We all hear this word “fibre” and kind of know what it is and where it comes from. But it’s important that we understand exactly what fibre is and what its function is. When we really comprehend something it is easier to remember it and apply it. And fibre is a pretty important one, yet often overlooked.
What is Fibre
Fibre, also referred to as “roughage” or “bulk”, is essentially the carbohydrate compounds in plants that are indigestible for humans. It passes through the digestive system relatively unchanged, offering no nutrients or energy to our bodies. Nevertheless, fibre plays a very important role in helping our complex digestive systems function and stay healthy.
There are two types of fibre. Soluble and insoluble, although most fibrous foods contain both. To a degree, their names speak for themselves, although their functions tend to overlap a fair bit. In general, they perform slightly different tasks within the body.
- Soluble fibre dissolves in water to form a gel like substance that holds sugars and nutrients, allowing the body to absorb them more slowly.
- Insoluble fibre does not dissolve in water but attracts more of it to the stool, making it softer and easier to pass.
Why We Need Fibre in Our Diets
Fibre Helps Important Good Gut Bacteria Function
Fibre passes through our systems mostly unchanged until it hits the large intestine. Here resides our wonderful gut flora where there are hundreds of different species of bacteria, just waiting to digest some fibre. Human cells tend to absorb a lot of nutrition from most foods before it reaches the large intestine, leaving our gut flora to fend from the leftovers. Hence, the important function that fibre plays in fueling our good bacteria.
Maintaining a positive relationship with our friendly bacteria is crucial to the body’s health. Amongst other benefits, our good gut bacteria produces short-chain fatty acids (such as butyrate) which function as probiotics. They provide our systems with extra protection, lowering the risk of colon cancer, along with reducing gut inflammation and improving digestive disorders such as IBS, Crohn’s disease and ulcerative colitis.
Blood Sugar, Diabetes and Weight Gain
When the fibre in our systems traps certain components of foods, like sugar, it makes it more difficult for the body to digest. This means that it takes longer to absorb. Keeping things like blood sugar levels steadier for longer. The lower GI of fibre also helps to prevent larger spikes in our blood sugar, which could lead to a sudden rise in blood insulin, a hormone linked with obesity and diabetes.
The delay in nutrient absorption will also mean that high fibre foods could make you feel fuller for longer and help you maintain steady energy levels.
The Important Function Fibre Plays in Cholesterol
High cholesterol is another one to be careful of. When cholesterol levels are high, fat is deposited along the artery walls. This makes them narrower and increasing the chances of heart disease.
Studies have shown that a more soluble fibre may bind with bile salts, taking them away upon excretion. Bile salts are needed to break apart fat content in food. So once the body realises that it needs a top-up of bile acids, it removes cholesterol from the liver to produce more.
Roughage and Constipation
Not everyone is totally convinced that fibre plays a positive role in helping with constipation. Studies have shown that the effects depend on the type of fibre consumed. Suggesting that insoluble fibre, which increases the water content of our stool, allows the stool to pass more easily. Decreasing transit time and helping prevent constipation along with its associated problems, such as hemorrhoids.
I maintain that everyone has a different system, and the only way to figure it out for yourself is to try it. If you struggle with constipation, try a higher fibre diet for a few days and see what happens. If it doesn’t improve, then try a low fibre diet. Below is a shortlist of high fibre foods, separated into what is believed to contain predominantly soluble or insoluble fibre. With this list (and the help of google to get more food ideas), try consuming both types separately and see what happens.
Just remember, you need to be consuming a healthy amount of water on a daily basis in order for fibre to be able to perform the important functions that it does. Especially when it comes to helping alleviate constipation.
How much Fibre Do we Need
Again, it’s important to remember that every one of us is different and we should each monitor and listen to our own systems. However, on the point of fibre we can give a ballpark figure as to what our daily consumption should be according to age and sex.
- Middle aged men should get 30g each day
- MIddle aged women should get 25g each day
Younger humans will need less according to their age, it starts from about 18g per day, so it’s not a lot less. And as we age we also need less fibre in our diets. But again only a couple of grams less per day.
25 – 30g doesn’t sound like a lot. But when you realise that there is about 10g of fibre in a single portion of oats and about 0.5g in the average rice cracker, one starts to wonder how to get in the full amount per day without overeating. But if you stick to whole foods it wont be a problem at all. For example, rather than eating two slices of white bread which will give you less than 1g of fibre, try eating a sweet potato that will give you about 4g of fibre. Or a handful of almonds, which provides you with about 3g of roughage per 28g serving.
Foods High in Fibre
Most fibre foods contain both soluble and insoluble fibre. And it is important to note that we should be getting our fibres from wholefoods and not fibre supplements.
Here is a list of high fibre foods separated into two groups; those that contain more soluble fibre and those that contain more insoluble fibre.
Soluble Fibre Foods
- Black Beans
- Kidney beans
- Brussel Sprouts
- Citrus Fruit
- Sweet Potato
- Flax Seeds
- Sunflower Seeds
- Dark Chocolate (Yay!)
Insoluble Fibre Foods
- Whole-wheat flour
- Wheat bran
- Green Peas
- Cooked Prunes
- Dark Leafy Greens
Things to be Aware of
If you are wanting to up your fibre intake, be sure to slowly introduce it to your system. A sudden switch to a high fibre diet may lead to abdominal pain and increased gas.
Also, if you are managing to get in too much fibre, you may want to gradually decrease your consumption a bit. Very high fibre diets (more than 40g per day) have been linked to a decreased absorption of minerals. Increasing the risks of developing deficiencies.
And here are two more important points that bear repeating should you want fibre to function well in your system:
- Drink enough water daily to ensure that fibre can assist the way it should.
- Get your fibre from natural food sources as opposed to supplements.