Whether you think green vegetables and grains are rabbit food or not, the fact remains that they have amazing health benefits. 

All plants – fruit, grains, legumes, seeds, and nuts contain invaluable fibre, vitamins, minerals, and phyto-nutrients (plant nutrients). 

The fibre in these foods have been demonstrated to decrease the risk of bowel cancer. Just by having 90g of wholegrains each day you are 17% less likely to develop bowel cancer. This risk reduction increases to 61% when you include other changes to your lifestyle including: 

• Participating in bowel cancer screening to your personal risk level*, including participating in the National Bowel Cancer Screening Program and having regular endoscopic screening (flexible sigmoidoscopy /colonoscopy)*; and having polyps removed as they are identified* 
• Taking aspirin every day for at least five years*; please consult your doctor before taking aspirin as there are associated risks
• Managing your weight  
• Limiting, or abstaining from alcohol 
• Consuming 400mg of calcium* each day from dairy products or supplements  
• Being physically active everyday 
• Not smoking and avoiding exposure to tobacco smoke (vaping is likely to be included in this list as research develops) 
• Limiting red meat (for example, beef, lamb, pork, and goat) to a maximum of 350-500g per week and eating very little, if any, processed meat (for example, bacon, ham, salami, and sausages). 

Why does fibre reduce the risk of cancer? 

There are different types of fibre, including insoluble and soluble fibres, and resistant starch. Insoluble fibre is the rough skins and outside of wholegrains, vegetables, fruit, nuts, and seeds. Soluble fibre is soft and gel-like, it is found in the flesh of fruit and vegetables, in some grains like oats and barley, and legumes and dried beans. Resistant starch is found in oats, legumes and dried beans, as well as rice and potatoes which have been cooked and cooled. 

Insoluble fibre is believed to bulk your bowel contents and dilute potential cancer-causing agents, binding them, and allowing the body to pass them in your stool (poo). Soluble fibre is believed to help stabilise blood glucose, improve insulin responses, lower levels of inflammatory biomarkers (for example, C-reactive protein and interleukin-6), and reduce total and low density lipoprotein (LDL or “bad”) cholesterol. Resistant starch has a potentially protective role by providing fuel for gut microbiota so they produce short-chain fatty acids (SCFAs). SCFAs are believed to play a role in maintaining the metabolic health of our bodies, as they are key regulators of anti-inflammatory effects. All types of fibre make us feel fuller which can reduce our energy intake, helping us maintain a healthier weight and waistline. 

How much fibre is recommended? 

In Australia the Dietary Guidelines recommend adults have 30g of fibre per day for men and 25g of fibre per day for women (more if you are pregnant or lactating, varying with age).  

Research shows the more fibre you eat, the lower your risk of bowel cancer. More fibre also reduces your risk of dying from all causes, cardiovascular disease, and cancer in general. 

If your fibre intake is low, increase it slowly to reduce gas production and bloating. And make sure your drink 8-10 cups of water or fluid each day, as the fibre will absorb the fluid. 

Check the quick calculator below, to calculate your fibre intake. Remember there may be large variations in some products, so you can check your favourite brands’ food labels for specific information for a more accurate count. 

Quick calculator for your fibre intake 

Food, serve	Fibre per serve (g)
Higher fibre breakfast cereal, ½ cup	3-7g
Lower fibre breakfast cereal, ½ cup	0.2-1g
Wholegrain or wholemeal bread, 1 slice	2g
White bread, 1 slice	0.9g
Brown rice, cooked, ½ cup	3g
White rice, cooked, ½ cup	0.8g
Legumes, canned, drained, ½ cup	5-8g
Nuts, whole, 30g	2-3g
Non-starchy vegetables, uncooked, ½ cup	1-3g
Potato or sweet potato, cooked, 150g	2-5g

As with everything related to diet, having a wide variety of foods will provide you with a range of types of fibre as well as the vitamins, minerals, phyto-nutrients found along with them. 

And, of course, one of the bonuses of fibre for people living with diabetes is higher fibre foods generally have a lower glycaemic index (GI), which is beneficial for keeping blood glucose levels more stable.  

If you would like more information about your diet and fibre, contact your local accredited practising dietitian. 

* Please consult your doctor. 

By Dale Cooke, Accredited Practising Dietitian