When I was growing up my Mum called it roughage, and it was green and apparently good for you. I have to give it to her, my Mum was right, fibre is good for us; as hard training athletes we should be even more concerned with fibre than the average Joe.
Why? Fibre is essential to keep that long muscular tube that starts at our mouths and end at our bottom in tip top working order. If our gastro-intestinal tract doesn’t work properly then we don’t get what we should from our food, and our bodies don’t work quite right. Optimum performance comes from diet, but a perfect diet only works if we get what we need out of it, and to get the best from our food we need our inside bits to be working properly.
In addition to keeping our GI tract functioning properly, fibre has additional benefits; from helping muscular gains to reducing heart disease and cancer risks.
First off, what is fibre? Fibre is a generic term which is used to describe those parts of plants which we cannot digest. It comes in two forms, soluble and insoluble.
Soluble fibre is gum like, made of pectins, gums and mucilages; it if found in fruits, oats, barely, and legumes such as peas and beans. In some circles fibre will be referred to as non-starch-polysaccharides (NSP), although technically not the same for our purposes they act the same. Fibre includes NSP, but NSP may not be the same as fibre. There are also other terms to describe what is known as fibre depending on its properties.
Now we know what fibre is, what are the benefits for us?
- Fibre helps us process dietary fat: fibre binds some of the dietary fat in a meal and pulls it through the body.
- Fibre slows carbohydrate digestion: the slower a carbohydrate is digested the better (except just after a workout), because slowly released carbs are more likely to end up stored in muscle as glycogen and less likely to be stored as body fat.
- This action is due to insulin: slowly released carbohydrates mean a lower insulin response and more stable levels which are great for energy levels and fat utilisation – helping us stay lean and energised.
- Fibre helps increase insulin sensitivity – especially soluble fibre. The sensitivity of muscle insulin receptors is often a limit for growth; this is a natural way to help the muscle get growing.
- Fibre can help you look harder – yes, vegetables contain indoles, which can, in males, lower oestrogen levels. Lower oestrogen levels are good for growth, and reduce water retention – every little helps.
- Fibre keeps it all moving: this almost goes without saying, but if food doesn’t move through and out then you don’t feel too good, and your health really suffers.
- Keeping it all moving helps reduce the incidence of colorectal cancer. For those of us that like a good steak, a health fibre intake can help offset the higher risk high red meat consumption can confer.
- Finally: heart health. Yes fibre helps reduce serum cholesterol and that’s good for us all.
So how much do we need? Average intake in the UK is around 12g per day, but to get the full health benefits we really need around 30g per day. Get it right: don’t just jump in and boost your fibre intake, fibre decreases transit time and it takes a while for our body to get used to having it there to process. Sudden changes upward in fibre intake will result in you and your toilet becoming very good friends, and your friends not wanting to be in your windy company!
Secondly fibre is like a sponge; your GI tract is a pipe. Try stuffing a dry sponge down a pipe – it’s hard and it doesn’t really work. If you eat fibre without increasing your fluids, you are trying to do the same thing. Get that fibre wet for the best effects for you, if you don’t drink, then your body will be dehydrated as a result.
So there you have it, more reasons to eat those fruits, veggies and whole grains that we all know and love.
So how does fibre reduce cholesterol then?
- Soluble fibre decreases gastrointestinal absorption of cholesterol. This leads to a decrease in the cholesterol content of liver cells, an up-regulation of LDL receptors and thus an increased removal of LDL-C from the blood.
- Fibre increases bile acid secretion, causing the liver to synthesize new bile acids using cholesterol – further decreasing serum levels.
- Fibre may lead to an inhibition of the liver enzyme HMG-CoA reductase that enables the liver to make cholesterol, decreasing cholesterol synthesis.
- Short-chain fatty acids such as acetate, butyrate and propionate, formed from the bacterial degradation of fibre in the small intestine inhibit hepatic synthesis of cholesterol.