Introduction 

Have you ever wondered why your healthcare provider advises you to add more fibre to your diet? Or looked at the nutrition label on a cereal box and wondered why it includes an amount for fibre? Fibre plays a huge role in our daily nutrition. From its role in promoting gut health to its importance in cholesterol regulation and heart health. Although fibre is an important component of every human's diet, consuming adequate amounts of it becomes even more important as we age.

In this article, we will discuss what is referred to as “dietary fibre”, the types of dietary fibre, its health benefits, and its role in the treatment and management of several diseases.

What is dietary fibre?

Dietary fibre is a type of non-digestible carbohydrate that is found as polysaccharides in plant-based foods. Polysaccharides found in plant cell walls are what majorly make up dietary fibre.¹ There are two types of fibre: soluble and insoluble fibre. Soluble fibres, as the name implies, can mix with water. This form of fibre comes from sources like vegetables, fruits, and some grains. Insoluble fibres act as bulk in our gut to help move waste along. They are found in whole-grain foods, root vegetables and cereals.²

Apart from their role in helping bulk up waste in your gut so it passes through easier fibre helps improve metabolism, control cholesterol and blood sugar and maintain a healthy BMI.

So, how much fibre should you be eating? 

British Heart Foundation recommends that adults eat 30 grams of fibre a day. However, as we discussed earlier, not all fibre is the same. Fibre consists of a lot of different components that are found in varying degrees in different foods. Here are examples of the different fibre components and some of the foods they are found in.

• Cellulose: a type of insoluble fibre, cellulose is the major structural component of plant cell walls. It is found in most plants, vegetables, and fruits
• Hemicellulose is a cell wall polysaccharide. It is also water-insoluble and is found in whole grains and legumes
• Lignin: A non-carbohydrate cell wall component, lignin is water-insoluble and is found in the woody parts of plants, such as the stems and roots. Additionally, it resists being broken down by bacteria, making it of little nutritive value but great at bulking up waste in the gut.³
• Pectin: a gel-forming, water-soluble form of fibre. It is mainly present in fruits like berries, apples and stone fruits. Vegetables like carrots and cucumbers also contain some amounts of pectin
• Gums and Mucilages: these are derived from the seeds of plants like gua, locust bean, and agar agar. They have a gel-like consistency and are water-soluble. These are often used in the pharmaceutical industry in the formulation of medicines

Health benefits of high-fibre foods 

Digestive health 

• Prevention of constipation: One of the major roles of fibre is to promote gut motility and prevent constipation. It prevents constipation by adding bulk to stool and absorbing water, making it easier to move through you.
• Management of Irritable Bowel Syndrome (IBS): IBS is a gastrointestinal disorder of the intestines that sometimes presents with constipation and has been thought to be caused by a deficiency in dietary fibre intake.³ Increased soluble fibre intake has been shown to improve symptoms for some people with IBS.

Weight management 

• Reduced calorie absorption: Because some forms of fibre cannot be absorbed by the body, including them in foods helps increase food bulk without adding calories. This helps you eat the same quantity of food but absorb fewer calories which promotes weight loss. 

Heart health 

• Lowering cholesterol levels: A high-fibre diet has been shown to help reduce LDL cholesterol in the blood.
• Managing blood pressure: Studies have shown that increased fibre intake indirectly promotes lower blood pressure through decreased body weight and decreased blood sugar.⁴

Reducing the risk of type 2 diabetes 

• Stabilising blood glucose levels: Some studies show that a diet rich in insoluble fibre increases the rate at which food passes through the gut which leads to less time in the gut and less absorption of simple sugars. Fibre also helps control glucose levels through its role in decreasing appetite.⁵

Colon health 

• Reducing the risk of colon cancer: Consuming whole grains as a major component of your diet has been shown to decrease the risk of cancer and other colon-related diseases like diverticulosis. Fibre helps decrease the risk of colon cancer by increasing stool bulk, diluting faecal carcinogens, and decreasing transit time, thus reducing the contact between carcinogens and the lining of the colorectum.⁶
• Promoting regular bowel movements: Fibre also promotes regular bowel movements much in the same way it protects against colon cancer by increasing stool bulk, decreasing stool transit time, and enhancing beneficial bacteria in the gut

Fibre content in common foods

Below is a table of different foods that are a source of fibre.⁷

Tips for incorporating high-fibre foods into your diet 

Gradual transition to higher fibre intake 

Although introducing adequate amounts of fibre to your diet has multiple benefits, it is important to do it the right way. If you are not used to eating fibre, you need to introduce it gradually into your diet. One way to up your fibre intake is to choose wholegrain versions of foods you are already eating. Other good easy sources of fibre are fruits, vegetables, and legumes. Another way to increase fibre in your diet is to include any edible peels of the foods you eat, like potatoes, apples and pears.

Reading food labels 

The amount of fibre in any food, especially processed foods, is dependent on how they are prepared and how much of the foods you eat. It is important to read nutrition labels on packaged foods to better understand how much fibre you are getting from a serving of that food.

Hydration and fibre intake 

Fibre absorbs a lot of water, so increasing your fibre intake also means increasing your water intake throughout the day.

Potential challenges and how to overcome them 

Digestive discomfort

The benefits of fibre to your health cannot be understated. However, you should listen to your body when increasing fibre in your diet as it may lead to stomach cramps, gas, bloating, constipation or diarrhoea. A gradual increase rather than a sudden one can help with these symptoms. Also, staying hydrated and cooking certain vegetables instead of eating them raw might help make them easier to tolerate. Consider changing foods that cause you discomfort to other fibre-rich foods that you are better able to tolerate.

Taste preferences

Let us face it: sometimes ultra-processed fibre-deprived foods may taste better than whole grain foods. However, there are plenty of high-fibre foods that taste great too. Choosing fresh foods and introducing more variety in the foods you eat will help you discover great-tasting foods. Also, eating more natural fibre-rich foods will make you eventually adapt to the natural tastes of foods.

Dietary restrictions 

People with certain dietary restrictions like lactose intolerance and gluten sensitivity should avoid high-fibre foods that contain the compounds they are sensitive to. Some medications may interact with fibre to make them more or less effective. It is advisable to talk to your healthcare provider about any medications you are taking and how your change in diet might affect them.

Summary

Fibre can be grouped into soluble and insoluble forms; it is primarily found in plant-based foods and contributes to various aspects of our health. Soluble fibre is most commonly found in foods like vegetables and fruits. These can be dissolved in water. Insoluble fibre is present in legumes, whole grains, and root vegetables, and it helps add bulk to the waste passing through the gut.

High-fibre foods have a plethora of health benefits, including blood sugar regulation, weight management, protection from colon cancer, and heart health promotion. Fibre also prevents constipation by improving gut motility, which helps manage some symptoms of conditions like irritable bowel syndrome (IBS). 

Incorporating high-fibre foods into your diet has to be done gradually to avoid any ill effects. Opting for whole grain versions of your favourite foods, adding fruits, vegetables, and legumes, and consuming the edible peels of foods you already eat are good ways to increase fibre intake. Reading food labels can help you understand what type of fibre and how much fibre is in your food. As fibre intake increases, there is also a need to increase water consumption as fibre absorbs water.

Some challenges associated with increased fibre intake, such as digestive discomfort and changing taste preferences and medication interactions, can be combated by experimenting with different types of fibre-rich foods, introducing fibre gradually and always consulting with your healthcare provider.