Fibre is an essential nutrient in our diet which mainly comes from wholefoods such as fruits, vegetables, wholegrains and nuts. An adequate fibre intake is key to a healthy gut and regular bowel movements. How much fibre do we need, why is it good for us and should we take a fibre supplement? Let’s find out!November 16, 2022 6:00 pm March 30, 2022 5:34 pm
What is fibre?
Dietary fibre is a component of plant foods that is not fully digested by our bodies. High fibre intakes in the diet lead to multiple health benefits including reduced constipation, decreased risk of developing type 2 diabetes, heart disease and colorectal cancer. In fact, the healthiest diets always include dietary fibre. Overall there are multiple types of dietary fibres which can be classified by their characteristics which include solubility, fermentability and viscosity.
The nature of each type of dietary fibre determines the specific role they play in the body.
Moreover, fibre is often categorised as either soluble or insoluble, however there are other physiochemical characteristics of fibre that we need to consider in order to understand the full spectrum of dietary fibre.
Fermentability of fibre
Fermentability is one of three essential properties to characterise fibre. In addition, the other two are solubility and viscosity. Fermentability is a scientific term to describe the process which occurs when fibre is broken down by the bacteria in our gut.
Fermentation takes place in our large intestine, where our gut bacteria essentially “eats” fibre and as a result, produces short-chain fatty acids and gases as by-products of the fermentation process.
If you think about how alcoholic beverages such as wine and beer are made, it involves a similar process. Put simply, alcoholic fermentation occurs when yeast uses sugar as fuel to produce ethanol, carbon dioxide and other byproducts. In fact, sugar is the fuel for yeast much like fibre is the fuel for our gut bacteria.
Viscosity of fibre
Dietary fibre can also be categorised based on its viscosity. Viscous fibres develop a thicker consistency when mixed with liquids. Examples of viscous fibres include psyllium, beta-glucans (found in oats, barley and fungi) and pectins (found in fruit, vegetables and legumes). When we eat viscous fibres, they form a gel like substance in our gut, this can decrease the absorption rate of certain nutrients such as glucose.
Moreover, other fibres such as cellulose (found in cell walls of green plants) and resistant starch (found in cooked and cooled starchy foods such as potatoes are non-viscous. Cellulose is also an insoluble fibre and resistant starch has very low solubility in water. However, these types of fibres play a different role in the body from viscous fibres. In fact, they add bulk to our stool and help keep our bowel movements regular. (1)(2)
“High intakes of dietary fibre play a preventative role in reducing the risk of developing type 2 diabetes.”
Fibre for optimal gut health
Sources of low fermentable fibre (for example, cellulose found in all leafy greens) help prevent constipation by adding bulk to stool. It is important to ensure that you are getting enough fluid intake to go accompany your fibre intake. In addition, low fibre diets have been linked to conditions such as diverticulitis and in the worst cases, colorectal cancer. Diverticulitis occurs when pouches form inside your intestines and become inflamed or infected. A fibre-rich diet will keep your gut in good shape!
Fibre for a healthy heart
Some fermentable fibres such as beta-glucans found in oats have been found to reduce cholesterol levels. In fact, a review of the scientific literature found that an intake of at least 3g per day of oat beta-glucans may reduce total cholesterol and LDL (bad) cholesterol levels by up to 10% in both people with high cholesterol and normal cholesterol.(3)
Fibre to regulate blood sugars
Moreover, dietary fibre intake can improve glycaemic control and plays a crucial role in the management of type 2 diabetes. In fact there is evidence to show that high intakes of dietary fibre play a preventative role in reducing the risk of developing type 2 diabetes. Overall, a fibre-rich diet has also been shown to increase satiety and delay the onset of hunger.(4)(5)
How much fibre do I need?
In the UK, most people are averaging about 18g of fibre per day, this is well below the recommended 30g/day for adults. Children need less fibre than adults although even they are not hitting their daily targets. Younger children between 2 and 5 years of age require approximately 15g/day, 5 to 11 year olds require roughly 20g/day, and older children (11 to 16 years) require 25g/day.
Fibre is naturally abundant in a large variety of foods, particularly fruits, vegetables and whole grains.
Eat more fruits and vegetables – fruits and vegetables are some of the highest natural sources of fibre! Not only are they full of essential vitamins and minerals, they will also help keep your gut in top condition thanks to their fibre content. Remember that drinking fruit juice is not the same as eating whole fruit because you are often missing out on all the gut-friendly fibre!
- Have fibre-rich snacks. Snacking on fibre-rich foods is a great way to increase your daily fibre intake. Our fibre-rich crackers are a tasty way to sneak more fibre into your day.
- Switch from regular grains to whole grains. Switch from regular white bread to wholemeal bread or bread with grains and seeds, white rice to brown rice, regular pasta to wholewheat pasta. These small changes will add up to increase your fibre consumption. Oats and porridge are also great options for a fibre-friendly breakfast!