Mention the word fibre in a conversation about health and most people will tell you that they eat fibre-rich foods to ‘keep regular’. But delve a bit deeper and ask “what types of fibre do you eat?” and you may get a few blank stares and some vague responses.
Most of us know that fibre plays an important role in digestive health. However, few people know that there are a range of different types of fibre, each with its own specific health benefit. Part of the reason for the low awareness of fibre types is the abundance of very general advice such as “eat more fibre”, when there should be a stronger emphasis on specifically eating a diverse range of fibres to achieve optimal gut health.
In Australia (and other Western countries), we have what is known as the ‘Fibre Paradox’. Even though our average fibre consumption has increased over the last 20 years, our rates of bowel cancer have not dropped accordingly, with 12 Australians dying every day from this disease.1 One of the reasons for this paradox is that whilst we’re eating a lot of insoluble fibre (often known as roughage), we are missing out on eating the right combination of different fibre types, including the very important fermentable fibres, which provide protection for the gut and can help to prevent diseases like bowel cancer.
What type of fibre support good gut health?
Fibre can be grouped into three different types – soluble, insoluble and resistant starch. Each of these fibres provide health benefits via different mechanisms. Evidence shows that there is a greater positive impact on digestive health when these fibres are eaten in combination. 2
A diet high in a range of fibres can help to manage common gut issues such as constipation and irritable bowel syndrome (IBS), as well as diverticular disease, haemorrhoids and other gut-associated diseases.
| Soluble | Insoluble | Resistant Starch | |
| Function | Slows down digestion (food takes longer to pass through the stomach and intestine) and reduces blood cholesterol levels | Has the greatest influence on the large bowel – absorbs water and thereby helps to soften stools and increase the number of bowel movements | Starches that resist breakdown in the small intestine and feed the good bacteria in the large bowel, thereby producing short chain fatty acids that protect the bowel |
| Food Sources | BARLEYmax®TM, oats, beans, lentils, peas, nuts, seeds, some vegetables and fruits | BARLEYmax®TM, wholegrain breads and cereals | BARLEYmax®TM, cold cooked potato / rice / pasta, firm bananas, lentils, beans |
The all-important resistant starch
All fibres are important and play different roles. However, resistant starch is perhaps the least well known of the different types of fibre and may be the most important for human health. Eating more resistant starch protects the bowel from cell damage associated with having a hungry microbiome.
Research has found a stronger association between starch consumption and reduced bowel cancer, when compared to total dietary fibre intake.3 This inverse association between starch (and therefore resistant starch) and bowel cancer corresponds with the theory that fermentation of resistant starch in the large bowel is a potential mechanism for bowel cancer prevention. Through fermentation, the good bacteria in the gut produce short chain fatty acids (specifically butyrate). Butyrate is the preferred energy source for the cells that line the bowel wall.
To achieve good digestive health, make sure you up your intake of the all-important resistant starch.
How much resistant starch should I be eating?
There is no data specifically looking at current intakes of resistant starch. However, the recommended intake should be about 20g per day. 20g per day is almost 4x greater than a typical Western diet provides.4
What foods contain resistant starch?
As mentioned in the table above, resistant starch is present in legumes such as lentils and beans, as well as cooked and cooled starches such as rice, potato and pasta. Products with BARLEYmax®TM are one of the best sources of resistant starch, as BARLEYmax®TM contains four times more resistant starch compared to most grains.
Do you have any foods or recipes that are high in resistant starch? Send us an email with your ideas for increasing resistant starch intake and achieving good gut health. We’d love to hear from you!
Teri Lichtenstein
BSc (Hons), MNutrDiet, Grad, Dip Business
References:
- http://www.gutfoundation.com.au/bowel_cancer_awareness_week
- http://www.nature.com/bjc/journal/v69/n5/abs/bjc1994181a.html
- Bird AR, Vuaran M, Crittenden R, Hayakawa T, Playn MJ, Brown IL and Topping DL. Comparative effects of a high-amylose starch and a fructooligosaccharide on fecal bifidobacteria numbers and short-chain fatty acids in pigs fed Bifidobacterium animalis. Digestive Diseases and Sciences. 2009; 54: 947-954.
- Baghurst PA, Baghurst KI, Record SJ. Dietary fibre, non-starch polysaccharides and resistant starch – a review. Food Aust.1996;48(Suppl):S3-S35.
Intended as general advice only. Consult your health care professional to discuss any specific concerns.
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