Dietary Fibre: More Than Just Regularity

Dietary fibre does more than just keep you regular. Research suggests that a high-fibre diet can reduce the risk of various cancers. From promoting a healthy gut to preventing constipation, fibre is a powerhouse nutrient that deserves a spotlight in your diet. Let's dive into how adding more fibre to your meals can help protect against cancer and boost your overall health. Plus, discover delicious ways to include fibre with recipes from Feel Better Nutrition’s head dietitian, Alex Salmon APD AN. Her latest recipe e-guide, Nourish for Survivorship is available now via the FBN Resource Hub.

The Importance of Dietary Fibre for Health

Dietary fibre is an essential part of a healthy diet, playing a crucial role in reducing the risk of various cancers. This plant-based carbohydrate consists of non-starch polysaccharides, cellulose, pectin, hydrocolloids, oligofructose, and resistant starch, classified into soluble and insoluble types.

Soluble vs Insoluble Fibre: What’s The Difference?

Soluble fibre dissolves in water to form a gel-like substance that helps lower blood cholesterol and glucose levels. It's found in vegetables like carrots and broccoli, fruits like apples and berries, legumes, nuts, and seeds. Insoluble fibre, which does not dissolve in water, adds bulk to the stool and aids in food passage through the digestive system. It's found in whole grains, cereals, vegetables, nuts, and seeds.

Most People Don’t Eat Enough Fibre

Despite fibre being present in many foods, many people do not meet daily recommended servings. Including sufficient soluble and insoluble fibre in your diet can help reduce cancer risk. Fibre promotes healthy bowel movements, binds to carcinogens, supports healthy gut microbiota, aids in weight stability, and regulates blood sugar levels.

A 2023 umbrella review highlighted the impact of dietary fibre on reducing cancer risk. Fibre can increase stool volume and speed up transit time, diluting carcinogens in the colon and reducing exposure. By binding to bile acids and altering their path through the liver and intestine, fibre can improve cholesterol levels. Secondary bile acids, linked to colorectal cancer, are produced by bile acid metabolism and contribute to oxidative stress and inflammation. Fibre is broken down by intestinal flora into short-chain fatty acids, reducing the conversion of bile acids to carcinogenic forms. Additionally, fibre removes nitrates from the stomach, lowering gastric cancer risk. [1]

A High Fibre Diet Reduces Breast Cancer Risk

Breast cancer, affecting 1 in 7 women at some stage of their lives, is often influenced by oestrogen stimulation. Research suggests that dietary fibre can decrease circulating oestrogen by inhibiting bacterial beta-glucosidase activity in the intestine, preventing oestrogen reabsorption, and increasing faecal oestrogen excretion, thus reducing breast cancer risk. Similarly, fibre's oestrogen-inhibiting effects may also protect against endometrial cancer by lowering blood pressure and diabetes risk factors. [1]

Fibre's Role in Ovarian and Prostate Cancer Prevention

Dietary fibre also plays a role in reducing ovarian cancer risk by modifying gut flora and enhancing oestrogen excretion. It improves insulin sensitivity, affecting insulin-like growth factor, a risk factor for ovarian cancer. This mechanism is similar in prostate cancer, where fibre helps reduce insulin resistance. Fibre also offers protective effects against pancreatic cancer due to its anti-inflammatory properties. Some studies have shown that fibre can down- regulate genes related to inflammatory factors, likely due to the anti-inflammatory properties of its fermentation products. [1]

Colon Cancer and the Protective Benefits of Fibre

Many studies have shown that dietary fibre can protect against colon cancer through increased intakes of fruits, vegetables, and whole grains. This benefit extends to hormone-related cancers like breast cancer. For example, a Canadian cohort study found a 32% reduction in breast cancer risk among women with high fibre diets. [2] While some studies may not establish a direct link, the overall positive impact of fibre on health is clear. By incorporating more dietary fibre from fruits, vegetables, and whole grains, we can harness these protective benefits and potentially reduce the risk of several types of cancer

How to Meet Daily Fibre Recommendations

Consider adding the following foods to your diet to meet the recommended daily intake of 25g for women and 30g for men [2]:

• Soluble fibre: oats, legumes (beans/lentils), fruits, vegetables, seeds, and nuts.

• Insoluble fibre: high-fibre and wholegrain breads, cereals, pasta, and the outer skin of some fruits and vegetables.

Easy Food Swaps to Boost Fibre Intake

You may consider the following food swaps to increase fibre in your diet:

• Enjoy wholegrain, wholemeal or mixed grain breads/pastas/rice and cereals in place of white varieties

• Use wholemeal flours to thicken sauces/gravies and stews

• Include a snack of wholemeal crisp breads with vegetable-based dips, such as hummus, capsicum, sweet potato and cashews or avocado.

Adding these foods to your meals and snacks can help you meet your fibre goals and support overall health. However, be mindful that excessive fibre intake may cause side effects like flatulence, bloating, loose stools, or abdominal cramps. It’s a good idea to increase fibre intake slowly, and if in doubt, speak to your medical provider or dietitian for support.

Understanding the vital role of dietary fibre in cancer prevention can help you make informed choices for your long-term health. Start by incorporating more fruits, vegetables, and whole grains into your daily meals. Your body—and your future self—will thank you.

Delicious Fibre-Rich Recipes for Better Long Term Health

Adding more fibre to your meals can help protect against cancer and boost your overall health. Discover delicious ways to include fibre with recipes from Feel Better Nutrition’s latest e- book, Nourish for Survivorship for breast cancer survivors, available now via the link below!

1. Hu J, Wang J, Li Y, Xue K, Kan J. Use of Dietary Fibres in Reducing the risk of several cancer types: An umbrella review. Nutrients. [Internet]. 2023 Jun [cited 2024 May 18]:15(11):2545. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10255454/

2. National Health and Medical Research Council (NHMRC). Nutrient Reference Values for Australia and New Zealand: Dietary Fibre. Australian Government (NHMHC)[Internet]. c2005 [cited 2024 May 18]. Available from https://www.eatforhealth.gov.au/nutrient-reference-values/nutrients/dietary-fibre

Written by Cat Moscatello Student Dietitian

Supported and Edited by Feel Better Nutrition