All you need to know about FIBRE

Not a popular subject because it sounds worthy and brown but… Read on to find out why it’s so important as an adjunct to gut health.

Dear Subscriber, let’s talk about Fibre!

if you’re as old as me, you will definitely be familiar with All-Bran, and maybe even the F-plan diet of the 1980’s devised by Audrey Eyton; the Slimming Magazine founder was inspired by the research of surgeon Denis Burkitt, who’d observed that colorectal cancer rates were higher in those who didn’t eat much fibre, although the basis of the F-plan diet was actually that eating 35-50g of fibre a day would keep you fuller for longer so you’d be less likely to eat rubbish!

Fibre consumption varies around the world although as we eat more junk, rates are falling. The Hadza hunter-gatherers in Tanzania (who,incidentally, have some of the finest gut health in the world) eat loads; about 100g every day. The average American manages only about 15g and here in the UK it’s about 20g. Government guidelines suggest 30g / day and a recent study has found that an extra 5g / day could reduce inflammation and consequently the likelihood of heart disease by 14% !

Yes, yes but what actually is Dietary Fibre?

Dietary fibre is only found in plant foods (ie not in meat, fish or dairy), and refers to complex carbohydrates that our bodies can’t digest, because unlike icows, we don’t have the right enzymes. It’s basically what plants are made of. It’s found in vegetables, fruits, herbs, spices, seeds, nuts, legumes, pulses, grains and cereals.

This stuff reaches our large intestine just as it started, without being broken down, other than by physical gnashing and mashing en route. Dietary fibre is a general term - there are lots of different types, existing in varying amounts in various plants, - here are some examples:

Inulin (fructose-oligosaccharide; Jerusalem artichokes, garlic, onions, leeks, fruits)

Galacto-oligosaccharides (pulses)

Pectin (fruits, vegetables)

Beta-glucans (oats, barley, fungi)

Cellulose and Lignin (all plant cells).

We don’t tend to use these separate terms much because as usual with gut health, variety is key, and it’s pretty much all good for you ( * unless you’ve IBS or IBD in which case you might have been advised to restrict certain types).

You may also have heard of resistant starch; this is where starch molecules that we can usually digest become altered by cooking or chilling, and then are “resistant” to the enzymes - this can then act like dietary fibre. Chilled and reheated pasta is a good example.

Usually (resistant starch excepted), the more processed a food is, the more fibre will have been stripped out of it. So white flour, white rice, white pasta, white bread are all white because they’ve been refined and had much of the fibre removed - they usually contain about 75% less than their brown counterparts.

OK, But what does fibre do?

You might remember that when we eat simple carbohydrates, e.g. sucrose (table sugar), or more complex starch, they’re broken down into simple sugars (like glucose and fructose) by enzymes in our alimentary tract and are readily absorbed into the bloodstream. From there, our bodies use them for energy, or store them in the liver as glycogen or convert to fat if they’re not needed.

Our indigestible dietary fibre is destined for greater things: Much of it will be used as a food source for our trillion gut microbes; they’ll ferment it and produce short-chain fatty acids (SCFA), a group of bioactive molecules that are quite simply, essential. Some fibres, cellulose and lignin for example, can’t be easily fermented and behave as bulking agents, basically helping your waste products to move along smoothly and allowing you to make a stool with the perfect texture!

You might also hear fibre described as being either soluble or insoluble; Generally, soluble fibre is fermentable, and insoluble provides bulk.

And these SCFAs? Why are they important?

Oh in so many ways! SCFAs (mainly butyrate, acetate and propionate) are involved in pathways that…….

• Keep your gut lining in tip top condition, helping you avoid “leaky gut”, where gaps appear between the cells, allowing particle into the surrounding tissues causing inflammation.

• Regulate the amount of mucus produced. No one likes to think about mucus, but it really matters!

• Protect against inflammation by regulating the immune responses.

• Outside the gut, affect appetite control, fat activation, liver function and sleep

• Improve brain function, protect the integrity of the blood-brain barrier, may slow the progress of Alzheimer’s Disease.

• Help with blood sugar control

  In fact SCFAs are involved in almost every aspect of healthy metabolism. Quite how they do it is far above my pay grade, but it involves interactions between these molecules and receptors on various cells, stimulation of nerve pathways, induction of hormones etc…

There are lots of metabolic disorders, gut disorders and brain disorders in which SCFAs, or lack of, might have a role - they’re a hot research topic right now.

Are you getting enough?

So I hope that outlines why you might want to make sure you’re eating enough fibre, but… Are you? In an instagram poll I asked people who follow my account (who one might assume, mostly have an interest in gut health), about their fibre intake. Here are the results…..

Where do you fit in? As you can see only 21% of people who responded are confident they’re doing enough. I’m usually hitting 30g, but I do have to consciously think about it, and it’s not easy when I’m also keeping an eye on calorie intake (contentious I know, more on this another time), eating 30 different plants a week, eliminating ultra processed food, being mindful of blood glucose levels etc…..

How to eat more fibre

Any increase to the amount of fibre you eat should be undertaken slowly. If you go in hard and start necking a 500g jars of kidney beans, you’ll probably regret it. If you’re currently eating about 15g, you might aim to build up to 30g over a period of a couple of months. Moderation is key.

To begin with, you might need to do a bit of research - you can get data on almost any foodstuff these days simply by typing eg “peas nutrition facts” into google. Note the amount that’s been used - it might be per 100g which isn’t necessarily the same as a portion. Also, it’s all approximate because factors including cultivar of fruit or vegetable, ripeness, where it was grown, can all influence fibre content, so don’t follow these figures too religiously, or get too obsessed about it - if you’re not eating enough, then just be content to gradually make some changes. If on the other hand, you like measuring things, one of those free food tracker apps is probably the best solution - they contain a lot of information .

1. You could increase your consumption of straight-up vegetables. Brassicas, that’s cabbage, brussels, broccoli, spring greens are your friends here. Avocado and peas are also suprisingly high in fibre, and the skin of a jacket potato too. Enhance salads by always sprinkling with nuts or seeds and some lentils or chickpeas.

2. Pulses. Lots of fibre in these and we really don’t eat enough of them. These includes beans lentils and peas. You don’t have to cook them yourself from dried, if that’s off-putting. Tinned are just as fibre-y, but if you can stretch to it, opt for organic ones because they are usually additive free. You don’t have to do anything grand with them - just mash some chickpeas roughly with some yoghurt, lemon herbs and seasoning for a rough dippy/spread arrangement. And Lentils - these even come ready cooked for you in packets, though avoid ones with lots of additives and flavourings. Tipped into any form of stew, pie or ragu they are fortifying and often can go un-noticed. Or follow the Bold Bean Company and Jenny Chandler ) (fabulous pulse ambassador) on their socials ( get me with all the modern terms!) for some “Beanspo” inspiration of what to do with them. Most of your fibre intake will be instantly sorted - a cupful can have about 10g fibre.

3. Eat the brown things. Start a gradual transition to wholemeal bread from white, brown rice from white, etc.. brown noodles from white… I am not implying that you should NEVER eat white anything, but aiming to have them as the exception rather than the rule is a good goal. Did you know that if you use wholemeal self raising flour, or even Teff, which is very high in fibre, in your baking it’s extremely unlikely that anyone will notice? It adds a lot of extra flavour, in crumbles, biscuits etc… And veggies in cake is another way of sneaking in fibre where you’d least expect it. A decent loaf of wholemeal bread could provide as much as 5g fibre per slice.

4. Eat fruit wisely, as you need to also watch the sugar content - if you ate 200g of delicious sweet and juicy grapes you’d get 2 grams of fibre but also about 30g of sugar! An apple is a better bet - with the skin on that’s about 3.8 g of fibre and 10g sugar.

5. Nuts and seeds - high in fibre highly calorific so don’t start mainlining them and end up eating 4000 calories a day ( even though Zoe says that we don’t absorb all the calories from nuts, personally I seem to!), but a sprinkling of chia seeds and flax seeds upon a bowl of milk kefir breakfast can get those fibre levels up. All seeds and nuts are quite high in fibre - marvellous for adding crunch to a salad.

   But does this work in real life? It can do - here’s what I ate yesterday, and I used “my net diary” - one of those diet tracker apps to calculate the fibre content. I made it - just!

Congratulations! We’ve got to the end! Sorry it’s so long - it’s like one of my workshops once I start I cannae stop. Do let me know if you have any top tips for increasing fibre, or any burning questions that I can research….

NB

• This is fibre from a gut health enthusiast’s perspective. I am not a medic, a nutritionist, or part of Zoe! If you’ve got any sort of gut issue, I suggest you do some more homework or talk to a specialist.

• Increase fibre intake slowly. More isn’t necessarily better - we are not Hadza tribespeople. Too much fibre could actually cause constipation, it has been reported

REFERENCES

• Dietary fibre in gastrointestinal health and disease PMID: 33208922

• The Role of Short-Chain Fatty Acids From Gut Microbiota in Gut-Brain Communication PMID: 32082260. (Search PubMED with this number).

• Stopping or reducing dietary fiber intake reduces constipation and its associated symptoms PMID 22969234