Today, there is so much information available about different diets and healthy eating, yet many of us are still confused about how to stay healthy. If you've followed any sort of diet or diet plan before, you're probably familiar with the concept of monitoring your carbohydrate, fat or protein intake. But if these are all you're focusing on, it’s likely you're missing out on one other very important nutrient, fibre!
But, what is fibre exactly? Dietary fibre is a non-digestible carbohydrate found in plants. We lack the enzymes to break down these fibres, so they go through our digestive tract mostly intact until they reach the colon. In the colon, they're either fermented by gut bacteria and used as fuel or to bulk the stool, making it easier to pass. Dietary fibre can be separated into two categories:
Soluble fibre includes pectin, found in pears and apples; beta glucans, found in oats; and prebiotics. It can feed your good gut bacteria, acting like a ‘fertiliser’, and helps to prevent the growth of bad bacteria. This good bacteria then produces useful molecules like short chain fatty acids (SCFA), which can help reduce inflammation, feed the cells in your colon, maintain the structure of your gut lining and support your immune system.
Insoluble fibre includes cellulose, found in fruit, vegetables, whole grains and nuts. This type of fibre doesn't dissolve in water or get digested by your gut bacteria, but supports bowel movements by adding bulk to stools, making them heavier and easier to pass.
Most plants contain a mixture of soluble and insoluble fibre, but may vary in amounts.
Health benefits of fibre
Fibre has a vast range of benefits, yet most of us aren't eating enough of it! The majority of the foods we eat today are processed, refined and stripped of fibre and other important nutrients.
Health benefits of fibre for digestion
The main health benefit of fibre is that it improves digestive function. Fibres such as resistant starch can improve gut dysbiosis by stimulating the growth of beneficial bacteria while also suppressing the colonies of bad bacteria at the same time.
Prebiotic fibres may also play a role in the management of autoimmune diseases like Hashimoto’s thyroiditis. Evidence suggests that, in addition to genetic and environmental factors, leaky gut syndrome may also be a contributing factor to the development of autoimmune diseases.
Health benefits of fibre for blood sugar levels
Another key health benefit of fibre is that it helps to balance your blood sugar levels. Eating fibre-rich foods can balance blood sugar levels by lowering the glycaemic index of meals, helping to prevent an initial sharp increase in blood sugar levels that is followed soon after by a crash. This can help to improve insulin sensitivity and reduce the risk of developing type 2 diabetes.
Fibre supports weight management
The way fibre benefits blood sugar levels has a knock-on effect on supporting weight management. In addition, excess glucose in your diet tends to be converted to fats and gets stored in fatty tissue rather than being used for energy, so consuming dietary fibre can support a healthy balance. This modulation of blood glucose may be associated with particular fibres promoting the secretion of hormones involved in appetite regulation (e.g. ghrelin) which can lower hunger and increase feelings of fullness. It has also been said that obesity has been associated with an imbalanced gut microbiome, so prebiotic fibres could be especially beneficial.
Fibre supports healthy cholesterol levels
Another essential health benefit of fibre, especially beta glucans, is that it helps to maintain healthy cholesterol levels. Consuming fibres in combination with probiotics has also been shown to help reduce total cholesterol and inflammatory markers, while increasing the levels of high-density lipoprotein (HDL) (aka ‘good’ cholesterol).
Health benefits of fibre for hormone balance
Another way fibre can benefit your health is by binding to hormones in your gut after they’ve been detoxified by your liver, and safely eliminating them from the body.
Health benefits of fibre for the immune system
Prebiotics, in particular arabinogalactans (found in foods like leek and radishes) can strengthen your innate immune system, your first line of defence against pathogens.
Sources of fibre
It’s important to remember that many sources of fibre, especially fruit and vegetables, contain lots of other beneficial nutrients such as vitamins, minerals, flavonoids and polyphenols, which all contribute to keeping you healthy. Increasing your intake of fibre, especially prebiotic fibre, should be at the top of your list if you want to improve your health.
Here are some tips for increasing your intake of fibre-rich foods:
Add fibre-rich foods into your diet:
Jerusalem artichoke, banana, asparagus, garlic, onions and chicory.
Leeks, carrots, radish, pears, tomato and turmeric.
Legumes, eg. peas, lentils and beans.
Green bananas, cooked and cooled potatoes.
Make simple swaps: An easy change you can make is by swapping your white and refined carbohydrates such as bread, pasta and rice for whole grain alternatives. These also naturally contain other beneficial nutrients that support overall health.
Increase your daily intake of vegetables and fruits: Aim to eat 7 portions of vegetables and 3 portions of fruits daily. ‘Eat the rainbow’ by including lots of variety and colourful plants. Frozen vegetables and fruits are convenient and have a long shelf life, and are just as nutrient dense as fresh varieties, so stock up your freezer!
Eat the whole vegetable: Broccoli stalks, cauliflower leaves, carrot tops and potato peels are all high in fibre and rich in other nutrients.
How much fibre do you need?
The UK government recommends a daily fibre intake of 30g for adults. Although fibre-rich foods are easily available, most adults consume only about 18g per day, which is far less than what we should be getting in our diets. This trend is also seen in children.
Some people might avoid fibre because they have a sensitive gut and experience symptoms of bloating and gas, or have digestive conditions such as IBS (Irritable Bowel Syndrome). If so, aim to start by eating small amounts and increase your fibre intake slowly to allow your digestive system to adjust over time.
Getting enough fibre in your diet is key for optimal health. The health benefits of fibre are numerous, so eating more fibre will likely make you feel better in both the short and long term, especially as fibre-containing foods tend to be nutrient dense, so you will up your daily intake of other essential vitamins and minerals too.
Focusing on incorporating more fruits and vegetables into every meal and swapping refined grains for whole grain versions will help you to reach your daily fibre goal.
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The impact of soluble dietary fibre on gastric emptying, postprandial blood glucose and insulin in patients with type 2 diabetes
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