Bowel cancer: How to avoid Australia’s silent killer

In Australia, one in 20 people will develop bowel cancer by the time they are 85 years old. Bowel cancer was estimated to be the fourth most commonly diagnosed cancer in Australia in 2021, and the second most common cause of cancer death. These stats aren’t estimated to change in the coming years according to Cancer Australia. 

So the likelihood that you, or someone you love will be affected is high. 

The good news is that bowel cancer is highly treatable when discovered early. You can even take steps to help reduce your chances of getting it in the first place by making some simple lifestyle adjustments. Read on to find out how to reduce your risk of bowel cancer.  

Bowel cancer, also known as colorectal cancer, develops in the large bowel (colon) or rectum. Most bowel cancers start as non-cancerous growths called polyps, which can turn into cancer over time (usually this takes years). 

Often there are no symptoms in the early stages. When bowel tumour symptoms do develop they can include:  

• blood or mucus in stools  

• unexplained weight loss  

• extreme tiredness  

• a persistent change in bowel habits (going to the toilet more or less than usual, looser or narrower stools than usual 

• abdominal (tummy) pain  

If you develop symptoms, don’t ignore them. Make an appointment to see your doctor as soon as possible. 

While there are several risk factors for bowel cancer that you can’t change, such as your age and family history, there is still a lot you can do to reduce your risk. In fact, bowel cancer is one of the most preventable cancers. The two main things you can do include making lifestyle changes and participating in the National Bowel Cancer Screening Program. 

The following healthy lifestyle changes are things you can do to reduce your risk of developing the disease. A few small changes can make a big difference to your risk of getting bowel cancer.

1. Don’t smoke

Smoking increases your risk of bowel cancer along with many other cancers and serious illnesses. Stop smoking to reduce your risk and improve your health in general. 

2. Watch your alcohol intake

Research has shown that having two or more alcoholic drinks a day significantly increases the risk of bowel cancer. So, keep your alcohol intake to fewer than two drinks per day. 

3. Adjust your diet

Recommendations on what to eat and what not to eat can sometimes be confusing. In general, wholegrains, high-fibre and dairy foods help reduce your risk of bowel cancer, while red and processed meats can increase your risk. 

Processed meats are meats that have been smoked, cured, salted or processed in some way. Think salami, hot dogs, ham, bacon, canned meat, jerky and corned beef. Try to avoid these as much as possible. 

The Cancer Council Australia recommends eating a maximum of 455 grams of lean, cooked red meat per week (like beef, veal, pork, lamb, mutton, venison and goat). Also avoid burning meat when cooking on the BBQ, as burnt or charred meat can also contribute to an increased risk of bowel cancer.

While it’s still unproven, there is some evidence to show that fish and foods containing vitamin C might be protective against bowel cancer. 

4. Get moving

Did you know that incorporating just 30 minutes of physical activity into your daily routine, at least 5 times a week, can significantly lower your risk of bowel cancer? Research suggests that engaging in more than 150 minutes of physical activity per week could prevent over 1,800 cases of bowel, breast (post-menopause), and endometrial cancer annually.

Make it a goal to engage in at least 30 minutes of moderate to intense activity each day, ensuring your heart rate is elevated. As your fitness improves, aim for 60 minutes daily or increase the intensity level. Remember to minimise sedentary behaviors like prolonged TV watching for optimal health benefits. 

5. Maintain a healthy weight

Having excess body weight can increase your risk of bowel cancer. Excess body fat, particularly toxic visceral fat around organs, produces harmful chemicals and hormones that can lead to inflammation and abnormal cell growth. This increased risk of abnormal cell production makes cancer more likely to develop. 

Cancer Council recommends aiming for a waist circumference of less than 94 cm for men, and 80 cm for women. 

nib offers Healthy Weight for Life Essentials available to eligible nib members at no additional cost¹ who’ve been diagnosed with a chronic disease and have a BMI of 28 or over. Head to our Health Management Programs page for more information. 

If you’re aged 45 or older, the National Bowel Cancer Screening Program should be on your radar. As part of the program, all Australians are sent a free test kit in the mail every two years until they are 74. 

As of July 2024, the Australian government will lower the eligible screening age from 50 to 45. This means people aged 45 to 49 can join the program. 

• People aged 45 to 49 can request their first bowel cancer screening kit be mailed to them. 

• People aged 50 to 74 will continue to receive a bowel cancer screening kit in the mail every two years. 

Screening aims to find bowel cancers early, before they’ve grown large enough to cause symptoms. When you detect bowel cancer at an early stage, cure is much more likely. The bowel cancer screening program has been shown to reduce deaths from bowel cancer and the program could save up to 500 lives each year.  

Who should do the test?

Because the risk of bowel cancer starts to increase sharply from the age of 45, screening is recommended from this age for most people.

People who have a higher than average risk due to their family history or other conditions (such as inflammatory bowel disease) may be advised to have tests from a younger age.  

And anyone who has symptoms should see their GP. The test used in the screening program is not recommended for people experiencing symptoms. 

What’s involved?

The test used in the National Bowel Cancer Screening Program is called a faecal immunochemical test (FIT), which can detect tiny amounts of blood in your stool that you can’t see with the naked eye.  

You do the test at home and then send the test card in a postage paid envelope to a lab for testing. The results will be sent to you and your GP if you ask for this to occur. Depending on the results, further tests may be recommended. 

Don’t die of embarrassment 

Most of us feel slightly uncomfortable at the thought of doing this type of test. But it’s really simple and not actually that embarrassing. And it could save your life. Surely that’s worth putting up with the ‘ick’ factor? 

What does a positive test mean?

A positive test means that some blood has been detected. But the test can’t tell what is causing the blood in your stool. Bowel inflammation, haemorrhoids, polyps and early bowel cancer can all cause bleeding. Most people with a positive test don’t have bowel cancer. 

If your results are positive for blood, your doctor will recommend that you have another test - usually a colonoscopy - to look inside your bowel to see what could be causing the bleeding. If polyps are found during the colonoscopy, they may be able to remove them during the procedure.  

What to do if you get a negative result

If your screening test result comes back negative, it means that no blood was found. In most cases you don’t need to do anything until the next test arrives in the post in two years’ time.  

But a negative result doesn’t guarantee that you don’t have or won’t get bowel cancer. So if you do develop symptoms - especially bleeding - at any time, see your doctor straight away. The bowel cancer screening test is not a replacement for a regular check-up with your doctor. 

Keen for more information on how to reduce your risk of bowel cancer? Check out our article Why fibre should be on your shopping list. 

The information in this article is general in nature and should not replace any personalised advice provided by your healthcare professional.

¹ Available to eligible nib members who’ve held Hospital Cover for 12 months and served their relevant waiting periods. Additional criteria vary according to each program. Contact us for more information and to confirm your eligibility for a program.