Colorectal cancer has overtaken lung cancer to become the most common cancer in Hong Kong, with 4,979 new cases of colorectal cancer diagnosed in 2014.
Can colorectal cancer be prevented?
Colorectal cancer, also known as bowel cancer, is the most common cancer in Hong Kong. It is also one of the most preventable types of cancer.
What is bowel cancer?
The bowel is part of our digestive system and it’s divided into two parts: the small bowel and the large bowel. Nearly all bowel cancers are found in the large bowel, which is made up of the colon and the rectum.
Most of the nutrients from the food we eat are absorbed in the small bowel. Food then passes into the colon where water and any remaining nutrients are absorbed, leaving behind solid waste products. These waste products then move through the colon and the rectum before leaving the body.
Bowel cancer starts when cells in the bowel lining are damaged and then grow uncontrollably, forming a tumour.
There are lots of different reasons why bowel cancer develops – some of the most important factors are diet and lifestyle.
Who is most at risk of bowel cancer?
As with all cancers, the risk of developing bowel cancer depends on a number of factors and varies from person to person.
Lifestyle risk factors
- Eating too much red and processed meat
- Not eating enough fibre-containing foods
- Not eating enough wholegrains
- Being overweight or obese
- Not doing enough physical activity (colon cancer only)
- Drinking alcohol
- Smoking tobacco
Other risk factors
- Age – risk increases as you get older
- Family history of colorectal cancer
- Height – taller individuals are at greater risk
- Personal history of polyps or inflammatory bowel disease
If any of these risk factors apply to you, it does not mean that you will develop colorectal cancer – it just means that your risk may be higher than average. The good news is that there are steps you can take to reduce your risk.
How can you reduce your risk of colorectal cancer?
These steps are based on research from our Continuous Update Project (CUP).
There is strong evidence that eating processed meat (such as salami, bacon and ham) increases your bowel cancer risk, as does eating a lot of red meat (such as beef, lamb, pork or goat). Try to limit your red meat intake to no more than 500g (cooked weight) a week and avoid processed meat whenever possible.
Eating more wholegrains (such as brown rice, wholegrain pasta and wholemeal bread) has been shown to reduce the risk of bowel cancer. Foods that contain fibre have also been shown to lower bowel cancer risk and help keep your digestive system healthy. Try to include more fibre-rich foods such as wholegrains, pulses, vegetables and fruit in your diet – take a look at our healthy recipes for inspiration.
There is also evidence to show that consuming dairy products and calcium decreases the risk of bowel cancer. However, because we are unsure about the effect on other cancers, we don’t make any recommendations about dairy products and calcium. If you do eat dairy products, choose lower fat options, such as skimmed to semi-skimmed milk rather than full fat to help maintain a healthy weight.
Being overweight or obese increases your risk of bowel cancer. Try our Body Mass Index calculator to check if you’re a healthy weight for your height.
Being physically active uses up extra calories and helps you avoid gaining weight. It also helps food to move through your digestive system more quickly. Try our exercise calorie calculator for ideas on how to be more active.
There’s strong evidence that drinking alcohol increases bowel cancer risk. Find out more about the link between alcohol and cancer or find out how many calories are in alcoholic drinks by using our alcohol calorie calculator.
If you do smoke, stopping smoking will reduce your risk.
What about screening?
The majority of colorectal cancer cases can be successfully treated if they are diagnosed early. Nonetheless, the better approach would be to prevent the development of colorectal cancer by adopting a healthy diet and lifestyle.
For more information about screening for colorectal cancer, please visit www.chp.gov.hk.