Reducing your risk
You can't control every risk factor, but there are real, practical things you can do to lower your chance of developing bowel cancer.
What increases your risk?
Having one or more risk factors doesn't mean you'll get bowel cancer – and some people with no known risk factors still develop it. But understanding these factors helps you make informed choices.
Factors you can't change
Age
Risk increases significantly after age 50. Most bowel cancers are diagnosed in people aged 60 and over. However, rates among younger people are rising.
Family history
Your risk is higher if a close relative (parent, sibling, or child) has had bowel cancer, especially if they were diagnosed before age 50.
Hereditary conditions
Lynch syndrome, familial adenomatous polyposis (FAP), and other inherited conditions significantly increase lifetime risk.
Inflammatory bowel disease
Long-standing ulcerative colitis or Crohn's disease increases your risk, particularly if the condition affects a large area of the bowel.
Personal history
If you've previously had bowel cancer or large adenomatous polyps, you have a higher chance of it developing again.
Ethnicity
In New Zealand, Māori are more likely to be diagnosed at a later stage, which affects outcomes. Equitable access to screening is critical.
Factors you can influence
Diet
A diet high in processed meat and red meat, and low in fibre, is linked to higher bowel cancer risk. Eating plenty of fruit, vegetables, and whole grains is protective.
Physical activity
Regular physical activity reduces your risk. Even moderate exercise – like a daily 30-minute walk – makes a difference.
Body weight
Being overweight or obese increases bowel cancer risk, particularly for men. Maintaining a healthy weight is one of the most effective things you can do.
Smoking
Smoking increases the risk of bowel cancer as well as many other cancers. Quitting at any age reduces your risk.
Alcohol
Drinking alcohol – even at moderate levels – increases bowel cancer risk. The more you drink, the higher the risk.
Screening
Getting screened is one of the most powerful prevention tools. Screening can find and remove polyps before they become cancer.
What you can do
Small, consistent changes can have a real impact. You don't need to overhaul your life overnight – start with what feels manageable.
Eat well
- •Eat more fibre – whole grains, legumes, fruit, and vegetables
- •Limit processed meat (bacon, sausages, salami, ham) and red meat to no more than 500g of cooked meat per week
- •Include garlic, onions, and cruciferous vegetables (broccoli, cauliflower, cabbage) which may offer protective benefits
- •Stay hydrated and limit sugary drinks
Move more
- •Aim for at least 30 minutes of moderate activity most days
- •Walking, cycling, swimming, gardening – it all counts
- •Even small increases in activity reduce risk
Cut back on alcohol and quit smoking
- •If you drink, keep it to a minimum – there is no safe level of alcohol when it comes to cancer risk
- •If you smoke, seek support to quit – your GP can help, or call Quitline on 0800 778 778
Get screened
- •If you're aged 58–74, you're eligible for free bowel screening through the National Bowel Screening Programme
- •If you have a family history or other risk factors, talk to your GP about earlier or more frequent screening
- •Don't put it off – screening saves lives by catching polyps before they become cancer
Know your family history
- •Ask your whānau about any history of bowel cancer or polyps
- •If a close relative has had bowel cancer (especially before age 50), tell your GP
- •You may be referred for genetic counselling or earlier colonoscopy surveillance
Prevention starts with a conversation
Talk to your GP about your personal risk factors and whether earlier screening might be right for you.