The Health Benefits of Fibre

96% of the UK population fails to eat enough fibre and this statistic is consistently high across much of the developed world. The UK recommended daily amount for fibre is 30g yet the average consumption by an adult is only 20g. Fibre is a nutrient with numerous health benefits. Addressing this fibre gap could have a major effect on public health but it will require behaviour change on behalf of consumers and innovation from manufacturers.

What is fibre?

There are 4 main types of fibre, [DN - link to article] all of which have one thing in common: they are not digested in our small intestine and therefore reach our colon, or large intestine, intact, where they can fulfil a number of beneficial roles. Some will be digested by our gut bacteria, and some will pass all the way through us, playing a more mechanical role in supporting digestion.

The UK Scientific Advisory Committee on Nutrition published a comprehensive report on carbohydrates and health, including an in-depth review of the benefits of fibre to health. Here, we’ll review the main findings.

They key point to make is that, to get the benefits of fibre, it’s necessary to consume the recommended 30g per day from multiple sources, including wholegrains, pulses, nuts, seeds, vegetables and fruits.

Cardiovascular health

•       Dietary fibre is linked to a reduced risk of cardiovascular disease (CVD), coronary events and stroke

•       Insoluble fibre, which is found in wholegrains, pulses, nuts and seeds, and vegetable fibre may help reduce risk of CVD and coronary events

•       Higher consumption of cereal fibre, such as that from wholegrains like oats, wheat, and rye is linked to reduced risk of coronary events

•       Oat bran and beta glucans may help reduce blood pressure

•       Both of these are also linked to reductions in total and LDL-cholesterol and triglycerides (a type of fat found in the blood)

•       Consuming cereals, high fibre breakfast cereals and wholegrains is linked to a lower risk of CVD and stroke

•       A type of fibre that’s soluble and small in size, known as resistant oligosaccharides, specifically fructo-oligosaccharides and inulin may help reduce LDL-cholesterol but only in very large amounts, inconsistent with current daily diet. However, brands are beginning to use these fibres in food or they can be purchased as supplements so consumption may increase in the future.

Cancer risk reduction

•       Higher consumption of dietary fibre is linked to a reduced risk of colon and rectal cancer

•       Cereal fibre is linked to a reduced risk of colorectal cancer

•       Wholegrain intake is associated with a reduced risk of colon cancer

Type 2 diabetes

•       Higher consumption of dietary fibre, specifically cereal fibre is linked to a reduced risk of type 2 diabetes

•       Eating more insoluble and soluble fibre may reduce risk of type 2 diabetes

•       Wholegrains including wholegrain bread and high fibre cereals are associated with a reduced risk of type 2 diabetes

Gut health

•       Dietary fibre overall, particularly wheat and non-wheat cereal fibre and fruit/veg fibre may increase stool weight and reduce intestinal transit time, thereby supporting digestion

•       Fibre from pulses is also linked to increased stool weight

•       Cereal fibre may reduce constipation while wheat fibre might reduce intestinal transit time in those with constipation

•       Resistant starch is linked to increased stool weight and, when digested by our gut bacteria, can produce short chain fatty acids (SCFA), which can potentially benefit gut and immune function). Again, this is at levels higher than current consumption, so we shout try to increase the amount of resistant starch that we eat. It can be found in unripe bananas, grains, pulses, rice and potatoes (if cooked and cooled), dried pasta (after cooking)

•       Resistant oligosaccharides (galacto- and fructo-oligosaccharides and inulin) may change bacterial balance in the stool, SCFA production and stool pH in babies but it’s unclear how this might affect their health

Weight management

•       While it feels logical to assume high fibre foods will increase feelings of fullness and thereby reduce calorie intake (and consequently weight), it is hard to show this in studies. We therefore need to do more research on how fibre might influence appetite and weight

•       Higher wholegrain vs refined grain consumption is linked with a lower overall calorie intake

It’s clear that increasing fibre intake, from a wide variety of sources, to try to achieve the 30g daily target is a strongly evidence-based public health target. For more information on how you can increase your fibre intake, have a look at our article here. [DN – link to how to eat more fibre article]