance.
Fibre for healthy bowel movements
Insoluble fibres are traditionally found in higher amounts in vegetables, wheat, and most grains and are important to maintaining gut health. They have the remarkable capacity to hold water and to bulk up stool, resulting in more gentle bowel movements that are softer, reducing incidents of constipation as well as the abdominal straining. Reduction in abdominal straining is particularly important as straining is thought to potentially result in increased incidents of haemorrhoids, varicose veins as well as pressure related changes to the bowel known as diverticula.
Useful in both diarrhea and constipation
One of the most interesting things to know about fibre is how it can alter the speed of transit of bowel contends depending on the situation. We’ve already discussed how insoluble fibre can help improve stool softness and increase transit time in times of constipation; it is important to note that soluble fibre can also do this to a lesser extent. In times of undesired loose bowel movements or diarrhea, insoluble fibre helps slow transit time so that loose stools can become more bulky.
Insoluble fibre is also used as fuel for the bacteria found in the colon, stimulating growth of a number of beneficial bacteria that ferment the fibre to form short chain fatty acids that improve the health of surrounding bowel and lower the pH of the intestine to improve gut flora (2). One type of insoluble fibre, Xylooligosaccharide (XOS), is particularly useful as a prebiotic that promotes growth of Bifidobacterium –important inhabitants of healthy guts known for helping provide stability and prevention of disease (3). XOS is also able to lower cholesterol, improve blood sugar as well as absorption and production of B-complex vitamins (2).
Fibre to feel full
Soluble fibre, found in fruits, oats, barley as well as legumes, can combine with liquids to form a gel that slows gastric emptying. This gel can help activate stretch receptors in the stomach, providing a pronounced feeling of fullness which can decrease overeating. Soluble fibres are also especially useful in their ability to lower blood cholesterol by reducing fat abortion.
Fibre to improve blood sugar
Both soluble and insoluble fibres have been shown to improve glycaemic control, help in maintaining gut health and reduce cholesterol in those with type 2 diabetes mellitus (4). Those that consumed a diet rich 50 g of fibre per day (fruits, vegetables, grains and legumes) for six weeks had significant improvements in their fasted blood glucose levels and urinary glucose levels. It was recommended that 50% of the fibre be soluble to help ensure that overconsumption of carbohydrates was limited and to delay gastric emptying so that carbohydrate levels in the small intestine were more consistent over time without quick increases.
Fibre for protection against colon cancer
There is a growing body of literature that suggests that dietary fibre intake likely plays a part in decreasing risk of colon cancer development. Colorectal cancer is among the most frequent cancers in the world and is influenced by diets with heavier intake of red meats, high saturated fats and reduced vegetable intake (6). Based off of cancer reporting rates; areas of the world with lower fibre intake have higher incidents of colon cancer. It should also be noted that vegetarians are found to have a significantly lowered incident of colon cancer, presumably because of their increased intake of dietary fibre (5). How does fibre provide this potential preventative action? Referred to as the “fibre hypothesis”, it is believed that fibre might bind & dilute carcinogens in the gut and increase intestinal transit time, which would allow for reduced contact time between carcinogens and the bowel wall. Additionally many sources of fibre are rich in lignins; unique compounds with anti-cancer properties. While the causes of colorectal cancer are still unclear, the evidence continues to show that fibre may have an important protective function.
- Gaby, Alan R. Nutritional Medicine. 1st. Concord : Fritz Perlberg Publishing, 2011. pp. 211-214.
- Xylooligosaccharides: an economical prebiotc from agroresidues and their health benefits. Jain, Ira, Kumar, Vikash and Satyanarayana, T. 2015, Indian Journal of Experimental Biology, pp. 131-142.
- The Role of Bifidobacteria in Health. Reyed, Reyed M. 2007, Research Journal of Medicine and Medical Sciences, pp. 14-24.
- A diet containing food rich in soluble and insoluble fibre inmproves glycemic control and reduces hyperlipidemia among patients with type 2 diabetes mellitus. Mcintosh, Michael and Miller, Carla. 2, 2001, Nutrition Reviews, Vol. 59, pp. 52-55.
- Mechanism and experimental and epidemiological evidence relating dietary fibre (non-starch polysaccharides) and starch to protection against large bowel cancer. Bingham, Sheila A. 1990, Proceedings of the Nutrition Society, pp. 143-171.
- Polyphenols, glucosinolates, dietary fibre, and colon cancer: understanding the potentail of specific types of fruit and vegetables to reduce bowel cancer progression. Eid, Noura, et al., et al. 2014, Nutrition and Aging, pp. 45-67.
- Soluble fiber polysaccharides: effects on plasma cholesterol and colonic fermentation. Topping, DL. 1991, Nutrition Review, pp. 195-203.