( Nutrition )
ARE YOU EATING
ENOUGH FIBRE ?
DR JOANNA
Dr Joanna explains the importance of fibre for optimum health . I t is of great concern that grains are currently being demonised , when wholegrains are one of our best sources of fibre . Furthermore , grains including wheat and rye contain some of the highest levels of prebiotic fibre – those that fuel the good bacteria in the gut – and they seem to have a particularly protective effect against colon cancer .
Six out of ten Australians are failing to meet the recommended 25g to 30g of fibre a day , and even more are falling short on achieving the right balance of the different types of fibre . These different types of fibre are important as they all have different roles and health benefits in the body . Broadly speaking they can be defined as :
Insoluble fibre : This is what you might think of as ‘ roughage ’. It ’ s the rough outer husk of grains such as bran from wheat , the ‘ brown ’ part of brown rice and the visible rough ‘ bits ’ in wholegrain breads . You ’ ll also find insoluble fibres in some veggies , fruit , nuts and seeds , especially in the skins and the stringy parts . Insoluble fibre is brilliant for keeping you regular , but is less fermentable than other fibre types meaning it has less effect on the gut bacterial population .
Soluble fibre : As the name suggests this fibre is soluble in water . It absorbs water in the gut to form a gel that slows down the attack of digestive enzymes on the food you eat , in turn slowing down the absorption of food . This has a double whammy effect of helping you to feel fuller for longer , delaying the return of hunger pangs , while also helping to control blood glucose levels . Specific types of soluble fibre , like beta-glucan from oats and barley , also help to promote a healthy blood cholesterol profile , reducing LDL cholesterol and improving the total to HDL cholesterol ratio – both important cardiovascular disease risk factors . Soluble fibres are also highly fermentable by the resident gut bacteria and this process is crucial for good gut health , including reducing the risk of colon cancer . In addition to oats and barley , you ’ ll find soluble fibres in whole wheat , rye , fruits , veggies , nuts , seeds and legumes .
Resistant starch : This a more recently recognised class of fibre . It is literally a form of starch that our own enzymes cannot break down and so it passes into the colon where , like soluble fibres , it is a gold star fuel for the resident bacteria . You ’ ll find resistant starch in firm bananas , cooked and cooled potatoes , rice or pasta , and legumes .
The fermentation process in the colon is the link between fibre and many of its knock-on health effects . The resident bacteria are able to break down fibre via fermentation and the result is the release of short chain fatty acids ( SCFA ). One of these , butyrate , is used preferentially by the colonic cells and is important in keeping them healthy and cancer free .
The other SCFA are absorbed up into the bloodstream where they then impact on the liver and cholesterol production , the brain and the immune system . There are also immune boosting effects within the gut itself along with anti-inflammatory actions .
This makes fibre important for many inflammatory diseases from those within the gut such as inflammatory bowel disease , but research is building to suggest it even effects inflammation elsewhere in the body in conditions including asthma and arthritis . Pretty extraordinary for a group of indigestible carbohydrates .
Foods richest in fibre per serve are legumes and wholegrains , with a few standouts in other foods groups such as carrots and brassica ( or cruciferous ) veggies , fruits like apples , oranges and raspberries , and chia seeds . To view a list of the fibre content in common foods click here .
You can see how diets that eliminate all grains and legumes make it exceptionally difficult to meet fibre requirements – you have to eat a truckload of veggies , fruit , nuts and seeds to get there . It ’ s certainly possible , and indeed it is what our ancient ancestors did and they succeeded in getting an estimated 90g of fibre a day ! But today most of us would find that kind of plant food intake difficult to maintain .
The bottom line is that by including a good variety of each of these food groups across the week , including your smart carb choices at most meals using your blocks to guide your portion control , you can meet your fibre requirements and boost your gut and overall health . Plus these foods fill you up , deliver bags of other nutrients and they don ’ t cost the earth .
TO FIND OUT MORE CONNECT WITH DR JOANNA VIA : Web : drjoanna . com . au Facebook : drjoannamcmillan Twitter : @ joannanutrition Instagram : @ drjoannamcmillan
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! MAGAZINE ( NOVEMBER 2016 ) 9